Hydraulic Motor Test Rigs

Test Benches for performance study of Hydraulic Motors

Hydraulic Motor Test Rig

Hydraulic Motor Test Rigs carry out detailed performance studies on special hydraulic motors with facilities for limited tests on certain ratings of fixed speed and variable speed DC servomotors.

Hydraulic motors are put through low-speed tests and high-speed tests to evaluate their performance. Loading arrangement in such applications should be capable of exerting the rated torque right from zero speeds up to the rated speed of the motor. Eddy current dynamometers are capable of high speeds, and are popular for power dissipating capability, but they need a minimum slip of above 200 rpm to exert the rated torque.

Dynaspede Powder dynamometers have an excellent control of torque in the low speed region right upto zero speed. However, they are not suitable for high speed and high power applications.

To meet this challenging requirement, a tandem dynamometer including a powder dynamometer to exert braking torque at low speeds and an eddy current dynamometer to exert braking torque in the high speeds is effectively used in the test bench with an automatic changeover.

Test Set-up

Mounting Structure: The mounting structure to accommodate the motor mounting fixture, torque, speed transducer and dynamometers is a sturdy mechanical structure designed for low vibrations. Safety guards for all the rotating elements are provided on the test bed with interlocks for safe operation.

Motor Mounting Arrangement: The motor mounting fixture is provided with a machined base with a mounting bracket for flange mounting of the motor under test. The bracket and motor slide along a mating guiding key, which ensures perpendicularity of the test motor with respect to the axis of rotation.

Loading Arrangement: This is a tandem Dynamometer consisting of a powder dynamometer in tandem with an eddy current Dynamometer mounted on a common structure with necessary transducers for measurement of test parameters. Powder dynamometer provides loading in the low speed region and eddy current dynamometer provides loading in the high-speed region with automatic changeover.

Torque-monitoring arrangement: To monitor the load torque applied on the motor a high accuracy in line brush-less rotating transducer is provided.

Speed monitoring: A high accuracy optical encoder is coupled to the non-driven end of the dynamometer shaft for sensing the angular position of the motor shaft under dynamic conditions, as needed during low-speed tests on hydraulic motors.

Test conducted on the rig:

For Hydraulic Motors

  • Study of frictional characteristics
  • Performance evaluation of motors in Low speeds
  • Performance evaluation of motors in High speeds
  • Endurance tests

For DC servo motors

  • Torque speed characteristics of the servomotors at different speeds
  • Performance test
  • Thermal time constant evaluation
  • Endurance tests

Control System

PC-based control system serves all the control needs of the Test Bench. The PC console houses all digital controls and peripherals such as the PLC, PC, Colour Monitor, Keyboard and Track ball. It facilitates the following:

  • Automatic sequencing of various tests according to a prescribed programme and storage of the results in tabular and graphical form
  • Study of motor characteristics