JP2003035718A - Roller bearing unit with encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller bearing unit by which an operation to externally fit and fix an encoder 19d to a shoulder part 35 at an inner ring 6 by a close fitting operation can be performed while the central axis of the encoder 19d is made to agree with that of the inner ring 6. SOLUTION: A support ring 20c constituting the encoder 19d comprises a first cylinder part 44 and a second cylinder part 45. The part 44 from among them is externally fitted and fixed to a shoulder part 35. When its external fitting and fixing operation is performed, the part 45 is fitted to a circular recess 43 at a press fitting tool 42 so as to be without backlash. In a state that the central axis of the tool 42 is made to agree with that of the inner ring 6, the tool 42 is pressed to the inner ring 6, and the part 44 is externally fitted and fixed to the shoulder part 35. Since the central axis of the tool 42 is made to surely agree with that of the support ring 20c, the part 44 can be externally fitted and fixed to the shoulder part 35.

Description

Detailed Description of the Invention

[0001]

A rolling bearing unit with an encoder according to the present invention rotatably supports a vehicle wheel with respect to a suspension device, and detects the rotational speed of the wheel in combination with a sensor for detecting the rotational speed. Use to do. A rolling bearing unit with a rotation speed detecting device can be obtained by combining a rolling bearing unit with an encoder and a rotation speed detecting sensor installed in a stationary portion such as a cover coupled to the outer ring.

[0002]

Rolling bearing units are used to rotatably support the wheels of an automobile relative to a suspension system.
Further, in order to control the antilock brake system (ABS) and the traction control system (TCS), it is necessary to detect the rotation speed of the wheels. For this reason, a rolling bearing unit with a rotation speed detecting device in which a rotation speed detecting device is incorporated in the above rolling bearing unit,
In recent years, it has become widespread to rotatably support the wheel with respect to a suspension device and detect the rotational speed of the wheel.

A rolling bearing unit with a rotation speed detecting device used for such a purpose is disclosed in Japanese Patent Laid-Open No. 11-2359.
No. 6, gazette discloses a structure as shown in FIGS.
The structure shown in FIG. 13 is described in JP-A-332723. First, the rolling bearing unit 1 with a rotation speed detecting device of the first example of the conventional structure shown in FIG.
Includes a rolling bearing unit 2 and a rotation speed detecting device 3 incorporated therein. The rolling bearing unit 2 among them has a hub 5 and an inner ring 6 rotatably supported on the inner diameter side of the outer ring 4. The outer end of the hub 5 (outer in the axial direction means the outer side in the width direction when assembled to a vehicle, and is the left side in each of the drawings except FIGS. 2, 7, and 9. Except for the right side of each drawing, the widthwise center side when assembled to a vehicle is referred to as the inside. The same applies throughout the present specification.) A first flange 7 for mounting a wheel is provided on the outer peripheral surface of the intermediate portion. First inner ring raceways 8 are provided on the outer peripheral surfaces, respectively. The first inner ring raceway 8 may be provided integrally with the hub, or may be provided on the outer peripheral surface of the inner ring that is separate from the hub.

Further, the inner ring 6 has a second inner ring raceway 9 on its outer peripheral surface, is formed in a portion near the inner end of the hub 5, and is outside the portion where the first inner ring raceway 8 is provided. It is externally fitted to the stepped portion 10 having a reduced diameter. A first outer ring raceway 11 facing the first inner ring raceway 8 and a second outer ring raceway 12 facing the second inner ring raceway 9 are provided on the inner circumferential surface of the outer ring 4, and the outer circumferential surface is provided with the second outer ring raceway 12 facing the second inner ring raceway 9. Second flanges 13 for supporting the outer ring 4 on the suspension device are respectively formed. A plurality of rolling elements 14 and 14 are provided between the first and second inner ring raceways 8 and 9 and the first and second outer ring raceways 11 and 12, respectively. The hub 5 and the inner ring 6 are rotatably supported on the side.
In the state where the inner ring 6 is fitted onto the step portion 10, a nut 15 is screwed into a male screw portion formed on the inner end portion of the hub 5 to hold down the inner ring 6 and the inner ring 6 and the inner ring 6 together. Hub 5
We are trying to prevent separation from the.

Further, an inner end (right end in FIG. 11) opening of the outer ring 4 is closed by a cover 16. This cover 16
Is a bottomed cylindrical main body 17 formed by injection molding a synthetic resin.
And a fitting cylinder 18 connected to the opening of the main body 17. The fitting cylinder 18 is joined to the opening of the main body 17 by molding the base end portion of the main body 17 during injection molding. The cover 16 configured in this way is
The front half portion (left half portion in FIG. 11) of the fitting cylinder 18 is externally fitted and fixed to the inner end portion of the outer ring 4 by interference fitting, thereby closing the inner end opening portion of the outer ring 4.

On the other hand, in order to configure the rotational speed detecting device, an encoder is provided on the outer peripheral surface of the inner end portion of the inner ring 6 fitted and fixed to the inner end portion of the hub 5 at a portion deviated from the second inner ring raceway 9. 19 is externally fitted and fixed. This encoder 19
Is composed of a support ring 20 and a permanent magnet 21. The supporting ring 20 is formed by bending a magnetic metal plate such as a carbon steel plate such as SPCC into an annular shape with an L-shaped cross section, and is fixed to the inner end of the inner ring 6 by interference fitting. ing. Further, the permanent magnet 21 is formed by, for example, attaching rubber mixed with ferrite powder to the inner side surface of the ring portion forming the support ring 20 by baking or the like. The permanent magnets 21 are magnetized, for example, in the axial direction (left-right direction in FIG. 11), and the magnetizing directions are changed alternately and at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals in the circumferential direction on the inner surface of the encoder 19, which is the detected portion.

