JP2001249141A - Rotation detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation detection apparatus capable of detecting rpm (rotational speed) and the direction of rotation at the same time by means of one sensor by devising magnetization of a pulsar ring. SOLUTION: The rotation detection apparatus includes a multipolar magnetization type pulsar ring 18 concentrically mounted to the rotating ring side of a bearing device and a sensor 15 mounted to the fixed ring side of the bearing device, the bearing device having a rolling element 11 disposed between an inner ring 5 and an outer ring 8, with one of the rings serving as a rotating ring and the other serving as a fixed ring. The pulsar ring 18 is magnetized in such a manner that its magnetic flux density increases or decreases repeatedly in a gradual fashion at every predetermined number of poles. The direction of the rotating ring can be detected based on whether the output of the sensor 15 repeats gradual increases or decreases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device suitably used for a bearing device for an axle of an automobile, and more particularly, to a rotation detecting device capable of simultaneously detecting the rotation direction with one sensor.

[0002]

2. Description of the Related Art In a conventional general axle bearing device used in automobiles and the like, a rolling element is disposed between an inner ring on which a hub is mounted and an outer ring outside the hub, and the inner ring is used as a rotating wheel. The outer ring is mounted on a suspension system of an automobile as a fixed wheel.

In such an axle bearing device, for example, a multipolar magnetized pulsar ring or the like is concentrically mounted on the inner ring side (rotating wheel side) in order to detect rotation of the inner ring.
The sensor is mounted on the outer ring side (fixed wheel side).

[0004]

However, since the above-mentioned multi-pole magnetized pulsaring is magnetized so that its magnetic flux density becomes equal at each pole, the rotation speed can be reduced by one sensor. There has been a problem that even if it can be detected, it cannot be detected up to the rotation direction.

To cope with such a problem, it is conceivable to mount two sensors on the outer ring (fixed wheel) side or change the sensors themselves to special ones capable of detecting the rotation direction. Countermeasures are both costly and technically difficult and poorly feasible.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the magnetization of the pulsar ring so that the rotation speed (rotation speed) and the rotation direction can be controlled by one ordinary sensor. Is to provide a rotation detecting device that can simultaneously detect the rotation.

[0007]

In order to achieve the above object, a rotation detecting device according to the present invention has a rolling element disposed between an inner ring and an outer ring, and one of the inner and outer rings is a rotating wheel and the other is a rotating wheel. A rotation detecting device comprising a multi-pole magnetized pulsar ring concentrically mounted on the rotating wheel side of a bearing device having a fixed wheel, and a sensor mounted on the fixed wheel side,
The multipolar magnetized pulsaring is characterized in that it is a pulsaring magnetized such that its magnetic flux density is repeatedly increased or decreased every fixed number of poles.

In such a rotation detecting device equipped with such a multipolar magnetized pulsar ring, when the pulsar ring rotates together with the rotating wheel, a sensor detects each magnetized pole of the pulsar ring, and based on the output, the sensor detects the magnetized pole. The number of rotations and the rotation speed are detected. In this case, when the pulsar ring rotates forward with the rotating wheel, the output of the sensor repeats gradually increasing or decreasing according to the magnetic flux density that is repeatedly increased or decreased for each fixed number of poles. Output gradually decreases or increases in the opposite manner to the above. Therefore, the rotation direction of the rotating wheel can be detected depending on whether the output of the sensor repeats gradual increase or decrease.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an axle bearing device equipped with a rotation detecting device of the present invention, FIG. 2 is a conceptual diagram of a multi-pole magnetized pulsar ring of the rotation detecting device, and FIG. 3 is an output of the rotation detecting device. It is a waveform diagram which shows a state.

The axle bearing device equipped with the rotation detecting device of the embodiment shown in FIG. 1 is a so-called hub unit,
Reference numeral 1 denotes a hub, and a flange portion 2 for fixing a wheel is formed at an outer end (left end in FIG. 1) of the hub 1. A first inner raceway 3a and a step portion 4 are formed on the outer peripheral surface of the intermediate portion of the hub 1. The outer periphery of the hub 1 on the inner end side (the right end side in FIG. An inner ring 5 having a second inner ring raceway 3b formed on the outer peripheral surface is externally fitted, and its outer end surface is in contact with the step portion 4. A male screw 6 is formed on the outer peripheral surface of the inner end (right end in FIG. 1) of the hub 1, and the inner ring 6 is pressed and fixed by a hexagon bolt 7 screwed and tightened to the male screw 6. Have been.

An outer ring 8 is provided around the hub 1 and the inner ring 5.
A mounting portion 9 for mounting the outer ring 8 to a suspension is protruded from an outer peripheral surface of an intermediate portion of the outer ring 8. On the inner peripheral surface of the outer ring 8, first and second outer ring raceways 10a and 10b are formed to face the first and second inner ring raceways 3a and 3b, respectively. The hub 1 and the inner ring 5 can be freely rotated inside the outer ring 8 by arranging the plurality of rolling elements 11 between the raceway.

A seal ring 12 is mounted between the inner peripheral surface of the outer end of the outer ring 8 (the left end in FIG. 1) and the outer peripheral surface of the hub 1 inside the outer ring 8. The outer end opening of the space that contains the rolling elements 11 is closed.

On the other hand, a cover 13 is attached to the inner end opening (the right end opening in FIG. 1) of the outer race 8, and the cover 1
3 prevents intrusion of dust or rainwater from the inner end opening of the outer ring 8. The cover 13 is manufactured by means such as drawing a metal plate, and has a flange-shaped locking portion 14 at a position near an opening on the outer end side of the cover. The cover 13 is attached by fitting the outer end opening of the cover 13 into the inner end opening of the outer ring 8 until the locking portion 14 contacts the inner end surface of the outer ring 8.

