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1
Gears Operations Training Material(Soft and Hard
Machining)Gear Engineering
Luiz FranzoniGeraldo de OliveiraManassés
Lima Rafael Matuguma
Edition 02
2
Agenda
1. Basic Concepts (Overview) 2. Pinion Turning 3.
Ring Gear Turning 4. Traceability Imprint 5.
Spline and Thread Rolling 6. Boring and
Threading 7. Key Milling 8. Teeth Cutting 9. P26
and P40 Report Interpretation 10. Shot
Peening 11. Straightening 12. Induction 13. Hard
Turning (Ring Gear Pinion) 14. Grinding 15.
Contact Testing and Adjusting 16. Gear Set
Washing 17. Contact Testing and Harmonics 18.
Traceability Printing 19. Phosphatization 20.
Packaging and Storage 21. Indicators vs. Scrap
3

• Presentation

The purpose of this annual training is to qualify
and level the technical expertise of all
employees involved in the gear process and to
understand all issues of this process through
discussions with all participants.
4
Initial AssessmentEmployee Name
1 - What is the difference between part zero and
machine zero? 2 - Please explain how to
correct tools and geometry entered in the CNC?
3 - What precautions are needed when
reworking the shim face due to high deflection?
Why? 4 - What is a taper? What is it used
for? 5 - What is the impact of a poor tooth
finish?
5
Initial Assessment
6 - What does the chamfer on the top of the ring
gear serve for in hard machining? 7 - Please
explain the purpose of the straightening process.
What is the tolerance? What happens if this
operation is not executed? 8 - What can
happen with a part with no induction? 9 -
What is a pin plate? What precautions are needed
when using this device?
6
Initial Assessment
OK or NOK? Why?
OK or NOK? Why?
7
NVH 2013 Performance
8
NVH 2014 Performance
9
FTQ Gears Performance 2013 vs 2014
Average FTQ 2013 90.02 Average FTQ 2014
93.35
10
Scrap Gears Performance 2013 vs 2014
Average Scrap 2013 R 112,037.95 Average Scrap
2014 R 17,545.14
11
Gears Line Quality Recent History
1 - LATHE PINION OP. 10 Problem 60 gr center
bore out of spec (8.6 12x41 gt indexes) Cause
Deflection on the bearings' Ø , even when
approved in op. 10 they were rejected in hard
turning op. 100 after the heat treatment
External Supplier Issue Action Complaint
filed with supplier GMC. Problem Batch of 8.6
9x41 parts with deflections on the shim face, 20
rejected (152 units) in the pinion hard machining
from a batch of 600 parts manufactured. Cause
Lack of metal stock in OP.010. The measuring
frequency of 100 was not being followed.
Deviation in the measuring method for GMI due to
a recess on the head. Action Operation
training. 2 - ANDERSON COOK PINION OP.
30 Problem Tail stock preset changed. Cause
Spline measurement variation and time wasted with
adjustments and SCRAP due to a pinion backlash
during the spline rolling (distance between the
front and the back of the tail stock changed.) 3
- VOMAT PINION OP. 35 KEY Problem Alarm sequence
during the cycle Cause Cycle stopped when one
side of the key was done it was reset and the
part was removed with the machining
incomplete. Detected only during assembly causing
a scrap with teardown, and in some cases
during the hard machining due to a tool
breakdown when the part was tooled after the heat
treatment.
Action Machine replacement Error Proofing
12
Gears Line Quality Recent History
4 - TEETH CUTTING OP. 40 Problem Size variation
in P26/P40 for all models, especially 8.6" 9x41,
causing excessive corrections in op. 40 and
resulting in several changes to the grinding
summary later on. Cause Improper correction of
the tooth face angle in OP.010 where, when
correcting the tooth face angle, the tooth height
is changed and, consequently, the top of the
tooth causing an improper correction in P26/40
when the probe touches the face of the tooth.
Effect High SCRAP and rework rate, as well as
low OEE and FTQ. Action Operation
training. Problem Caliper breakdown Cause The
part was not mounted properly causing more cutter
wear and reducing its life. Effect The cycle
was aborted during the teeth cutting and the part
was lost every time this happened. Action The
procedure used with the hard machining arbors was
adopted, that is, the arbor components are washed
at every setup and their condition is checked
through the W.O. 5 - PRESS PINION OP.
90 Problem Incomplete setup from model 8.6 to
8.9 Cause During the setup, only the hammer was
removed and the blocks were not replaced, thus
the hit point was critical for the process
sequence Effect Excessive hammer hits,
premature wear of the devices. Action
Operation training.
13
Gears Line Quality Recent History
Problem Break in the process flow between op.
85, 90, and 95 of the Pinion. Cause Excessive
parts stored on a bench between op. 85, 90, and
95 Effect Parts were rejected in the cutters
because the deflection on the tooth was different
from the rod, with strong likelihood of these
being non-straightened parts. Action Operation
training development of the Hess M.A.E press 6
- Op. 100 Hard turn Problem Vibration on the
bearing diameters. Cause Mounting force, insert
geometry. Effect Scrap and loss of
productivity. Action Search for options with
suppliers, new insert testing. 7 - OP. 10 Gear
Ring Problem Tapper out of spec Cause Trimming
not leaving enough metal stock to finish in the
same operation. Effect Diverging contact between
the Gears and the 3rd member Action Operation
training. 8 - Op.15 GEAR RING Problem Damaged
caliper face and diameter. Cause Deflection on
the toothed face and consequently on the tooth
after op. 40 cutter. Action Replacement.
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1. Basic Concepts (Overview)

• 1 - What is the purpose of process sheets?
• They are documents that help the operator by
  providing standard instructions for the
  process/setup execution as well as information on
  tool codes, devices, and process drawings to make
  it easer to visualize the control plan using
  specifications common to both.

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1. Basic Concepts (Overview)

• 2 - What is the purpose of CAD process sheets?
• They are documents that must help the operator to
  identify the dimensions in the control plan
  through specifications, helping the operator to
  see the part dimension to control.

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1. Basic Concepts (Overview)

• 3 - What is the purpose of the control plan?
• They are documents the specify the dimensions of
  the product to be manufactured. The control plan
  gives the operator access to the dimensions,
  corresponding gage number, measuring frequency,
  reaction plan, and characteristics (critical or
  not). The operator can find dimensions that are
  monitored or not in the control plan.

17
1. Basic Concepts (Overview)

• 4 - Do you know what is a standard work sheet?
• They are documents that show the operator the
  order of execution of the tasks of a give
  workstation. The main purpose of this document is
  to facilitate the operation of that workstation.