Further, an insertion hole 22 is formed in a part of the main body 17 forming the cover 16 facing the inner surface of the permanent magnet 21 forming the encoder 19.
Is formed in the axial direction of the outer ring 1 in a state of penetrating. Then, a sensor 23 (including a sensor unit in which a detection element and the like are embedded in a synthetic resin. The same applies throughout the present specification) is inserted into the insertion hole 22. This sensor 23 is a Hall element or a magnetoresistive element (MR element).
A magnetic detection element for changing the output according to the flow direction of the magnetic flux and an IC incorporating a waveform shaping circuit for adjusting the output waveform of the magnetic detection element and the permanent magnet 21 (or the permanent magnet 21). A magnetic pole piece or the like for guiding a magnetic flux flowing into the magnetic detection element into a synthetic resin.

Such a sensor 23 is provided at a portion near the tip (the left end in FIG. 11), and has a cylindrical insertion portion 24 which can be inserted into the insertion hole 22 without rattling, and a base end of the insertion portion 24. And a flange portion 25 having an outward flange shape, which is formed on the portion (the right end portion in FIG. 11). A locking groove is formed on the outer peripheral surface of the intermediate portion of the insertion portion 24, and the O-ring 2 is formed in the locking groove.
6 is locked.

On the other hand, at a part of the outer surface of the cover 16 (the side surface opposite to the space 27 in which the rolling elements 14, 14 are to be closed, which is the right side surface in FIG. 11 to be closed), the insertion hole 22 is formed. A locking cylinder 28 is provided around the opening. In the sensor 23, the insertion portion 24 is inserted into the locking cylinder 28, the collar 25 is abutted against the tip end surface of the locking cylinder 28, and the locking spring 29 causes the locking cylinder 28 to move. 28, and is supported. Incidentally, regarding such a coupling and supporting structure by the locking spring 29, the above-mentioned Japanese Patent Laid-Open No. 11-2359 is used.
It is described in detail in Japanese Patent Publication No. 6 and is not related to the gist of the present invention, so detailed illustration and description thereof will be omitted.

When the rolling bearing unit with the rotational speed detecting device as described above is used, the second flange 13 fixedly mounted on the outer peripheral surface of the outer ring 4 is coupled and fixed to the suspension device by a bolt (not shown). By fixing the wheel to the first flange 7 fixed to the outer peripheral surface of the hub 5 by the stud 30 provided on the first flange 7, the wheel is rotatably supported with respect to the suspension device. . When the wheel rotates in this state, the vicinity of the end face of the detecting portion of the sensor 23 is brought into contact with the north pole and the south pole existing on the inner side surface of the permanent magnet 21.
The poles alternate with each other. As a result, the direction of the magnetic flux flowing in the sensor 23 changes, and the output of the sensor 23 changes. The frequency at which the output of the sensor 23 changes in this manner is proportional to the rotational speed of the wheel. Therefore, if the output of the sensor 23 is sent to a controller (not shown), ABS and T
The CS can be controlled appropriately.

Further, the above-mentioned Japanese Patent Laid-Open No. 11-23 shown in FIG.
In the case of the second example of the conventional structure described in Japanese Patent Publication No. 596, the cylindrical portion 31 is formed at the inner end portion of the hub 5a, and the end portion of the cylindrical portion 31 projects from the inner end surface of the inner ring 6a. The caulking portion 34 is formed by expanding the caulking outward in the diametrical direction, and the caulking portion 34 joins and fixes the inner ring 6a to the hub 5a. If such a structure is adopted, the number of parts is reduced and the assembly is reduced as compared with the structure in which the inner ring 6 is coupled and fixed to the hub 5 by the nut 15 as in the first example of the conventional structure shown in FIG. The cost can be reduced by reducing the time and effort. In the case of the second example of the conventional structure shown in FIG. 12, the structure of the portion in which the sensor 23a is coupled and supported by the locking spring 29a to the locking cylinder 28 provided in the main body 17 of the cover 16 is the above-described first structure. Different from the example.
However, the coupling support structure by such a locking spring 29a is also
It is described in detail in JP-A-11-23596, and since it is not related to the gist of the present invention, detailed illustration and description thereof will be omitted.

Further, in the case of the structure of the second example, the encoder 19a also differs from the case of the first example described above.
That is, the encoder 19a of this example has a cross-sectional shape formed by bending a magnetic metal plate such as a mild steel plate to form the circular ring portion 3
It has an L-shape having 2 and is formed into an annular shape as a whole. Then, a plurality of through holes 33 are radially formed in the circular ring portion 32, and the magnetic characteristics of the circular ring portion 32 are changed alternately and at equal intervals in the circumferential direction. In accordance with this, the internal structure of the sensor 23a is also different from that of the first example described above. Further, in the case of the structure of the second example, the small diameter step portion 36 is formed in the inner half portion of the shoulder portion 35 provided at the inner end portion of the inner ring 6a, and the small diameter step portion 36 is formed inside the encoder 19a. The cylindrical portion 37 formed on the peripheral edge is
It is fitted by an interference fit. By adopting such a structure, the width dimension of the circular ring portion 32 in the radial direction is secured, and the output of the sensor 23a facing the inner side surface of the circular ring portion 32 can be secured.

Further, in the case of the third example of the conventional structure shown in FIG. 13, the encoder 19b externally fitted and fixed to the inner end portion of the inner ring 6a has a magnetic metal plate as in the case of the first example. The support ring 20a and the permanent magnet 21 are combined. The support ring 20a has a T-shaped cross section and is formed in an annular shape as a whole, and includes a fitting tubular portion 38 and an annular portion 39. The permanent magnet 21 is attached to the inner surface of the circular ring portion 39. Encoder 1 like this
9b is obtained by fitting the fitting tubular portion 38 onto the outer peripheral surface of the shoulder portion 35 provided at the inner end portion of the inner ring 6a by interference fitting.
It is supported and fixed to the inner end portion of the inner ring 6a. In this state, the permanent magnet 21 has a portion near the inner circumference of the shoulder portion 35.
Is inserted into the small-diameter stepped portion 36 provided in the inner half.

On the other hand, a bottomed cylindrical cover 16a made of a metal plate such as a steel plate or a stainless steel plate is fitted and fixed to the inner end of the outer ring 4 to close the inner end opening of the outer ring 4. I'm out. The sensor 23b is embedded and fixed in the synthetic resin 40 inside the cover 16a. In this state, the sensor 23b faces a part of the permanent magnet 21 in the circumferential direction with a minute gap therebetween. Also in the case of the rolling bearing unit with the rotation speed detecting device of the present embodiment configured as described above, the width dimension in the diameter direction of the permanent magnet 21 configuring the encoder 19b is increased so that the permanent magnet 21 extends in the circumferential direction. It is possible to increase the change in magnetic characteristics and improve the accuracy of rotation speed detection by the rotation speed detection device.

