JPH1123600A - Rolling bearing unit with rotating speed detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a construction capable of detecting rotating speed of a front wheel to be a driving wheel and of easy assembling work. SOLUTION: First and second inner race members 4a, 5a are combined together to constitute a hub 6a. An encoder 23 is outerly fitted and fixed to the intermediate part of the second inner race member 5a, and the detecting face of a sensor unit 47 supported with a cover 18c fixed to an outer race 1a is opposed to the outer circumferential face of the outer half part of the encoder 23. Further, the extreme end edge of a seal lip 41 constituting a seal ring 19b supported with the cover 18c is slidably contacted with the outer circumferential face of the inner half part of the encoder 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A rolling bearing unit with a rotation speed detecting device according to the present invention rotates a front wheel of a front-wheel drive front-wheel drive vehicle or a four-wheel drive vehicle (four-wheel drive vehicle) with respect to a suspension device. It is freely supported and used to detect the rotational speed of the front wheels.

[0002]

2. Description of the Related Art In order to rotatably support a wheel with respect to a suspension device, various types of rolling bearing units for wheels are used in which an outer ring and an inner ring are rotatably combined via rolling elements. In addition, the FF which is both a steering wheel and a driving wheel
A rolling bearing unit for wheels for supporting the front wheels of a car or a 4WD car is combined with a constant velocity joint to smoothly rotate the drive shaft with respect to the wheels irrespective of the steering angle given to the wheels ( It must be transmitted (with constant velocity). A rolling bearing unit for a wheel which can be configured to be relatively small and lightweight in combination with such a constant velocity joint is disclosed in Japanese Patent Application Laid-Open No. 7-317754.

FIG. 6 shows a conventional structure described in this publication. In an assembled state to a vehicle, the outer ring 1 that does not rotate while being supported by the suspension device has a first mounting flange 2 for supporting the suspension device on the outer peripheral surface, and a double-row outer ring raceway 3 on the inner peripheral surface. 3 respectively. A hub 6 formed by combining the first and second inner ring members 4 and 5 is arranged inside the outer ring 1. First inner ring member 4 of these
The second mounting flange 7 for supporting the wheel is provided at one end (leftward in FIG. 6) of the outer peripheral surface, and the first inner raceway 8 is provided at the other end (rightward in FIG. 6). It is formed in a provided cylindrical shape. On the other hand, the second inner race member 5 has one end (the left end in FIG. 6) as a cylindrical portion 9 for externally fixing the first inner race member 4, and the other end (FIG. 6). (The right end of the housing) is a housing part 10 which becomes an outer ring of the constant velocity joint, and a second inner raceway 11 is provided on the outer peripheral surface of the intermediate part. By providing a plurality of rolling elements 12, 12 between the outer raceways 3, 3 and the first and second inner raceways 8, 11, respectively, the hub 6 is provided inside the outer race 1. Are rotatably provided.

At positions where the inner peripheral surface of the first inner race member 4 and the outer peripheral surface of the second inner race member 5 are aligned with each other, locking grooves 13 and 14 are formed, and a retaining ring is formed. 15 is provided in such a manner as to extend over both of the locking grooves 13 and 14 so that the first inner ring member 4 is connected to the second inner ring member 5.
Prevents getting out of. Further, a weld 17 is attached to the outer peripheral edge of one end face (left end face in FIG. 6) of the second inner ring member 5 and the inner peripheral edge of the step 16 formed on the inner peripheral face of the first inner ring member 4. The first and second inner ring members 4, 5
They are connected and fixed.

A substantially cylindrical cover 18a, 18b made of a metal such as a stainless steel plate is provided between the openings at both ends of the outer ring 1 and the outer peripheral surface of the intermediate portion of the hub 6, and an elastic material such as rubber or elastomer. Annular seal ring 19a, 1
9b. The covers 18a, 18b and the seal rings 19a, 19b
The part where the second and second parts 12 are installed is shut off from the outside to prevent the grease existing in this part from leaking outside and prevent foreign matters such as rainwater and dust from entering the part. Further, inside the middle portion of the second inner ring member 5, a partition plate portion 20 for closing the inside of the second inner ring member 5 is provided.
The rigidity of the second inner ring member 5 is ensured, and foreign matter that has entered the inside of the second inner ring member 5 from the opening (the left end in FIG. 6) of the second inner ring member 5 is removed by the housing 10. To prevent it from reaching the constant velocity joint provided inside.

When assembling the rolling bearing unit for a wheel configured as described above to a vehicle, the first mounting flange 2
, The outer wheel 1 is supported by the suspension device, and the front wheel, which is also a driving wheel, is fixed to the first inner wheel member 4 by the second mounting flange 7. Further, the tip of a drive shaft (not shown), which is rotationally driven by the engine via a transmission, is spline-engaged inside the inner ring 21 constituting the constant velocity joint. When the automobile is running, the rotation of the inner ring 21 is transmitted through a plurality of balls 22 to the hub 6 including the second inner ring member 5.
To drive the front wheels to rotate.