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1. Basic Concepts (Overview)

• 5 - What is the difference between part zero and
  machine zero? Identify them in the machine.
• Part zero is the initial reference of the
  dimensions defined in a CNC program. Its is the
  point of origin of the part. E.g. G54, G55, G56,
  G57, etc.
• Machine zero is the reference defined by the
  machine manufacturer. Its is the point of origin
  of the machine. E.g. G53.
• 6 - What type of correction must be done in the
  CNC program? Is it alright to correct Progress
  and RPM in the CNC?
• None. Occasionally, only with the Head of
  Production/Supervisor's approval - and he or she
  must notify Engineering of such.
• 7 - Please explain how to correct tools and
  geometry entered in the CNC?
• The tool corrector is used to offset tool wear
  during the life of a tool - for high values the
  geometry needs to be checked.
• Tool geometry is used to tell the machine the
  actual length of a tool support to avoid
  collisions.
• 8 - Is it correct to work with a
  potentiometer higher or lower than 100, yes or
  no? Why? No. Because this affects the tools'
  life directly.
• In specific cases, only with the Head of
  Production/Supervisor's approval - and he or
• she must
  notify Engineering of such.

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1. Basic Concepts (Overview) Examples of
tool corrections - item 05 and 07 (tool wear and
geometry offset).
Incorrect case High correction values that
interfere with setups, in which it is assumed
that there were changes due to unreported
potential collisions (light and/or
heavy). Correct case Zeroing the tools for this
operation and adjusting the wear corrector zero
(Lines 01 and 02) to at least near zero.
CORRECT
INCORRECT
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1. Basic Concepts (Overview)

• 9 - What is the importance of cooling during the
  machining of a part?
• It is directly related to the useful life, and to
  dimensional stability, since the part will always
  be at
• a constant temperature. Cooling helps the removal
  of chips.
• 10 - What can cause a broken/damaged insert block
  during machining?
• Variation in dimensions, premature tool wear,
  potential machine collision.
• 11 - You do a visual check and see premature tool
  wear, potential machine collision.
• The check must be done according to the
  measurements, surface part finishing, and useful
  life.
• 12 - How important is it to comply with a tool's
  useful life?
• To keep dimensional stability, reduce costs,
  reduce scrap.
• 13 - What should you do if the rated useful life
  of a tool does not match the actual tool life?
• Inform the Head of Production/Supervisor
  immediately of such, and they must inform
  Engineering
  about the incident.

21
1. Basic Concepts (Overview)
Examples of items 9, 10, and 12 Inserts, blocks,
sensor fixture showing damages that affect
machining quality, as well as stripped fixation
screws.
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1. Basic Concepts (Overview)

• 14 - What is a critical feature of a product?
  How do you identify it in the documentation?
• These are dimensions defined by the customer (GM,
  VW, etc.) through the product drawing, which are
  considered critical due to the risk it may pose
  to the end user (customer).
• Those features are identified by the code KPC00
  in process drawings and control plans.
• 15 - What is a critical feature of a process?
  How do you identify it in the documentation?
• Those are dimensions defined by AAM Engineering
  through the process drawing, which are considered
  critical due to the risk that it may pose to
  subsequent operations or the internal customer
  (axle assembly).
• Those features are identified by the code KCC in
  process drawings and control plans.
• 16 - What is FIFO? How important is it?
• It means "First In First Out", that is, the first
  to enter is the first to exit. It ensures the
  repetitiveness of parts as it allows us to
  minimize dimensional variations in the parts by
  maintaining the useful life of a cutter, insert,
  etc. This action affects the grinding process
  directly, since the lower the variation from one
  part to the next, the greater will be its
  grinding efficiency, reducing scrap
  significantly.

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2. Pinion Turning

• 17 - How would you identify a misaligned tool?
  What action must be taken to correct this type
• of problem. What does measurement variation mean
  to you?
• By measuring a diameter and checking the
  measurements on two extreme points of this
  diameter, and the measuring must be repeated and
  be equal to the value programmed in the CNC.
• It is the non-repetitiveness of a dimension
  without any interference on it (machine, tool,
  raw material, etc.)
• 18 - How would you identify an ovalization of the
  machining diameter of a pinion? What action must
  be taken to correct this type of problem?
• By measuring a diameter and checking the
  measurement in two points, 0º and 90º of that
  diameter, with repeated measuring.
• To correct it, check the clamping pressure, the
  part deflection (bearing, tail stock, device,
  etc.)
• 19 - How would you identify a conicity of the
  machining diameter of a pinion? What action must
  be taken to correct this type of problem?
• By measuring a diameter and checking the
  measurements on two extreme points of this
  diameter, and the measuring must be repeated and
  be equal to the value programmed in the CNC.
• You must inform Maintenance immediately
  because this type of problem is related to
  machine misalignment.

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2. Pinion Turning

• 20 - What tools are used in the machining of a
  pinion? Please explain.
• CAPTO supports used for quick tool changeover to
  partially replace the support.
• Triangular inserts commonly used for the
  machining of trimmings with 1.2 mm radius.
• Diamond-shaped inserts commonly used in general
  too long due to their specific shape.
• Drag insert used exclusively to turn the part,
  with intact geometry in its entire edge since,
  differently from a conventional machining where
  only the insert radius touches the part, in this
  case the edge actually touches the part.
• Insert block used to provide support/stability to
  the insert during the machining operation, and
  whose height must always be checked.
• 21 - In case of a deflection in the pinion rod
  diameters, which variables mainly cause this?
  What is the maximum deflection in bearing
  diameters allowed in pinion machining?
• Tail stock wear, tail stock bearing on the
  oversleeve side, plate side, clamping pressure,
  broken drag insert.
• Maximum value 0.050 mm
• Note A higher deflection value directly affects
  the cutting operation.
• 22 - What does the clamping pressure affect
  during the lathe turning of a pinion?
• Deflection, broken drag insert, dimensional
  variation.

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2. Pinion Turning

• 23 - What precautions are needed when machining
  the shim face? Why?
• Roughness, shim face height, deflections or
  damages to this surface. Because the shim face is
  the reference for teeth cutting, the less
  variation the highest will be the quality of the
  part in the grinding process and contact testing.

26
2. Pinion Turning

• 24 - What precautions are needed when reworking
  the shim face due to high deflection? Why?
• When reworking a part, you must ensure that, in
  addition to the bearing diameters, the shim face
  is also reworked, since the shim face is the
  reference for the entire teeth cutting, grinding,
  and testing process.
• See the pinion machining operation video via
  Go-Pro
• 25 - What is the impact of using pinions with the
  center bore plugged or oxidized?
• Excessive blank deflection, teeth cutting,
  grinding and testing, low FTQ, high scrap,
  potential scrap in NVH.

