JP2001234928A - Rolling bearing unit with encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure eliminating the degradation of the performance of a rotating speed detector composed of an encoder 3a and a sensor unit even if the dimension of a rolling bearing unit about a diametrical direction is small. SOLUTION: The encoder 3a having a generally T-shaped cross section is externally fixed on an inner end portion of an inner wheel 7 composing a rotating wheel with a hub 2a. An inner diameter side portion of an encoder main body 34 composing the encoder 3a axially superimposes an outer diameter side portion of the inner wheel 7b. In this structure, the width dimension of the encoder main body 34 about a diametrical direction is ensured, thereby resolving the problem.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A rolling bearing unit with an encoder according to the present invention rotatably supports a wheel of a motor vehicle with respect to a suspension device, and is used for detecting a 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. 10 shows an example of a conventional structure of a rolling bearing unit with a rotation speed detecting device used for such a purpose, which is described in Japanese Utility Model Laid-Open No. 7-31539. This rolling bearing unit with a rotation speed detecting device rotatably supports a hub 2 which is a rotating wheel which rotates during use inside an outer ring 1 which is a stationary wheel which does not rotate during use. The rotation speed of the fixed encoder 3 can be detected by a sensor 4 supported on the outer ring 1. That is, on the inner peripheral surface of the outer ring 1 which is a stationary side peripheral surface, double rows of outer ring raceways 5 and 5 each of which is a back side combination, which are stationary side orbits, are provided. Also, on the outer peripheral surface of the hub 2 and the inner ring 7 which constitutes the rotating wheel together with the hub 2 in a state of being externally fitted to the hub 2 and fixedly connected to the hub 2 by a nut 6 as a rotating side peripheral surface. Is
Inner ring tracks 8, 8 each of which is a back side combination, each of which is a rotation side track, are provided. And each of these inner ring raceways 8,
A plurality of rolling elements 9 and 9 are provided between the outer ring raceways 5 and 5 so as to roll freely while being held by retainers 10 and 10, respectively, and the hub is provided inside the outer ring 1. 2 and the inner ring 7 are rotatably supported.

A portion of the hub 2 that protrudes in the axial direction from the outer end of the outer race 1 at the outer end (the end that is outward in the width direction when assembled to an automobile and is the right end in FIG. 10). Is provided with a flange 11 for attaching a wheel.
Also, the inner end of the outer race 1 (the end that is located at the center in the width direction when assembled to an automobile, and the left end in FIG. 10) is
A mounting portion 12 for mounting the outer ring 1 to a suspension device is provided. A gap between the outer end opening of the outer race 1 and the outer peripheral surface of the intermediate portion of the hub 2 is closed by a seal ring 13. 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.

In order to incorporate the rotational speed detecting device into the rolling bearing unit as described above, the encoder 3 is provided on the outer peripheral surface of a portion of the end of the inner ring 7 which deviates from the inner ring raceway 8.
Is externally fixed. The encoder 3 is formed by subjecting a magnetic metal plate such as a mild steel plate to plastic working to form an entire ring having an L-shaped cross section, and includes a cylindrical portion 15 and a circular ring portion 16 as a detected portion. Prepare. The encoder 3 is fixed to the inner end of the inner ring 7 by tightly fitting the cylindrical portion 15 out of the inner ring 7 to the end of the inner ring 7.
The annular portion 16 is formed by forming a large number of slit-shaped through holes 17, 17 which are long in the diameter direction of the annular portion 16, radially at equal intervals in the circumferential direction. The magnetic characteristics of the circular ring portion 16 are changed alternately at regular intervals in the circumferential direction.

