ECO-FRIENDLY LINEAR MODULE THROUGH HYDROSTATIC BEARING CONFIGURATION

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ECO-FRIENDLY LINEAR MODULE THROUGH HYDROSTATIC
BEARING CONFIGURATION
With the rapid progress electronic and optical
devices, ultra-precision and micro-machining
technologies are increasingly required to meet
high precision. Linear motion axes are
ever-present in manufacturing systems and
therefore in order for ultra-precision machines
to meet the high accuracy demands,
ultra-precision linear motion axes would need to
be developed. Linear and angular bearing
technology play an important role in linear
motion axes and ultimately determine the machine
tools performance. It is well known that friction
has a major influence on the positional accuracy.
This is due to its high non-linearity, and
friction degrades the dynamic performance and
positioning accuracy . In order to eliminate
friction from the linear module, a linear motor
will be used as the drive and as the guiding
element, hydrostatic bearings will be used.
Function Actual Part
1 Sealed tank Glass Jar
2 Hydraulic pump 12V Bosch fuel injector pump
3 Relief valve Bosch fuel pressure relief valve
4 Variable resistor with a ball valve FESTO pneumatic variable resistor
5 Pressure gauge Bourdon-tube gauge
6 Inlet restrictors M6 set screw
7 Bearing pad resistance Bearing pad
8 Sump Guideway base
LINEAR MOTOR FORCER
GUIDE
PAYLOAD SPINDLE / WORKPIECE / TOOL HOLDER
RAIL
RAIL
PADS
LINEAR MOTOR MAGNETIC TRACK
PADS
BASE
Part
1 Base
2 Guide
3 Rail
4 Manifold
5 End Plate
BEARING A
BEARING C
Proximity Sensor
Test Rig
Parallel Block
PAD
A deflection of the guide will result in a
deflection of the parallel block. This deflection
will be observed by a proximity sensor.
Pressurized fluid inlet from hydraulic power pack
BEARING B
BEARING D
O-RING
RESTRICTOR
INLET PASSAGE
RAIL
GUIDE
1 High pressure fluid is distributed by manifold to each bearing pad inlet passage.
2 Fluid flows through inlet passage to the bearing pad.
3 Fluid flows outwards from the bearing pad land into the sump.
4 The used fluid is collected from the sump and extracted via the return lines back to the tank.
1
BASE
2
3
4
Return of fluid back to tank
Force Analysis
Deflection Analysis
Stiffness Analysis
Author B. Janse van Rensburg Supervisor
Associate Professor R. Kuppuswamy
Project number 52 2009