27

• 3. Ring Gear Turning

26 - How would you identify an ovalization of the
machining diameter of a gear ring? What action
must be taken to correct this type of problem? By
measuring a diameter and checking the measurement
in two points, 0º and 90º of that diameter, with
repeated measuring. To correct this, check the
clamping pressure, check the condition of the
drag inserts (clamping jaw) OP.010, chips on the
gear ring seat (Op.010/015), wear of the (03)
gear ring supports OP.010, broken/damaged
caliper 27 - How do you avoid "wrought defect"
scraps? Why? Check the split of the wrought
between operations OP.010 and 015 to avoid, as
much as possible, changing the CNC program to
prevent mixups between the parts produced between
the setups. It is extremely important to see if
the air check is working and, when the operation
so requests, to check the wear of the (03)
supports of the gear ring. Scrap is the worst
"enemy" of the company's bottom line. 28 - What
tools are used in the machining of a gear ring?
Please explain. CAPTO supports used for quick
tool changeover to partially replace the
support. Square inserts commonly used for the
machining of trimmings with 1.2 mm radius.
Drag insert (clamping jaw) used exclusively to
center / properly secure the part
correctly, with its
geometry intact for proper application. Insert
block used to provide support/stability to the
insert during the machining
operation, and whose height
must always be checked.
28

• 3. Ring Gear Turning

29 - What is a taper? What is it used for? It is
the gear ring face slope (seat) used to offset
the distortion from the furnace where it is
controlled by the CNC program. This offset is
related to the final assembly of the gear ring in
the diff case, and is partially responsible for
the position of the contact on the differential
axle and consequently on the NVH. Always
checked. 30 - How does the mounting device
affect the gear ring machining? The gear ring
mounting devices Op.010 and Op.015 must be free
from damages, dents, surface flaws, cams -
including clamp jaws - and chuck supports of
Op.010.
29

• 4. Traceability Imprint (Gear Ring and Pinion)

31 - What is the purpose of traceability
imprints? It is the only way for the company to
track wrought data and that batch's manufacturing
date in case of a potential field problem. 32 -
How important is it to enter the information
correctly? In the case described above, it will
be possible to limit the number of parts to be
tracked and the corresponding costs, giving peace
of mind to the customer. It also helps to
identify the shift for any potential assembly
issues. 33 - Do you understand all the
information provided in this imprint? See
attachment 34 - How important is it to do the
traceability imprint at a predefined point in the
process? Ease of information viewing as well a a
standard defined in the drawing, thus avoiding
non-conformity with another subsequent operation,
for example Imprint with the diff case seat face
on the gear ring or interference with the bearing
diameter. 35 - When is there a need to replace
the print head?
When the imprint is not legible.
30

• 4. Traceability Imprint (Gear Ring and Pinion)

The traceability imprint for soft machining was
changed in 2014 from shift to time in order to
provide more precise information and improve the
traceability of a potential non-conformity.
31

• 5. Spline and Thread Rolling

36 - What is the impact caused by a spline "on
top" of the relief radius? Potential crack point
causing a breakage in the field. 37 - What is
the role of the stop in the rolling process? It
ensures correct/adequate distance between the
spline and the shim face. 38 - How do you know
when to replace the rolling racks? When the
pass/no pass gage starts to show interference and
there are visual signs of markings on the threads
and splines. 39 - What is the role of cooling in
the spline/thread rolling process? It ensures the
racks' useful life and the part's dimensional
stability. 40 - What precautions are needed when
replacing the racks? For reworked racks, it is
extremely important to check for the presence of
blocks. 41 - What is the impact of a poorly
adjusted/misaligned pinion support
berth? Potential part collision, damage to the
rack. 42 - Can you interpret/identify a
non-conformity on the thread and spline
visually? Yes, by the thread or spline fillet
thickness, shape, markings, etc.
32

• 5. Spline and Thread Rolling

33

• 6. Boring and Threading

43 - How does the presence of chips affect the
boring device supporting face? Displacement of
the part during the boring process resulting in a
part with a misplaced bore, scrap. 44 - How do
you identify a misplaced bore visually? By the
variation in the "size" of the chamfer on the
same part. 45 - What precautions are needed for
a reliable boring and threading process? An
"intact" caliper, respecting the useful life of
the tools, cooling used to expel chips from
inside the bores, the thread visual aspect 46 -
What is the importance of cooling during the
machining of a part? It is directly related to
the useful life, and to dimensional stability,
since the part will always be at constant
temperature. Cooling helps the removal of chips,
especially from inside the threaded bore in this
case.
34

• 6. Boring and Threading

35

• 7. Key Milling

47 - What is the role of the key when assembling
the spindle? It locks the nut that secures the
flange between the pinion and the Carrier 48 -
How does a missing key affect company's
costs? Rework, scrap, low OEE, etc. 49 - What is
the impact of machining the key before rolling
the thread? Burrs inside the key, making it out
of spec.
EP0490
36
8. Teeth Cutting (Pinion Gear Ring)

• 50 - What is the impact of releasing production
  using a cutter mounted on the machine with
  deflection above 0.020 mm?
• Non-conform product, probably the biggest issue
  will be in grinding and testing, generating
  scrap, rework, low OEE, etc.
• 51 - When does the cutter deflection need
  checking? How often?
• Setup release/cutter changeover/process
  intervention (power surge, P26/40 report showing
  dimensions at their limits, etc.)
• 52 - How do you identify a gear ring and pinion
  cutter without any identification on the box?
• Cut direction, blade thickness.
• 53 - Why is an internal blade different from an
  external one?
• The blades are responsible for cutting the teeth,
  and depending on the model to be cut (left hand
  or right hand), the internal and external blades
  will be responsible for each face of the tooth
  (coast or drive, concave or convex)
• 54 - What is the impact of a poor tooth finish?
• Non-conform product, probably the biggest issue
  will be in grinding and testing, generating
  scrap, rework, low OEE, etc.