Further, a cover 18 is fitted and fixed to the inner end opening of the outer ring 1 in a state of facing the inner side surface of the circular ring portion 16 of the encoder 3. The cover 18, which is formed by plastically processing a metal plate, has a fitting cylindrical portion 19 that can be fitted and fixed in the inner end opening of the outer ring 1, and a closing plate portion 20 that closes the inner end opening. The sensor 4 is supported on a portion of the closing plate portion 20 near the outer periphery, and the tip end surface (the right end surface in FIG. 10) of the detecting portion 14 of the sensor 4 is attached to the inner surface of the ring portion 16 of the encoder 3 by a minute. They face each other through a 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 3 externally fitted and fixed to the inner end of the sensor 4 rotates, the vicinity of the end face of the detection unit 14 of the sensor 4 is
The through holes 17, 17 formed in the above and the pillars existing between the circumferentially adjacent through holes 17, 17 alternately pass through. As a result, the density of the magnetic flux flowing in the sensor 4 changes, and the output of the sensor 4 changes. The frequency at which the output of the sensor 4 changes is proportional to the rotational speed of the wheel.
Therefore, if the output of the sensor 4 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 configured as described above, if the dimension of the rolling bearing unit in the diameter direction is small,
Accuracy of rotation speed detection by the rotation speed detection device constituted by the encoder 3 and the sensor 4 may decrease. That is, in the case of a rolling bearing unit having a small dimension in the diametrical direction, the inner peripheral surface of the inner end of the outer ring 1 and the outer peripheral surface of the inner end of the inner ring 7, where the circular ring portion 16 (detected portion) of the encoder 3 is disposed. The width of the part between the plane and the surface is narrow. Therefore, when the encoder 3 is incorporated in such a rolling bearing unit, the width of the annular portion 16 in the diameter direction must be reduced.

However, when the width of the annular portion 16 in the diametrical direction is reduced, the change in magnetic characteristics of the annular portion 16 in the circumferential direction is also reduced. Because of this,
Even when the encoder 3 rotates with the rotation of the wheel, the sensor 4 facing the circular ring portion 16 of the encoder 3
The change in the amount of magnetic flux flowing through the inside becomes small, and the change in the output of the sensor 4 also becomes small. Therefore, when the width of the circular ring portion 16 in the diameter direction is reduced, the accuracy of the rotation speed detection by the rotation speed detection device is reduced. Such a phenomenon occurs, for example, when the rotational speed detecting device is of an eddy current type, other than the magnetic detection type. In view of such circumstances, the rolling bearing unit with the encoder of the present invention has been invented in order to improve the accuracy of rotation speed detection by the rotation speed detection device even when the size of the rolling bearing unit in the diametrical direction is small. is there.

[0010]

As described above, each of the rolling bearing units with an encoder according to the present invention, together with the sensor, constitutes a rolling bearing unit with a rotation speed detecting device, like the conventional rolling bearing unit with an encoder. An outer ring that has an outer ring raceway on the inner peripheral surface and does not rotate during use, and an inner ring that has an inner ring raceway on the outer peripheral surface and rotates during use, and is provided so as to roll freely between the outer raceway and the inner raceway. Provided with a plurality of rolling elements, a cylindrical portion and a circular ring portion, of which the characteristics of the circular ring portions are alternately and equidistantly changed in the circumferential direction to form a detected portion, and the end of the inner ring The inner ring is fitted concentrically with the encoder by externally fitting the cylindrical portion to the portion. And the detected part of this encoder is
It is supported on a portion that does not rotate, and is used in a state where it faces a detection unit of a sensor that changes an output signal in response to a change in the characteristic of the detection target.

In particular, in the rolling bearing unit with the encoder according to the first aspect, the encoder includes a support ring and an encoder body. The support ring is formed by bending a metal plate and includes a cylindrical portion, an overlapping portion, and a circular ring portion. Of these, the overlapping portion is formed by folding a part of the metal plate by 180 degrees at the inner peripheral edge of the ring portion, and overlapping the metal plates on both sides of the folded portion. The cylindrical portion is formed by bending an outer peripheral edge of the overlapping portion at a right angle toward the opposite side to the circular ring portion. The encoder body is a permanent magnet in which S poles and N poles are alternately arranged on side surfaces. And, in a state where the cylindrical portion is externally fitted to the end of the inner ring, a portion near the inner diameter of the encoder main body attached to the side surface of the circular ring portion, and a portion where the cylindrical portion is externally fitted at the end of the inner ring. Are axially superimposed over the entire circumference.

On the other hand, in the rolling bearing unit with the encoder according to the second aspect, the encoder is formed by bending a metal plate, and includes a cylindrical portion, an overlapping portion, and a ring portion. . Of these, the overlapping portion is formed by folding a part of the metal plate by 180 degrees at the inner peripheral edge of the ring portion, and overlapping the metal plates on both sides of the folded portion. The cylindrical portion is formed by bending an outer peripheral edge of the overlapping portion at a right angle toward the opposite side to the circular ring portion. In addition, a large number of through holes are formed at equal positions in the circumferential direction at positions where the annular portion and the overlapping portion match each other. Then, in a state where the cylindrical portion is externally fitted to the end of the inner ring, a portion near the inner diameter of each through hole formed in the circular ring portion, and a portion where the cylindrical portion is externally fitted at the end of the inner ring. , In the axial direction.