[0007]

In the case of the conventional structure shown in FIG. 6, a wheel rolling bearing unit for rotatably supporting a front wheel which is also a driving wheel can be made small and lightweight. No consideration is given to detecting the rotational speed of the motor. In order to control an antilock brake system (ABS) or a traction control system (TCS), it is necessary to detect the rotation speed of the front wheels. In order to detect the rotation speed, the encoder is supported on a part of the hub 6 which rotates together with the front wheel, and the outer wheel 1 is rotated.
It is necessary to make the sensor supported by this encoder face this encoder. Further, in order to prevent these encoders and sensors from being soiled by muddy water or the like, it is necessary to provide these encoders and sensors between the pair of seal rings 19a and 19b.

[0008] Even when the encoder is provided between the pair of seal rings 19a and 19b, it is necessary to prevent troublesome assembling work of the rolling bearing unit with the rotation speed detecting device. That is, an encoder is mounted on the hub 6, and a pair of seal rings 19 a is mounted on the outer race 1.
It is preferable from the viewpoint of facilitating the above-mentioned respective mounting operations that the operation of mounting the respective hubs 19b can be performed before the hub 6 is mounted inside the outer race 1. The present invention
In view of the above-mentioned circumstances, the rotation speed of the front wheel is small and light, and the rotation speed of the front wheel can be easily detected.
An object of the present invention is to provide a practical rolling bearing unit with a rotation speed detecting device.

[0009]

All of the rolling bearing units with a rotation speed detecting device according to the present invention are, like the above-mentioned conventional rolling bearing unit for a wheel, provided on the outer peripheral surface of the first rolling bearing unit. An outer ring having a mounting flange, a double-row outer ring track on the inner peripheral surface, and a second mounting flange for supporting the wheel at a portion near one end of the outer peripheral surface, and a first inner ring at a portion near the other end. The tracks are respectively provided cylindrical first inner ring members, one end portion is a cylindrical portion for externally fitting and fixing the first inner ring member, and the other end portion is a housing portion serving as an outer ring of a constant velocity joint. A second inner race member provided with a second inner raceway on the outer peripheral surface of the intermediate portion, a plurality of rolling elements provided between the outer raceways and the first and second inner raceways, respectively, Double-row outer raceway and first and second inner raceways on both axial sides Both end opening and the first of the outer ring in a state of sandwiching et first provided between the intermediate portion outer peripheral surface of the second inner ring member, and a second sealing ring.

Further, the rolling bearing unit with the rotation speed detecting device of the present invention is a part of the outer ring or a part fixed to the outer ring, the other end opening of the outer ring and the second inner ring. A sensor provided between the second seal ring for closing the outer peripheral surface of the intermediate portion of the member and a plurality of rolling elements disposed on the second inner raceway portion; and a sensor for the second inner race member. An annular encoder fixed to a portion of the outer peripheral surface of the intermediate portion opposed to the detection surface of the sensor and having characteristics circumferentially changed alternately and at equal intervals.

In particular, in the case of the rolling bearing unit with the rotation speed detecting device according to the first aspect, the second seal ring has an outer diameter side portion fixed directly to the other end of the outer ring or to the outer ring. A member in which the distal end edge of a seal lip provided over the entire circumference on the inner diameter side portion is externally fitted to the outer peripheral surface of the second inner ring member or an intermediate portion of the second inner ring member. And the diameter of the sliding contact portion between the leading edge of the seal lip and the mating surface is equal to or greater than the outer diameter of at least the portion of the encoder facing the detection surface of the sensor.

Further, in the case of the rolling bearing unit with the rotation speed detecting device according to the second aspect, the second seal ring supports an inner diameter side portion at an intermediate portion of the second inner ring member, and The distal end edge of the seal lip provided over the entire circumference on the radial side portion is brought into sliding contact with the other end of the outer ring or a member fixed to this outer ring, and the sliding contact between the distal end edge of the seal lip and the mating surface is made. The diameter of the portion is equal to or larger than the outer diameter of the encoder.

[0013]

In the case of the rolling bearing unit with the rotation speed detecting device of the present invention constructed as described above, prior to assembling the rolling bearing unit, the second seal ring is attached to the outer ring or the second inner ring. The encoder can be attached to the member and the second inner race member, respectively. That is, the second seal ring is attached to the outer ring or the second inner ring member, and the encoder is attached to the second inner ring member.
The second inner ring member is inserted with a plurality of rolling elements interposed therebetween, and the two inner ring members are connected to each other to form a hub, and the hub can be rotatably supported inside the outer ring. The second seal ring to the outer ring or the second inner ring member,
Since the work of mounting the encoder on the second inner ring member can be performed in a state where the components of the outer ring and the second inner ring member are single components, the work of mounting the encoder and the second seal ring can be easily performed.

