JPH01254401A - Bearing unit for wheel of automobile - Google Patents

Abstract

PURPOSE:To prevent the entrance of mud, etc., and improve the detecting accuracy of rotating speed in the captioned unit housing a rotation detecting means by providing a recessed-portion member on an inner ring member, providing an encoder portion and a revolution detector in the recessed portion thereof, and covering the recessed portion with a cover. CONSTITUTION:A recessed portion 6a is formed on a nut 6 for fixing an inner ring member 4 fitted on an axle 3 to the axle 3 via a washer 5, and a pulser 10 having cylindrical pulser portions 10a, 10a... in the axial direction is fixed to the inner peripheral face thereof to form an encoder. A cover case 11 is fixed to the end portion 1e of an outer ring 1 so as to cover the nut 6. Further, a revolution detector 12 is provided in the recessed portion 6a with its detecting portions 12a being opposed to the pulser portions 10a in the radial direction, and fixed to the cover 11 with a U-shaped installing plate 13. By this structure, the entrance of earth/sand and dirty matter can be prevented, ensuring the accuracy for a long time.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a transfer member, a retainer, an outer member on the vehicle body side, an inner member on the wheel side, an encoder section attached to the inner member, The present invention relates to a bearing unit for an automobile wheel having a rotation detector for detecting the rotation speed of an inner member thereof.

<Conventional technology> In automobiles, when the brakes are applied suddenly on a frozen road surface, the rotation speed of each wheel is detected by a rotation detector to prevent the wheels from locking, and the It controls the operation of the brake cylinder.

Conventionally, as a unit of an automobile wheel bearing to which such a rotation detector is attached, a unit as shown in FIG. 5 is known. This wheel bearing unit consists of an axle end 50 for an idler wheel protruding from the lower side of the vehicle body.
an inner ring 51 fixed to the inner ring 51, a retainer 52 that holds a number of rolling elements 53 and is fitted onto the inner ring 51, and an outer ring that is rotatably fitted around the rolling elements 53 and has a wheel 54 attached thereto. 55, a pulser 56 made of a ferromagnetic material that is fitted and fixed to the end of the outer ring 55 opposite to the axle 54 and has a gear-shaped protrusion on the outer periphery, and a pulser 56 that is spaced apart from the outer periphery of the pulsar 56 by a slight distance. The speed sensor 57 is fixed to the base of the axle end 50 of the vehicle body and includes a permanent magnet and a coil. When the pulsar 56 rotates together with the wheel 54, the magnetic flux emitted from the permanent magnet of the speed sensor 57 is changed by the gear-shaped protrusion on the outer periphery of the pulsar, and an alternating current voltage with a frequency proportional to the number of rotations of the pulsar is generated in the coil. , by detecting the frequency wave number of this alternating voltage.
I am trying to find the number of revolutions.

<Problems to be Solved by the Invention> However, in the conventional automobile wheel bearing unit described above, the speed sensor 57 is fixed to the base of the axle end 50 of the vehicle body so as to protrude from the protective cover 58 of the vehicle body. This protective cover 5 is placed on the detection end of the speed sensor 57.
There is a drawback that earth and sand or muddy water enters from the outside in the direction of the arrow through the gap between the plate 8 and the plate knee 59 fixed to the outer ring 54, damaging the detection end. In addition, the dirt and muddy water can also damage the gears on the outer periphery of the balsa 56, and if they adhere to the grooves of the gears, they can clog the gears. do.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to detect the rotation speed with high accuracy, without the risk of damage due to the intrusion of dirt or muddy water from the outside, and without the need to adjust the clearance between the encoder section and the rotation detector. It is an object of the present invention to provide a small and lightweight bearing unit for an automobile wheel that can be used for a long period of time.

