JPH1172501A - Roller bearing unit with rotational speed sensor and assembling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure which facilitates work of assembling an encoder at a normal position of an inner race assembly. SOLUTION: A mounting recessed part 18 is provided at the intermediate part of a hub 2a composing an inner race assembly 7a together with an inner race 3a and an encoder 4a is externally fitted and fixed into the mounting recessed part 18. The outer diameter D4a of the encoder 4a is made smaller than the diameter R9a of the inscribed circles of a plurality of rolling bodies 9a and 9a. The encoder 4a can be externally fitted and fixed into the hub 2a before the insertion of the hub 2a into an outer race 1a. This facilitates the work of correctly fitting the encoder 4a externally into the mounting recessed part 18.

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 rotatably supports a wheel of an automobile with respect to a suspension device, and is used for detecting the rotation speed of the wheel.

[0002]

2. Description of the Related Art Rolling bearing units are used to rotatably support the wheels of an automobile with respect to a suspension system.
Further, 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 wheel. For this reason, the above-mentioned wheel is rotatably supported with respect to the suspension device by a rolling bearing unit with a rotation speed detecting device in which a rotation speed detecting device is incorporated in the above-mentioned rolling bearing unit, and the rotation speed of the wheel is detected. However, it has been widely practiced in recent years.

FIG. 9 shows an example of a conventional structure of a rotational speed detecting device used for such a purpose as disclosed in Japanese Patent Application Laid-Open No. 62-24 / 1987.
No. 9069 is disclosed. The rolling bearing unit with a rotation speed detecting device rotatably supports a hub 2 serving as a first inner ring and an inner ring 3 serving as a second inner ring that rotate during use inside an outer ring 1 that does not rotate during use. Encoder 4 fixed to outer peripheral surface of intermediate part of hub 2
Can be detected by the sensor 5 supported on the outer ring 1. That is, the outer race of the inner race 3, which forms an inner race assembly 7 together with the hub 2 and the hub 2 with the outer raceways 6, 6 in a double row fixed on the inner circumferential surface of the outer race 1, is fixed to the hub 2 and the hub 2. Inner ring tracks 8, 8 are provided on the surface, respectively. A plurality of rolling elements 9, 9 are provided between the inner raceways 8, 8 and the outer raceways 6, 6, respectively.
Are rotatably provided while being held by retainers 10, 10, respectively, and the inner ring assembly 7 is provided inside the outer ring 1.
Is rotatably supported.

A portion of the hub 2 which protrudes in the axial direction from the outer end of the outer race 1 at the outer end (the end which is outward in the width direction when assembled to an automobile, and which is the left end in FIG. 9). Is provided with a flange 11 for attaching a wheel.
Further, a mounting portion 12 for mounting the outer ring 1 to a suspension device is provided on an outer peripheral surface of an intermediate portion of the outer ring 1. Also, the opening at both ends of the outer ring 1, the outer peripheral surface of the intermediate portion of the hub 2, and the inner end of the inner ring 3 (the end that is the center in the width direction when assembled to an automobile, the right end in FIG. 9) Are closed by seal rings 13 and 13, respectively. Although balls are used as the rolling elements 9 in the illustrated example, tapered rollers may be used as these rolling elements in the case of a heavy-duty rolling bearing unit of an automobile.

[0005] In order to incorporate the rotational speed detecting device into the rolling bearing unit as described above, the encoder 4 is mounted on the outer peripheral surface of the intermediate portion of the hub 2 between the pair of inner raceways 8,8. Externally fitted and fixed. The encoder 4 is formed in an annular shape from a magnetic metal such as mild steel, and is formed as a whole in a gear shape by forming concavo-convex portions on the outer peripheral edge in the circumferential direction. The magnetic properties are changed alternately and at equal intervals in the circumferential direction. Such an encoder 4 is fixed to the hub 2 by being fitted around the hub 2 by interference fit.

Further, a mounting hole 14 is formed at an axially intermediate portion of the outer ring 1 at a position radially outward of the encoder 4 such that an inner peripheral surface and an outer peripheral surface of the outer ring 1 communicate with each other. ing. Then, the sensor 5 is inserted and fixed in the mounting hole 14, and a detection unit provided on the front end surface (the lower end surface in FIG. 9) of the sensor 5 is attached to the outer peripheral surface of the encoder 4.
They are opposed to each other via a minute gap.

