Torsional actuation NVH test method

• US 20040069053A1
• Filed: 10/11/2002
• Published: 04/15/2004
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: American AXLE & Manufacturing Incorporated (American AXLE & Manufacturing Holdings Incorporated)
• Original Assignee: American AXLE & Manufacturing Incorporated (American AXLE & Manufacturing Holdings Incorporated)
• Inventors: Sun, Zhaohui, Schankin, David Paul, Ranek, Mark Norman, Kurecka, Donald Joseph
• Granted Patent: US 6,802,206 B2
• Time in Patent Office: Days
• US Class Current: 73/114
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis

Abstract

A method for evaluating energy transmission from an axle through a vehicle suspension system. The methodology employs a torsional actuator to apply input energy to the vehicle in a manner that mimics the energy that is generated by the axle during the operation of the vehicle so that both the driving load and the vibration induced by gearset motion variation are simulated. Since the energy input can be quantified and monitored, the same amount of torque can be applied during each test to permit the technician to fully comprehend differences in the designs of several axles on the transmission of noise and vibration.

Claims

1. A method for evaluating energy transmission over one or more transfer paths between an axle and a vehicle suspension system, the axle having an axle gearset with an input pinion, the method comprising the steps of:

coupling a torsional actuator to the input pinion;

controlling the torsional actuator such that the torsional actuator applies a torque input to the input pinion, the torque input having a static portion and a dynamic portion, the static portion simulating power train torque and the dynamic portion simulating torsional vibration induced by gearset motion variation; and

monitoring the energy that is transmitted to the vehicle suspension through each of the transfer paths.

2. The method of claim 1, wherein the static portion has an approximately constant magnitude.

3. The method of claim 1, wherein the dynamic portion has an oscillating magnitude.

4. The method of claim 1, wherein the controlling step is performed by a servo-control system.

5. The method of claim 4, wherein the servo-control system is driven by a hydraulic pump.

6. The method of claim 1, wherein the input pinion includes a pinion flange and the actuator is coupled to the pinion flange.

7. A method for evaluating energy transmission into a vehicle over at least one transfer path between an axle and a vehicle suspension system, the axle having an axle gearset, the method comprising the steps of:

applying a torsional input to the axle gearset to torsionally excite the axle in a manner that mimics the axle gearset'"'"'s excitation of the axle during operation of the vehicle; and

monitoring the energy that is transmitted through the vehicle suspension system into the vehicle via the at least one transfer path.

8. The method of claim 7, wherein the torsional input includes a portion having a substantially constant magnitude.

9. The method of claim 8, wherein the torsional input includes another portion having an oscillating magnitude.

10. The method of claim 7, wherein in the monitoring step, each of the transfer paths is individually monitored.

11. The method of claim 7, wherein the torsional input is applied by an actuator, the actuator including a servo-control system that is driven by a hydraulic pump.