Means for Solving the Problems To achieve the above objects, the present invention provides an outer member fixed to a vehicle body, an inner member attached to a wheel, and a transfer member disposed between the outer member and the inner member. and a bearing unit for an automobile wheel, comprising a retainer and rotatably supporting the inner member on the outer member via the rolling member, the bearing unit being attached to an end of the inner member and having a recess at the outer end. a recessed member formed in the recessed member; an encoder unit that is provided on the inner peripheral surface of the recessed portion of the recessed member and generates a signal according to the rotation speed; a sealing member that is fixed to the outer member and covers the recessed member; the sealing member, located within the recess and radially opposed to the encoder portion;
The rotation detector is fixed and detects a signal generated by the encoder section.

<Operation> The rotation detector fixed to the vehicle body-side fixing member detects the rotation of the encoder portion fixed to the wheel-side rotating member of the wheel bearing unit of the automobile. The sealing member prevents dirt and mud from entering the area where the rotation detector and encoder section are located. Further, an encoder portion is provided on the inner circumferential surface of a recess formed at an outer end of a recessed member attached to an end of the inner member, and a rotation detector is provided in the recess so as to face the encoder portion in a radial direction. Since the rotation detector is located inside the encoder and fixed to the vehicle body side fixing member, there is no need for rearance adjustment, which is often necessary when the rotation detector is axially opposed to the encoder section.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a bearing unit for an automobile wheel, in which 1 is an outer ring fixed to a vehicle body (not shown), 2 has a flange 3c at one end to which a wheel (not shown) is attached, and the other end The inner ring is made up of an axle 3 having a threaded portion 3b on the inside thereof, and an inner ring member 4 that fits externally into a fitting portion 3e provided at the other end of the axle 3. The inner ring member 4 is fixed to the axle 3 with a washer 5 and a nut 6. As shown in FIGS. 2(a) and 2(b), this nut 6 is provided with a recessed portion 6a with its axis aligned with the outer end thereof.

In other words, this nut 6 also serves as a concave member that forms a concave portion. Further, between the outer ring 1 and the inner ring 2, a plurality of balls 7.8 as rolling elements are arranged annularly in a cage 9.9 at regular intervals from each other in the circumferential direction. ” The second ball 7 is the outer ring 1 and the car! +I+ 3 opposing raceway grooves 1a,
3a, the above-mentioned rod 8 is fitted between the opposing raceways 7741b and 4b of the outer ring l and the inner ring member 4, respectively, so as to be freely removable. On the inner circumferential surface of the recess 6a of the old nut 6, axially cylindrical pulsar portions 10a, 10a are provided at regular intervals in the circumferential direction.
A pulser lO as an encoder section having... is fixed. A cover case 11 as a sealing member is fixed to the end le of the outer ring l so as to cover the nut 6.

A rotation detector 12 is disposed within the recess 6a of the nut 6. This rotation detector +2 has a detection part 12a facing the balsa parts 10a, IOa, . This mounting plate 13 is fixed by inserting engaging claws 13a, 13a provided at both ends into slit holes (not shown) provided in the cover case +1 and bending them at right angles.

The pulser 10 is manufactured and attached to the nut 6 in the following manner. First, Figure 3(a), (
As shown in b), a plate material having a thickness t is hexagonal in shape with the same external dimensions as the nut 6, and has a hole 10c in the center.
Punch out a hexagonal plate lO° with radially communicating slits lOb, 10b, etc. at 0c. The above slit l Ob,
The diameter Y of the circle connecting the bottoms of l Ob,... is the recess 6
It is made to be larger than the diameter X of a. The portions between the slits 10b, I Ob, . . . will later become the balsa portions 10a, 10a, . Next, as shown by the imaginary line in FIG. 4, the hexagonal plate lo.

is attached coaxially with the nut 6 and in contact with its outer end surface 6b by welding or the like. Finally, the hexagonal plate lo above.

The recess 6a of the nut 6 is attached to the nut 6.
The protrusion 30a of a jig 30 having a diameter smaller than the diameter Crimp. In this way, the above-mentioned pulser IO is easily manufactured.