37
8. Teeth Cutting (Pinion Gear Ring)

• 55 - What procedure must be followed for a bad
  cutter?
• Inform the head of production and replace the
  cutter.
• 56 - What is the impact of releasing production
  using an arbor mounted on the machine with
  deflection above 0.020 mm?
• Non-conform product, probably the biggest issue
  will be in grinding and testing, generating
  scrap, rework, low OEE, etc.
• 57 - When does the arbor deflection need
  checking? How often?
• Setup release/cutter changeover/process
  intervention (power surge, P26/40 report showing
  dimensions at their limits, etc.).
• 58 - Please describe the role and importance of
  the dinging ball
• It helps serial production by detecting
  non-conformities pertaining to a tooth thickness
  or deflection measurement for which the dinging
  ball vs P26/40 relation must be known more
  rapidly
• 59 - What precautions must be taken to use the
  dinging ball?
• Zeroing through the master, zeroing pressure not
  above 0.5 mm, dirt on the support, room
  vs controlled temperature, identifying
  the measured teeth compared to P26/40.

38
8. Teeth Cutting (Pinion Gear Ring)

• 60 - How important is it to use the correct
  packaging after OP.040?
• Ensuring the quality of the parts to be treated,
  avoiding hits, dents, damages that can become
  potential issues during grinding and testing, as
  well as to facilitate inventory and organization.
• 61 - How important is it to measure 03 parts in a
  payload?
• This is the minimum acceptable to assess
  dimensional behavior after the heat treatment.
• We must ensure that those 03 "soft" measured
  parts are also "hard" measured to check the
  actual distortion, always marking with a dot to
  distinguish them.
• Note We cannot forget the loading sheet with
  those parts, ever.

39
8. Teeth Cutting (Pinion Gear Ring)

• 62 - Please describe the procedure used to mount
  the cutter on the machine.
• Follow the BWI procedure below.

40
8. Teeth Cutting (Pinion Gear Ring)

• 63 - Please describe the procedure used to
  unmount the cutter from the machine.
• You must use the cutter puller to pull the
  cutters. The puller preserves the spindle nose
  and helps the useful life of the cutters and,
  consequently, the quality of the parts produced.
  When there is wear to the spindle nose, it is
  harder to achieve a perpendicular between it and
  the support face, wasting time with setup and
  quality.
• As from this date, we are providing plates with
  screws for proper cutter changeover, and its use
  will be mandatory to exchange "cutter" tools.
  This item is already included in the process
  sheet any questions can be submitted to
  Engineering when needed. If those items are
  misplaced please inform the head or supervisor
  immediately.

SPINDLE NOSE
CUTTER PULLER
41
8. Teeth Cutting (Pinion Gear Ring)

• 64 - Please describe the procedure used to mount
  the arbor on the machine.
• Follow the BWI procedure below.

42
8. Teeth Cutting (Pinion Gear Ring)

• 65 - Please describe the procedure used to mount
  the arbor on the machine.
• The "arbor distance" values in the cut summary
  are extremely important for the quality of the
  manufactured parts, and are printed in inches and
  millimeters in all arbors we get from Gleason. In
  normal conditions no corrections are needed, but
  it is important to check and understand what they
  affect, and if the value in the summary is
  different from the actual arbor value you must
  not only correct it but also inform the
  production or gear engineering head/supervisor -
  the quicker the information is passed on, the
  fewer problems will occur.
• Note When this value is incorrect in the
  summary, the corrections issued through CMM
  P26/P40 offsets it. The severity of this
  non-conformity varies from model to model
  depending on the part design, but the summary
  starts to distance itself from the original
  values, which may cause some issues on the line
  or even the assembly.

43
8. Teeth Cutting (Pinion Gear Ring)
66 - MOUNTING DEVICES (ARBORS) Values outside the
STD can generate scrap and dimensional
discrepancies via P26/40.
ATTENTION 1 MOUNTING DISTANCE HAS NOTHING TO DO
WITH ARBOR HEIGHT. THE MOUNTING DISTANCE IS
DEFINED BY THE PRODUCT DRAWING. ATTENTION 2
INCORRECTLY ADJUSTING THE ARBOR HEIGHT IN THE
SUMMARY WILL CAUSE SEVERE COLLISIONS.
44
8. Teeth Cutting (Gear Ring-specific)

• 67 - How important is the chamfer on the gear
  ring?
• To prevent "gear tip chipping", that is, chipping
  of the top of the tooth caused by micro cracks
  from the shot peen process. Such micro cracks can
  appear soon after the shot peen process or only
  when the axle is already on the end user
  (customer) vehicle, making the customer unhappy
  with the noise or even having the vehicle
  returned under warranty.
• This action was implemented after numerous field
  complaints, at a high cost to the company.
• 68 - What should be the size of the chamfer? Why?
• The chamfer does not have an exact size. This
  chamfer must follow the specification in the
  process sheet and the standard for the line.
• If this chamfer is too small, we still have a
  risk of chipping, but it is less likely. If the
  chamfer is too large, it will interfere directly
  in the grinding and testing process, showing high
  harmonics with no possible correction. "RNC on
  quantity only".
• The lack of a chamfer will result in a formal
  complaint from the VW/GM customer or the end user
  (customer), at a high cost to the company.
• 69 - How do we create the chamfer on the gear
  ring?
• This chamfer results from 02 variables. The first
  variable is that there are already 02 blades on
  the cutter (positions 01 and 02),
  which are directly responsible for the chamfer
  and come "preset" from the tool center.
  The second variable is the height of the gear
  ring, that comes from OP.015. It is important to
  remember the tool wear above the tooth
  height in the P26/40 report.

45
8. Teeth Cutting (Gear Ring-specific)
70 - What should be done to correct the gear ring
chamfer? If, when mounting the cutter, there is
no chamfer visible, the operator should only try
a "light" correction at OP.015 not forgetting the
tooth height as documented in the process. If
this does not work, the operator must inform the
Head of Production/Supervisor immediately and
have that cutter replaced so that the Center can
provide the correction. 71 - What is the
importance of the part release chart in soft
machining? In addition to ensuring the quality of
the parts released via setup, this chart holds
the history of all P26/40 reports of soft and
hard parts. This allows us to track the parts in
case of a crisis at NVH or grinding issue. It is
part of the sample parts visual management
process.
46
8. Teeth Cutting (Gear Ring-specific)

• 72 - How important is it to use the payload
  follow-up sheet in hard machining?
• The payload follow-up sheet is a document
  containing all the required information for the
  payload that is being processed at a given time
  (soft measuring, hard measuring, Furnace treated,
  straightened parts, etc.). This sheet allows us
  to identify any anomalies in the process and help
  us to resolve any grinding issues by fast and
  effective decision-making.
• 73 - How important is it to measure 03 parts in a
  payload?
• This is the minimum acceptable to assess
  dimensional behavior after the heat treatment.
• We must ensure that those 03 "soft" measured
  parts are also "hard" measured to check the
  actual distortion, always marking with a dot to
  distinguish them.
• Note We cannot forget the payload
  follow-up sheet with those parts,
  ever.

