Training Presentation

1
Training Presentation
2

• UNDERCARRIAGE SYSTEM
• Component Assembly
• Operation Principles

3
Bulldozer Assembly

• Power Take-off
• Torque Converter
• Universal Joint
• Transmission Unit
• Main Drive
• Steering Clutch
• Steering Brake
• Final Drive
• Track Equipment
• Control System
• Working Equipment
• Cabin
• Floor Fender
• Track Frame

4
Power Train

• Engine
• Torque Converter
• Universal Joint
• Gear Box
• Main Drive
• Steering Clutch
• Final Drive
• Track System

5
Power Take-off

• Function
• PTO power
• Equipment
• Work system pump
• Transmission pump
• Steering Pump

6
Torque Converter Assembly

• Type
• 3-element
• 1 stage
• 1 phase
• Assembly Pump, Turbine and Stator
• There are many vanes on these components for
  using oil to transfer power

7

• These 3 components combined with oil, give us as
  smooth power transmission.
• Safety valve fitted to oil input, ensures the
  input oil pressure is no more than 0.87MPa.
• Relief Valve fitted on oil output, ensures the
  oil pressure inside the torque converter is
  maintained below 0.45MPa.

8
(No Transcript)
9
Principles of Torque Converter

• Oil Flow Pump? Turbine ? Stator? pump
• There is 2 mm clearance between pump and Turbine,
  and transfers power by Oil. There is no
  mechanical impact, they protect each other
• Assist hydraulic system to resist loss of oil
  to maintain the normal oil temperature.

10
Operation of Torque Converter

• When the load increases, the dozer ground speed
  is reduced, causing turbine speed to slow down.
  But at this time the energy from the pump
  transfer to torque converter is not reduced. This
  energy is still transferring to the stator
  through the slowing turbine. Then the energy to
  stator from turbine, results in the turbine
  gaining torque, then the turbine output torque is
  increasing.

11
Torque Converter Operation

• 1.Change torque automatically
• 2.Absorb vibration, prolong working life
• 3.Good power transmission capability, driving at
  slow speed
• 4.Simple operation
• 5. Start smoothly, eliminates any shocks in power
  train
• 6.Easy maintenance

12
High Torque Converter Oil Temperature

• Normally, SD22 Torque Converter Temperature
  of output oil is 115-120oC. For a short time, a
  higher temperature of 130-135oC is allowed, but
  long term high temperature shows there is
  something wrong, for the following reasons
• 1.Shortage of Oil
• Torque converter, transmission, main drive,
  steering and final drive will take 30 of engine
  rated power. This power will transfer to heat
  energy, and increase the oil temperature.
  Therefore it requires enough oil to absorb this
  heat.
• If the oil quantity is not sufficient, the
  oil temperature will be too high.

13
2.Oil Pressure of input and output are incorrect
If torque converter input oil pressure is not
correct (Standard 0.87MPa) or the oil is dirty,
the piston of valve will stay at relief position,
so the oil pressure to the torque converter is
low. This leads to a loss of efficiency and
excessive oil temperature. If torque converter
output oil pressure is not correct (Standard
0.45MPa) or the oil supply is blocked, return oil
temperature will be too high. The flow of oil to
oil cooler is reduced, and the oil temperature
too high
14
3. Incorrect Operation Excessive use of low
engine speed for extended time, torque converter
will work at low efficiency. Torque converter
will lose power, and transfer heat energy leading
to high oil temperature.
15
Power Transmission Case

• The types of Transmission Case
• Base Operation type
• 1.Manual Gearshift2.Hydraulic
  booster3.Powershift
• Base Transmission type
• 1.mechanical type 2.Planetary Gear
• Planetary type powershift transmission case type
  Planetary Gear, Multi-disc clutch, Hydraulic
  control, forced lubrication.
• Function
• 1.Enable forward and reverse
• 2.Select different gear ratio
• 3.Matched with the torque converter, enables a
  wide range of power output and ground speed

