Technology meets future.

Synchronization test bench

The synchronization test bench was developed to test transmission components and complete transmissions under different ambient temperatures and to determine the torque, shifting force and speed of the input and output. The test bench uses a swiveling mounting table on which the transmission types can be mounted. It comprises a drivetrain with torque measuring point and flywheel mass, an oil supply unit, a gear shifting unit with separate hydraulic supply, an air circulation temperature control unit, an insulated test chamber and a test box. The measurement data is recorded and evaluated by a computer and the system is designed for three-shift operation.


Transmission components and complete transmissions are to be examined.

The test must be carried out under different ambient temperatures. It must be possible to determine the torque, the shifting force and the speed of the input and output in these conditions.

It must be possible to test the relative movement of the synchronizer rings during a gear shift of a pair of gears (1st and 2nd gear).

It must be possible to specify the braking torques via a load unit.

The input and output speeds as well as the differential speed, shift force, shift fork friction torque, synchronization torque, synchronizer ring movement and shift rod movement must be measured during the shifting process and evaluated by a computer.

In order to subject the test to realistic conditions, a flywheel mass is connected downstream of the electric motor, which has to simulate the thrust of the vehicle.



To solve this task, a swiveling mounting table was set up.

A clamping bracket sits on this in a groove field, to which the various gearbox types can be bolted.

The test bench essentially consists of:

  • Test stand frame, tiltable, with clamping plate for test box or complete gearbox
  • Drive train with torque measuring point and flywheel mass
  • Oil supply unit
  • Gear shift unit with separate hydraulic supply
  • Circulating air temperature control unit
  • insulated test room
  • Test box
  • Load unit for test box
  • Calibration medium for the torque measuring shaft in the drive train
  • Drive motor
  • Switch cabinet for power section
  • 19″ cabinet for measuring and control inserts
  • Control panel
  • Calculator for recording measured values


Control panel

The control panel is designed as a control panel in a 19″ cabinet.


Calculator for recording measured values

The measurement data is recorded and analyzed via a computer. The measurement logs are output via a printer.

The digital values are taken from an interface card and fed into the computer.


Description of the individual components

Test stand frame with clamping plate for test box or complete gearbox. The test stand frame is built on a solid tubular frame and can be tilted to one side up to a maximum of 5 degrees. The clamping plate for the test box is fitted with T-slots and equipped with appropriate sealing lips for the cool box on the outer circumference. The clamping plate complies with DIN regulations and has the corresponding accuracy.

The entire test stand frame is machined on the top surface in accordance with quality level 3 DIN 876.

The main drive motor is located in the base frame of the test stand and runs at 3,000 rpm. This results in a maximum drive shaft speed of approx. 5,000 rpm.


Drive train with torque measuring point and flywheel mass

The drive train sits on an adjustment plate in the middle of the test field and can be precisely adjusted there. Adjustment is possible for all three axes.

The flywheel mass sits between two bearings and is balanced and stabilized for the high speeds.

The drive shaft is dynamically balanced (quality level G 2.5 according to VDI 2060).


Oil supply unit

The oil supply unit is used to supply heated or cooled oil to the gearbox.

The hydraulic unit can be used at operating temperatures between 20 °C and 150 °C.

The system pressure is max. 10 bar.

Different viscosities of oil can be used with the heating unit.

The entire oil unit can cope with the extreme temperature conditions and fluctuations in oil types.

The heating time is approx. 60 minutes to reach a temperature of 150 °C.

A safety temperature limiter with release button in accordance with VDE for 0 °C to 250 °C is installed for safety control.

The entire oil unit is designed to be mobile.

Oil circuit and hydraulic components meet the highest requirements of hydraulic technology.

The movement sequences are hydraulically controlled and monitored by two force and displacement measuring devices.

The measuring amplifiers and control plug-in units belonging to the gear shift unit are housed in the 19″ cabinet.

The gear shift unit has RS 232 serial interfaces to the programmable logic controller, to the measured value acquisition computer and an interface for programming the system via a hand-held terminal.