In the case of the rolling bearing unit with the rotation speed detecting device as described above, the flange 11 provided at the outer end of the hub 2
To the suspension that supports the outer ring 1,
Can be rotatably supported. Also, with the rotation of the wheels, the hub 2
When the encoder 4 fitted and fixed to the intermediate portion of the encoder 4 rotates, the concave portion and the convex portion provided on the outer peripheral edge of the encoder 4 alternately pass near the detecting portion provided on the distal end surface of the sensor 5. As a result, the density of the magnetic flux flowing in the sensor 5 changes, and the output of the sensor 5 changes. The frequency at which the output of the sensor 5 changes is proportional to the rotation speed of the wheel.
Therefore, if the output of the sensor 5 is sent to a controller (not shown),
ABS and TCS can be controlled appropriately.

[0008]

In the case of the rolling bearing unit with the rotation speed detecting device constructed as described above, the assembling work is troublesome, and it is difficult to achieve both quality maintenance and cost reduction. The reason is that the rolling elements 9 and 9 and the cage 1 are provided inside the double-row outer raceways 6 and 6 provided on the inner peripheral surface of the outer race 1 respectively.
After assembling the rolling elements 9 and 9,
This is because the encoder 4 cannot be assembled between them.

That is, in the method of assembling a rolling bearing unit which is currently generally performed, the rolling elements 9, 9 and the cage are provided inside the double-row outer raceways 6, 6 provided on the inner peripheral surface of the outer race 1, respectively. After assembling the rolling elements 9 and 9, the hub 2 and the inner ring 3 are assembled inside the rolling elements 9 and 9, respectively. The hub 2 to which the encoder 4 is externally fitted and fixed may be assembled inside the outer ring 1 by applying the conventional process as it is, but the conventional rolling bearing unit with a rotational speed detecting device shown in FIG. In the case of (1), the outer diameter of the encoder 4 is larger than the diameter of the inscribed circle of the plurality of rolling elements 9 disposed inside the outer raceways 6. Therefore, the encoder 4 cannot pass through the inside of the plurality of rolling elements 9, 9, and the assembling work by the conventional process as described above is impossible.

For this reason, when assembling the conventional structure shown in FIG. 9, the hub 2 is inserted inside the outer ring 1 with only one of the rolling elements 9, 9 mounted on the left side (FIG. 9). After that, before mounting the rolling elements 9 and 9 and the inner ring 3 on the other side (the right side in FIG. 9), it is necessary to externally fix the encoder 4 on the outer peripheral surface of the intermediate portion of the hub 2. However, in this state, the intermediate portion of the hub 2 is located in a deep portion of the cylindrical space 15 between the inner peripheral surface of the outer race 1 and the outer peripheral surface of the hub 2, so that the outer fitting of the encoder 4 Fixing work is troublesome. For this reason, if this external fitting fixing work is not performed carefully, the mounting position of the encoder 4 becomes incorrect,
There is a possibility that accurate rotation speed detection cannot be performed.

A structure similar to that shown in FIG. 9 is disclosed in Koyo Eiko Co., Ltd., published in March 1997.
NGINEERING JOURNAL No. 151, page 35, FIG. However, even in this publication, there is no description in consideration of facilitating the operation of externally fixing the encoder to the outer peripheral surface of the intermediate portion of the hub. In view of the above-described circumstances, the rolling bearing unit with a rotation speed detecting device and the method of assembling the same according to the present invention can easily perform an operation of externally fixing an encoder to a constituent member of an inner ring assembly in a wide place. It was invented to be.

[0012]

Means for Solving the Problems In the present invention, claim 1 is provided.
The rolling bearing unit with rotation speed detection device described in
Similarly to the above-described conventional rolling bearing unit with a rotation speed detecting device, it includes an outer ring, an inner ring assembly, a rolling element, an encoder, and a sensor. Of these, the outer ring has a double-row outer ring track on the inner peripheral surface, and does not rotate during use. The inner ring assembly is formed by combining a first inner ring having a first inner raceway on an outer peripheral surface and a second inner race having a second inner raceway on an outer peripheral surface, and rotates during use. A plurality of rolling elements are provided between each of the outer raceways and each of the first and second inner raceways so as to be able to roll in a plurality of rows. or,
The encoder has a portion to be detected in which characteristics in a circumferential direction are alternately changed at equal intervals, and a portion sandwiched between the double-row inner ring raceways on an outer peripheral surface of an axially intermediate portion of the inner ring assembly. And is fixed concentrically with the inner ring assembly. Further, the sensor has a detecting portion, and the detecting portion is supported in a mounting hole provided at an axially intermediate portion of the outer ring in a state where the detecting portion is opposed to a part of an outer peripheral surface of a detected portion of the encoder, The output signal is changed according to the change in the characteristic of the detected part. Especially,
In the rolling bearing unit with the rotation speed detecting device of the present invention, the outer diameter of the encoder is the diameter of an inscribed circle of a plurality of rolling elements provided in each of the rows, and Is less than or equal to the diameter of the inscribed circle of the rolling elements in the row passing therethrough.