[0013]

With the rolling bearing unit with the rotation speed detecting device with encoder of the present invention configured as described above, the wheel is rotatably supported with respect to the suspension device, and the operation itself when detecting the rotation speed of the wheel is performed. Is the same as that of the conventional structure described above. In particular, in the case of the rolling bearing unit with the rotation speed detection device with the encoder of the present invention, even if the size in the diameter direction of the rolling bearing unit is small,
It is possible to prevent the accuracy of rotation speed detection by the rotation speed detection device from decreasing. That is, in the case of the present invention, the encoder that is supported and fixed to the end of the inner ring has a part in the radial direction overlapped with a part in the radial direction of the inner ring in the axial direction over the entire circumference. . Specifically, a portion of the encoder body near the inner diameter attached to the side surface of the annular portion constituting the encoder and a portion of the inner ring at which the cylindrical portion is externally fitted are attached (in the case of claim 1) or a circle. The portion of the through-hole formed in the ring portion near the inner diameter and the portion of the inner ring at which the cylindrical portion is externally fitted (in the case of claim 2) are overlapped in the axial direction. Accordingly, the width of the detected portion of the encoder in the diameter direction can be increased by the amount of the overlap. For this reason, even when the size of the rolling bearing unit in the diametric direction is small, the amount by which the characteristic of the detected portion changes in the circumferential direction is increased, and the accuracy of rotation speed detection by the rotation speed detection device is improved. Can do things.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a first example of a structure of a reference example which is not an embodiment of the present invention but can improve the accuracy of rotation speed detection by a rotation speed detection device.
It should be noted that the features of the reference example and the present invention are such that even if the rolling bearing unit has a small dimension in the diametrical direction, the rotation speed detecting device is configured so that the accuracy of the rotation speed detection by the rotation speed detecting device does not decrease. The point is that the structure of the mounting portion of the encoder 3 is devised. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIG. 10 described above, the same parts are denoted by the same reference numerals, and duplicated description is omitted or simplified. The following description focuses on features of the present invention and portions different from the above-described conventional structure. It should be noted that the reference example and the figures showing the embodiment of the present invention are the same as those in FIG. 10 showing the above-described conventional structure, except that the inside and outside directions in the width direction of the vehicle are reversed left and right.

Inner ring 7a which forms a rotating wheel together with hub 2a
At the inner end of the inner ring, a small-diameter stepped portion 21 is provided concentrically with the inner ring 7a over the entire circumference at a portion deviated axially inward from the inner ring raceway 8 (to the right in FIGS. 1 and 2). 7a is formed to be recessed inward in the diameter direction from the outer peripheral surface. The encoder 3 similar to the encoder incorporated in the conventional structure shown in FIG. That is, the encoder 3 includes a cylindrical portion 1 formed on an inner peripheral edge portion.
5 is externally fitted to the outer peripheral surface of the step portion 21 by interference fit.
It is fixed to the inner end of the inner ring 7a. Further, in this state, a portion near the inner periphery of the circular ring portion 16 (detected portion) constituting the encoder 3 enters the step portion 21 (the inner ring 7).
a) is located diametrically inward of the outer peripheral surface of the a).

Further, the inner end of the outer ring 1 which is a stationary wheel (FIGS. 1-2)
Right end) is closed by the cover 18a. The cover 18a includes a bottomed cylindrical main body 22 formed by injection molding of a synthetic resin, and a fitting cylinder 23 coupled to an opening of the main body 22. The fitting tube 23 is formed by plastically deforming a corrosion-resistant metal plate such as a stainless steel plate. The fitting tube 23 has an L-shaped cross section and is entirely annular.
The fitting cylindrical portion 24 includes an inward flange portion 25 that is bent inward in the diameter direction from a base end edge (right end edge in FIGS. 1 and 2). Such a fitting cylinder 23 is formed by connecting the inward flange 25 to the main body 22.
Is joined to the opening of the main body 22 by molding at the time of injection molding. The cover 18a thus configured
The outer ring 1 is fixed by tightly fitting the fitting tube portion 24 of the fitting tube 23 to the inner end of the outer ring 1.
Closes the inner end opening.

