Crank drives are frequently used in compressors and pumps. They cause vibration due to the oscillating masses and forces. Under the alternating stress in the drive mechanism, bearing clearance, for example, can generate shock impacts with high-frequency exciter spectra. In addition, free mass forces generate harmonic vibrations due to their non-linear kinematics. The PT 500.16 accessory set enables the stroke, mass balance and bearing clearance on the crosshead to be adjusted. The speed is adjusted using the base unit PT 500. Gas pressure forces such as occur in compressors or combustion engines can be simulated using springs. Experiments with gas pressure forces require higher torques which are attained by reducing the speed of the drive motor from the base unit PT 500. This reduction is achieved either with the PT 500.14 belt drive or the PT 500.15 gear unit.
The transmission of alternating torque in toothed gearing mechanisms can be investigated together with accessory set PT 500.15 (for investigating damage to gears). The accessory set is mounted on the base plate of the machinery diagnostic base system PT 500.
To measure and evaluate the experiment, the computerised vibration analyser PT 500.04 is required. It includes all the necessary sensors, a measurement amplifier and analysis software to record the vibration phenomena.
Learning Objectives / Experiments
- experimental modal analysis of mechanical
- influence of bearing clearance and shock impact - inconsistent torque characteristic - wear measurement on piston rods
- understanding and interpreting frequency spectra - use of a computerised vibration analyser
in conjunction with PT 500.15 - transmission of alternating torque in toothed
in conjunction with PT 500.14 or PT 500.15 - influence of gas pressure forces on the vibration
* Vibrations of crank drives1 * Bearing clearance or slack in oscillating machine
 investigation of the vibrations of crank drives  crank drive with adjustable stroke  interchangeable bearing bushes permit simulation of bearing clearance  springs simulate gas pressure forces  can be used together with gear damage accessory set PT 500.15  belt drive PT 500.14 or gear unit PT 500.15 required for experiment with gas pressure forces  accessory set for PT 500 machinery diagnostic training system  stackable box for all components
Stroke: 50 - 75 - 100mm Balance mass total
- 490g, rated for operation with 50mm stroke
Bearing clearance: 0...1mm
Pressure spring - relaxed length: 170mm - spring stiffness: R=0,55N/mm
Dimensions and Weight
LxWxH: 600x400x170mm (box) Weight: approx. 8kg
Scope of Delivery
1 crank drive 2 springs 2 balance masses 1 set of tools 1 storage box with foam inlay 1 manual