Further, in the method of assembling a rolling bearing unit with a rotation speed detecting device according to claim 2, a plurality of the rolling elements are mounted on the inner diameter side of at least one of the outer raceways in the double row. After externally fixing the encoder at the axially intermediate portion of the first inner ring, the first inner ring is inserted into the inner diameter side of the outer ring from the side of the outer ring track on which the rolling elements are mounted, and the encoder is inserted. The plurality of rolling elements are passed through the inner diameter side.

[0014]

The rolling bearing unit with the rotation speed detecting device of the present invention constructed and assembled as described above rotatably supports the wheel with respect to the suspension device, and detects the rotation speed of the wheel. This is the same as the above-described conventional rolling bearing unit with a rotation speed detecting device. In particular, in the case of the rolling bearing unit with the rotation speed detection device of the present invention and the method of assembling the same, the rotation speed detection device can be used even when the encoder is externally fixed to the first inner ring which is a constituent member of the inner ring assembly in advance. Assembly work of the rolling bearing unit can be performed. Accordingly, the operation of externally fixing the encoder to the first inner ring constituting the inner ring assembly can be easily performed in a wide place.

[0015]

1 to 4 show a first embodiment of the present invention. In the drawings showing the embodiment of the present invention, FIG.
The inward and outward directions at 3 and 5 are left and right opposite to FIG. 9 showing the above-described conventional structure (FIGS. 7 and 8 are the same as FIG. 9). The rolling bearing unit with the rotation speed detecting device of the present invention is also the same as that shown in FIG.
As in the case of the conventional structure shown in FIG. 1, a hub 2a as a first inner ring and an inner ring 3a as a second inner ring rotatably supported inside the outer ring 1a which does not rotate during use. . The rotation speed of the encoder 4a fixed to the outer peripheral surface of the intermediate portion of the hub 2a can be detected by a sensor 5a supported on the outer ring 1a.

For this purpose, double rows of outer raceways 6a, 6a are provided on the inner peripheral surface of the outer race 1a, with the hub 2a and the hub 2a.
The inner ring assembly 7 is mounted together with the hub 2a in a state where the inner ring
a on the outer peripheral surface of the inner ring 3a constituting the inner ring track 8a, 8
a is provided. A plurality of rolling elements 9a, 9a are respectively provided between the inner raceways 8a, 8a and the outer raceways 6a, 6a.
The inner ring assembly 7a is rotatably supported inside the outer ring 1a while being held by 0a and 10a.

A flange 11a for attaching a wheel is provided at a portion protruding in the axial direction from the outer end of the outer ring 1a at the outer end (the right end in FIG. 1) of the hub 2a. The outer ring 1a is provided on the outer peripheral surface of the intermediate portion of the outer ring 1a.
a is provided on the suspension device. Also, the opening at both ends of the outer ring 1a, the outer peripheral surface of the intermediate portion of the hub 2a, and the inner end of the inner ring 3a (the left end in FIG. 1).
The gap between the outer peripheral surface is a seal ring 13a,
13a. In some cases, tapered rollers are used as the rolling elements 9a, 9a, as in the case of the above-described conventional structure.

At the inner end of the hub 2a, a small-diameter step 16 for externally fixing the inner ring 3a is provided.
And concentrically formed. The inner ring 3a is connected to the small diameter step 1
6, the inner end of the inner race 3a projects axially inward (leftward in FIG. 1) from the inner end surface (left end in FIG. 1) of the hub 2a. In the assembled state to the vehicle, the inner end surface of the inner ring 3a protruding inward in the axial direction from the hub 2a in this manner contacts the step surface of a constant velocity joint (not shown). Further, a spline shaft attached to the constant velocity joint is inserted into a spline hole 17 provided at the center of the hub 2a, and the tip of the spline shaft projects outward from the outer end surface of the hub 2a. A nut (not shown) is screwed into the male screw portion provided in the portion, and further tightened. The stepped surface of the constant velocity joint strongly presses the inner end surface of the inner ring 3a based on the tightening of the nut, and prevents the inner ring 3a from coming out of the small diameter stepped portion 16.