The second to third conventional structures shown in FIGS.
In the case of the example, the cost can be reduced by reducing the number of parts and labor for assembling, but it is still desired to improve the following points. That is, the encoder 19 is a rolling bearing unit for a relatively large automobile such as an ordinary passenger car.
If the installation space of a (or 19b) can be sufficiently secured, there will be no particular problem. However, in the case of a rolling bearing unit to be mounted on a small vehicle such as a light vehicle, it becomes difficult to secure the installation space. . Then, the caulking portion 34 and the sensor 23a formed on the inner end portion of the hub 5a
(Or 23b) easily interferes. Then, in the case of interference, the detection unit of the sensor 23a (or 23b) and the detected unit of the encoder 19a (or 19b) cannot be brought close to each other. In order to ensure the reliability of the rotation speed detection, the distance between the detection part of the sensor 23a (or 23) and the detected part of the encoder 19a (or 19b) needs to be about 0.1 to 2.0 mm. However, as described above, it is not preferable that the distance between the detection section and the detected section cannot be shortened due to the interference between the caulking section 34 and the sensor 23a (or 23b).

[0016]

In view of the above-mentioned circumstances, Japanese Patent Application No. 2000-3821 discloses a structure capable of preventing the interference between the caulking portion and the sensor while ensuring the dimension of the detected portion in the diameter direction.
There is a structure disclosed in No. In the structure according to this prior invention, as shown in FIG. 14, the shoulder portion 35 of the inner ring 6 supports an encoder 19c including a support ring 20b made of a magnetic metal plate and a permanent magnet 21. Such an encoder 19c
Is supported and fixed to the inner end portion of the inner ring 6 by fitting the base end portion (outer end portion) of the cylindrical portion 37a of the support ring 20b onto the shoulder portion 35 of the inner ring 6 by interference fitting. There is. Then, the circular ring portion 32a of the support ring 20b and the permanent magnet 21 are positioned axially inward (rightward in the drawing) of the crimp portion 34, and the circular ring portion 32a and the crimp portion 3 are located.
It is separated from 4. Therefore, in this state, the inner peripheral edges of the circular ring portion 32a and the permanent magnet 21 are fixed to the caulked portion 34.
Located diametrically inward of the outer peripheral edge of.

Further, as described above, the encoder 19c is attached to the inner ring 6
The inner side surface of the permanent magnet 21 is positioned more inward than the inner end surface of the caulked portion 34 while being externally fitted and fixed to the shoulder portion 35. Then, the detecting portion provided on the tip end surface of the sensor 23 is opposed to the inner surface of the permanent magnet 21 via a minute gap 41. The thickness of the minute gap 41 is 0.1 to 2.0 mm (generally 0.5 to 1.0 m as described above).
m).

As described above, in the case of the rolling bearing unit with the rotational speed detecting device according to the previous invention, the inner surface of the permanent magnet 21, which is the circular ring-shaped detected portion constituting the encoder 19c, is the crimped portion. It projects more axially inward than 34. Therefore, even if the inner surface of the permanent magnet 21 and the detection portion of the sensor 23 are brought close to each other, the sensor 23 and the caulking portion 34 do not interfere with each other. Therefore, it is possible to shorten the distance between the detecting portion of the sensor 23 and the inner surface of the permanent magnet 21 to ensure the reliability of the rotation speed detection.

[0019]

In the case of the structure according to the prior invention as described above, the encoder 19c is manufactured by an industrial method.
When the base end portion of the cylindrical portion 37a of the support ring 20b constituting the above is externally fitted and fixed to the shoulder portion 35 of the inner ring 6, there is a possibility that the central axis of the inner ring 6 and the central axis of the encoder 19c do not match. is there. The reason for this will be described with reference to FIG.

The base end of the cylindrical portion 37a is connected to the shoulder portion 35.
In order to fit and fix the encoder 19c to the outside, the press-fitting jig 42 and the inner ring 6 are held in a state where the encoder 19c is fitted and held in a circular recess 43 provided in a pot-like press-fitting jig 42 such as a thick petri dish. Position and concentrically. Then, in this state, the press-fitting jig 42 is pressed against the inner ring 6. As a result, while the diameter of the cylindrical portion 37a is elastically expanded, the cylindrical portion 37a is externally fitted and fixed to the shoulder portion 35 by interference fitting.

A circular ring portion 32a provided on the support ring 20b and a caulking portion 34 provided on the inner end portion of the hub 5a (see FIG. 14).
In order to separate the outer ring and the inner ring 6 from each other, the outer fitting and fixing work must be completed with the outer surface of the circular ring portion 32a and the inner end surface of the inner ring 6 kept separated from each other. In order to make the center axis of the inner ring 6 and the center axis of the encoder 19c coincide with each other by the outer fitting fixing work that ends in such a state, the center axis of the inner ring 6 and the center axis of the press-fitting jig 42. In addition to matching the above, it is necessary to match the central axis of the press-fitting jig 42 with the central axis of the support ring 20b.
Of these, making the center axis of the inner ring 6 and the center axis of the press-fitting jig 42 coincide with each other is a setting problem of the press-fitting device, and can be easily and surely performed. On the other hand, the center axis of the press-fitting jig 42 and the center axis of the support ring 20b are likely to be inconsistent.