47
8. Teeth Cutting

• 74 - Which are the main points that must be
  analyzed in the P26/40 report?
• The main items that directly affect part quality
  are listed below.
• Sum of squares
• TOOTH THICKNESS SEE THE SPECIAL NOTE
  ABOUT THIS ITEM
• Spiral angle (concave and convex)
• Pressure angle (concave and convex)
• Teeth deflection
• Tooth height
• Tooth topography
• Tooth face angle (root and face)

48
9. P26/40 Report Interpretation
75 - How do we interpret the P26/40 report?
49
9. P26/40 Report Interpretation
1st Step
50
9. P26/40 Report Interpretation
2nd Step
51
9. P26/40 Report Interpretation
3rd Step
52
9. P26/40 Report Interpretation
4th Step
53
9. P26/40 Report Interpretation
5th Step
54
9. P26/40 Report Interpretation
76 - How do I correct the tooth face vs root
angles? Check the OP.015 gear ring and OP.10
pinion gage check readings against the P26/40
report, because the gage checks read two points
and display the average values. Correct the
most extreme tolerance point using the P26/40
report as shown in the previous slide. Note
Check the gear ring tooth chamfer thickness if it
is uniform in toe vs heel, as well as tooth
thickness. 77 - How does the thickness of the
tooth negatively affects the quality of the
part? It the tooth thickness is non-conform,
there will be issues when taking measurements in
P26/40 because the machine probe will not have
enough support and can thus produce an incorrect
adjustment that in turn will cause a potential
surge at NVH in the near future.
ATTENTION PARTS WITH OUT OF SPEC THICKNESS MUST
BE SCRAPPED IMMEDIATELY.
55
10. Gear Software
151 - In addition to the resources explained
before, we also have a software from Gleason that
supports our continuous improvement changes
including contact, micro-radian, NVH, etc.
56
10. Gear Software
In addition to the resources explained before, we
also have a software from Gleason that supports
our continuous improvement changes including
contact, micro-radian, NVH, etc.
57

• 11. Shot Peening

• 78 What is shot peen? Please describe the
  parameters of this process. What is their
  significance in this process?
• Shot peen is a residual stress relief process
  whose main purpose if to strengthen the root of
  the tooth, increasing its useful life in the end
  product (vehicle). This process cannot interfere
  with the part's geometry.
• The parameters are pressure, time, nozzle
  alignment, grit hardness/size, nozzle direction,
  nozzle distance. Other important factors include
  the almen blade and the dirt on this machine.
• These parameters ensure the conformity of the
  part according to the specifications via lab
  testing, controlled monthly by the Tech Center.
• 79 - What impact do the devices have on this
  process?
• The devices (plate for the gear ring and nylon
  for the pinion) are critical to ensure the
  quality of these parts. Therefore, proper
  positioning of the parts on the device directly
  affects the process parameters listed above
  (nozzle alignment and distance).
• 80 What is Gear Tip Chipping? How does it
  happen?
• "Gear tip chipping" is the chipping of the top of
  the tooth caused by micro cracks from the shot
  peen process. Such micro crack can appear soon
  after the shot peen process or only when the axle
  is already on the end user (customer) vehicle,
  making the customer unhappy with the noise or
  even having the vehicle returned under warranty.
  Non-compliance with the parameters defined for
  the process causes this non-conformity.
  For VW-RPU gear rings, this non-conformity is
  null, that is, it is protected by
  the chamfer that the gear ring has.

58
11. Shot Peening
81 - What does the chamfer on the top of the ring
gear serve for in hard machining? This chamfer
should prevent gear tip chipping, explained
before. Note If the chamfer is large, the impact
will be on the harmonics, while a small chamfer
creates micro cracks that can appear soon after
the shot peen process or only when the axle is
already on the end user (customer) vehicle,
making the customer unhappy with the noise or
even having the vehicle returned under
warranty. Remember that this action was
implemented after numerous field complaints, at a
high cost to the company.
Gear ring with micro cracks or gear "tip chipping"
Gear ring without gear "tip chipping" due to the
presence of a chamfer
59
12. Straightening

• 82 - Please explain the purpose of the
  straightening process. What is the tolerance?
  What happens if this operation is not executed?
• The purpose of the process is to correct any
  deviations of the part geometric shape,
  especially rod vs head. Such deviation is the sum
  of soft machining deflection heat treatment.
• The maximum tolerance is 0.050 mm.
• NOTE 1 NOT EXECUTING THIS OPERATION CORRECTLY
  RESULTS IN SCRAP IN GRINDING AND TESTING AS WELL
  AS PRODUCTION LOSS AND LOW OEE.
• NOTE 2 50 OF THE GEAR SETS RETURNED FROM
  TEARDOWN FOR ANALYSIS IN 2014 HAVE DEFLECTION
  ABOVE TOLERANCE LIMITS
• 83 - Which factors/parameters contribute to the
  inefficiency of this process?
• Press force, number of hits, device condition
  (larger and smaller bearing supports,
  straightening hammer), location of the hit on the
  part
• 84 - When should magna flux be used? Why?
• Every time a part is straightened, it is
  mandatory to inspect it in the magna flux
  (inspection by magnetic particles), that is, 100
  of the straightened parts have to be inspected.
• Because - during the straightening process -
  some parts may show micro cracks that may or
  may not propagate in the field,
  that is, when the vehicle is under load. This can
  lead a company to
  bankruptcy due to a RECALL.

60
12. Straightening

• NOTE
• All press procedures must be executed correctly
  to avoid possible issues in subsequent
  operations.
• The setup, for example, requires strict attention
  to the support devices, blocks, stops, touch
  probe adjustment, tail stocks. A small issue in
  straightening op.090 can strongly impact
  subsequent operations, including excessive
  cutter adjustment, low productivity, SCRAP in the
  gears line, or even in the assembly line.

parts straightened in 2014 parts straightened in 2014
Model / Ratio Percentage
8.9" 10x37 22.08
8.9" 10x41 20.00
8.9" 10x43 16.63
8.6" 9x41 30.90
8.6" 11x41 29.16
8.6" 12x41 38.09
7.6" 11x41 29.51
7.6" 12x41 19.77
parts straightened in 2013 parts straightened in 2013
Model / Ratio Percentage
8.9" 10x37 40.46
8.9" 10x41 41.02
8.9" 10x43 40.73
8.6" 9x41 46.00
8.6" 11x41 39.06
8.6" 12x41 42.86
7.6" 11x41 42.95
7.6" 12x41 40.28
61
13. Induction