The main body 22 constituting the cover 18a
A portion of the bottom plate portion 26 facing the inner surface of the annular portion 16 constituting the encoder 3 is provided with the bottom plate portion 26.
Is formed in a cylindrical portion 27 protruding inward. Inside the cylindrical portion 27, an insertion hole 28 is formed in the axial direction of the outer ring 1 so as to communicate the inner end surface of the cylindrical portion 27 and the outer surface of the bottom plate portion 26. And this insertion hole 2
The portion near the front end of the sensor unit 29 in which the sensor is embedded in a holder made of a synthetic resin is inserted into 8. The detection unit of the sensor is disposed on the tip surface of the sensor unit 29. Also, a sensor unit 29 including the above sensor
Are, for example, permanent magnets magnetized in the axial direction (left and right directions in FIGS. 1 and 2), Hall elements, magnetoresistive elements (MR elements), etc.
A magnetic detection element that changes its characteristics according to the amount of magnetic flux passing therethrough, and an IC incorporating a waveform shaping circuit for adjusting the output waveform of the magnetic detection element are embedded in the synthetic resin holder. Become. Further, an end of a harness 30 for sending an output signal output as a shaped waveform from the IC to a controller (not shown) is directly connected to the sensor unit 29 (without a connector or the like). Incidentally, as the sensor, instead of a magnetic detection element, a combination of a pole piece and a coil made of a magnetic material is incorporated, and a voltage is induced in this coil in response to a change in the amount of magnetic flux flowing in the pole piece. A passive type can also be used.

Further, with the sensor unit 29 inserted into the insertion hole 28 as described above,
Is opposed to the inner end surface of the annular portion 16 of the encoder 3 via a minute gap. In this case, in order to facilitate and quickly perform the operation of attaching and detaching the sensor unit 29 to and from the cover 18a as described above, in the case of this example, the column portion 2 is used.
A pair of connecting springs 31 formed by bending a wire having elasticity and corrosion resistance, such as stainless steel spring steel, is mounted on the outer peripheral surface of the cylindrical portion 27. It is provided in a state where it is set. The distal ends of the coupling springs 31 are engaged with and disengaged from a pair of engagement grooves (not shown) provided on the inner end surface of the sensor unit 29, respectively. To be able to do. However, since this part is not a main part of the present invention, detailed description is omitted.

Further, in the case of the illustrated example, the hub 2a
A cylindrical portion 32 is formed at the inner end of the inner ring 7a, and a portion protruding from the inner end surface of the inner ring 7a at the distal end of the cylindrical portion 32 is radially outwardly expanded to form a swaged portion 47. Then, the inner ring 7a is pressed against the inner end of the hub 2a by the caulking portion 47, whereby the inner ring 7a
Are fixedly connected to the hub 2b. By adopting such a structure, the number of parts and the labor for assembling can be reduced by reducing the number of parts and the assembly as compared with the structure in which the inner ring and the hub are connected and fixed by a nut as in the conventional structure shown in FIG. Cost can be reduced. When the tip of the cylindrical portion 32 is swaged outward in the diametric direction, a force directed outward in the diametric direction is applied to a part of the inner ring 7a. When this force is large, it is conceivable that the diameter of the inner raceway 8 changes and the preload applied to the rolling elements 9 changes. However, in the case of this example, the stepping force formed at the inner end of the inner ring 7a receives the force caused by the swaging and the force is hardly applied to the inner ring raceway 8 portion. Therefore, the preload hardly changes.

The rolling bearing unit with the encoder according to the present embodiment configured as described above rotatably supports the wheel with respect to the suspension device, and the operation itself for detecting the rotation speed of the wheel is the same as the conventional one described above. It is similar to the case of the structure. In particular, in the case of this example, even if the rolling bearing unit has a small dimension in the diametrical direction, it is possible to prevent the accuracy of the rotation speed detection by the rotation speed detecting device constituted by the encoder 3 and the sensor unit 29 from deteriorating. That is, in the case of the present example, the encoder 3 supported and fixed to the inner end of the inner ring 7 a causes the portion near the inner circumference of the circular ring portion 16, which is the detected portion, to enter the stepped portion 21, and The deviated portion is overlapped with the outer deviated portion of the inner ring 7a in the axial direction over the entire circumference. Therefore, the width in the diametrical direction of the annular portion 16 can be increased by the amount of the overlap. For this reason, even when the size of the rolling bearing unit in the diameter direction is small, the amount of change in the circumferential direction of the magnetic characteristics of the circular ring portion 16 is increased to improve the accuracy of rotation speed detection by the rotation speed detection device. Can be improved.