[0014]

1 and 2 show a first embodiment of the present invention corresponding to claim 1. FIG. In each of the illustrated examples, a rolling bearing unit is formed, the encoder 23 is externally fitted and fixed to the hub 6a that rotates together with the front wheel, and the encoder 23 and the sensor unit 47 incorporating the sensor are combined to detect the rotational speed. In addition to constituting the device, the first inner ring member 4a and the second inner ring member 5a, each of which is made of carbon steel, which constitutes the hub 6a, can be securely coupled so as to transmit a large torque. Adopts a coupling structure. The reason for adopting such a coupling structure different from the conventional structure shown in FIG. 6 described above is as follows.

That is, in the case of the conventional structure shown in FIG.
It is difficult to secure the bonding strength between the first and second inner ring members 4 and 5, and it is difficult to put it into practical use. In this case, a large torque is applied to the joint between the first and second inner ring members 4 and 5 in order to run the automobile. In spite of such a large torque, the first and second inner ring members 4, 5
In order to prevent the relative rotation between them, it is not sufficient to simply fit the first and second inner ring members 4 and 5 together. Accordingly, in practice, a weld 17 portion provided between the outer peripheral edge of one end surface of the second inner race member 5 and the inner peripheral edge of the step 16 formed on the inner peripheral surface of the first inner race member 4 Therefore, it is necessary to support the torque.

On the other hand, a first inner raceway 8 exists near the weld 17. In order to sufficiently secure the strength of the above-mentioned welded portion 17, it is preferable that the welded portion 17 is a thick-walled overlaid weld. However, if the welding 17 is a thick-walled full-surrounding weld, distortion occurs due to thermal deformation in the first inner raceway 8 and the performance as a rolling bearing unit for wheels deteriorates. More specifically, vibration is likely to occur during operation, and sufficient durability cannot be obtained. In addition, the heat of the welding causes the first inner raceway 8 to be returned to the hardened state, and the hardness of the first inner raceway 8 cannot be sufficiently maintained, and the rolling fatigue life of the first inner raceway 8 is reduced. descend. Any of the illustrated embodiments can solve the above-mentioned disadvantages and can be configured to be small and lightweight.
A practical rolling bearing unit with a rotational speed detecting device can be provided freely.

In connection with the incorporation of the rotational speed detecting device, the structure of the assembling portion of the encoder 23 and the sensor unit 47 is changed to the inside of the second seal ring (toward the center in the width direction when assembled to the vehicle). 1 and the structure and operation of portions other than the structure of the connecting portion between the first and second inner ring members 4a and 5a described above. Since the structure is the same as that of the conventional structure shown in FIG. 6 described above, the same parts are denoted by the same reference numerals, and duplicate description is omitted or simplified.

A large-diameter portion 25 near one end (close to the left end in FIG. 1) is provided on the inner peripheral surface of the first inner ring member 4a constituting the rolling bearing unit with the rotation speed detecting device of the present invention;
A small diameter portion 26 near the other end (near the right end in FIG. 1) and a continuous portion 27 that connects the large diameter portion 25 and the small diameter portion 26 are provided. The continuous portion 27 is formed in a tapered shape whose inner diameter gradually increases from the small diameter portion 26 to the large diameter portion 25. In such a continuous portion 27, a serration groove is formed, and a hardening treatment such as induction hardening is performed. A step 28 is provided between the large-diameter end of the continuous portion 27 and the large-diameter portion 25.

On the other hand, a cylindrical portion 9a which can be inserted without rattling inside the small diameter portion 26 is provided at a portion near one end of the second inner ring member 5a. The housing portion 10 for constituting the constant velocity joint and the portion of the base half portion (the right half portion in FIG. 1) of the cylindrical portion 9a which fits inside the small diameter portion 26 are hardened by induction hardening or the like. A hardening treatment is applied. On the other hand, the first half of the cylindrical portion 9a (FIG. 1)
Is not subjected to such quenching and hardening treatment,
Leave raw. The outer peripheral surface of such a cylindrical portion 9a is
Before the first and second inner ring members 4a and 5a are combined, the inner ring members 4a and 5a have a single cylindrical surface shape (straight shape).