Further, at a portion between the inner raceway 8a formed on the outer peripheral surface of the hub 2a and the small-diameter step 16 at an intermediate portion in the axial direction of the hub 2a, a diameter larger than the small-diameter step 16 is provided. A mounting recess 18 having a smaller diameter than the inner raceway 8a is formed concentrically with the hub 2a over the entire circumference. And
The encoder 4a is externally fitted and fixed to the mounting recess 18 by interference fit. In a state where the hub 2a and the inner ring 3a are combined to form the inner ring assembly 7a, the encoder 4a is located at a position sandwiched by a pair of inner ring tracks 8a, 8a from both sides in the axial direction. The encoder 4a is formed entirely of a magnetic metal plate such as a mild steel plate into a cylindrical shape, and is long in the axial middle portion in the axial direction (left and right directions in FIGS. 1 and 3 and front and back directions in FIGS. 2 and 4). By forming a large number of slit-shaped through holes 19 at equal intervals in the circumferential direction, the magnetic characteristics are changed alternately and at equal intervals in the circumferential direction.

Such an encoder 4a is connected to the mounting recess 1 described above.
8, the outer diameter D of the encoder 4a is fixed.
_4a is a plurality of rolling elements 9a arranged inside the outer ring raceways 6a, 6a (arranged in an annular shape with a part of the rolling surface in contact with the outer ring raceways 6a, 6a). , 9
The diameter of the inscribed circle a is less than or equal to R _9a (D _4a ≦ R _9a ).
It should be noted that the relationship between the outer diameter D _4a and the diameter R _9a is regulated in this manner, as described later, in a state where the encoder 4a is externally fixed to the mounting recess 18 in advance, and the hub 2a is
This is to allow the rolling elements 9a to be freely inserted inside the outer race 1a to which the rolling elements 9a are previously mounted. Therefore, if the diameter of the pitch circle of the rolling elements 9a, 9a arranged in a double row is the same as in a general rolling bearing unit, the outer diameter _D4a is equal to the diameter of the rolling elements 9a, 9a in both rows. It is smaller than the diameter R _{9a of the} tangent circle. On the other hand, when the diameters of the pitch circles of the rolling elements 9a, 9a arranged in a double row are different from each other, the outer diameter D _{4a is set} to:
The diameter of the inscribed circle R _9a of the rolling elements 9a, 9a in the row (the right row in FIG. 1) through which the encoder 4a passes during the assembling operation may be reduced.

Further, a mounting hole 14a is provided at an axially intermediate portion of the outer ring 1a at a position radially outward of the encoder 4a.
Are formed such that the inner peripheral surface and the outer peripheral surface of the outer ring 1a communicate with each other. Then, the sensor 5a is inserted and fixed in the mounting hole 14a, and a detecting portion provided on the front end surface (the lower end surface in FIGS. 1, 3 and the left end surface in FIGS. 2, 4) of the sensor 5a is attached to the encoder 4a. It is opposed to the outer peripheral surface via a minute gap 20. In the illustrated example, the mounting hole 14a is formed at a substantially horizontal position, that is, at a position substantially perpendicular to the direction in which gravity acts. The reason for this is
This is to prevent the strength of the outer ring 1a from being reduced due to the formation of the mounting holes 14a at both ends in the vertical direction of the outer ring 1a which strongly receives the bending moment due to the vehicle weight. In other words, by providing the mounting hole 14a at a substantially horizontal position where a problem in strength is unlikely to occur, the required strength can be secured without particularly increasing the thickness of the outer ring 1a.

The outer peripheral surface of the outer ring 1a has the mounting hole 1
4a, a flat mounting surface 2 which is present in a direction orthogonal to the central axis of the mounting hole 14a is provided around the outer end opening.
1 are formed. A conical concave chamfered portion 22 is formed in a continuous portion between the mounting surface 21 and the inner peripheral surface of the mounting hole 14a. On the other hand, a mounting portion 23 is fixed to the base end (the upper end in FIG. 1 and the right end in FIG. 2) of the sensor 5a, and a screw 24 inserted through the end of the mounting portion 23 is used.
The mounting portion 23 is fixedly connected to the outer ring 1a. In this state, the O-ring 25 externally fitted to the base end of the sensor 5a is elastically compressed between the chamfered portion 22 and the portion where the sensor 5a is mounted is sealed, and the mounting hole 14 is closed.
Through a, foreign substances such as rainwater are prevented from entering the outer ring 1a.