• 85 - What is induction?
• Induction is the tempering treatment that the
  pinion must undergo to reduce hardness in the
  spline/thread area where the torque to attach the
  pinion to the flange on the carrier is applied.
• 86 - Which factors/parameters contribute to the
  inefficiency of the induction process?
• Heating time, cooling time ( shower),
  temperature, shower flow, laser position, height
  of the induction cup.
• 87 - How can the operator visually do to detect
  non-conformity in this operation?
• The visual aspect of the part color in the
  "induced" region, as well as the visual aspect
  when the part is burned (color).
• 88 - What are the consequences of not complying
  with these factors/parameters?
• The pinion can break when the axle is assembled
  or - more likely - in the field, in which case it
  can put the life of the vehicle's occupants at
  risk. This can put a company in serious trouble
  with the end user (customer), for example, with a
  RECALL.
• SEE THE AXLE EXPLANATORY VIDEO

62
13. Induction (Inductor Setup)

• NO BLOCKS BETWEEN THE INDUCTOR CUP AND SHAFT
• NO CLEARANCE BETWEEN THE CUP ATTACHMENT SHAFTS
• 3 SHAFT ALIGNMENT SCREWS
• 01 PROGRAM PER FAMILY (8.9, 8.6, AND 7.6)
• NO TAIL STOCK WEAR

63
14. Hard Turning (Pinion Gear Ring)

• 89 - What is the difference between part zero and
  machine zero? Identify them in the machine.
• Part zero is the initial reference of the
  dimensions defined in a CNC program. Its is the
  point of origin of the part. E.g. G54, G55, G56,
  G57, etc.
• Machine zero is the reference defined by the
  machine manufacturer. Its is the point of origin
  of the machine. E.g. G53.
• 90 - What type of correction must be done in the
  CNC program? Is it alright to correct Progress
  and RPM in the CNC?
• None. Occasionally, only with the Head of
  Production/Supervisor's approval - and he or she
  must notify Engineering of such.
• 91 - Please explain how to correct tools and
  geometry entered in the CNC?
• The tool corrector is used to offset tool wear
  during the life of a tool - for high values the
  geometry needs to be checked.
• Tool geometry is used to tell the machine the
  actual length of a tool support to avoid
  collisions.
• 92 Which variables impact the hard turning
  process?
• Broken/damaged insert block, premature tool wear
  due to a potentiometer not at 100, part surface
  finishing level, roughness, tool useful life not
  achieved.

64
14. Hard Turning (Pinion Gear Ring)

• 93 - How should I exchange inserts without
  generating scrap?
• Today, one of the worst scrap and non-conformity
  issues are undoubtedly parts from inserts
  exchanged without proper adjustment.
• The correct steps to exchange inserts are
  detailed below
• 1 - Clean the insert to be replaced by loosening
  the mounting screw with a torx screwdriver and
  then remove the insert to be replaced.
• 2 - Clean the insert housing using compressed
  air, a cloth, etc.
• Note This housing must be in perfect condition,
  it can never be damaged.
• 3 - Check the condition of the block with the
  same care as the insert.
• 4 - Place the new insert and tighten it using
  "normal" force.
• 5 - Open the "X" tool wear corrector and enter
  0.100 mm for the pinion or 0.100 mm for the gear
  ring to avoid scrap caused by unknown dimensions.
• 6 - mark the gear ring teeth according to the pin
  plate supports and the pinion tooth according to
  the drag pin to facilitate any rework on this
  first part made with the insert.
• 7 - Make any adjustments according to the gage
  readings.

65
14. Hard Turning (Pinion)

• 94 - What is a hard turning?
• Hard turning is the turning process for finishing
  close to a grinding (Ra around 0.8). The hard
  turn is more versatile than a grinding process,
  since it is a machining process that does not use
  cooling oil and costs much less than grinding
  because it uses only a CBN insert and an STD tool
  support instead of the famous grindstones,
  dressers, copying rulers, etc.
• 95 - How would you identify a misaligned tool?
  What action must be taken to correct this type of
  problem? What does measurement variation mean to
  you?
• By measuring a diameter and checking the
  measurements on two extreme points of this
  diameter, and the measuring must be repeated and
  be equal to the value programmed in the CNC.
• It is the non-repetitiveness of a dimension
  without any interference on it (machine, tool,
  raw material, etc.)
• 96 - How would you identify an ovalization of the
  machining diameter of a pinion? What action must
  be taken to correct this type of problem?
• By measuring a diameter and checking the
  measurement in two points, 0º and 90º of that
  diameter, with repeated measuring.
• To correct it, check the securing pressure, the
  part deflection (bearing, tail stock, device,
  etc.)

66
14. Hard Turning (Pinion)

• 97 - How would you identify a conicity of the
  machining diameter of a pinion? What action
• must be taken to correct this type of problem?
• By measuring a diameter and checking the
  measurements on two extreme points of this
  diameter, and the measuring must be repeated and
  be equal to the value programmed in the CNC.
• You must inform Maintenance immediately because
  this type of problem is related to machine
  misalignment.
• 98 - In case of a deflection in the pinion rod
  diameters, which variables mainly cause this?
  What is the maximum deflection in bearing
  diameters allowed in pinion machining?
• Tail stock wear, tail stock bearing on the
  oversleeve side, plate side, clamping pressure,
  broken drag insert.
• Maximum value 0.025mm
• 99 - What does the clamping pressure affect
  during the lathe turning of a pinion?
• Deflection, dimensional variation, vibration.
• 100 - What should be the metal stock of the
  pinion? What procedure must be followed to
  correct it?
• Maximum 0.080 mm. Use an optional stop to
  interrupt the program between the trimming and
  the finishing operation. At this time, the
  operator must measure the tooled diameters and
  check them against the value mentioned before.

67
14. Hard Turning (Gear Head)

• 101 - What is a taper? What is it used for?
• It is the gear ring face slope (seat) used to
  offset the distortion from the furnace where it
  is controlled by the CNC program. This offset is
  related to the final assembly of the gear ring in
  the diff case, and is partially responsible for
  the position of the contact on the differential
  axle and consequently on the NVH.
• Always checked.
• 102 - What is a pin plate? What precautions are
  needed when using this device? How do you check
  the pin plate condition?
• Pin Plate is the device responsible for the
  internal machining of the gear ring diameter, in
  which it guides the process through the teeth
  already cut, keeping the drawing reference. The
  main element is the gear ring support pin, which
  must not show excessive wear and must have the
  same height.
• 103 - How would you identify an ovalization of
  the machining diameter of a gear ring? What
  action must be taken to correct this type of
  problem?
• By measuring a diameter and checking the
  measurement in two points, 0º and 90º of that
  diameter, with repeated measuring.
• To correct it, check the clamping pressure, check
  the condition of the pins on the pin plate
  (wear), chips on the gear ring seat (between the
  gear ring teeth and the pin plate pins), insert
  wear.