In any case, in the case of the structure according to the above-mentioned invention, the support ring 2 is provided on the outer peripheral edge of the encoder 19c.
0b is only the folded portion of the metal plate and the outer peripheral edge of the permanent magnet 21. Not only the width dimension in the axial direction of the outer peripheral edges of the folded-back portion and the permanent magnet 21 is small, but also the folded-back portion and the permanent magnet 21.
It does not mean that the outer diameters of the outer peripheral edges of the two do not match each other. Therefore, unless the inner surface of the permanent magnet 21 is brought into contact with the inner surface of the circular recess 43 of the press-fitting jig 42 over the entire circumference, the center axis of the press-fitting jig 42 and the center of the support ring 20b. It tends to be inconsistent with the axis. The inner surface of the permanent magnet 21 and the inner surface of the circular recess 43 are in contact with each other over the entire circumference unless the press-fitting jig 42 is left below the encoder 19c. It is hard to stay in contact. However, the press-fitting jig 42 is connected to the encoder 19
It is not preferable to perform the press-fitting work while keeping it located under the c from the viewpoint of ensuring smooth assembly workability. By the magnetic force of the permanent magnet 21 magnetized in advance, the inner surface of the circular recess 43 of the press-fitting jig 42 made of a magnetic material and the circular ring portion 32a of the support ring 20b are circulated over the entire circumference via the permanent magnet 21. It is also possible to carry out the press-fitting work while abutting and keeping the central axes aligned. However, such a method is not always a reliable method because the central axes are likely to be inconsistent with each other when an external force is applied.

For the reasons described above, the central axis of the press-fitting jig 42 and the central axis of the support ring 20b are likely to be inconsistent with each other. When the jig 42 is pressed against the inner ring 6 and the base end portion of the cylindrical portion 37a is externally fitted and fixed to the shoulder portion 35, the encoder 19c is externally fitted and fixed to the inner ring 6 in a tilted state. In such a state, accurate rotation speed detection cannot be performed. In a further significant case, the tip edge of the cylindrical portion 37a may scrape the outer peripheral surface of the shoulder portion 35 to cause rattling in the fitting portion, or the encoder 19c may be damaged during the fitting operation. is there. Problems like this
The external fitting and fixing work is completed with the outer surface of the circular ring portion 32a and the inner end surface of the inner ring 6 being separated from each other, which is remarkable in the structure according to the previous invention. It may occur even when the inner end surface of 6 is brought into contact.
In view of such circumstances, the rolling bearing unit with an encoder of the present invention has been devised to realize a structure in which the central axis of the encoder and the central axis of the press-fitting jig can be easily and surely aligned with each other.

[0024]

A rolling bearing unit with an encoder according to the present invention includes a rolling bearing unit and an encoder, similar to the previously known rolling bearing unit with an encoder. The rolling bearing unit is provided with a first flange for mounting a wheel on the outer peripheral surface of the outer end portion and a first inner ring raceway on the outer peripheral surface of the intermediate portion in the axial direction, either directly or through a separate inner ring. With a hub
A second inner ring raceway is formed on the outer peripheral surface, and the inner ring is externally fitted to a step portion provided on the inner end portion of the hub and having an outer diameter smaller than that of the portion provided with the first inner ring raceway. And a second outer ring raceway facing the first inner ring raceway on the inner circumferential surface and a second outer ring raceway facing the second inner ring raceway on the outer circumferential surface for supporting the suspension device on the second side. An outer ring having flanges formed thereon, and a plurality of rolling elements provided between the first and second inner ring raceways and the first and second outer ring raceways are provided so as to be rollable. Further, the encoder has a circular ring-shaped detected portion in which the magnetic characteristics of the inner surface are alternately changed in the circumferential direction, and a portion deviated from the second inner ring raceway on the inner end outer peripheral surface of the inner ring. In addition, it is fixed concentrically with this inner ring.

Particularly, in the rolling bearing unit with an encoder according to the present invention, the encoder is provided with a first cylindrical portion which is provided at an outer end portion and is externally fitted and fixed to the inner end portion of the inner ring by an interference fit. , A second cylindrical portion provided concentrically with the first cylindrical portion at the inner end portion, and a continuous portion that connects the inner end edge of the first cylindrical portion and the outer end edge of the second cylindrical portion to each other. And a circular ring portion bent at a right angle to the second cylindrical portion on the same side as the continuous portion in the radial direction from the inner end edge of the second cylindrical portion. The detected portion is provided on the inner side surface of the circular ring portion.

[0026]

The rolling bearing unit with an encoder of the present invention configured as described above uses the second cylindrical portion,
The center axis of the encoder and the center axis of the press fitting jig can be aligned. That is, by fitting the second cylindrical portion having a sufficiently large axial dimension as compared with the conventional structure with the cylindrical surface portion provided on the press-fitting jig, the center axis of the press-fitting jig and the encoder The central axis can be matched. Therefore, by pressing the press-fitting jig against the inner ring in a state where the center axis of the press-fitting jig and the center axis of the inner ring are aligned with each other, the encoder can be attached to the inner ring and the center axis of the inner ring and the encoder. It can be fitted and fixed in a state where they are matched.

[0027]

1 to 3 show a first example of an embodiment of the present invention. The feature of the present invention is that the shape of the support ring 20c constituting the encoder 19d is devised so that the center axis of the encoder 19d and the center axis of the inner ring 6 are aligned with respect to the inner ring 6. The point is that it can be fitted and fixed in the closed state. Since the configuration and operation of the other parts are the same as the structure according to the previous invention shown in FIG. 14 described above, the same reference numerals are given to the same parts, and the overlapping description will be omitted or simplified. The characteristic part of the invention will be mainly described.

The encoder 19d includes the support ring 20.
c and a ring-shaped permanent magnet 21 are combined. Of these, the support ring 20c has an annular shape as a whole, and includes first and second cylindrical portions 44 and 45, a continuous portion 46, and an annular portion 47. Of these, the first cylindrical portion 44 is provided at the outer end portion, and in the assembled state, is externally fitted and fixed to the shoulder portion 35 provided at the inner end portion of the inner ring 6 by interference fitting. Further, the second cylindrical portion 45 has an inner end portion with the first cylindrical portion 44.
And the diameter is larger than that of the first cylindrical portion 44 in this example. In addition, the continuous portion 46
Is the inner end edge of the first cylindrical portion 44 and the second cylindrical portion 4
5 is continuous with the outer edge, and in the case of this example, it is formed in a partially conical tube shape. Further, the circular ring portion 47 is
The second cylindrical portion 45 is bent at a right angle from the inner end edge of the second cylindrical portion 45 to the same side as the continuous portion 46 in the radial direction, in the present example, the inner diameter side.

