Rotation-speed sensor device

• US 6,830,379 B2
• Filed: 10/18/2002
• Issued: 12/14/2004
• Est. Priority Date: 10/18/2001
• Status: Active Grant

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Endo, Shigeru, Morita, Kouichi, Nakamura, Yuji, Miyazaki, Hiroya, Sakamoto, Junshi, Sakatani, Ikunori
• Primary Examiner(s): Footland, Lenard A.
• Application Number:
  US10/274,413
• Publication Number:
  US 20030093188A1
• Time in Patent Office: 788 Days
• Field of Search: 384/448, 384/446, 384/544, 324/174, 324/173
• US Class Current: 384/448
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/042 cooperating with wheel hub mounted speed sensors
• CPC Class Codes: F16C 19/185 with two raceways provided integrally on a part other than a race ring, e.g. a shaft or housing
• CPC Class Codes: F16C 19/186 with three raceways provided integrally on parts other than race rings, e.g. third generation hubs
• CPC Class Codes: F16C 19/386 in O-arrangement
• CPC Class Codes: F16C 2326/02 Wheel hubs or castors in general B60B
• CPC Class Codes: F16C 41/004 Electro-dynamic machines, e.g. motors, generators, actuators
• CPC Class Codes: F16C 41/007 Encoders, e.g. parts with a plurality of alternating magnetic poles
• CPC Class Codes: F16C 41/008 Identification means, e.g. markings, RFID-tags; Data transfer means
• CPC Class Codes: G01P 1/026 for speed measuring devices, e.g. pulse generator
• CPC Class Codes: G01P 3/443 mounted in bearings bearings F16C
• CPC Class Codes: G01P 3/446 mounted between two axially spaced rows of rolling elements

Abstract

A rotation-speed sensor device is provided to comprise an encoder supported by a rotating race of a rolling bearing unit for vehicle wheel support to be concentric with the rotating race and having a detected portion the characteristics of which are alternately changed in a circumferential direction, a rotation detection sensor supported by a non-rotating member on the vehicle chassis side and having a detecting portion facing the detected portion to produce a detection signal, a wireless transmission device for sending the detection signal from the rotation detection sensor to a controller provided on the vehicle chassis side, and a self-diagnosis circuit to judge whether there is an error or not in the rotation detection sensor.

Claims

1. A rotation-speed sensor device comprising:

an encoder supported by a rotating race to be concentric with the rotating race and having a detected portion the characteristics of which are alternately changed in a circumferential direction, the rotating race composing a rolling bearing unit for wheel support to rotate together with a wheel when moving,

a first rotation detection sensor supported by a non-rotating member and having a detecting portion facing the detected portion to produce a detection signal,

a wireless transmission device for sending the detection signal from the first rotation detection sensor to a controller provided on a vehicle chassis side, and

a self-diagnosis circuit to judge whether there is a problem or not in detecting rotation-speed.

2. The rotation-speed sensor device of claim 1, wherein the first rotation detection sensor has a coil to generate electric power therethrough by way of magnetic flux change caused as the encoder rotates, and wherein the self-diagnosis circuit comprising a battery provided in the non-rotating member to be charged with the electric power generated by the first rotation detection sensor, and a judgement circuit supplied with power from the battery to judge whether there is a problem in detecting rotation-speed, and wherein the self-diagnosis circuit has a function to send a signal indicating a problem when the problem in detecting the rotation-speed is detected by the judgement circuit.

3. A rolling bearing unit with a rotation-speed sensor device for use in wheel support:

the rolling bearing unit comprising a rotating race which rotates together with a wheel when moving,

the rotation-speed sensor device comprising an encoder supported by a rotating race to be concentric with the rotating race and having a detected portion the characteristics of which are alternately changed in a circumferential direction,

a rotation detection sensor supported by a non-rotating member and having a detecting portion facing the detected portion to produce a detection signal,

a wireless transmission device for sending the detection signal from the rotation detection sensor to a controller provided on the vehicle chassis side, and

a self-diagnosis circuit to judge whether there is a problem or not in detecting rotation-speed, and wherein the wireless transmission device has a transmission circuit which is kept with the rotation detection sensor in a single holder to form a sensor unit.

4. The rotation-speed sensor device of claim 3, wherein the encoder and the rotation detection sensor are located in a closed space from the outside space.

5. The rotation-speed sensor device of claim 3, wherein the transmission device has an antenna located outside the enveloping line of the metal parts of the rolling bearing unit.