68
14. Hard Turning (Gear Head)
104 - How do you identify a potential deflection
problem on the gear ring pilot diameter?
1 - Clean the device and the machine turret where
the base with the touch probe dial will be
mounted. 2 - Check the condition of the pins on
the pin plate visually. 3 - Zero the dial at the
larger end of one of the pins (1/2 turn) 4 -
Turn the device manually to check the height of
the pins. 5 - If the difference between the
largest and the smallest values is more than
0.050 mm, the operator must replace the pins or
adjust them (by turning them) on an area that
touches the part that is is good condition. NOTE
After the setup, the operator must always measure
the 1st part of the setup using the gage check,
to avoid SCRAP in grinding and testing.
69
15. Grinding
105 - Why should we use the original grinding
summary attached to the line"? Because this
summary was developed to include all gear
manufacturing operations, as well as assembly and
NVH. You must remember that there are
interactions with the corporate Gear Lab during
those tests.
70
15. Grinding
105 - Why shouldn't we create other grinding
programs? Modified and/or duplicated grinding
summaries totally interfere with the FTQ, since
torque, RPM, and VH values different from the
grinding standards generate out of order rework.
Another aspect is the non-compliance with the
summaries defined by Engineering, which are
summaries approved in all its steps
(BlankCutHeat TreatmentGrinding Testing
3rd Member NVH).
INCORRECT
STANDARD
71
15. Grinding
107 - What is grinding? Please describe the
parameters/factors of this process. Grinding is
the process used to correct all imperfections on
the gear and ensure the quality of the teeth in
terms of noise. Those imperfections are basically
potential flaws in the teeth cutting process and
heat treatment. Those imperfections cannot be
considered geometry corrections, that is,
Grinding is merely a "finishing" process, not
capable of removing large amounts of
material. Parameters include Abrasive compound,
torque, time, number of passes, rpm, delay,
backlash, setup gage, abrasive pipe direction,
abrasive flow, abrasive temperature, arbors. 108
- What is a lapping compound? What is it used
for? How often should it be replaced? It is a
mineral oil-based abrasive compound with silicon
carbide. It works as a "cutting tool", that is,
is used to remove materials from the gear to be
cut. The replacement schedule must be followed to
replace worn lapping that loose their material
removing property after a number of grinding
cycles. 109 - Do the temperature and the
"abrasive" lapping compound flow interfere with
the quality of the parts? Yes. Every time that
you notice that the flow or the temperature is
outside specs you must call maintenance and
inform the head of production and/or supervisor
immediately. 110 - When should the abrasive pipe
be adjusted? The abrasive pipe must be checked at
every setup. In some cases where the gears are
similar there is no need to adjust, only check
the distances. NOTE IT IS ESSENTIAL THAT THE
OPERATOR AVOIDS HANDLING THE
PINION ROD (BEARING DIAMETER) AND THE
GEAR RING PILOT
DIAMETER WITH LAPPING COMPOUND GLOVES
72
15. Grinding
111 - LAPPING COMPOUND A"Old" lapping sludge
stuck to machinery cowls has strong likelihood of
contaminating new lapping because this "sludge"
reduce quality as it is dead volume with no
grinding power.
INCORRECT
73
15. Grinding
EXCESSIVE LAPPING SLUDGE
CORRECT
74
15. Grinding
112 What is a setup gage? How important is it?
How often should it be used? Setup gage is the
standard provided by Gleason to verify that the
setup was executed correctly to ensure precision
during the grinding process. The setup gage
requires special care for its use to avoid
affecting quality. Maintaining this equipment is
extremely important and everyone involved in this
process is responsible for it. Because the gear
set consists of a set of parts (gear ring and
pinion) with hypoid teeth, using traditional
zeroing methods is not appropriate for time and
precision reasons. Any questions on the standards
or the values obtained (difference between
current and past values) must be taken
immediately to the head of production,
supervisor, or gear engineering. The setup gage
must be used as often as indicated in the control
plan, that is, every time a setup is executed or
every 2 days if there was no interference with
the process.
113 - When would you use 4 passes in the cutter?
How do you return to 3 passes? Please
explain. When imperfections are identified on the
part before the grinding process - through values
obtained from the tester (harmonics) or visual
markings. By monitoring the values obtained from
the tester (single flank and five position),
usually at payload changeovers.
75
15. Grinding
114 - How important is it not to change the
deflection parameters of cutters and testers? To
prevent gear sets with deflection from getting to
assembly and then NVH, since gears with
deflection represent potential rejection issues
at NVH. Note The limit must be 0.003" maximum,
set on the machine.
76
15. Grinding

• 115 - Why do we need to inform the arbor height
  values in the cutter and tester setups?
• The "arbor distance" values in the grinding
  summary are extremely important for the quality
  of the manufactured parts, and are printed in
  inches and millimeters in all arbors we get from
  Gleason. In normal conditions no corrections are
  needed, but it is important to check and
  understand what they affect, and if the value in
  the summary is different from the actual arbor
  value you must not only correct it but also
  inform the production or gear engineering
  head/supervisor - the quicker the information is
  passed on, the fewer problems will occur.