Next, FIG. 3 shows a first embodiment of the present invention corresponding to claim 1. In the case of this example, the encoder 3a externally fitted and fixed to the inner end of the inner ring 7a is formed by combining a support ring 33 and an encoder body 34 corresponding to a detected part. The support ring 33 is formed by bending a magnetic metal plate such as a mild steel plate to form an entire ring having a T-shaped cross section. And the overlapping portion 36 and the ring portion 3
7 is provided. The overlapping portion 36 is formed by folding a part of the metal plate 180 degrees around the inner peripheral edge of the circular ring portion 37 and overlapping the metal plates on both sides of the folded portion. In addition, the fitting cylinder 3
Reference numeral 5 denotes the outer peripheral edge of the overlapping portion 36,
It is formed by bending at a right angle toward the side opposite to 7. The encoder body 34 is attached to the inner surface (the right side surface in FIG. 3) of the circular ring portion 37 among them.

The encoder body 34 is formed in a ring shape entirely by a permanent magnet such as a rubber magnet mixed with ferrite powder, and is magnetized in the axial direction (the left-right direction in FIG. 3). . The magnetization directions are changed alternately at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal intervals on the inner surface of the encoder body 34. Encoder 3a as described above
The outer peripheral surface of the overlapping portion 36 (the left side surface in FIG. 3) is fitted to the outer peripheral surface of the shoulder portion 38 provided at the intermediate portion of the inner ring 7a by interference fit. It is supported and fixed to the inner end of the inner ring 7a in a state of abutting the step surface of the step portion 21. In this state, the encoder body 34 has its inner peripheral portion entering the step portion 21 so that the inner peripheral portion overlaps the outer peripheral portion of the inner ring 7a in the axial direction over the entire circumference. .

On the other hand, a bottomed cylindrical cover 18b formed of a metal plate such as a steel plate or a stainless steel plate is fixedly fitted to the inner end of the outer ring 1 so that the inner end opening of the outer ring 1 is fixed. I'm blocking. Then, inside the cover 18b, a magnetic detecting element such as a Hall element and a magnetoresistive element, which changes the output in accordance with the flow direction of the magnetic flux, and a waveform shaping circuit for adjusting the output waveform of the magnetoresistive element are incorporated. I
C and the sensor 4a. The sensor 4a is held and fixed to a holding portion 40 formed on the cover 18b in a state of being embedded in a synthetic resin 39 having a substantially rectangular cross section and formed in an arc shape. In this state, the sensor 4a is opposed to a part of the encoder body 34 in the circumferential direction via a minute gap. Also, the sensor 4a
The connector 41 for taking out the signal of the
b on one side (right side in FIG. 3) of the closing plate portion 20a,
It protrudes from the holding portion 40 at a position deviating therefrom. In the case of this example, the axial dimension of the entire apparatus is reduced by providing the connector 41 at a position separated from the holding section 40 in this manner.

In the case of the rolling bearing unit with the encoder of the present embodiment having the above-described configuration, the portion closer to the inner periphery of the encoder body 34 constituting the encoder 3a and the portion closer to the outer periphery of the inner ring 7a are overlapped in the axial direction. Accordingly, the width of the encoder body 34 in the diameter direction can be increased. Therefore, even when the size of the rolling bearing unit in the diametrical direction is small, the encoder body 34
Can be increased in width in the diameter direction. As a result,
By increasing the amount of change in the magnetic characteristics of the encoder body 34 in the circumferential direction, it is possible to improve the accuracy of rotation speed detection by the rotation speed detection device. Other configurations and operations are the same as those of the above-described first example of the reference example.

Next, FIG. 4 shows a second embodiment of the present invention corresponding to claim 1. In the case of this example, the inner half of the inner ring 7b which is fitted and fixed to the inner end of the hub 2a is
As in the case of the conventional structure shown in FIG. 10, a shoulder 38a having a single cylindrical outer peripheral surface is formed. And
An encoder 3a similar to that incorporated in the first example shown in FIG. 3 described above is externally fitted and fixed to the inner end of such a shoulder 38a. That is, the encoder 3 a
5 is fitted to the outer peripheral surface of the shoulder portion 38a by interference fit, and the outer surface (the left side surface in FIG. 4) of the overlapping portion 36 is abutted against the inner end surface of the inner ring 7b. It is supported and fixed to the inner end of. In this state, the encoder main body 34 (detected portion) constituting the encoder 3a has an inner peripheral portion overlapped with the outer peripheral portion of the inner ring 7b in the axial direction over the entire circumference. In the state where the encoder 3a is supported and fixed to the inner end of the inner ring 7b as described above, the encoder 3a is formed by a caulking portion 47 formed on the inner end of the outer ring 1 or the inner end of the hub 2a. Does not protrude inward from the inner edge.