In order to connect and fix the first and second inner ring members 4a and 5a having the above-described structure to form the hub 6a, first, the first inner ring is attached to the cylindrical portion 9a of the second inner ring member 5a. The small diameter portion 26 of the member 4a is fitted to the outside without looseness,
6 is abutted against a stepped portion 29 provided on the outer periphery of the base end of the cylindrical portion 9a. Then, while keeping the first inner ring member 4a against the stepped portion 29, the first half of the cylindrical portion 9a is strongly swaged outward in the diametrical direction, and the tip of the cylindrical portion 9a is It is further swaged toward the step 28 to suppress the step 28. Since the first half of the cylindrical portion 9a is raw, the serration grooves formed in the continuous portion 27 are formed on the outer peripheral surface of the first half of the cylindrical portion 9a with the diametrically outward expanding operation. Dig into it. In this state, the first and second inner ring members 4
a, 5a are engaged with each other in the circumferential direction between the outer peripheral surface of the first half of the cylindrical portion 9a and the continuous portion 27. Therefore, between the first and second inner ring members 4a, 5a,
Large torque can be transmitted freely. Each rolling element 1 is held in a state where the first inner ring member 4a is abutted against the stepped portion 29.
In order to apply an appropriate preload to the second and the second steps 12,
Etc. are regulated. When a moment load is applied to the rolling bearing unit by the turning motion of the automobile, a large stress is generated at the corner R at the base of the step portion 29 of the second inner ring member 5a. In order to withstand such stress, a hardened hardened layer having a sufficient depth is provided at the corner R, and the corner R is formed in a virtual space in which the diaphragm 20 is extended in the diameter direction. And a design for sufficiently increasing the section modulus of the portion including the corner R.

In the case of the rolling bearing unit with the rotation speed detecting device of the present embodiment, the second mounting flange is formed by the leading edge of the cylindrical portion 9a and a part of the inner peripheral surface of the first inner ring member 4a. A weld 17a is applied to the portion located on the inner diameter side of 7. It is not necessary for the weld 17a to have a role of transmitting torque between the first and second inner ring members 4a and 5a, and the diameter of the first half of the cylindrical portion 9a is reduced as described later. It is enough if it can be prevented. Accordingly, the first inner ring raceway 8 formed at the portion near the other end of the outer peripheral surface of the first inner ring member 4a is not welded by small build-up welding or intermittent in the circumferential direction so as not to be affected by heat. Spot welding is enough.

Further, a cylindrical surface portion 30 is formed on a portion of the outer peripheral surface of the intermediate portion of the second inner ring member 5a slightly closer to the housing portion 10 than the second inner ring raceway 11. The cylindrical surface portion 30 is concentric with the second inner ring member 5a. The encoder 23 is externally fitted and fixed to the cylindrical surface portion 30 by interference fitting. The encoder 23 is made of a mild steel plate whose surface has been subjected to corrosion-resistant treatment such as chrome plating or zinc plating, or SUS42.
The whole is formed in a cylindrical shape with an L-shaped cross section using a magnetic metal plate having corrosion resistance, such as a stainless steel plate having magnetism of 0, 430 or the like. That is, the encoder 23 includes a cylindrical portion 31 and a flange portion 32 formed in an outward flange shape by bending an inner end of the cylindrical portion 31 outward at right angles in a diametrical direction. Also, the outer half of the cylindrical portion 31 (refers to the outer half in the width direction when assembled to a vehicle;
In the left half of the cylindrical portion 31, a large number of slit-shaped through holes 33, each of which is long in the axial direction (the left-right direction in FIGS. 1 and 2), are formed at equal intervals in the circumferential direction. The magnetic properties of the outer half are changed alternately and at equal intervals in the circumferential direction. In such an encoder 23, the flange 32 is abutted against a step 34 formed at the inner end of the cylindrical surface 30, and is externally fitted and fixed to the cylindrical surface 30.

On the other hand, a cover 18 is provided on the inner end of the outer race 1a.
c is externally fixed. The cover 18c includes a sleeve 35 in which a metal plate such as a steel plate and a stainless steel plate is formed in an annular shape with an L-shaped cross section, and a cover body 36 made of synthetic resin.
Consisting of The cover body 36 is formed in an annular shape as a whole with a crank-shaped cross section. The cover body 36
The inner half (the right half in FIGS. 1-2) in the circumferential direction of
A thick holding portion 37 is provided. Also, compared to the fitting cylindrical portion 38 having a large inner diameter existing on the outer half side and the fitting cylindrical portion 38 existing over the entire circumference at a portion corresponding to the inner diameter side portion of the holding portion 37. And the small-diameter inner cylindrical portion is
Is continuous. When the cover body 36 is injection-molded, the sleeve 35 is inserted in a state of being bridged from the inner half part of the fitting cylindrical part 38 to the step part 39 and exposed from the cover body 36. . Further, the outer peripheral side portion of the core metal 40 constituting the seal ring 19b is also embedded and supported at the inner end of the inner diameter side cylindrical portion when the cover body 36 is injection molded. For this reason, in the illustrated example, the inner peripheral edge of the inner end portion of the inner diameter side cylindrical portion is slightly projected inward in the diametrical direction. Note that the seal ring 19b is formed by connecting an inner peripheral edge of the cored bar 40 to an outer peripheral base of a seal lip 41 made of an elastic material such as rubber or elastomer.