The support ring 20c is integrally formed by bending and forming a magnetic metal plate such as a carbon steel plate or a stainless steel plate in the process as shown in FIG. That is, first, by punching a metal plate as a material,
A circular blank 48 as shown in FIG. Next, drawing processing is applied to the base plate 48 to form a petri dish-shaped first intermediate material 49 as shown in FIG. The cylindrical portion formed on the outer peripheral edge of the first intermediate material 49 becomes the second cylindrical portion 45. Then, the first intermediate material 49 is subjected to the first-stage curl processing, and the second intermediate material 50 as shown in FIG. 7C is subjected to the second-stage processing to obtain the second intermediate material 50. The third intermediate material 51 as shown is used.
The cylindrical portion existing in the opening of the third intermediate material 51 becomes the first cylindrical portion 44. Finally, the center portion of the bottom of the third intermediate material 51 is punched out to form the circular ring portion 47, and the support ring 20 as shown in FIG.
Completed as c. The punching process of the central portion of the bottom part can be performed immediately after forming the first intermediate material 49 or the second intermediate material 50, and at the same time as the punching process of the blank 48. The encoder 19d is attached to the inner side surface of the circular ring portion 47 of the support ring 20c thus manufactured concentrically with the circular ring portion 47,
The inner side surface of is the detected portion in which the S poles and the N poles are alternately arranged.

The rolling bearing unit with an encoder of the present invention constructed by incorporating the support ring 20c as described above uses the second cylindrical portion 45, so that the central axis of the encoder 19d and the press-fitting jig 42 are connected. The central axis can be matched. That is, the second cylindrical portion 45 having a sufficiently large axial dimension as compared with the conventional structure is fitted into the circular concave portion 43 provided in the press-fitting jig 42, so that the central axis of the press-fitting jig 42. And the central axis of the encoder 19d can be matched. In this case, it is necessary to make the outer diameter of the second cylindrical portion 45 and the inner diameter of the circular recess 43 substantially equal to each other, but it is easy to make these both dimensions equal to each other.

In this way, if the second cylindrical portion 45 having an outer diameter that substantially matches the inner diameter of the circular recess 43 is fitted into the circular recess 43 without rattling, as shown in FIG. The center axis of the encoder 19d and the center axis of the press-fitting jig 42 automatically coincide with each other. As long as the second cylindrical portion 45 does not come out of the circular recess 43, the central axis of the encoder 19d and the central axis of the press-fitting jig 42 are kept in the same state regardless of external force such as gravity. To be done. Therefore, by pressing the press-fitting jig 42 against the inner ring 6 in a state where the central axis of the press-fitting jig 42 and the central axis of the inner ring 6 are aligned with each other, the shoulder provided on the inner end portion of the inner ring 6 is pressed. The first cylindrical portion 44 of the support ring 20c constituting the encoder 19d can be externally fitted and fixed to the portion 35 with the central axis of the encoder 19d and the central axis of the inner ring 6 aligned. Moreover, the tip edge of the first cylindrical portion 44 does not bite the outer peripheral surface of the shoulder portion 35 due to the external fitting and fixing work. Further, as described above, it is possible to prevent the central axes from becoming inconsistent even when an external force is applied, as compared with the case where the central axes are made to coincide with each other by utilizing the magnetic force of the permanent magnet 21. At times, the function of preventing the inclination of the encoder 19d becomes reliable.

Next, FIGS. 4 to 5 show a second example of the embodiment of the present invention. In the case of this example, the encoder 19
The first and second cylindrical portions 44 constituting the support ring 20d of FIG.
The magnitude relationship between the diameters of a and 45a is opposite to that in the case of the first example described above. That is, in the case of this example, the inner end edge of the relatively large-diameter first cylindrical portion 44a and the outer end edge of the relatively small-diameter second cylindrical portion 45a are connected to each other by a partially conical cylindrical continuous portion 46.
It is made continuous by a. A circular ring portion 47a for installing the permanent magnet 21 is formed by bending at a right angle radially outward from the inner end edge of the second cylindrical portion 45a.

The support ring 20 of the encoder 19e as described above.
When the first cylindrical portion 44a of d is externally fitted and fixed to the shoulder portion 35 of the inner ring 6, a press-fitting jig 42a having a circular convex portion 52 in the central portion of the outer surface as shown in FIG. 5 is used. . Then, in a state where the second cylindrical portion 45a is fitted onto the circular convex portion 52 without rattling, the central axis of the press-fitting jig 42a and the central axis of the inner ring 6 are made to coincide with each other, The press-fitting jig 42a is pressed against the inner ring 6. As a result, the encoder 19e is externally fitted to and supported by the inner ring 6 with their central axes aligned with each other.

Next, FIGS. 6 to 7 show a third example of the embodiment of the present invention. Among the present examples, the basic shape of the support ring 20e that constitutes the encoder 19f, which is a feature of the present invention, is the same as in the case of the first example described above.
However, in the case of this example, the continuous portion 46b forming the support ring 20e is formed in a direction perpendicular to the first and second cylindrical portions 44, 45. Therefore, the continuous portion 46b and the circular ring portion 47 are parallel to each other.

Further, the structure of this embodiment is a portion not directly related to the invention described in the claims, but the outer ring 4
16b for closing the opening of the inner end of the cover and this cover 16b
The sensor 23c to be mounted on is different from the above-described first example and the above-described second example. First, the cover 16
In order to form b, the fitting cylinder 18a made of a metal plate inserted into the opening of the main body 17a made of synthetic resin is
It projects from the inner peripheral edge of the opening a. With such a structure and in order to make the inner diameter of the cover 16b as large as possible, the inner peripheral surface of the fitting cylinder 18a is exposed to the inner peripheral surface of the cover 16b over the entire axial length. A plurality of through holes are formed in the outward flange-like flange portion formed at the base end portion (inner end portion, right end portion in FIG. 6) of the fitting cylinder 18a so as to penetrate in the axial direction. The main body 17 is placed in the through hole.
By injecting the synthetic resin that constitutes a, the main body 17
The coupling strength between a and the fitting cylinder 18a is secured. With the cover 16b having such a configuration, the outer ring 4 is
In the state where the inner end opening of the outer ring 4 is closed, the fitting cylinder 18a is fitted into the inner end of the outer ring 4 by an interference fit, and the main body 17
The tip surface of a is abutted against the inner end surface of the outer ring 4. Then, this abutting portion is sealed with an O-ring.
In addition, the inner diameter side surface of the locking groove for mounting this O ring is
An outer peripheral surface of an intermediate portion of the fitting cylinder 18a is configured.