In the case of the above-mentioned rolling bearing unit with a rotation speed detecting device, the flange 1 provided at the outer end of the hub 2a is used.
1a, a stud 26 fixed to the flange 11a,
The wheel fixed by utilizing 26 can be rotatably supported by the suspension device supporting the outer wheel 1a. When the encoder 4a externally fitted and fixed to the mounting recess 18 formed in the intermediate portion of the hub 2a rotates with the rotation of the wheel, the sensor 5
In the vicinity of the detecting portion provided on the distal end surface of the encoder 4a, the through holes 19 provided in the axially intermediate portion of the encoder 4a and the pillar portion present between the circumferentially adjacent through holes 19 are provided. Pass alternately. As a result, the density of the magnetic flux flowing in the sensor 5a changes, and the output of the sensor 5a changes. The frequency at which the output of the sensor 5a changes is proportional to the rotation speed of the wheel. Therefore, if the output of the sensor 5a is sent to a controller (not shown), the ABS and TCS can be appropriately controlled.

In particular, in the case of the rolling bearing unit with a rotation speed detecting device of the present invention, even if the encoder 4a is externally fixed to the hub 2a which is a constituent member of the inner ring assembly 7a in advance, the rotation speed detecting device can be used. Assembly work of the rolling bearing unit can be performed. That is, even in a state where the encoder 4a and fixedly fitted to the mounting recess 18 of the hub 2a, a plurality of rolling elements 9a of the outer diameter D _4a is disposed inside the outer ring raceway 6a of the encoder 4a, 9a inscribed circle of Diameter R _9a
Because of the following, the encoder 4a can pass through the inside of the plurality of rolling elements 9a, 9a. Therefore, the operation of externally fixing the encoder 4a to the mounting recess 18 can be performed in a wide place in advance. For this reason, encoder 4
a can be easily and reliably performed to accurately fix a to the predetermined portion of the hub 2a.

That is, when assembling the rolling bearing unit with the rotation speed detecting device of the present invention, first, the outer race 1
a of the outer raceway 6a in one row (outer side, right side in FIG. 2) of the double row outer raceway 6a provided on the inner peripheral surface of
A plurality of rolling elements 9a, 9a are mounted. At the same time, the encoder 4a is provided at an intermediate portion of the hub 2a as the first inner ring.
Is externally fixed. As described above, since the outer fitting work can be performed in a wide place, the encoder 4a can be easily and accurately fixed to a predetermined portion of the hub 2a as described above. Thus, a plurality of rolling elements 9a are provided on the inner peripheral surface of the outer race 1a.
After mounting the encoder 4a on the outer peripheral surface of the intermediate portion of the hub 2a, the hub 2a is mounted on the inner diameter side of the outer ring 1a on the outer raceway where the plurality of rolling elements 9a, 9a are mounted. 6a. Then, the encoder 4a is passed through the inner diameter sides of the plurality of rolling elements 9a, 9a. Thereafter, a plurality of rolling elements 9a are provided on the inner diameter side of the outer raceway 6a of the other (inner side, left side in FIG. 2) of the double row outer raceways 6a provided on the inner peripheral surface of the outer race 1a.
9a and the inner ring 3a as the second inner ring are mounted.

Next, FIGS. 5 and 6 show a second example of the embodiment of the present invention. In the case of this example, the encoder 4b
In this case, a support cylinder 27 with an encoder body 28 attached to the outer peripheral surface is used. This encoder body 28
Is a permanent magnet such as a rubber magnet in which a powder made of a ferromagnetic material such as ferrite is mixed in rubber, and is magnetized in the diameter direction. 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 outer peripheral surface of the encoder body 28. Such an encoder body 28 is attached to the outer peripheral surface of a support cylinder 27 made of a magnetic metal plate such as a mild steel plate. In the encoder 4b, the support cylinder 27 is formed on the outer peripheral surface of an intermediate portion of the hub 2a. It is fixed to the hub 2a by being fitted over the mounting recess 18 by interference fit. Also in the case of this example, the encoder main body 2 which is the outer diameter of the encoder 4b
8 is the diameter R of the inscribed circle of the plurality of rolling elements 9a, 9a.
Since it is smaller than _9a (see FIG. 1), the operation of accurately fixing the encoder 4b to a predetermined portion of the hub 2a can be easily performed. Except for changing the structure of the encoder 4b, the configuration and operation are the same as those of the first example described above.