The cable of the sensor 12 is a rubber bushing fitted into the pull-out hole 11b provided in the cover case 11! 5 to the outside of the cover case 11. In addition, sensor 1
The second type is one with a built-in permanent magnet and coil,
There are various types, such as those using magnetic resistance elements, but this example shows one with a built-in permanent magnet and coil.

The outer ring 1 is fixed at several places to the lower end of a strut attached to the vehicle body (not shown) with bolts (not shown) inserted into bolt holes 1d of a flange 1c formed at the rear end. On the other hand, the flange 3c of the inner ring 2 has
The wheel, that is, the tire is attached by a bolt (not shown) inserted into the bolt hole 3d. The space between the front end of the outer ring l and the inner ring 2 is sealed with an oil seal 14, and this and the cover case 2 connect the pulser lO provided on the nut 6 and the sensor 1 fixed to the case 11 itself.
2. Inner ring inserted into outer ring l. Balls 7.8 and cage 9 are completely sealed from the outside.

In the automobile wheel bearing unit having the above configuration,
When the automobile runs, the axle 3 and nut 6 to which the wheels are attached rotate, and the pulsar part 10a of the pulsar 10 also rotates together with them. Then, a sensor 1 provided on the cover case 11 on the vehicle body side radially opposite to this
The magnetic flux emitted from the permanent magnet 2 is connected to the pulsar section 10 of the pulsar 10.
It changes due to the protrusion formed in the cross section of a, and the coil of sensor I2 has a pulser! An alternating voltage with a frequency proportional to the rotational speed of 0 is generated. Then, the above-mentioned intersection tTL? outputted from the sensor 12? The frequency of the It pressure is detected by a detector (not shown) to determine the number of rotations of the wheel.

At this time, the tips of the pulsar lO and the sensor 12 are completely sealed from the outside by the cover case 11 and the sealing member 14, so that no dirt or muddy water enters into these parts from the outside. This part will not be damaged or clogged to cause any problems, and the pulser lO and sensor 12 will accurately detect the rotational speed of the wheel over a long period of time.

Furthermore, since the pulsar IO is provided on the inner ring 2 instead of on the outer ring as in the conventional example, the pulsar can be made smaller.

The weight can be reduced, and the wheel bearing unit can be made more compact. Furthermore, the pulsar section 10 of the pulsar 10
A is formed in a cylindrical shape in the axial direction on the inner circumferential surface of the concave portion 6a of the nut 6, and a sensor as a rotation detector is provided in the pulser portion 10a. Since the two detection parts 12a are installed facing each other in the radial direction, the clearance does not change even if the detection part 12a moves in the axial direction, and the rotation speed of the wheel can always be detected. It is convenient for mass production because the clearance adjustment that is often necessary when facing each other in the axial direction is not necessary.

In the embodiment described above, the pulsar 10, which is a separate part, is attached to the inner circumferential surface of the recess 6a of the nut 6, but the pulsar may be formed on the inner circumferential surface of the nut itself, for example, by forging.

Furthermore, in the above embodiment, the inner ring 2 is the outer ring! Above 7,7
．． ...and 8,8. Although the recess 6a is provided on the outer end surface of the nut 6, which is rotatably attached via..., in other words, the nut 6 also serves as a recess member forming the recess, the invention is not limited to this, for example. It may be arranged as shown in FIG. FIG. 5 will be explained below. However, the same members as those in the above embodiment are given the same numbers and the explanation thereof will be omitted, and only the different members will be explained. In FIG. 5, reference numeral 23 is an axle, and the threaded portion 3b is attached to a portion corresponding to the threaded L portion 3b at the end of the axle 3 of the above embodiment where the nut 6 is screwed.
The axle 3 is the same as the axle 3 described above except that it has a threaded portion 30 with a short shape and a fitting portion 31 connected to the threaded portion 30.The threaded portion 30 has the nut 6 of the embodiment described above. Shape 1 in which the recess 6a side is cut out by a certain length in the axial direction
A nut 26 of the same size is screwed together. As in the above embodiment, the inner ring member 4 is fastened to the axle 23 via the washer 5, and thereby the inner ring 2 is rotatably attached to the outer ring l via the balls 7 and 8. The fitting portion 31 that protrudes from the nut 26 in the axial direction has an annular cross-sectional shape with a fitting hole 36c in the center, and has an outer end surface 36c.
A recess 36 having the same shape and dimension as the recess 6a is provided at the center of the recess 6b.
The fitting hole 36b of the recessed member 36 having a diameter of 1.a is fitted externally. This concave member 36 is attached to the inner ring 2 so as to be rotatable together. Here, this attachment is performed by press-fitting, and the press-fitting of the recessed member 36 into the fitting portion 32 also serves to prevent the nut 26 from loosening. The pulsar 10 is fixed to the recess 36a of the recess member 36 in the same manner as in the above embodiment. Of course, the concave member 36 to which the nut 26 and the pulser 10 are fixed is fitted and fixed to the end 1e of the outer ring i while being fixed to the axle 3 of the inner ring 2 as described above. It is rotatably housed in the cover case 2 in a non-contact manner.