Further, since the insertion hole 22a formed in the cover 16b for mounting the sensor 23c is installed as radially outward as possible, the insertion hole 22a is formed by a part of the peripheral wall 53 constituting the cover 16b. The portion corresponding to (4) projects more radially outward than the other portions. However, since the opening side half (outer half) of the peripheral wall 53 is required to mold the base half of the fitting cylinder 18a and to form a locking groove for locking the O-ring, the inner half is required. It is thicker than the part and is formed in a simple cylindrical shape whose diameter does not change in the middle. Therefore, a step portion is formed at the end portion on the space 27 side of the opening portions at both ends of the insertion hole 22a at the peripheral wall 53 side portion. On the other hand, a peripheral step portion 54 is formed in a portion of the outer peripheral surface of the peripheral wall 53, which is separated from the insertion hole 22a. The peripheral step portion 54 is provided with the cover 16b so as to close the inner end opening of the outer ring 4 by the fitting cylinder 18.
It is used to abut the tip surface of the pressing jig when press-fitting a into the inner end of the outer ring 4. Since the peripheral step portion 54 is discontinuous in the insertion hole 22a portion, the pressing portion of the pressing jig has a hollow cylindrical shape in which the discontinuous portion is missing. Since this discontinuous portion is only a part in the circumferential direction, the existence of this discontinuous portion does not cause a problem in the press-fitting work.

The reason for installing the insertion hole 22a near the outer diameter of the cover 16b with such a structure is to increase the magnetic flux flowing through the sensor 23c (strongly) to improve the reliability of rotation speed detection. Is. That is, since the magnetized regions of the permanent magnets 21 constituting the encoder 19e are fan-shaped, the width dimension in the circumferential direction becomes wider toward the outer side in the radial direction. Then, the permanent magnet 21 which is the surface to be detected.
The intensity of the magnetic flux that emerges from the inner side surface of and reaches the sensor 23c increases as the width dimension increases and the magnetized area increases. From this point of view, in the case of this example, the insertion hole 2
2a is installed near the outer diameter of the cover 16b.

Particularly in the case of this example, the insertion portion 55 of the sensor 23c to be inserted into the insertion hole 22a has a cylindrical shape, and this insertion portion 55 serves as the detection portion of the sensor 23c. A rectangular IC 56 as shown is embedded.
Therefore, there is no choice but to have a structure in which the IC 56 does not exist at the radially outermost position of the sensor 23c. In order to improve the rotational speed detection performance, it is necessary to dispose the IC 56 and the inner surface of the permanent magnet 21 as radially outward as possible so that the opposing area between them is as large as possible. Therefore, by embedding the rectangular IC 56 in the cylindrical insertion portion 55, the IC 5 is inserted in the radial direction of the cover 16b.
In the case of the structure in which the insertion portion 55 existing even closer to the outer diameter than 6 is provided, the IC5 described above is used as in the structure of this example.
It is important to widen the facing area between 6 and the inner surface of the permanent magnet 21.

Further, in the case of this example, as the sensor 23c, one having a mounting flange 57 at the base end portion (right end portion, inner end portion in FIG. 6) of the insertion portion 55 is used. To assemble the sensor 23c to the cover 16b, the distal end portion (the lower end portion in FIG. 6) of the mounting flange 57 with the insertion portion 55 inserted into the insertion hole 22a.
Is connected to a screw hole 58 provided at the center of the cover 16b with a bolt 59. The watertightness between the outer peripheral surface of the insertion portion 55 and the inner peripheral surface of the insertion hole 22a is
It is held by an O-ring which is locked in a locking groove on the outer peripheral surface of the intermediate portion of the above, and the watertightness of the screw hole 58 is held by a blind plate 60 formed at the rear end of the screw hole 58.

Since the blind plate 60 forms the screw hole 58, when the nut piece 61 is inserted into the center of the main body 17a of the cover 16b, it is molded in the main body 17a together with the nut piece 61. That is, the hat-shaped blind plate 60 is butted against the opening of one end (the left end in FIG. 6) of the nut piece 61, and is joined and fixed by spot welding or the like. A large number of protrusions are formed on the outer peripheral surface of the nut piece 61, and the nut piece 61 is attached to the main body 17a.
The nut piece 61 is molded into the main body 1
With respect to 7a, it is arranged so as not to be displaced in either the rotational direction or the axial direction. When such a nut piece 61 is molded in the central portion of the main body 17a, a positioning protrusion protruding into the cavity of the injection molding die is inserted into the recess formed in the central portion of the blind plate 60, With the nut piece 61 positioned, the body 17a is injection molded.

A portion where synthetic resin does not exist is formed in a portion of the central portion of the main body 17a which is aligned with the screw hole 58 formed by the nut piece 61 by the amount of the positioning protrusion inserted into the concave portion. This part is the blind plate 60
Is blocked by. Therefore, foreign matter such as rainwater does not enter the cover 16b through the screw hole 58.
The nut piece 61 may be cylindrical with a bottom and the blind plate 60 may be omitted. Further, the positioning of the nut piece 61 during injection molding of the main body 17a is performed by opening the nut piece 61 from the inner end (right end in FIG. 6) opening.
It can be done only by another positioning protrusion inserted inside,
If the discontinuous portion of the synthetic resin is removed from the central portion of the main body 17a, the foreign matter can be prevented from entering more reliably. However, even in this case, in order to prevent the synthetic resin from entering the screw hole 58, it is necessary to provide the blind plate 60 or use the nut piece 61 having a bottomed cylindrical shape. .