On the other hand, a bottomed cylindrical cover 18c formed of a metal plate such as a steel plate or a stainless steel plate and fixed to the inner end of the outer race 1 has a sensor (see FIG. (Not shown) is held and fixed. The above-mentioned sensor is, like the sensor 4a incorporated in the first example of the above-described embodiment, a magnetic detecting element such as a Hall element or a magneto-resistive element that changes the output in accordance with the flow direction of the magnetic flux, I incorporating a waveform shaping circuit for adjusting the output waveform
C. Further, in this state, one surface (detection unit) of the sensor is opposed to a part of the encoder body 34 in the circumferential direction via a minute gap. In the case of this example, the connector 41a for extracting the signal of the sensor is used.
Is provided so as to protrude inward in the axial direction from a through hole 58 formed in the closing plate portion 20b constituting the cover 18c.

In this embodiment, the axial dimension of the shoulder 38a formed at the inner end of the inner ring 7b is larger than that of the conventional structure shown in FIG. Therefore, in the case of this example, in order to hold down the inner ring 7b to the inner end of the hub 2a, when the tip of the cylindrical portion 32 provided at the inner end of the hub 2a is swaged outward in the diameter direction, The force directed outward in the diametrical direction accompanying this caulking spread is applied to the shoulder 38a.
The inner end of For this reason, the force accompanying the above-mentioned swaging is hardly applied to the inner ring raceway 8 formed on the outer peripheral surface of the intermediate portion of the inner ring 7b. Therefore, the diameter of the inner raceway 8 changes with the swaging, and the preload applied to the rolling elements 9 hardly changes.

Also in the case of the rolling bearing unit with encoder of the present embodiment having the above-described configuration, the inner peripheral portion of the encoder main body 34 constituting the encoder 3a and the outer peripheral portion of the inner ring 7b are overlapped in the axial direction. Accordingly, the width of the encoder body 34 in the diameter direction can be increased. Therefore, even when the diameter of the rolling bearing unit is small, the width of the encoder body 34 in the diameter can be increased. As a result, the amount of change in the magnetic characteristics of the encoder body 34 in the circumferential direction is increased, and the accuracy of rotation speed detection by the rotation speed detection device can be improved.

As the encoder supported and fixed to the inner end of the inner ring 7b, in addition to the encoder 3a as described above,
The structure described in claim 2 may be employed.
That is, as shown in FIG. 5, for example, at a position where the annular portion 37 and the overlapping portion 36 are aligned with each other, a large number of the annular portions 37 and the overlapping portion 36 are positioned at equal intervals in the circumferential direction. The one having the through hole 59 is used. However, when such an encoder is used, the sensor constituting the rotation speed detecting device together with the encoder includes the sensor 4 used in the above-described conventional structure, or the sensor unit 29 used in the first example of the reference example. Use a similar structure.
Other configurations and operations are the same as those in the second example of the above-described embodiment.

Although not shown, the structure of the second example of the above-described embodiment can also be applied to a rolling bearing unit with an encoder in which the inner ring 7b is a stationary wheel and the outer ring 1 is a rotating wheel. In this case, the inner end of the outer ring 1 is provided with an encoder having a diametrically opposite inner and outer configuration with the above-described encoder 3a. The outer ring 1 is supported and fixed in a state of being superposed in the axial direction over the entire inner circumference of the inner end of the outer ring 1 and the entire circumference.

