US 4,300,383 A · Crankshaft damper resonance monitor

Abstract

A method and apparatus for testing an elastomeric torsional vibration damper by oscillating the hub thereof on a shaker table to thereby simulate actual conditions of use. Prior testing methods and apparatus have not compensated for changes in the mechanical properties of the elastomer which often occur during testing. Such changes are usually due to build-up of heat within the elastomer. According to the practice of this invention, changes in the mechanical properties of the elastomer are compensated for by continuously monitoring the phase difference between the hub and the inertia ring. If the phase difference varies from a predetermined amount, the hub input frequency is then varied in such a manner as to maintain the predetermined phase difference between the hub and inertia ring. In this manner a predetermined phase difference may be maintained throughout the test.

Claims5

Dependent claims

An apparatus for testing a torsional vibration damper, the damper being of the known type having a hub and an inertia ring coupled thereto by elastomer, the apparatus including a shaker table for rotationally oscillating the hub of a damper to thereby simulate actual conditions of usage of the damper, means for continuously measuring the phase angle between the hub and the inertia ring of the damper, the improvement comprising, means for varying the frequency of oscillation of the hub so as to maintain a desired, predetermined phase angle between the hub and inertia ring, whereby compensation is made for changes in mechanical properties of the elastomer over the period of time of damper testing, such changes being caused by heat generated within the elastomer and changes in the environment.

An apparatus for testing a torsional vibration damper including a shaker table for rotationally oscillating the hub of a damper of the known type comprising a hub, an elastomer and an inertia ring, the shaker table being of the type whose frequency of oscillation is proportional to the voltage fed to it, the apparatus comprising,

(a) a ramp generator whose output voltage is fed to the shaker table, the ramp generator producing an increasing output voltage after its own operation is commenced,
(b) means for generating a voltage (termed a first voltage) corresponding to the actual phase angle between the hub and the inertia ring which occurs during operation of the shaker table,
(c) means for establishing a voltage (termed a second voltage) corresponding to a desired, predetermined phase angle,
(d) means for comparing the first and second voltage,
(e) means for stopping the voltage increase of the ramp generator to the shaker table when the said compared first and second voltages become equal after the apparatus commences its operation, so that the ramp generator thereafter feeds a fixed voltage to the shaker table.

2 more elements

Dependencies are inferred from the claim text.

Crankshaft damper resonance monitor

Life of this patent

Crankshaft damper resonance monitor

Life of this patent

Abstract

Claims5