The cover 18c described above is supported and fixed to the inner end of the outer ring 1a by tightly fitting the sleeve 35 to the cylindrical surface 42 formed on the outer peripheral surface of the inner end of the outer ring 1a. doing. In this state, the leading edge of the seal lip 41 is in sliding contact with the outer peripheral surface of the inner half portion of the cylindrical portion 31 and the outer peripheral surface of the flange portion 32 of the encoder 23 over the entire circumference. Then, foreign matter such as muddy water is prevented from entering the inside of the cover 18c and the outer ring 1a from the annular gap existing between the inner peripheral edge of the cover 18c and the outer peripheral surface of the encoder 23. The seal lip 41
The reason why the front end edge of the inner ring is not in direct sliding contact with the second inner ring member 5a but in sliding contact with the encoder 23 is that the surface of the second inner ring made of a material such as bearing steel which is difficult to maintain a smooth surface due to corrosion. This is because the encoder 23 is less likely to rust than the member 5a, and the surface thereof is easily maintained smooth.

Further, a chamfered portion 43 is formed on the inner peripheral edge of the outer end opening of the fitting cylindrical portion 38.
The O-ring 45 is elastically compressed between the cylindrical surface portion 42 and the step portion 44 bent outward in the diameter direction from the end of the cylindrical surface portion 42. The O-ring 45 prevents foreign matter such as muddy water from entering the inside of the cover 18c and the outer ring 1a from the fitting portion between the cover 18c and the outer ring 1a. The outer diameter of the cylindrical portion 31 is equal over the entire length in the axial direction. Therefore, in the case of this example, the outer diameter of the portion where the large number of through holes 33 are formed and the diameter of the sliding contact portion between the leading edge of the seal lip 41 and the inner half outer peripheral surface of the cylindrical portion 31 are: Equal to each other.

Further, a part of the holding portion 37 constituting the cover body 36 and a portion facing a large number of through holes 33 formed in the outer half of the cylindrical portion 31 constituting the encoder 23 has a sectional shape. Is formed in a state penetrating from the outer peripheral side surface to the inner peripheral side surface of the holding portion 37. The sensor unit 47 is inserted through the inside of the insertion hole 46 from the outer diameter side to the inner diameter side. The sensor unit 47 includes a permanent magnet, a magnetic sensing element such as an MR element and a Hall element that changes the output in response to a change in magnetic flux density, and an IC that forms a waveform shaping circuit that adjusts the output waveform of the magnetic sensing element. And
It is configured by being embedded in a synthetic resin holder. Such a sensor unit 47 has an inner end surface (FIG. 1).
2 are opposed to the outer half of the cylindrical portion 31 via a minute gap 48 extending in the radial direction. The density of the magnetic flux flowing in the magnetic sensing element is such that the through-holes 33 and the pillars existing between the circumferentially adjacent through-holes alternately pass through the portion where the inner diameter side end surface faces. , And as a result, the output of the magnetic sensing element changes. Since the frequency at which the output changes in this manner is proportional to the rotation speed of the hub 6a that rotates with the wheels by fixing the encoder 23 to the outside, if the output is input to a controller (not shown), the ABS or TCS can be appropriately adjusted. Can be controlled.

An O-ring 50 is mounted in a locking groove 49 formed in the outer peripheral surface of the intermediate portion of the sensor unit 47 so that the outer peripheral surface of the sensor unit 47 is inserted into the insertion hole 46.
To prevent foreign matter such as muddy water from entering the inside of the cover 18c and the outer ring 1a. An outward flange-shaped flange portion 51 is formed at the outer diameter side end of the sensor unit 47. The sensor unit 47 is inserted into the insertion hole 46, and the inner side surface (the lower surface in FIGS.
The outer side surface (the upper surface in FIGS. 1 and 2) of the flange portion 51 is brought into contact with the outer peripheral surface of the holding portion 37 by a holding portion provided at an intermediate portion of the holding spring 52. It is holding down. The pressing spring 52 is formed in a gate shape as a whole, and both base ends thereof are pivotally supported on both circumferential sides of the holding portion 37. When the sensor unit 47 is inserted into the insertion hole 46, the pressing spring 52 is retracted to the side from the outer diameter side end opening of the insertion hole 46. Then, after the inner side surface of the flange portion 51 is brought into contact with the outer peripheral side surface of the holding portion 37, the pressing portion of the pressing spring 52 is caused to ride on the flange portion 51, and the flange portion 51 is held by the holding portion. 37.

In the case of the rolling bearing unit with the rotation speed detecting device of the present invention configured as described above, the cover 18c having the seal ring 19b connected and supported thereon is attached to the outer race 1a prior to the assembling operation of the rolling bearing unit. The encoder 23 can be mounted on the second inner race member 5a. That is, the cover 18c, which supports the seal ring 19b, is attached to the outer race 1a, and the encoder 23 is externally fixed to the intermediate portion of the second inner race member 5a. The second inner ring member 4a,
5a can be inserted with a plurality of rolling elements 12, 12 interposed. After the insertion, these inner ring members 4a,
5a are joined by caulking the tip of the cylindrical portion 9a outward in the diametrical direction and further applying welding 17a,
In addition to the hub 6a, the hub 6a can be rotatably supported inside the outer ring 1a. The seal ring 19b
Since the work of mounting the cover 18c and the encoder 23 on the outer ring 1a and the encoder 23 on the second inner ring member 5a, respectively, can be performed in a state of the parts of the outer ring 1a and the second inner ring member 5a alone. The mounting work of the encoder 23 and the cover 18c can be easily performed. The operation of mounting the sensor unit 47 on the outer race 1a is performed after the assembly operation of the rolling bearing unit is completed. Therefore, the portion of the sensor unit 47 that protrudes from the inner peripheral surface of the outer race 1a at the tip end does not hinder the assembling work.