In each of the illustrated embodiments described above, the encoder provided with the permanent magnet 21 constituting the detected portion is assembled, but the first embodiment of the embodiment described above is described. Regarding Examples 1 to 3, the detected portion of the encoder does not necessarily have to be a permanent magnet. For example, as shown in FIG. 12 described above, various conventionally known structures can be used, including a structure in which a large number of through holes 33 are radially formed in the circular ring portion 32 made of a magnetic material.

Next, FIG. 8 shows a fourth embodiment of the present invention.
An example is shown. This example and a fifth example described below are based on the assumption that the detected portion of the encoder is made of a permanent magnet made of a material softer than metal such as a rubber magnet or a plastic magnet. Then, the structure is configured to prevent the permanent magnets from being damaged when only the encoder is conveyed in the axially superposed state. The reason for paying such consideration is as follows.

From the encoder manufacturing factory to the encoder rolling bearing unit assembly factory, a large number of encoders are externally fitted to a holding cylinder such as a paper cylinder or the like in order to streamline the carrying work (collectively compact without bulky). It is fitted inside and conveyed in the state of being overlapped in the axial direction. In this case, in order to improve the efficiency of the work at the assembly factory of the rolling bearing unit with an encoder, all the encoders are oriented in the same direction and externally or internally fitted to the holding cylinder. That is, the trouble of the direction alignment during the assembling work, which occurs when the layers are alternately stacked, is eliminated. Therefore, the first shown in FIG.
In the case of the example structure, the support ring 2 that constitutes the encoder 19d
The edge of 0c is the permanent magnet 2 of the adjacent encoder 19d.
Hit one. As shown in FIG. 2, the end edges of the support ring 20c have fine and sharp irregularities due to burrs produced when the support ring 20c is cut by pressing. Therefore, the surface of the permanent magnet 21 may be damaged by vibration during transportation. Then, when it is markedly scratched, by the encoder 19d,
It becomes difficult to secure the reliability of rotation speed detection.

In consideration of such circumstances, the fourth example shown in FIG.
In the case of the example and a fifth example to be described later, when a plurality of encoders each including a support ring formed by bending a metal plate and a permanent magnet are combined in the same direction in the axial direction, The edge (cut edge) of the metal plate is prevented from coming into contact with the permanent magnet.

First, in the case of the fourth example shown in FIG. 8, the end portion of the first cylindrical portion 44 of the support ring 20f constituting the encoder 19g is bent radially outward by 90 to 180 degrees or. By folding back, a bent portion 62 or a folded portion is formed at the outer end portion of the first cylindrical portion 44. Such an encoder 19g should be transported from the encoder manufacturing factory to the rolling bearing unit assembly with encoder assembly factory.
As shown in FIG. 9, it is fitted onto the holding cylinder 63. In this case, all the encoders 19g and 19g are externally fitted to the holding cylinder 63 so that they are oriented in the same direction so as to be superposed in the axial direction in order to improve the efficiency of the work in the assembly factory of the rolling bearing unit with an encoder.

In this way, each of the encoders 19g, 19g
Encoders that are adjacent to each other with the
The axial end portions of 9g and 19g are connected to each other by the bent portion 62.
The outer surface and the inner surface of the permanent magnet 21 contact each other. The outer surface of the bent portion 62 is not a cut surface formed by press working but a smooth surface, and no sharp fine irregularities are present in this outer surface portion. Therefore, the inner surface of the permanent magnet 21 will not be damaged regardless of the vibration applied during transportation.
When the outer end portion of the first cylindrical portion 44 is folded back densely by 180 degrees, the outer end edge of this folded back portion is the permanent magnet 2
Hit one. Even in this case, since there are no sharp fine irregularities on the outer edge of the folded-back portion that damage the inner surface of the permanent magnet 21, damage to the permanent magnet 21 can be prevented. Further, in the case of this example, the dimensional accuracy of the encoder 19g is secured by covering the outer peripheral surface of the second cylindrical portion 45 and the inner peripheral edge of the circular ring portion 47, which constitute the support ring 20f, with the permanent magnet 21. At the same time, the cost of the mold is being reduced. That is, the encoder 19g having the required dimensional accuracy can be obtained without extremely increasing the dimensional accuracy of the support ring 20f and the mold. The configuration and operation of the other parts are the same as in the case of the first example shown in FIG.
A duplicate description will be omitted.

Next, in the case of the fifth example shown in FIG.
The end edge and the outer peripheral surface of the first cylindrical portion 44 of the support ring 20g forming the encoder 19h are covered with a soft material 64 such as rubber. Thus, since the edge of the first cylindrical portion 44 is covered with the soft material 64, the plurality of encoders 19h are axially moved so as to be transported from the encoder manufacturing factory to the encoder rolling bearing unit assembly factory. In the superposed state, the axial ends of the adjacent encoders 19h come into contact with each other between the soft material 64 and the inner side surface of the permanent magnet 21. Therefore, the inner surface of the permanent magnet 21 will not be damaged regardless of the vibration applied during transportation.

Although it is preferable to use rubber as the soft material 64, whether or not the permanent magnet 21 is made of a different material depends on when the permanent magnet 21 is magnetized. If this magnetizing work is performed before the encoder 19h is externally fitted to the inner ring 6, the soft material 64
As the material, a general rubber (which may be synthetic resin) containing no ferromagnetic powder such as ferrite is used. The reason for this is
By the magnetized permanent magnet 21 and the soft material 64,
This is to prevent the encoders 19h, which are overlapped in the axial direction and adjacent to each other, from becoming difficult to separate from each other, and to improve the efficiency of the assembly work of the rolling bearing unit with an encoder. Therefore,
In this case, the permanent magnet 21 and the soft material 64 are separately molded.

On the other hand, when the magnetizing work is performed after the encoder 19h is fitted on the inner ring 6,
As the soft material 64, a material containing ferromagnetic powder such as ferrite is used as in the permanent magnet 21. The reason is that the permanent magnet 21 and the soft material 64 are molded at the same time to improve the efficiency of the molding operation and reduce the cost. Since the magnetizing work is performed after the outer ring is fitted onto the inner ring 6, it is not difficult to separate the adjacent encoders 19h that are overlapped in the axial direction.