FIG. 7 shows a third embodiment of the present invention.
An example is shown. In this example, the hub 2b corresponding to the first inner ring
In addition, a second inner ring constituting the inner ring assembly 7b is constituted by an outer ring of a constant velocity joint (in order to prevent confusion with the outer ring 1b constituting the rolling bearing unit, a member corresponding to the second inner ring is constituted by an inner ring. 3b). The hub 2b and the inner ring 3b are connected and fixed to form the inner ring assembly 7b. Therefore, a male spline 29 is provided on the outer peripheral surface of the inner portion of the hub 2b near the middle, and the outer end of the inner ring 3b (see FIG. On the inner peripheral surface (left end of 7), female splines 30 are formed. When connecting and fixing the hub 2b and the inner ring 3b, first, the male spline 29 and the female spline 30
And the small-diameter portion 31 formed on the inner peripheral surface of the intermediate portion of the inner race 3b and the base end of the cylindrical portion 32 formed on the inner end (the right end in FIG. 7) of the hub 2b. Fit without looseness. The small diameter portion 31 and the outer peripheral surface of the base end of the cylindrical portion 32 are each subjected to precision finishing by grinding. Therefore, based on the engagement and the fitting, the hub 2b and the inner race 3b are combined non-rotatably and concentrically. Since the hub 2b and the inner race 3b are in spline engagement with each other, a large torque can be transmitted. Further, in a state where the hub 2b and the inner ring 3b are combined in this manner, a portion protruding inward from the small diameter portion 31 at the tip end portion (right end portion in FIG. 7) of the cylindrical portion 32 is diametrically outward. The caulked portion 33 is formed by caulking and spreading, and the inner surface side of the small diameter portion 31 is suppressed by the caulked portion 33. In this state, the hub 2b and the inner race 3b are non-separably coupled and fixed to form the inner race assembly 7b.

If the inner peripheral surface of the inner ring 3b is processed by broaching over the entire length in the axial direction, the processing operation can be easily performed. After forming the female spline groove including the small diameter portion 31 at the time of this processing, the inside diameter of the female spline 30 to be engaged with the male spline 29 is determined by the small diameter portion 3.
What is necessary is just to make it larger than the inside diameter of 1. When such processing is performed on the inner peripheral surface of the inner ring 3b, the inner peripheral surface of the small diameter portion 31 becomes a tooth tip circle of the female spline groove. Therefore,
The fitting surface between the inner peripheral surface of the small diameter portion 31 and the outer peripheral surface of the cylindrical portion 32 is not continuous in the circumferential direction and is intermittent.
Also, only by combining the inner ring 3b and the hub 2b,
In the state where the caulking portion 33 is not yet formed, even if there is a small gap between the small diameter portion 31 and the outer peripheral surface of the base end portion of the cylindrical portion 32, the distal end portion of the cylindrical portion 32 is expanded in diameter. When the caulking portion 33 is formed, the diameter of the cylindrical portion 32 increases, so that the minute gap is eliminated, and the fitting state between the small diameter portion 31 and the cylindrical portion 32 can be tightly fitted.

A mounting recess 18 for externally fixing the encoder 4a is formed on the outer peripheral surface of the outer end of the inner ring 3b. A mounting hole 14a formed in the outer race 1b is formed on the outer peripheral surface of the encoder 4a externally fitted and fixed in the mounting recess 18.
The detection unit disposed on the distal end surface of the sensor 5a that is inserted into the sensor 5a is opposed to each other through the minute gap 20. The inner ring 3b
The inner peripheral surface of each of them has a ball groove 34 for guiding a ball (not shown) constituting a constant velocity joint, and the inner peripheral surface of the inner surface has an end of a dustproof boot (not shown). Locking grooves 35 for stopping are formed respectively.

In the case of the structure of the present embodiment configured as described above, the outer raceways 6a, 6a formed on the inner peripheral surface of the outer race 1b.
The rolling elements 9a, 9a are arranged in advance on the inside of the outer ring 1a, and the seal rings 13b,
13b needs to be fixed inside. In other words,
After assembling the inner ring assembly 7b inside the outer ring 1b, the rolling elements 9a, 9a and the seal ring 13
It is impossible to assemble b and 13b. On the other hand, in the case of this example, the outer diameter D of the encoder 4a
_4a, and these rolling elements 9a, the diameter R _9a and the seal ring 13b of the inscribed circle of 9a, smaller than the inner diameter R _13b of _{13b (D 4a <R 9a <} R 13b) to which order, and the hub 2b,
The inner ring 3b to which the encoder 4a has been fitted and fixed in advance can be inserted and fixed to the inside of the outer ring 1b later. Thus, also in the case of this example, the encoder 4
The outer diameter D _4a of a, plurality of rolling elements 9a, the diameter R _9a and the seal ring 13b of the inscribed circle of 9a, is made smaller than the inner diameter R _13b of 13b, predetermined the encoder 4a of the inner ring 3b The work of fixing accurately to the part can be easily performed. Other configurations and operations are the same as in the case of the above-described first example.

