Vibration isolating bushing with embedded speed/position sensor

• US 7,360,756 B2
• Filed: 11/07/2005
• Issued: 04/22/2008
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Rodriguez, Hector H., Urquidi, Carlos A.
• Primary Examiner(s): SCHWARTZ, CHRISTOPHER P
• Application Number:
  US11/267,977
• Publication Number:
  US 20060220330A1
• Time in Patent Office: 897 Days
• Field of Search: 267/140.14, 267/140.15, 267292-294, 267279-282, 280/5.514, 280/6.157
• US Class Current: 267/293
• CPC Class Codes: B60G 17/01933 Velocity, e.g. relative velocity-displacement sensors
• CPC Class Codes: B60G 2200/142 with a single lateral arm, e.g. MacPherson type
• CPC Class Codes: B60G 2204/11 Mounting of sensors thereon
• CPC Class Codes: B60G 2204/116 Sensors coupled to the suspension arm
• CPC Class Codes: B60G 2204/143 on the vehicle body or chassis
• CPC Class Codes: B60G 2204/41 Elastic mounts, e.g. bushings
• CPC Class Codes: B60G 2204/41042 by using internal cam surfaces
• CPC Class Codes: B60G 2400/05162 the element being a suspension arm
• CPC Class Codes: B60G 2400/052 Angular rate
• CPC Class Codes: B60G 2400/202 Piston speed; Relative velocity between vehicle body and wheel
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2401/172 Hall effect
• CPC Class Codes: B60G 7/02 Attaching arms to sprung part of vehicle B60G7/006 takes precedence
• CPC Class Codes: F16F 1/38 with a sleeve of elastic material between a rigid outer sleeve and a rigid inner sleeve or pin , i.e. bushing-type hydraulically-damped bushes F16F13/14; suppression of vibrations in rotating systems by making use of elastomeric spring members between rotating elements, driveline torque being transmitted therebetween F16F15/126, by making use of a dynamic damping mass attached to a rotating element by means of elastomeric springs F16F15/14; pivots per se F16C11/00; elastic or yielding bearings or bearing supports F16C27/00; parts of sliding-contact bearings, e.g. bushes F16C33/04
• CPC Class Codes: F16F 2230/08 Sensor arrangement

Abstract

A bushing assembly adapted for application in vehicle suspension systems includes an embedded position sensor and an embedded speed sensor.

Claims

1. A bushing assembly comprising:

an outer member;

an inner member arranged substantially concentrically with the outer member;

an elastomeric member disposed between and interconnecting the inner and outer members; and

a sensor assembly at least partially embedded within the elastomeric member intermediate said inner and outer members, said sensor assembly comprising,

a stator assembly including a first flux guide carried by one of said members for displacement therewith,

a rotor ring including a second flux guide carried by the other of said members for displacement therewith concentrically with said stator assembly, said first and second flux guides defining opposed pole faces defining a radial air gap therebetween,

a magnet magnetically coupled with one of said flux guides,

a galvanomagnetic position sensing element coupled to one of said flux guides, and

an inductor magnetically coupled with one of said flux guides and operative to generate an output voltage signal as a direct function of the instantaneous relative speed of rotation between said stator assembly and rotor ring.

2. The assembly of claim 1, wherein the output signal from the speed sensor represents a relative speed between the members without having to differentiate the signal with respect to time.

3. The assembly of claim 2, wherein one of the members is established by said stator assembly and the other of the members is established by said rotor ring.

4. The assembly of claim 3, wherein the stator assembly includes at least first and second opposed radially tapered stator poles and the rotor assembly includes at least first and second radially inwardly extending tapered rotor poles.

5. The assembly of claim 3, wherein the stator assembly is on the first member and the first member is an inner member, the rotor being on the second member the second member surrounding the first member.

6. The assembly of claim 1, wherein the speed sensor is contactless.

7. The assembly of claim 1, wherein said air gap is established between the members which varies dimensionally as a function of the relative angular position of the members.

8. The assembly of claim 1, wherein the inductor comprises at least one coil wound around a portion of the stator assembly.

9. A speed sensing system, comprising:

at least one bushing assembly including a moving part, a non-moving part, and at least one elastomeric material therebetween, at least one sensor assembly being disposed at least partially in the elastomeric material intermediate said parts and generating a signal representing at least one parameter selected from the group including;

relative position between the parts, and relative speed between the parts; and

means receiving the signal for outputting a speed signal representing relative speed between the parts,

said sensor assembly comprising,

a stator assembly including a first flux guide carried with one of said parts for displacement therewith,

a rotor ring including a second flux guide carried with the other of said parts for displacement therewith concentrically with said stator assembly, said first and second flux guides defining opposed pole faces defining a radial air gap therebetween,

a magnet magnetically coupled with one of said flux guides,

a galvanomagnetic position sensing element coupled to one of said flux guides, and

an inductor magnetically coupled with one of said flux guides and operative to generate said speed signal as a direct function of the instantaneous relative speed of rotation between said stator assembly and rotor ring.

10. The system of claim 9, wherein the sensor assembly is a speed sensor and the means for outputting does not include an electronic circuit differentiating the signal with respect to time.

11. The system of claim 10, wherein the inductor comprises at least one coil wound around a portion of said stator assembly.

12. The system of claim 9, wherein the bushing assembly is engaged with a lower control arm of a vehicle suspension, and the speed signal is used by a control system to establish a stiffness of at least one shock absorber in the vehicle.

13. The system of claim 9, wherein the moving part is said rotor ring and the non-moving part is said stator assembly surrounded by the rotor ring.

14. A bushing assembly for a vehicle, comprising:

a stator assembly engageable with a first part of a vehicle;

a rotor ring engageable with a second part of the vehicle;

a resilient material disposed between the stator assembly and rotor ring; and

at least one sensor assembly engaged with the rotor ring or the stator assembly for outputting a signal that is directly proportional to the relative speed between the parts without having to differentiate the signal with respect to time,

wherein said sensor assembly is at least partially embedded within an elastomeric member intermediate said first and second parts, said sensor assembly comprising,

said stator assembly including a first flux guide carried by one of said parts for displacement therewith,

said rotor ring including a second flux guide carried by the other of said parts for displacement therewith concentrically with said stator assembly, said first and second flux guides defining opposed pole faces defining a radial air gap therebetween,

a magnet magnetically coupled with one of said flux guides,

a galvanomagnetic position sensing element coupled to one of said flux guides, and

an inductor magnetically coupled with one of said flux guides and operative to generate said signal as a direct function of the instantaneous relative speed of rotation between said stator assembly and rotor ring.

15. The assembly of claim 14, wherein the inductor comprises at least one coil wound around a portion of the stator assembly.

16. The assembly of claim 15, comprising said magnet on the stator assembly.

17. The assembly of claim 16, wherein the stator assembly defines at least one stator pole face and the rotor ring defines at least one rotor pole face, the pole faces being configured to establish an output of the coil sensor that varies substantially linearly with the relative speed between the rotor ring and stator assembly.

18. The assembly of claim 17, further comprising a position sensor on the rotor ring or the stator assembly.

19. The assembly of claim 14, wherein the bushing assembly is engaged with a lower control arm of a vehicle suspension, and the signal is used by a control system to establish a stiffness of at least one shock absorber in the vehicle.