High-Frequency Anti-Lock Clutch System and Method

• US 20090090592A1
• Filed: 10/05/2007
• Published: 04/09/2009
• Est. Priority Date: 10/05/2007
• Status: Abandoned Application

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Mordukhovich, Gregory, Phillips, Andrew W.
• Application Number:
  US11/867,864
• Publication Number:
  US 20090090592A1
• Time in Patent Office: Days
• US Class Current: 192/58.2
• CPC Class Codes: F16D 25/0638 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 2500/1026 Hydraulic
• CPC Class Codes: F16D 2500/3163 Using the natural frequency of a component as input for the control
• CPC Class Codes: F16D 2500/50293 Reduction of vibrations
• CPC Class Codes: F16D 2500/50296 Limit clutch wear
• CPC Class Codes: F16D 2500/5063 Shaft dither, i.e. applying a pulsating torque to a (transmission) shaft to create a buzz or dither, e.g. to prevent tooth butting or gear locking
• CPC Class Codes: F16D 48/066 Control of fluid pressure, e.g. using an accumulator F16D48/062, F16D48/068 take precedence

Abstract

A clutch assembly is provided including a controller, a plurality of vibration sensors, a clutch housing containing a lubricated clutch pack having a friction interface, a clutch piston responsive to a current command from the controller and operable for applying a compression force on the clutch pack, and a high-frequency (HF) oscillation source configured to generate at least one HF oscillation, and to direct the HF oscillation to the friction interface, wherein the controller is operable to detect clutch shudder and activate the source in response thereto to minimize the clutch shudder. The source includes HF hardware, and generates different HF oscillations applied directly to the clutch housing or to the clutch-apply current command. A method of reducing clutch shudder includes setting a threshold clutch shudder amplitude, detecting clutch shudder, and applying a HF oscillation to a friction interface to minimize clutch shudder when the detected shudder exceeds the threshold.

Claims

1. A clutch assembly having a pair of actuatable clutch plates forming a friction interface therebetween, the clutch assembly comprising:

a controller;

at least one sensor configured to detect shudder of the clutch assembly; and

a controllable source of high-frequency oscillation;

wherein said controller is configured to activate said source in response to said detected shudder to thereby apply at least one high-frequency oscillation to the friction interface for minimizing said detected shudder.

2. The clutch assembly of claim 1, wherein said controllable source includes high-frequency hardware, and wherein said at least one high-frequency oscillation includes a plurality of different high-frequency oscillations each having a different amplitude and frequency.

3. The clutch assembly of claim 2, including a clutch housing, wherein said high-frequency hardware is configured to deliver said plurality of different high-frequency oscillations directly to said clutch housing.

4. The clutch assembly of claim 1, including a controllable clutch actuation device responsive to a current command from said controller, wherein said controllable source of high-frequency oscillation is configured to apply said at least one high-frequency oscillation to said controllable clutch actuation device.

5. The clutch assembly of claim 4, wherein said at least one high-frequency oscillation is an AC component that is added to said current command.

6. A lubricated clutch assembly comprising:

a controller;

a plurality of vibration sensors;

a clutch housing at least partially containing a lubricated clutch pack having at least one friction interface;

a hydraulically-actuated clutch piston responsive to a current command from said controller, and operable for applying a compression force on said clutch pack in response thereto; and

an oscillation source configured to generate at least one high-frequency oscillation in response to said controller, and to direct said oscillation to said friction interface;

wherein said controller is operable to detect shudder of the lubricated clutch assembly and is operable to activate said oscillation source in response thereto for minimizing said detected shudder.

7. The clutch assembly of claim 6, wherein said oscillation source includes high-frequency hardware, and wherein said at least one high-frequency oscillation includes a plurality of high-frequency oscillations each having a different amplitude and frequency.

8. The clutch assembly of claim 6, wherein said high-frequency oscillation is applied directly to said clutch housing.

9. The clutch assembly of claim 6, wherein said oscillation source is configured to apply said at least one high-frequency AC component having a predetermined frequency and amplitude to said current command so that said clutch piston vibrates at said predetermined frequency and amplitude.

10. A method of reducing clutch shudder in a wet clutch having a controller and a clutch pack disposed within a clutch housing, the clutch pack having mating surfaces forming at least one friction interface therebetween, and said wet clutch being actuatable in response to a current command from said controller, the method comprising:

setting a threshold clutch shudder amplitude;

detecting the clutch shudder of the wet clutch; and

applying a high-frequency oscillation to the friction interface when said detecting determines that the clutch shudder exceeds said threshold clutch shudder amplitude, thereby minimizing said clutch shudder.

11. The method of claim 10, including applying said high-frequency oscillation to the clutch housing to thereby vibrate the clutch housing at said high-frequency oscillation.

12. The method of claim 10, including adding said high-frequency oscillation to the current command.

13. The method of claim 10, wherein the friction interface forms a mutual adhesive bond during low slip speed, the method further including sensing said slip speed and applying said high-frequency oscillation to the friction interface to thereby break said mutual adhesive bond.