In this way, in addition to the nut that is screwed onto the end of the inner ring 2 and rotatably attaches the inner ring 2 to the outer ring l via the transfer members 7 and 8, a recess is formed in the center of the outer end surface of the end. The concave member may be attached so as to be rotatable together with the inner ring 2. This makes assembly easier and allows the use of commercially available nuts.

Other functions and effects are the same as in the above embodiment.

<Effects of the Invention> As is clear from the above description, the automotive wheel bearing unit of the present invention includes a sealing member that covers at least the portion where the encoder portion and the rotation detector face each other. and the part facing the rotation detector,
Since this part is not damaged by dirt or muddy water entering from the outside, wheel rotation speed can be detected with high accuracy over a long period of time.

Further, in the automotive wheel bearing unit of the present invention, the encoder section is mounted on the outer end of a concave member attached to the end of the inner member rotatably supported by the outer member via a rolling member. A rotation detector is provided coaxially with the concave member on the inner periphery of the formed concave portion, and a rotation detector fixed to the outer member is positioned within the concave portion so as to face the encoder portion in the radial direction. Even if the rotation detector shifts in the axial direction, the clearance between the rotation detector and the encoder section does not change, eliminating the need for clearance adjustment that would be required if they were placed facing each other in the axial direction, and making the encoder section smaller and lighter. It can be made more compact, and even more compact.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing one embodiment of the present invention, and FIG.
) and (b) are a side view and a front view of a nut having a concave portion, respectively, FIGS. 3(a) and (b) are a cross-sectional view and a front view of a hexagonal plate, and FIG. 4 is a pulsar formed into a cylindrical shape. An explanatory diagram of the method, FIG. 5 is a diagram of a modified example, and FIG. 6 is a longitudinal sectional view of a bearing unit for an automobile wheel having a conventional rotation detector. 1...Outer ring, 2...Inner ring, 3,23...
Axle, 3b... Threaded portion, 4... Inner ring member, 5... Washer, 6.36... Concave member, 6a, 36a... Concave portion, 7.8... Rolling element, 9... Retainer, 10... Pulsar, II... Cover case, I2... Sensor, 3
1... Fitting part. Patent applicant: Koyo Seiko Co., Ltd. Agent
Patent attorney Aoyama Ao Haka (1 person) Figure 6

Claims (1)

[Claims] (1) An outer member fixed to the vehicle body, an inner member attached to the wheel, a rolling member and a retainer disposed between the outer member and the inner member, and the inner member is rotated to the outer member. A bearing unit for an automobile wheel rotatably supported via a moving member includes: a recessed member attached to an end of the inner member and having a recess formed at an outer end; and an inner circumferential surface of the recess of the recessed member. an encoder section that is provided on the outer member and generates a signal according to the rotation speed; a sealing member that is fixed to the outer member and covers the recessed member; 1. A bearing unit for a wheel of an automobile, comprising: a rotation detector fixed so as to face each other in a radial direction, and detecting a signal generated by the encoder section.