FIG. 6 shows a third embodiment of the present invention corresponding to claim 1. The first example of the above-described reference example and the first and second examples of the above-described embodiment are all
While the present invention has been applied to a rolling bearing unit with an encoder for supporting a driven wheel of an automobile (a rear wheel of an FF vehicle, a front wheel of an FR vehicle and an RR vehicle) on a suspension device, the present embodiment is directed to an automobile. The present invention is applied to a rolling bearing unit with an encoder for supporting driving wheels (front wheels of an FF vehicle, rear wheels of an FR vehicle and an RR vehicle, and all wheels of a 4WD vehicle) on a suspension device. For this reason, in the case of the rolling bearing unit with the encoder of the present embodiment, the hub 2b is formed in a cylindrical shape, and the hub 2b is formed.
The female spline portion 42 is formed on the inner peripheral surface of the b. A drive shaft 43 having a male spline formed on the outer peripheral surface is inserted into the female spline. Then, the nut 2 is tightened while the hub 2b is clamped between a nut 44 screwed to the distal end of the drive shaft 43 and a step 45 formed at the base end of the drive shaft 43. By doing so, the hub 2b and the drive shaft 43 are connected.

In order to connect the hub 2b and the drive shaft 43, when the drive shaft 43 is inserted inside the hub 2b, the inner peripheral surface of the inner end of the hub 2b and the inner end of the drive shaft 43 are connected. In order to prevent interference with the outer peripheral surface, a gap is formed over the entire circumference between these two peripheral surfaces. When the hub 2b and the drive shaft 43 are connected as described above, the caulked portion 4 is a portion that comes into contact with the step surface 46 of the step portion 45.
A large surface pressure acts on the inner end surface of the nut 7 based on the tightening of the nut 44. When such a large surface pressure is generated, the caulking portion 47 may be plastically deformed, and the nut 44 screwed to the tip of the hub 2b may be loosened.

For this reason, in the case of this example, the caulking section 4
By providing a flat surface 49 parallel to a flat surface 48 formed on the inner end surface of the inner ring 7a on the inner end surface of the inner ring 7a so as to make surface contact with the step surface 46, a surface added to the inner end surface of the caulking portion 47 is provided. The pressure is reduced. Furthermore, such a flat surface 4
At least a portion (a portion closer to the outer periphery) of the inner ring 7
The inner peripheral surface of the hub 2b is formed on the inner end of the hub 2b by being positioned diametrically outward of the inner peripheral surface of the inner ring 7a (if there is a chamfer at the inner end opening of the inner ring 7a, this chamfer is further provided). The bending stress in the direction in which the caulking portion 47 is loosened is prevented from being generated in the caulking portion 47. That is, due to the axial load applied to the caulked portion 47 based on the tightening of the nut 44, the flat surface 4 is formed at a portion near the outer periphery of the caulked portion 47.
The portion where 9 is formed is sandwiched in the axial direction between the flat surface 48 of the inner race 7a and the step surface 46. The bending stress is prevented from being generated in the caulking portion 47, and only the compressive stress is applied to the caulking portion 47.

In the case of the present embodiment, the inner peripheral surface of the inner end of the outer ring 1 constituting the rolling bearing unit is located at the diametrically outer position of the encoder 3a externally fitted and fixed to the inner end of the inner ring 7a.
The seal ring 50 is fitted inside. This seal ring 5
Reference numeral 0 denotes a combination of the core metal 51 and the seal lip 52. The core metal 51 is formed by forming a metal plate such as a steel plate into an annular shape with an L-shaped cross section. The cylindrical portion 53 is fitted and fixed to the inner end of the outer ring 1. A circular ring portion 54 is bent inward from the edge portion in the diameter direction. Further, the entire seal lip 52 is formed in an annular shape by an elastic material such as an elastomer such as rubber, and is attached to the inner peripheral edge of the annular portion 54 over the entire circumference.
Then, the leading edge of the seal lip 52 is brought into sliding contact with the outer peripheral surface of the fitting cylindrical portion 35 and the outer peripheral surface of the circular ring portion 37 constituting the support ring 33 of the encoder 3a over the entire circumference. The inner end opening of the space in which the rolling elements 9 and 9 are installed is closed.

In the case of this embodiment, the holder 57 is constructed in the same manner as the sensor 4a incorporated in the first embodiment of the above-described embodiment, and embeds and supports the sensor 4b constituting the rotation speed detecting device together with the encoder 3a. Is supported and fixed to a knuckle (not shown) constituting a suspension device, which is a non-rotating portion, by bolting or the like. In this state, the outer surface of the distal end portion (lower end portion in FIG. 6) of the holder 57, which is the detecting portion and is aligned with the position where the sensor 4b is embedded, is placed in the encoder main body 3 constituting the encoder 3a.
4 (part to be detected) is opposed to a part of the inner surface via a minute gap.

