1. Design of a Backlash Measurement System
ME 4020 – SENIOR DESIGN (FALL 2015)
ZF Transmissions Team B
Tyler Mode, Caleb Long, Conor Dillion, Zach Long
Advisors:
Dr. Kalyn Katuri
Dr. Daniel Fant
Dr. Rahul Renu
Sponsors:
Mr. Matt Peterson
Mr. Gerhard Polajner
ZF Transmissions
,
Introduction
Currently ZF Transmissions uses a manual
measurement and data entry process to measure
the backlash of their 8HP65A torque converter
assemblies. Because the current process relies
strictly on user input of data, unreliable results
were observed.
Problem Statement
To design a device to measure pinion backlash of
the 8HP65A torque converter assembly.
Driving Constraints
1. Measurement device must have a resolution of at least 5 microns
2. Data entry must be automated
3. System must have a less than 100 second overall cycle time
4. System must be able to verify reading once per shift on master device
5. System must take at least three measurements
6. System must verify differential is not seized
Final Prototype
1. JVL Motor w/ housing, forward slides,
linear position sensor, and coupler
2. Rotational Movement: Bearing hinges
3. Vertical Lift Table w/ lead screw
Final Design Detail
 Allows for adjustment to varying pinion placement
 Device rotates around to verify measurements on master part
 No pinch points or safety hazards
 Total Estimated Cost: $5450 - $6250
Motor Assembly
Master
Assembly
Lift Mechanism
Lift Mechanism
Enclosure
Rotational Adjustment
Prototype Results
Average: 0.2856°
St. Dev: 0.0016°
3
1
2
Process Overview
To measure backlash, the JVL servomotor first rotates the pinion of the torque
converter assembly, checking the system for seizure. The backlash measurement
process then begins, first rotating the pinion one full counterclockwise revolution
to assure that the crown gear and pinion gear are in contact. Once complete, the
motor rotates clockwise at 35% torque (not enough to rotate crown gear) until
contacting the adjacent crown tooth, measuring the displacement between the
two crown teeth. This measurement process is repeated to obtain four
measurements, which are then averaged to output the backlash of the unit.