16
Planetary Gear System
C
D
A

• The system consists of
• A Sun Gear
• B Planetary Gears
• C Ring Gear
• D Carrier
• The planetary gears are installed on the carrier
  being in constant mesh with the sun gear and the
  ring gear

B
17

• Planetary Gear system

18
Principle of Planetary Gear system
If the carrier is fixed, the torque is
transmitted from sun gear to planetary gear, and
is transmitted from planetary gear to ring gear
to make the ring gear rotate. Rotation direction
of ring gear is opposite from sun gear.
A Sun Gear B Planetary Gear C Ring Gear D
Carrier
19
Principle of Planetary Gear system
If the ring gear is fixed, the torque is
transmitted from sun gear to planetary gear. The
planetary gear rotates by itself, at the same
time rotates around sun gear. Rotation direction
of the planetary gear shaft is opposite from sun
gear. It is a slowdown outfit that power input
from sun gear, output from carrier
A Sun Gear B Planetary Gear C Ring Gear D
Carrier
20
The above principles are structure principle of
No.1,3,4 planetary gear system. The sun gear is
active in No.1 Planetary Gear system The carrier
is active in No.3 4 Planetary Gear system
21
This is structure and principle of No.2 planetary
gear system. The rotate direction is contrary
with No.1 planetary gear system.
22
SD22 powershift transmission system
Consists of 4 planetary gear systems with 4
clutches, and 1 locking clutch (no planetary gear
system) and housing, input shaft, end gear and
output bevel gear. No.1 clutch is for Forward
Gear No.2 clutch is for Reverse Gear No.3 clutch
is for 3rd Gear Shift No.4 clutch is for 2nd Gear
Shift No.5 lock clutch is for 1st Gear Shift
23
(No Transcript)
24
SD22 powershift transmission system

• The 4 planetary gear system clutchs washers and
  disc are the same, but the disc quantity is
  different. Its design is based on transmission
  torque.

25
No.1- 4 planetary gear systems structure are
same, clutches washer and disc are same, but the
disc quantity and piston is different.
26
Method of fixing of each planetary gear is as
this figure, it is actuated by the clutch.
Engagement of clutch is actuated by oil
pressure from control valve pushing piston 3.
27
Disengagement of clutch is actuated by return
spring 33 which pushes piston 3 to original
position after oil pressure is cut off. The
function of disc spring 42 is to improve
operating speed of piston 3 and improve release
the discs.
28
This figure is a drawing of No.5 locking clutch.
When the clutch disengages, oil in the cylinder
body 16 by the action of centrifugal force. Disks
cant disengage quickly, only by disk spring 29.
This can make the clutch half disengage. This
will cause difficulty for next gearshift. In
order to eliminate this problem, the ball check
valve 17 is incorporated in the piston after the
rotary clutch.
29
No.5 Clutch is a lock clutch. When this clutch
engages, pressure oil from controlling valve
enters into oil cavity and pushes piston 26, at
the same time, the oil pushes check valve ball 17
to plug the hole of valve. The clutch is engaged
quickly.
30
No.5 Clutch is a lock clutch. When the pressure
oil from controlling valve is cut off, by the
action of centrifugal force, ball 17 can move to
the direction of arrow in this figure. At this
time, the hole of valve cage is opened and the
oil is drained off.
31

• Forward 1st Speed

32

• Forward 2nd Speed

33

• Forward 3rd Speed

34

• Transmission Lubrication and Cooling
• Its a forced lubrication system, from above and
  below, two ways divided through a valve.
• Transmission Case lubrication pressure is
  0.124Mpa. Upper way lubricates the second half
  bearing and cools the second half discs lower
  way lubricates the first half bearing and cools
  first half discs.