Further, in the case of the illustrated example, the first and second inner ring members 4 are formed based on the engagement between the outer peripheral surface of the first half of the cylindrical portion 9a and the serration groove formed in the continuous portion 27.
a and 5a can be connected in a state where relative rotation is reliably prevented. In addition, the fact that the inner diameter of the portion engaged with the serration groove in the first half of the cylindrical portion 9a becomes smaller,
This is prevented by welding 17a provided between the leading edge of the inner ring member a and the inner peripheral surface of the first inner ring member 4a. Therefore, the cylindrical portion 9a
Is prevented from being deformed in the direction in which the diameter decreases, and the engagement between the outer peripheral surface of the first half and the serration groove can be reliably prevented. As a result, the first and second inner ring members 4 can be used for a long period of time.
a and 5a can be held in a state where relative rotation is reliably prevented, and the front wheels can be rotationally driven via the constant velocity joint.

In the illustrated example, the encoder 23 is made of a corrosion-resistant magnetic metal plate.
Of the seal lip 41 is slid on the surface of the seal lip 41.
With this configuration, the surface on which the leading edge slides is not rusted and roughened, so that a structure that maintains good sealing performance over a long period of time can be realized. However, if a certain degree of sealing performance can be maintained in other parts such as a separately provided cover, or if the material of the second inner ring member 5a is resistant to rust, the leading edge of the seal lip 41 is fixed to the second edge. Can be directly slid on the outer peripheral surface of the inner ring member 5a. In this case, for example, a large-diameter cylindrical portion, a small-diameter cylindrical portion, and a step portion or an inclined portion that connects these two cylindrical portions are formed on the outer peripheral surface of the intermediate portion of the second inner ring member 5a to form a cylindrical shape. The encoder thus formed is externally fitted and fixed to the small-diameter cylindrical portion, and the leading edge of the seal lip is brought into sliding contact with the large-diameter cylindrical portion. In the case of adopting such a structure, if the outer diameter of the encoder externally fitted and fixed to the small-diameter cylindrical portion is set to be equal to or less than the outer diameter of the large-diameter cylindrical portion, as in the example shown in the drawing, the mounting work of the constituent members is performed. Can be easily done.

Next, FIG. 3 shows a second example of the embodiment of the present invention, which also corresponds to claim 1. In the case of this example, a short cylindrical permanent magnet 53 supported and fixed to the outer half (left half in FIG. 3) of the holding cylinder 54 is used as the encoder 23a. The holding cylinder 54 is made of a corrosion-resistant magnetic metal plate similar to that of the encoder 23 (FIGS. 1 and 2) of the first example described above.
Like the encoder 23, the holding cylinder 54 includes a cylindrical portion 31a and a flange portion 32a formed in an outward flange shape by bending an inner end of the cylindrical portion 31a outward at right angles in a diametrical direction. . However, the cylindrical portion 31a of the holding cylinder 54 constituting the structure of this example is configured by connecting a small-diameter portion 55 of the outer half and a large-diameter portion 56 of the inner half by a step 57.

The permanent magnet 53 has a small diameter 5
5 is fixed to the outer peripheral surface by an appropriate means such as external fitting by close fitting, adhesion, and baking. The permanent magnet 53
Are magnetized in the diameter direction. The magnetization directions are changed alternately and at equal intervals in the circumferential direction. Therefore, on the outer peripheral surface of the permanent magnet 53, S poles and N poles are alternately arranged at equal intervals. A small gap 48 is formed between the permanent magnet 53 and the detection surface of the sensor unit 47.
, The direction of the magnetic flux flowing through the magnetic detection element provided in the sensor unit 47 changes at a frequency proportional to the rotation speed of the encoder 23a, so that the rotation speed can be detected. In the case of this example, in a state where the permanent magnet 53 is held and fixed to the outer peripheral surface of the small diameter portion 55, the outer diameter of the permanent magnet 55 is a sliding contact portion between the leading edge of the seal lip 41 and the mating surface, that is, The diameter is set to be equal to or less than the diameter of the outer peripheral surface of the large diameter portion 56. Therefore, also in the case of this example, prior to the assembling work of the rolling bearing unit, the seal ring 19b is used.
Can be mounted on the outer race 1a and the encoder 23 can be mounted on the second inner race member 5a, respectively.
8c can be easily mounted. Other configurations and operations are the same as those of the above-described first example, and thus redundant description will be omitted.