[0051]

Since the present invention is constructed and operates as described above, the encoder is fitted onto the inner ring by an industrial method with the center axis of the inner ring and the center axis of the encoder fitted. Can be fixed. Therefore, a rolling bearing unit with an encoder having stable performance can be realized at low cost. Further, like the structure of the previous invention, if the structure in which the detected portion of the encoder is installed more inward than the inner ring is adopted, the rolling bearing unit having a relatively small diameter is also excellent, as in the case of the above-mentioned invention. It is possible to assemble a rotation speed detection device having excellent detection performance. Therefore, it is possible to realize a compact rolling bearing unit with an encoder, which is incorporated in a small automobile such as a light automobile, and which has excellent handleability.

[Brief description of drawings]

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

2A to 2C are cross-sectional views showing an example of a method of manufacturing a support ring incorporated in the first example in the order of steps.

FIG. 3 is a partial cross-sectional view showing a state in which an encoder including the support ring is externally fitted and fixed to an inner ring.

FIG. 4 is a sectional view showing a second example of the embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a state in which an encoder is externally fitted and fixed to an inner ring in order to assemble the structure of the second example.

FIG. 6 is a sectional view showing a third example of the embodiment of the present invention.

FIG. 7 is a schematic view showing an installation state of an IC that constitutes a sensor incorporated in the third example, as viewed from the side of FIG.

FIG. 8 is a sectional view showing a fourth example of the embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a state in which encoders incorporated in the fourth example are superposed in the axial direction.

FIG. 10 is a sectional view showing a fifth example of the embodiment of the present invention.

FIG. 11 is a sectional view showing a first example of a conventional structure.

FIG. 12 is a partial cross-sectional view showing the second example.

FIG. 13 is a partial cross-sectional view showing the third example.

FIG. 14 is a sectional view showing an example of the structure of the prior invention.

FIG. 15 is a partial cross-sectional view showing a state in which the encoder is externally fitted and fixed to the inner ring in order to assemble the structure of the present invention.

[Explanation of symbols]

1 Rolling bearing unit with rotational speed detector 2 Rolling bearing unit 3 Rotational speed detector 4 outer ring 5, 5a hub 6,6a Inner ring 7 First flange 8 First inner ring raceway 9 Second inner ring raceway 10 steps 11 First outer ring raceway 12 Second outer ring raceway 13 Second flange 14 rolling elements 15 nuts 16, 16a, 16b cover 17, 17a body 18, 18a Fitting tube 19, 19a-19h encoder 20, 20a to 20g Support ring 21 Permanent magnet 22, 22a insertion hole 23, 23a-23c sensor 24 Insert 25 collar part 26 O-ring 27 spaces 28 Locking cylinder 29, 29a Locking spring 30 studs 31 Cylindrical part 32, 32a Circle part 33 through hole 34 Caulking part 35 shoulder 36 Small diameter step 37, 37a Cylindrical part 38 Fitting cylinder 39 Circle part 40 synthetic resin 41 minute gap 42, 42a Press-fitting jig 43 circular recess 44, 44a First cylindrical portion 45, 45a Second cylindrical portion 46, 46a, 46b Continuous part 47, 47a Circle part 48 blank 49 First Intermediate Material 50 Second Intermediate Material 51 Third Intermediate Material 52 circular protrusion 53 Perimeter wall 54 peripheral steps 55 Insert 56 IC 57 Mounting flange 58 screw holes 59 Volts 60 blind 61 nut pieces 62 Bent section 63 holding tube 64 Soft material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16C 41/00 F16C 41/00 (72) Inventor Katsuhashi Hashida 1-5-50 Kunmuma, Kugenuma, Fujisawa-shi, Kanagawa F-Term (reference) within NSK Ltd. 3D046 BB11 BB28 BB29 HH36 3J017 AA02 AA03 BA10 CA01 CA07 DA01 DB08 3J101 AA01 AA43 AA54 AA62 AA72 BA53 BA77 DA16 FA44 FA53 GA03

Claims (2)

[Claims] 1. A hub provided with a first flange for mounting a wheel on an outer peripheral surface of an outer end portion, and a hub provided with a first inner ring raceway on an outer peripheral surface of an axially intermediate portion directly or via a separate inner ring. , A second inner ring raceway is formed on the outer peripheral surface, and the second inner ring raceway is externally fitted to a step portion provided on the inner end portion of the hub and having an outer diameter smaller than that of the portion provided with the first inner ring raceway. The inner ring, the first outer ring raceway facing the first inner ring raceway on the inner circumferential surface, and the second outer ring raceway facing the second inner ring raceway on the outer circumferential surface for supporting the suspension device on the second side. Each of which has an outer ring formed with each of the flanges, and a plurality of rolling elements provided between the first and second inner ring raceways and the first and second outer ring raceways, respectively. Rolling bearing unit and the circular ring-shaped detected object in which the magnetic characteristics of the inner surface are alternately changed in the circumferential direction. A rolling bearing unit with an encoder, comprising: an encoder fixed concentrically with the inner ring at a portion of the outer peripheral surface of the inner end of the inner ring, which is out of the second inner ring raceway. Is a first cylindrical portion which is provided at the outer end portion and is externally fitted and fixed to the inner end portion of the inner ring by an interference fit, and a second cylindrical portion which is provided at the inner end portion concentrically with the first cylindrical portion. A cylindrical portion, a continuous portion that connects the inner end edge of these first cylindrical portion and the outer end edge of the second cylindrical portion,
On the same side as the continuous portion in the radial direction from the inner end edge of the second cylindrical portion, a circular ring portion bent at a right angle to the second cylindrical portion is provided, and the inner side surface of the circular ring portion has the above-mentioned shape. A rolling bearing unit with an encoder, which is provided with a detected part. 2. The inner ring is a caulking portion formed by caulking a cylindrical portion formed at a portion of the inner end portion of the hub projecting inwardly from the inner ring with respect to the hub and diametrically outwardly expanding. By being able to hold down the inner end face, it is fixedly connected to the hub, and the circular ring part that constitutes the encoder protrudes inward from the inner end face of the caulked part,
The rolling bearing unit with an encoder according to claim 1.