35
Main Drive (SD22)

• Assembly
• Bevel gears
• Horizontal Shaft
• Bearings
• Sprocket Hub
• Functions
• Power train gear reduction to increase the
  final drive torque

36
Steering Clutch

• Function
• To disengage the shaft drive and control
  steering
• Type
• Wet, multi-disc, spring loaded, hydraulic
  separated, normally engaged.
• Spring force
• F3.2 tons

37
Steering Clutch Operation
38
Steering Brake

• Function
• The brake on the outside of steering clutchs
  outside drum, reduced the rpm of the final drive
  on that side.
• Type
• Wet band, hydraulic boosted control

39
Steering Brake Operation
Forward
Reverse
40
Steering Brake Control

• Linkage through valves

41
Steering Case Lubrication and Breather

• There are 3 associated components, Main drive,
  Steering Clutch and Steering Brake. They are
  lubricated and cooled by the oil in steering
  case. The oil level can be checked with oil
  dipstick
• Steering case has a breather to balance inside
  and outside pressures.

42
Final Drive

• Final Drive One Set Final Drive on each side.
• 2 stage spur gears reduction. Floating Seal and
  O-ring to contain oil, then connected outside
  with breather.
• Assembling Sprocket hub and gear requires 60 tons
  force with special tools.

43
Track System --- Walking Gear

• Assembly
• Track Frames
• Track Rollers
• Carrier Rollers
• Recoil system
• Track Shoes
• Equalizer

44
Recoil system for Track

• Function
• 1. Maintain track tension
• 2 absorb the vibration of idler
• Note
• the fixed pressure is 20.38 tons, it requires
  special fitting tools

45
Measurement of Track Tension

• use a ruler placed on the track grousers between
  carrier roller and idler, the measure distance is
  C,C20-30mm
• SD32 track has more wide, the distance is bigger
  between carrier roller and idler, the measured
  distance is C30-40mm

Idler
Carrier roller
46
Idler

• Function
• Gives guidance for track chain and maintains
  track tension
• Lubrication
• There are lub oil in the cage that is sealed by
  floating seal, between idler and support housing.
  The oil capacity is 70.

47
To Adjust Idler Clearance

• If the clearance is over limit , the idler will
  swing, and track links off centre and will wear
  the sprocket.
• If Clearance in one side
• Agt4mm,
• it must be adjusted into
• A0.5-1mm
• If Clearance of up and down
• (BC)5mm
• it must be adjusted into
• (BC)2mm?

48
Track Roller

• First it carries dozer weight, secondly it
  prevent track chain moving off centre of track
  frame
• Bushing and float seal is similar to idler

49
Track Shoe Assembly

• Supports all of the dozer weight, and determines
  the ground pressure
• Four high strength bolts fix track shoe onto
  track link,
• bolt torque
• SD1670kg.m
• SD2276kg.m
• SD32100kg.m

50
Use and Maintenance of Track Shoe

• Track supports 30 tons bulldozer weight, and if
  the working conditions are bad, it will wear more
  quickly, so use and maintain it correctly.
• Often check the tension of track shoe. use a
  ruler put the track grousers between carrier
  roller and idler, the measure is C,C20-30mm
  SD32 track is more weight, the distance is more
  large between carrier roller and idler, the
  measure is C30-40mm
• When the work is hard, the track shoe assy will
  need to be adjust tighter if the work is
  moderate , the track shoe assy tension can be
  adjusted back.

51
Use and Maintenance of Track Shoe

• 2. The sprocket segments need be replaced when
  the sprocket segments wear under the limit.
• 3. Dont drive dozer hard and avoid track damage
  and excessive wear.
• 4. If there is excessive track play and noise,
  you must stop and check tracks and machine.
• 5. When the dozer across the railway line, you
  must drive it across the railway at right angle,
  and dont change speed, dont stop and reverse,
  avoid track shoes locking in railway line.
• 7. After working, you must check tracks, and if
  there is something wrong. If there is something
  wrong, must repair or replace.

52
End of this Training Module Thanks Your
Cooperation !!!