Next, FIG. 4 shows a third embodiment of the present invention corresponding to claim 2. In the case of this example, the seal ring 19c as the second seal ring
It is constituted by attaching a seal lip 41a to the outer diameter side of the core metal 40a. The core metal 40a is made of a steel plate,
Pressing a metal plate such as a stainless steel plate
It is formed in an annular shape as a whole, and is externally fitted and fixed to the inner half portion of the cylindrical surface portion 30 formed on the outer peripheral surface of the intermediate portion of the second inner ring member 5a by interference fit. The seal lip 41a is made of an elastic material such as rubber or elastomer, and is attached to the outer peripheral edge of the cored bar 40a over the entire circumference.

An encoder 23b is externally fixed to the outer half of the cylindrical surface portion 30 by interference fitting. The encoder 23b is formed of a magnetic metal plate such as a mild steel plate and has a cylindrical shape with an L-shaped cross section. That is, the encoder 23b includes a cylindrical portion 58 and an annular portion 59 formed in an outward flange shape by bending an outer end of the cylindrical portion 58 outward at right angles in a diametrical direction. A large number of slit-shaped through holes 33a, each long in the radial direction (vertical direction in FIG. 4), are formed in the circular ring portion 59 at equal intervals in the circumferential direction. The characteristics are changed alternately and at equal intervals in the circumferential direction. As described above, the magnetic surface of the circular ring portion 59 is changed, and the detection surface of the sensor unit 47a attached to the outer ring 1a is moved to the outer surface of the distal end of the sensor unit 47a (left side of the lower end in FIG. 4). Is provided.

The sleeve 35a embedded in the cover 18d fitted and fixed to the inner end of the outer ring 1a is
This cover 1
The cover body 36a made of a synthetic resin that constitutes 8d is also exposed to the inner diameter side of the inner end face and to the inner end face near the inner end. The distal end edge of the seal lip 41a is slid over the entire periphery of the sleeve 35a exposed at the inner diameter side portion of the inner end face and the inner end face near the inner end. Outer diameter D _23b of the encoder 23b, the a sliding contact portion between the edge and the mating surface of the seal lip 41a, the inner diameter R _35a in the following (D _23b ≦ R of the sleeve 35a
_35a ), the encoder 23b can pass freely through the inner diameter side of the sleeve 35a. Therefore, in the case of this example, the cover 18d is attached to the outer ring 1a and the seal ring 19c prior to assembling the rolling bearing unit.
Since the encoder 23b can be mounted on the second inner ring member 5a, the work of mounting the cover 18d, the seal ring 19c, and the encoder 23b can be easily performed. Other configurations and operations are the same as those of the above-described first example, and thus redundant description will be omitted.

Next, FIG. 5 shows a fourth embodiment of the present invention, also corresponding to claim 2. In the case of this example, as the encoder 23c, a ring-shaped permanent magnet 53a such as a rubber magnet is bonded to the inner side surface of the ring portion 61 constituting the holding ring 60 by bonding, baking, and its own magnetic attraction. We use thing which we supported. This permanent magnet 53
a is magnetized in the axial direction (left-right direction in FIG. 5).
The magnetization directions are changed alternately and at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals on the inner surface of the permanent magnet 53a. Further, in the case of this example, an insertion hole 46a for mounting the sensor unit 47 is formed directly on the inner end of the outer ring 1a. The cover 18d (FIG. 4) as in the third example described above is not provided. Accordingly, the leading edge of the seal lip 41a constituting the seal ring 19c is brought into sliding contact with the inner end face and the inner end face of the inner peripheral surface of the outer ring 1a. The outer diameter D ₆₀ of the holding ring 60 is changed to the inner diameter R of the inner end of the outer ring 1a.
_1a (D ₆₀ ≦ R _1a ), so that the encoder 23c can be inserted inside the inner end of the outer ring 1a. Therefore, also in the case of this example, since the seal ring 19c and the encoder 23b can be mounted on the second inner ring member 5a prior to the assembly operation of the rolling bearing unit, the mounting operation of the seal ring 19c and the encoder 23b is performed. Can be easily performed. Other configurations and operations are
Since this is the same as the case of the above-described third example, duplicate description will be omitted. In practicing the present invention, the types of the sensor and the encoder are not limited to the magnetic type as shown. Sensors and encoders that constitute a rotational speed detecting device having another structure such as an eddy current type may be employed.

[0037]

Since the present invention is constructed and operates as described above, it is possible to provide a rolling bearing unit with a rotation speed detecting device which can be made compact and lightweight, and which is practical and easy to assemble.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 4 is a view similar to FIG. 2, showing the third example.

FIG. 5 is a view similar to FIG. 2, showing the fourth example.

FIG. 6 is a partial cross-sectional view showing one example of a conventional structure.

