JP3559072B2 - Bearing unit for rotation speed detection - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a rotation speed detecting bearing unit for measuring a rotation speed (rotation speed) of an axle on which wheels of an automobile are mounted, for example.
[0002]
[Prior art]
When detecting the speed of a vehicle or the number of rotations of a wheel, or when operating an anti-lock brake system (ABS), a rotation number detecting device is attached to an axle equipped with wheels to measure the number of rotations of the axle (wheel). Various types of this rotation speed detection device have been proposed. For example, as disclosed in Japanese Utility Model Application Laid-Open No. 4-116012, an inner ring mounted so as to rotate integrally with an axle on which wheels are mounted, A pulse rotor is fitted and fixed to the inner ring of a bearing unit comprising an outer ring (fixed ring) fixed to a fixed portion such as a knuckle and a ball disposed between the inner and outer rings. A sensor attached to the outer ring (fixed ring) side is arranged to face the vicinity of the uneven teeth of the above.
[0003]
[Problems to be solved by the invention]
In recent years, a rotational speed detecting bearing unit has been used which is a sensor integrated type having a built-in sensor (electromagnetic pickup sensor) capable of preventing intrusion of mud or water. In order to improve maintainability of the bearing unit when replacing the sensor, it is desirable that only the sensor can be replaced without disassembling the bearing unit. However, the space around the knuckle and the axle was narrow (see FIG. 4), which was difficult due to the harness arrangement. A brake device is mounted on the axle in the vicinity of the bearing unit, but the temperature around the sensor mounting becomes high due to radiant heat generated by the brake device. However, since the sensor for detecting the rotation speed uses an electromagnet, it is necessary to avoid the position where the temperature becomes high as much as possible. The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a bearing unit for detecting a rotational speed in which a sensor can be replaced and an influence of radiant heat by a brake device or the like can be avoided. I do.
[0004]
[Means for Solving the Problems]
That is, in order to solve the above-mentioned problem, the invention according to claim 1 includes an inner ring fixed to an axle on which wheels are mounted and an outer ring fixed to a knuckle fixed to a vehicle body side. A bearing unit comprising: a rolling element disposed between an inner ring and an outer ring; and wherein the inner ring and the outer ring are hermetically sealed by a seal .
A pulsar ring is fitted and fixed to the outer periphery of the inner ring, and a flattened portion whose end is reduced in diameter is provided at a corner of the outer ring located between the axle and the knuckle, and a sensor is provided on the flattened portion. It is a bearing unit for detecting a rotational speed in which a tip portion of the sensor and the pulsar ring are arranged to face each other in a space between the inner ring and the outer ring which is attached and sealed by the seal .
[0005]
[Action]
When the bearing unit for detecting the rotational speed is the above means, the sensor can be easily assembled after assembling the bearing unit together with peripheral parts such as knuckles at the time of assembling or repairing an automobile. The sensor is least susceptible to the effects of radiant heat from the brake device, and the sensor can be replaced without disassembling an axle (drive shaft), a brake disk, a caliper, and the like.
[0006]
【Example】
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a bearing unit for detecting a rotational speed according to the present invention, and FIG. 2 is a sectional view in the axial direction. The bearing unit for detecting a rotational speed includes an axle (drive shaft) 1, a sleeve 2 integrally fitted to the axle 1, a brake disk 3 attached to a flange 2a and a track groove 2b provided, and a vehicle body. A knuckle 4 fixed to the knuckle 4, an inner ring 5 fitted to the sleeve 2, and an outer ring 6 fixed to the knuckle 4, and arranged between the outer ring 6, the sleeve 2 and the inner ring 5. Rolling members (balls) 7 and 7, a pulsar ring 8 fitted and fixed around the outer periphery of the inner race 5, and a tip end portion thereof disposed opposite to the pulsar ring 8, and formed at a corner of the outer race 6. And a sensor 9 attached thereto. Reference numeral 12 denotes a caliper on which pads 10 and 11 for applying pressure to the brake disk 3 are mounted, and reference numerals 13 and 14 denote seals for sealing between the outer ring 6 and the sleeve 2 and the inner ring 5.
[0007]
FIG. 3A is a partial cross-sectional side view of the outer race 6, FIG. 3B is a front view, and FIG. 3C is a view on arrow Q in FIG. 3A.
