One means for measuring torque is to mount the dynamometer housing so that it is free to turn except as restrained by a torque arm. The means for developing torque can be frictional, hydraulic, electromagnetic, or otherwise, according to the type of absorption/driver unit. Some means is provided to develop a braking torque between the rotor and housing of the dynamometer. The rotor is coupled to the engine or other equipment under test and is free to rotate at whatever speed is required for the test. An absorption unit consists of some type of rotor in a housing. π / 30 Detailed dynamometer description Įlectrical dynamometer setup showing engine, torque measurement arrangement and tachometerĪ dynamometer consists of an absorption (or absorber/driver) unit, and usually includes a means for measuring torque and rotational speed.
The prime mover is then allowed to accelerate the engine through the desired speed or RPM range. The dynamometer has a "braking" torque regulator - the power absorption unit is configured to provide a set braking force torque load, while the prime mover is configured to operate at whatever throttle opening, fuel delivery rate, or any other variable it is desired to test.
#Engine dyno programs generator#
Regenerative dynamometers, in which the prime mover drives a DC motor as a generator to create load, make excess DC power and potentially - using a DC/AC inverter - can feed AC power back into the commercial electrical power grid.Ībsorption dynamometers can be equipped with two types of control systems to provide different main test types. This power absorbed by the dynamometer is then converted into heat, which generally dissipates into the ambient air or transfers to cooling water that dissipates into the air. The power absorption unit (PAU) of a dynamometer absorbs the power developed by the prime mover. The dynamometer must be able to operate at any speed and load to any level of torque that the test requires.Ībsorbing dynamometers are not to be confused with "inertia" dynamometers, which calculate power solely by measuring power required to accelerate a known mass drive roller and provide no variable load to the prime mover.Īn absorption dynamometer is usually equipped with some means of measuring the operating torque and speed. Early hydraulic dynamometer, with dead-weight torque measurementĪn absorbing dynamometer acts as a load that is driven by the prime mover that is under test (e.g.