[Explanation of symbols]

 1, 1a Outer ring 2 First mounting flange 3 Outer ring track 4, 4a First inner ring member 5, 5a Second inner ring member 6, 6a Hub 7 Second mounting flange 8 First inner ring track 9, 9a Cylindrical part DESCRIPTION OF SYMBOLS 10 Housing part 11 2nd inner raceway 12 Rolling element 13 Locking groove 14 Locking groove 15 Retaining ring 16 Step 17, 17a Welding 18a, 18b, 18c, 18d Cover 19a, 19b, 19c Seal ring 20 Separator plate 21 Inner ring 22 Ball 23, 23a, 23b, 23c Encoder 25 Large diameter portion 26 Small diameter portion 27 Continuous portion 28 Step portion 29 Step portion 30 Cylindrical surface portion 31, 31a Cylindrical portion 32, 32a Flange portion 33, 33a Through hole 34 Step portion 35, 35a sleeve 36, 36a cover body 37 holding part 38 fitting cylinder part 39 step part 40, 40a core metal 41, 41a seal lip 42 yen Surface part 43 Chamfered part 44 Step part 45 O-ring 46, 46a Insertion hole 47, 47a Sensor unit 48 Micro gap 49 Locking groove 50 O-ring 51 Flange 52 Suppression spring 53, 53a Permanent magnet 54 Holding cylinder 55 Small diameter part 56 Large diameter Part 57 Stepped part 58 Cylindrical part 59 Ring part 60 Retaining ring 61 Ring part

Claims (2)

[Claims] An outer ring having a first mounting flange for supporting the suspension on the outer peripheral surface, a plurality of rows of outer ring raceways on the inner peripheral surface, and a wheel for supporting one end of the outer peripheral surface near one end. The second mounting flange, the first inner raceway is also provided at a portion near the other end, and a cylindrical first inner race member provided respectively, and one end portion for externally fixing the first inner race member. A cylindrical portion, the other end of which is a housing portion serving as an outer ring of a constant velocity joint, a second inner ring member having a second inner raceway provided on an outer peripheral surface of an intermediate portion, the outer raceways and the first and second raceways. A plurality of rolling elements respectively provided between the inner raceway and the outer raceway, the double-row outer raceway and the first and second inner raceways are sandwiched from both sides in the axial direction. The first and second seal rings provided between the second inner race member and the outer peripheral surface of the intermediate portion; The second seal ring and the second seal ring, which are a part of the outer ring or a member fixed to the outer ring, and block the gap between the other end side opening of the outer ring and the outer peripheral surface of the intermediate portion of the second inner ring member. A sensor provided between the plurality of rolling elements disposed on the inner ring raceway portion, and an annular circumference fixed to a portion of the intermediate portion outer peripheral surface of the second inner ring member facing the detection surface of the sensor. The second seal ring has an outer diameter side portion directly at the other end of the outer ring or via a member fixed to the outer ring. The outer peripheral surface of the second inner ring member or the outer peripheral surface of a member externally fitted to an intermediate portion of the second inner ring member is supported by sliding the leading edge of the seal lip provided on the inner diameter side portion over the entire circumference. And the diameter of the sliding part between the tip edge of the seal lip and the mating surface. Of the above-mentioned encoder, at least speed sensing rolling bearing unit with a equal to or greater than the outer diameter detection surface of the portion opposite of the sensor. 2. An outer ring having a first mounting flange for supporting the suspension on the outer peripheral surface, an outer ring having a plurality of rows of outer ring raceways on the inner peripheral surface, and a wheel supporting one end of the outer peripheral surface. The second mounting flange, the first inner raceway is also provided at a portion near the other end, and a cylindrical first inner race member provided respectively, and one end portion for externally fixing the first inner race member. A cylindrical portion, the other end of which is a housing portion serving as an outer ring of a constant velocity joint, a second inner ring member having a second inner raceway provided on an outer peripheral surface of an intermediate portion, the outer raceways and the first and second raceways. A plurality of rolling elements respectively provided between the inner raceway and the outer raceway, the double-row outer raceway and the first and second inner raceways are sandwiched from both sides in the axial direction. The first and second seal rings provided between the second inner race member and the outer peripheral surface of the intermediate portion; The second seal ring and the second seal ring, which are a part of the outer ring or a member fixed to the outer ring, and block the gap between the other end side opening of the outer ring and the outer peripheral surface of the intermediate portion of the second inner ring member. A sensor provided between the plurality of rolling elements disposed on the inner ring raceway portion, and an annular circumference fixed to a portion of the intermediate portion outer peripheral surface of the second inner ring member facing the detection surface of the sensor. The second seal ring supports the inner diameter side portion at the intermediate portion of the second inner ring member, and has the outer diameter side portion entirely. The leading edge of the seal lip provided over the periphery is slid in contact with the other end of the outer ring or a member fixed to the outer ring, and the diameter of the sliding contact portion between the leading edge of the seal lip and the mating surface is determined by: Rolling bearing unit with a rotation speed detector that is larger than the outer diameter of the encoder