As described above, the sensor 9 is attached to a corner portion of the outer ring 6. The inner portion of the outer ring 6 is formed to have a conical surface 6 a and a part of the outer corner has a constant thickness t. An inclined flat portion 6b is provided in such a direction as to be cut in an oblique direction to reduce the diameter of the end portion so as to secure it. The shaft 9b of the sensor 9 is provided with an insertion hole 6c and a sensor fixing bolt hole 6d in the inclined flat portion 6b at the corner of the outer ring 6, and the sensor 9 is mounted. As shown in FIG. 1, the sensor 9 has a sensor tip 9 a of a shaft 9 b passed through a washer 15 and a washer 15 fixed to the shaft 9 b, and the washer 15 is provided at a corner of the outer race 6. It is detachably fixed and attached to the flat portion 6b with the attachment bolts 16.
[0008]
The reason why the sensor 9 is attached to the corner of the outer ring 6 between the knuckle 4 and the axle (drive shaft) 1 as described above is as follows.
FIG. 4 is a view showing the internal structure of the bearing unit, and shows an experimental result of measuring the internal temperature distribution. That is, this bearing unit has almost the same configuration as the bearing unit shown in FIG. 2, but as shown in the measurement results of FIG. Below the flange 2'a of the sleeve 2 ', the lowest was near the outside of the fitting portion between the knuckle 4' and the outer ring 6 '. Therefore, the position most suitable for the sensor mounting position is near the corner of the outer ring 6 'between the knuckle 4' and the axle (drive shaft) 1 ', but this position is also a position lacking in maintainability such as sensor replacement. Therefore, the shapes and mounting structures of the knuckle 4 'and the outer ring 6' are changed as shown in FIG. 2, and furthermore, flat portions 6b are formed at the corners of the outer ring 6 as shown in FIG.
[0009]
When the bearing unit for detecting the rotational speed is configured as described above, the sensor can be easily assembled after assembling the bearing unit with peripheral parts such as a knuckle at the time of assembling or repairing an automobile. The surroundings of the sensor are hardly affected by radiant heat from the brake device and the like, and the sensor can be replaced without disassembling the axle (drive shaft), the brake disk, the caliper, and the like.
[0010]
【The invention's effect】
Since the rotational speed detecting bearing unit of the present invention has the above-described structure, the speed detecting sensor can be mounted at a position where the thermal influence from the brake device can be most avoided. Further, according to the present invention, it is possible to replace only the sensor without disassembling the bearing unit, which facilitates the assembling and maintenance. In particular, the assemblability of the sensor can be as high as that of the external sensor type. Further, since the sensor detecting section, that is, the pulsar ring and the sensor detecting section are provided in the bearing unit, the sensor signal is hardly affected by the external environment (mud, rust, iron powder, etc.). Corrosion-resistant treatment such as the use of stainless steel is not required. Furthermore, since the sensor and the bearing unit can be handled as separate parts, the manufacturing process of the bearing unit can be made the same as that of a bearing unit with a pulsar.
[Brief description of the drawings]
FIG. 1 is a perspective view of a bearing unit for detecting a rotational speed according to the present invention.
FIG. 2 is an axial sectional view of a rotational speed detecting bearing unit of the present invention.
3 (a) is a partial cross-sectional side view of the outer race, FIG. 3 (b) is a front view, and FIG. 3 (c) is a view on arrow Q in FIG. 3 (a).
FIG. 4 is a view showing an internal structure of the bearing unit, and shows an experimental result of measuring an internal temperature distribution.
[Explanation of symbols]
Reference Signs List 1 axle 2 sleeve 3 brake disk 4 knuckle 5 inner ring 6 outer ring 6a outer ring inner conical surface 6b inclined flat surface 8 pulser ring 9 sensor

Claims (1)

The vehicle includes an inner ring fitted and fixed to an axle on which wheels are mounted, an outer ring fixed to a knuckle fixed to the vehicle body, and rolling elements disposed between the inner ring and the outer ring. A bearing unit having a sealed structure by
A pulsar ring is fitted and fixed to the outer periphery of the inner ring, and a flattened portion whose end is reduced in diameter is provided at a corner of the outer ring located between the axle and the knuckle, and a sensor is provided on the flattened portion. A bearing unit for detecting a rotational speed , wherein a tip portion of the sensor and the pulsar ring are arranged to face each other in a space between the inner ring and the outer ring which is attached and sealed by the seal .

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