In the case of the structure of this embodiment, the dustproof boot attached to the constant velocity joint also has a function of preventing foreign matter such as muddy water from entering the spline engaging portion. Eliminates the need for a waterproof cap. The hub 2b is not only subjected to hardening treatment such as induction hardening on the inner raceway 8a and the male spline 29, but also subjected to a large load during caulking. The part is also subjected to the above-mentioned quenching and hardening treatment. On the other hand, the inner ring 3b is provided with ball grooves 34, 34 and a female spline 30 which constitute a constant velocity joint.
In addition to the quenching and hardening process, a large load is applied at the time of caulking, and the small-diameter portion 3 to which the end face abutting against the step portion of the hub 2b and the meat of the caulked portion 33 are caulked.
The quenching and hardening treatment is also applied to the inner side surface of No. 1.
Further, a flange portion 37 is formed on the inner ring 3b with which the seal lip of the inner seal ring 13b comes into sliding contact, and the outer peripheral edge of the flange portion 37 and the inner end surface of the outer ring 1b are brought close to each other to prevent foreign matter such as muddy water. It constitutes a labyrinth seal to prevent entry. Also, the inner seal ring 13b
In order to reduce the cost of the seal ring by using the same kind of parts as the outer seal ring 13b and to reduce the cost of the seal ring by increasing the number of mass-produced parts and simplifying the parts management, the mounting parts of these seal rings 13b and 13b The size of a portion of each of the seal rings 13b, 13b where the seal lip makes sliding contact is regulated. Further, the inner rolling elements 9a,
9a and the cylindrical portion 3 provided on the hub 2b.
2 is designed so that the intersection point P with the outer peripheral surface exists at the base end (or the male spline portion 29) of the cylindrical portion 32, which is not swaged outward in the diameter direction. The caulking portion 33, which is difficult to be thick, is provided with the inner rolling elements 9a,
A large load is not applied from 9a.

Next, FIG. 8 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, contrary to the case of the above-described third example, the female spline 30a is provided on the side of the hub 2c corresponding to the first inner ring provided with the flange 11a for fixing the wheel.
Corresponds to the second inner ring, and male splines 29a are formed on the side of the inner ring 3c which also functions as the outer ring of the constant velocity joint. Along with this, a cylindrical portion 32a forming a caulked portion 33a at the tip thereof is placed on the side of the inner ring 3c.
A small-diameter portion 31a is provided on the inner peripheral surface side of the hub 2c so as to fit tightly with the outer peripheral surface of the base end portion (right end portion in FIG. 8) of the hub 2c.

In the case of the present embodiment constructed as described above, the small-diameter portion 31 whose end face is suppressed by the caulking portion 33a.
a is provided on the inner peripheral surface side of the hub 2c and the small diameter portion 31 (FIG. 7) is omitted from the inner peripheral surface of the inner ring 3c.
Can be made shorter in the axial direction. As a result, this inner ring 3c
Can be reduced in size and weight by shortening the overall length of the rolling bearing unit including the above. The caulked portion 33a and the male spline 29a continuous from the caulked portion 33a
The cover 36 is fitted and fixed to the outer end (left end in FIG. 8) opening of the hub 2c as the engaging portion between the shaft 2 and the female spline 30a is exposed at the outer end opening of the rolling bearing unit.
Foreign matter such as rainwater is prevented from entering the inside of the hub 2c. In the case of the third example described above, such a cover 36
Is unnecessary. Other configurations and operations are the same as those of the third embodiment.
This is the same as in the example.

In each of the illustrated examples, the present invention is applied to a rolling bearing unit for supporting driving wheels (rear wheels of FR and RR vehicles, front wheels of FF vehicles, and all wheels of 4WD vehicles). As described above, the present invention can be applied to a rolling bearing unit for supporting driven wheels (front wheels of FR and RR vehicles, rear wheels of FF vehicles). Further, the feature of the present invention is to achieve both improvement of the assembling accuracy of the encoder and simplification of the assembling work.
The point is to regulate the outer diameter of the encoder in relation to the diameter of the inscribed circle of the rolling element. The structure of the rotation speed detecting device is not particularly limited. Therefore, the rotation speed detecting device is not limited to the magnetic detection type as shown in each of the examples shown in the drawings, but may be another type such as an eddy current type or a photoelectric type.

[0035]

Since the present invention is constructed and operates as described above, the assembling work is simple, and the assembling accuracy of the encoder is easily ensured. A rolling bearing unit with a speed detection device can be realized.

[Brief description of the drawings]

FIG. 1A shows a first example of an embodiment of the present invention,
-A sectional drawing.