A cylindrical body 1 is provided around the inner end of the inner ring 5.
A multi-pole magnetized pulsar ring 18 constituting the rotation detecting device of the present invention is externally fitted and fixed to the cylindrical body 17 and is mounted concentrically with the inner ring 5. The sensor 15 constituting the rotation detecting device of the present invention is attached to the cover 13 so that a detecting portion thereof faces the pulsar ring 18 at a predetermined interval, and an output signal from the sensor 15 is supplied to a connector 16. It is adapted to be taken out through a connected wire (not shown).

As shown conceptually in FIG. 2, the multi-pole magnetized pulsar ring 18 used in the present invention is a multi-stage NS in pairs such that the magnetic flux density is gradually increased or decreased for every fixed number of poles. Pulsaring magnetized on
In this embodiment, a multi-pole magnetized pulsar ring 18 is used that is magnetized so that the magnetic flux density is gradually increased for each of the five poles. As the sensor 15, a normal analog output MR element, a sensor IC, or the like is used.

The multipolar magnetized pulsaring 18 as described above
When the pulsar ring 18 rotates together with the inner ring 5, which is a rotating wheel, in the axle bearing unit incorporating the rotation detecting device including the rotation sensor and the sensor 15, the sensor 15 detects each magnetized pole of the pulsar ring 18 and outputs the same. , The rotation speed and rotation speed of the rotating wheel are detected. In this case, when the pulsar ring 18 rotates forward together with the inner ring 5, as shown in FIG. 3, the output of the sensor gradually increases in a stepwise manner according to the magnetic flux density which gradually increases every five poles. When the pulsar ring 18 rotates in the reverse direction with respect to the inner ring 5, the output of the sensor repeats a gradual decrease in the opposite manner. Therefore, depending on whether the sensor output taken out through a conducting wire (not shown) connected to the connector 16 repeats a gradual increase or a gradual decrease, whether the rotating wheel is rotating forward or backward is determined. The direction of rotation can be detected.

In the above-described embodiment, as the multi-pole magnetized pulsar ring 18, a pulsar ring in which NS is magnetized in multiple stages in pairs is used so that the magnetic flux density gradually increases every five poles. A pulsar ring magnetized so that the magnetic flux density gradually decreases may be used.In this case, if the sensor output repeatedly decreases, the rotation is determined to be normal rotation, and if the sensor output repeatedly increases, the rotation is determined to be reverse rotation. The direction is detected.

The number of poles for gradually increasing or decreasing the magnetic flux density is not limited to five, but may be more or less. However, when the number of poles is two, it is impossible to detect whether the magnetic flux density is gradually increasing or decreasing, so that the magnetic flux density is gradually increased or decreased at least every three or more poles. Need to be done.

The multi-pole magnetized pulsar ring 18 is not limited to the ring type, but is a disk-type multi-pole magnetized in which the magnetic flux density is repeatedly increased or decreased for every fixed number of poles. Molded pulsaring may be used.

Further, the pulsar ring 18 may be directly attached to the inner ring 8 or may be attached to the hub 1. In response to this, the sensor 15 may be directly inserted and attached to the outer ring 8 which is a fixed ring. Further, the fixing means of the sensor 15 may be press-fitted or by means of a fastener such as a screw.
3 may be integrally molded and fixed.

In the above embodiment, the inner ring is a rotating wheel,
Although the rotation detecting device of the present invention is incorporated in an axle bearing device including a hub unit having an outer ring as a fixed wheel, on the contrary, other bearing devices having an inner ring as a fixed wheel and an outer ring as a rotating wheel, The multi-pole magnetized pulsar ring 18 of the present invention may be incorporated on the rotating wheel side, and the sensor 15 may be incorporated on the fixed wheel side.

[0023]

As is apparent from the above description, the rotation detecting device of the present invention has a remarkable effect that the rotation speed (rotation speed) and the rotation direction can be simultaneously detected by one ordinary sensor.

[Brief description of the drawings]

FIG. 1 is a sectional view of an axle bearing device equipped with a rotation detecting device of the present invention.

FIG. 2 is a conceptual diagram of a multipolar magnetized pulsaring of the rotation detecting device.

FIG. 3 is a waveform chart showing an output state of the rotation detection device.

[Explanation of symbols]

 Reference Signs List 1 hub 5 inner ring 8 outer ring 11 rolling element 13 cover 15 sensor 18 multi-pole magnetized pulsaring

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G01B 7/30 101 G01B 7/30 101B G01D 5/245 G01D 5/245 XR G01P 13/04 G01P 13 / 04 CF term (reference) 2F034 AA09 EA01 EA04 EA05 EA09 EA21 EA24 2F063 AA35 BA09 BD16 DA05 EA03 GA52 GA68 GA72 KA02 KA04 2F077 CC02 NN04 NN19 NN24 PP14 QQ13 VV02 3J101 AA42 AAA AA42

Claims (1)

[Claims] 1. A multi-pole, wherein a rolling element is disposed between an inner race and an outer race, and one of the inner race and the outer race is a rotating race and the other is a fixed race, and is multi-pole mounted concentrically on the rotating race side. A rotation detection device comprising a magnetized pulsar ring and a sensor attached to the fixed wheel side, wherein the multipolar magnetized pulsar ring has a magnetic flux density that is repeatedly increased or decreased for every fixed number of poles. A rotation detection device, characterized in that it is a pulsar ring that is magnetized.