77
15. Grinding
116 - MOUNTING DEVICES (ARBORS) Values outside
the STD can generate scrap and contact
discrepancies.
ATTENTION 1 MOUNTING DISTANCE HAS NOTHING TO DO
WITH ARBOR HEIGHT. THE MOUNTING DISTANCE IS
DEFINED BY THE PRODUCT DRAWING. ATTENTION 2
INCORRECTLY ADJUSTING THE ARBOR HEIGHT IN THE
SUMMARY WILL CAUSE SEVERE COLLISIONS.
78
16. Contact Testing and Adjusting
117 - Interpret the contacts below, rate them,
and explain potential corrections.
Gear Set OK
Correction Setover V-0.003
Gear Set NOK, Drive to Heel
79
16. Contact Testing and Adjusting
Correction 1st Original Summary 2nd Hard
Measuring 3rd Setup Gage 4th Increase grinding
"power"
Correction Setover V-0.002
Gear Set NOK, Coast with interference, and Drive
at the limit
Correction 1st Check the abrasive pipe 2nd
Setover V-0.002, and H-0.001 3rd Time / Torque
/ Pass no.
Gear Set NOK, Drive at the limit, and suspicious
finishing
80
16. Contact Testing and Adjusting
Correction Setover V-0.002
Gear Set OK. Attention to the drive limit, that
is, central
Correction 1st Original Summary 2nd Drive
increase corners V and H Involve the Head
and Engineering
Correction 1st Coast setover H-0.002
Gear Set NOK. Coast low and Drive long/root and
thin
81
16. Contact Testing and Adjusting
Correction 1st Original Summary 2nd Hard
Measuring 3rd Setup Gage 4th Decrease grinding
"power"
Correction 1st Drive setover H-0.002
Gear Set NOK. Coast broken and drive low
Correction 1st Check the abrasive pipe 2nd
Setover V-0.002, and H-0.001 3rd Time / Torque
/ Pass no.
Correction 1st Coast setover H0.002
Gear Set NOK, coast tending to high, and drive
with poor finishing, as well as central/low.
82
16. Contact Testing and Adjusting
Correction 1st Original Summary 2nd Hard
Measuring 4th Increase grinding "power"
Correction 1st Original Summary 2nd Hard
Measuring 3rd Setup Gage 4th Decrease grinding
"power"
Gear Set NOK. Coast high/toe/thin. Drive broken.
Correction 1st Check arbor deflection
Correction Setover V-0.003
Gear Set NOK, Coast with deflection, and Drive to
Heel
83
16. Contact Testing and Adjusting
Correction 1st Original Summary 2nd Hard
Measuring 3rd Setover H-0,004, decrease grinding
"power"
Correction Setover V-0.002
Gear Set NOK, Coast root, and Drive to
central/heel
Correction Setover H0.003.
Correction 1st Original Summary 2nd Hard
Measuring 4th Decrease grinding "power"
Gear Set NOK, Coast high, and drive broken
84
17. Gear Set Washing
118 - What is the impact of testing parts with
"high" temperature or with residue from not
cleaning? False harmonics reading and contact
generating wrong corrections in the cutter,
directly impacting OEE and low FTQ. Another
important fact is marking compound and parts
mounting arbor contamination. 119 - What should
I do if I detect parts with lapping compound
after the washing process? Interrupt production
immediately and inform the head of production
about the incident. 120 - For how long can a
gear set have lapping compound before washing? No
waiting time is allowed, because this is a
critical item that may cause a RECALL. 121 -
What are the possible consequences of a part
released with lapping compound after the gear set
washing process? Which variables interfere with
gear set washing? They may present noise issues
that will only be detected in the final axle
assembly, "NVH" or even at the end customer, with
high costs caused by the non-conformity RECALL.
Artet washer cleaning, artet nozzle alignment,
filter replacement, bath temperature, bath
concentration, conveyor belt speed change, using
a smaller washer for production, post-cutter
parts accumulation before washing. Note Another
important fact is the potential contamination of
the phosphate baths, an issue that could
propagate to all manufactured parts.
85
18. Contact Testing and Harmonics
122 - What is a backlash? How do you check for
backlash? Lack of engagement between the gear
ring and the pinion. It must be checked using a
touch probe dial. The setup gage must be used as
often as indicated in the control plan, that is,
every time a setup is executed or every 2 days if
there was no interference with the process. 123
- Why is the grinder backlash different from the
tester backlash? As we already know, backlash is
lack of engagement in the grinder this clearance
must be smaller for improved abrasive
effectiveness since there will be a smaller
clearance between the gear teeth, while, in the
tester, it simulates the exact behavior of the
assembled axle, that is, only the room needed for
the oil to pass. Grinder 0.003" - defined by
Process Engineering Tester 0.006 - defined by
Product Design 124 - Can you use grinder arbors
in the tester? No. The lapping compound used in
the grinder may interfere with the quality of the
parts and the useful life of the arbors, and
there is a risk of contaminating the testers
contact ink. 125 - What are the consequences of
working with out of specs deflection in the
machine? Lost production, scrap,
non-repetitiveness of gear sets, low OEE. 126 -
What is the correct procedure to detect and
correct arbor deflection? See the next slide.
86
18. Contact Testing and Harmonics
127 - MOUNTING DEVICES (ARBORS) Grinding and
testing arbors (Gear Ring Pinion) with
excessive wear on the arbor mounting screws
interfere with deflection and cause rework and
low FTQ.
EXCESSIVE WEAR
87
18. Contact Testing and Harmonics
128
88
18. Contact Testing and HarmonicsBacklash
correction for the Oerlikon SFT machine
129 - The Oerlikon machine is a machine older
than the Gleason. Some automatic features in the
Gleason machine are done manually in the
Oerlikon, requiring more skills and knowledge of
the employees. Every time the Oerlikon is setup,
the operator needs to measure the backlash in 3
points like in the Gleason machines, then find
the average value that corresponds to 0.006" or
0.152 mm, which is the value specified for the
product. If it is out of specs, the operator must
follow these steps for correction 1 - If the
average value found for the part is below 0.152
mm, the operator must increase the value on the
machine dashboard by the same amount needed to
reach 0.152 mm, then redo the backlash on the 3
points. When the backlash value found is
significantly different from the value normally
found, e.g. (value below 0.1 mm or above 0.2
mm). The employee must redo the entire setup. If
the backlash remains out of spec with uncommon
values, the part and the machine must be
analyzed. Inform the head of production or
supervisor. Note The Oerlikon system uses
inches, so we need to pay attention when entering
values in the machine. An error of a thousandth
of an inch can cause issues with part quality in
harmonics and contact values.
Note An incorrect backlash can lead to
incorrect contact/harmonic results and cause the
part to be rejected in 3rd member/NVH. We
have already identified problems pertaining to
Oerlikon backlash in rejection issues.
89
18. Contact Testing and HarmonicsBacklash
correction for the Oerlikon Five-Position machine
130 - The Oerlikon five-position requires
operator skills and knowledge to perform the
backlash, and the operator of this machine must
be trained on its use. The Gleason training is
not valid for operating Oerlikon machines. Of
course, when we need to train an operator to use
the Oerlikon machine, if he or she already knows
the Gleason operation concepts/parts this makes
it much easier to train them and reduces the
training time. The backlash for five-position
must also be performed for every line setup. SFT
corrections also require five-position
corrections in the same proportion, in the 5
positions as shown in the previous slide, with
utmost care when entering correction values. To
identify the position of the five-position when
reading the report, use the same concept used for
Gleason. Lower drive backlash is toe
Higher drive backlash is heel Higher coast
backlash is toe Lower coast backlash is
heel Negative H is root Positive H is
top The concept described above is the same for
all machines and is a product