FIG. 2 is a diagram viewed from the left side of FIG. 1;

FIG. 3 is an enlarged view of a portion B in FIG. 1;

FIG. 4 is an enlarged view of a portion C in FIG. 2;

FIG. 5 is a view similar to FIG. 3, showing a second example of the embodiment of the present invention;

FIG. 6 is a view similar to FIG. 4;

FIG. 7 is a sectional view showing a third example of the embodiment of the present invention.

FIG. 8 is a sectional view showing the fourth example.

FIG. 9 is a sectional view showing an example of a conventional structure.

[Explanation of symbols]

 1, 1a, 1b Outer ring 2, 2a, 2b, 2c Hub 3, 3a, 3b, 3c Inner ring 4, 4a, 4b Encoder 5, 5a Sensor 6, 6a Outer ring track 7, 7a, 7b Inner ring assembly 8, 8a Inner ring track 9, 9a Rolling element 10, 10a Cage 11, 11a Flange 12, 12a Mounting portion 13, 13a, 13b Seal ring 14, 14a Mounting hole 15 Cylindrical space 16 Small diameter step 17 Spline hole 18 Mounting recess 19 Through hole 20 Micro Clearance 21 Mounting surface 22 Chamfered portion 23 Mounting portion 24 Screw 25 O-ring 26 Stud 27 Supporting cylinder 28 Encoder body 29, 29a Male spline 30, 30a Female spline 31, 31a Small diameter portion 32, 32a Cylindrical portion 33, 33a Caulking portion 34 Ball Groove 35 Lock groove 36 Cover 37 Flange

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01D 5/245 G01D 5/245 X

Claims (2)

[Claims] 1. An outer ring having a double row of outer ring raceways on an inner peripheral surface and not rotating during use, a first inner ring having a first inner raceway on an outer peripheral surface and a second inner race having a second inner raceway on an outer peripheral surface. An inner ring assembly formed by combining inner rings and rotating at the time of use, and a plurality of rolling members provided for each row between each of the outer ring raceways and the first and second inner raceways so as to freely roll. A moving body, and a portion to be detected in which characteristics in the circumferential direction are alternately and equally changed, and a portion interposed between the double rows of inner ring raceways on the outer peripheral surface of the axially intermediate portion of the inner ring assembly. Having an encoder fixed concentrically with the inner ring assembly, and a detection unit,
The detection portion is supported in a mounting hole provided at an axially intermediate portion of the outer ring in a state where the detection portion faces a part of an outer peripheral surface of the detected portion of the encoder, and corresponds to a change in characteristics of the detected portion. In a rolling bearing unit with a rotation speed detection device having a sensor that changes the output signal, the outer diameter of the encoder is the diameter of the inscribed circle of the rolling element provided in plurality for each row. A rolling bearing unit with a rotation speed detecting device, characterized in that at least the diameter of an inscribed circle of a row of rolling elements in which the encoder passes inside at the time of the assembling operation is smaller than the diameter. 2. An outer ring having a double-row outer ring raceway on an inner peripheral surface and not rotating even during use, a first inner ring having a first inner raceway on an outer peripheral surface and a second inner race having a second inner raceway on an outer peripheral surface. An inner ring assembly formed by combining inner rings and rotating at the time of use, and a plurality of rolling members provided for each row between each of the outer ring raceways and the first and second inner raceways so as to freely roll. A moving body, and a portion to be detected in which characteristics in the circumferential direction are alternately and equally changed, and a portion interposed between the double rows of inner ring raceways on the outer peripheral surface of the axially intermediate portion of the inner ring assembly. Having an encoder fixed concentrically with the inner ring assembly, and a detection unit,
The detection portion is supported in a mounting hole provided at an axially intermediate portion of the outer ring in a state where the detection portion faces a part of an outer peripheral surface of the detected portion of the encoder, and corresponds to a change in characteristics of the detected portion. A sensor for changing an output signal, wherein the outer diameter of the encoder is the diameter of an inscribed circle of a plurality of rolling elements provided for each of the rows, and the encoder passes at least during the assembling work at least during the assembling operation. A method for assembling a rolling bearing unit with a rotation speed detecting device having a diameter equal to or less than the diameter of an inscribed circle of a rolling element in a row, wherein the rolling element is provided on the inner diameter side of at least one outer ring track of the double row outer ring tracks. While mounting a plurality, after externally fixing the encoder to the axially intermediate portion of the first inner ring, the first inner ring on the inner diameter side of the outer ring,
Inserting from the side of the outer raceway on which the rolling elements are mounted, passing the encoder through the inner diameter sides of the plurality of rolling elements,
A method of assembling a rolling bearing unit with a rotation speed detecting device.