The rolling bearing unit with encoder of the present embodiment configured as described above is fixed to the suspension device by the mounting portion 12 provided on the outer race 1. And when driving a car,
The drive shaft 43 is rotationally driven via a constant velocity joint 55 connected to the base end (the right end in FIG. 6) of the drive shaft 43, and the rotational drive force causes the flange 11 of the hub 2b to rotate.
Rotate the wheel fixed to. As the rolling bearing unit, such a driving wheel side rolling bearing unit is adopted,
The configuration and operation other than changing the structure of each part accordingly are almost the same as those of the first example of the above-described embodiment.

In the first example of the reference example, the first example of the embodiment, and the third example, the inner periphery of the inner end portion of the outer ring 1 is a portion where the detected portion of the encoder is disposed. In order to increase the width of the portion between the surface and the outer peripheral surface of the inner end of the inner race 7a, a step 21 having a small diameter is provided at the inner end of the inner race 7a. However, in order to increase the width of the inter-portion, instead of omitting the step at the inner end of the inner ring 7a as in the second example of the reference example shown in FIG. The stepped portion 56 may be provided in such a manner as to be recessed diametrically outward from the inner peripheral surface of the outer ring 1. In this case, the encoder 3 causes the portion near the outer periphery of the circular ring portion 16 that is the detected portion to enter the stepped portion 56, so that the portion closer to the outer periphery extends over the entire periphery with the portion closer to the inner periphery of the outer ring 1. When the inner ring 7 is overlapped in the axial direction,
a.

Further, contrary to the first and second examples of the reference example described above and the first and third examples of the embodiment,
When the present invention is applied to a rolling bearing unit with an encoder in which the inner ring 7a is a stationary wheel and the outer ring 1 is a rotating wheel, as in the third example of the reference example shown in FIG. The encoder 3b, which is configured so that the inside and outside of the encoder 3 in the diametrical direction are reversed, is fixed to the step 56 formed in the portion by fitting the cylindrical portion 15a formed on the outer peripheral edge of the encoder 3b. Encoder 3b with cylindrical part 15a
The portion near the outer periphery of the circular ring portion 16a (detected portion) that constitutes the above can be made to enter the step portion 56. In this case, the outer peripheral portion of the annular portion 16a overlaps the inner peripheral portion of the outer ring 1 in the axial direction over the entire circumference. Alternatively, as in the fourth example of the reference example shown in FIG. 9, a cylindrical portion 15a formed on the outer peripheral edge of the encoder 3b is fitted inside the inner end of the outer ring 1 to constitute the encoder 3b together with the cylindrical portion 15a. The portion near the inner circumference of the circular ring portion 16a can be made to enter the step portion 21 formed at the inner end of the inner ring 7a. In this case, the inner ring portion of the circular ring portion 16a is
A is superimposed in the axial direction over the entire outer periphery of the portion a.

Although not shown, in the case of the first example of the above-described reference example, the first example of the embodiment, and the second to fourth examples of the above-described reference example, the inner end of the inner ring 7a is not Steps 21 and 56 may be provided on both the inner end of the outer race 1 and the inner end. When the step portions 21 and 56 are provided on both sides in this manner, a portion between the inner peripheral surface of the inner end of the outer race 1 and the outer peripheral surface of the inner end of the inner race 7a, which is the portion where the detected part of the encoder is arranged. Can be made larger, and the accuracy of rotation speed detection by the rotation speed detection device can be further improved.
In addition, the present invention is not limited to the structure incorporating the magnetic detection type rotation speed detecting device, but can also be carried out with a structure incorporating the eddy current type rotation speed detecting device.

[0040]

Since the rolling bearing unit with encoder of the present invention is constructed and operates as described above, even if the rolling bearing unit has a small dimension in the diametrical direction, the characteristic over the circumferential direction of the detected portion of the encoder is obtained. And the accuracy of the rotation speed detection by the rotation speed detection device can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of a reference example.

FIG. 2 is an enlarged view of the right part of FIG.

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

FIG. 4 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 5 is a partial cross-sectional view showing another example of the encoder used in the second example of the embodiment of the present invention.

FIG. 6 is a half sectional view showing the third example.

FIG. 7 is a partial sectional view showing a second example of the reference example.

FIG. 8 is a partial sectional view showing the third example.

FIG. 9 is a partial cross-sectional view showing the fourth example.

FIG. 10 is a sectional view showing an example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 2, 2a Hub 3, 3a, 3b Encoder 4, 4a, 4b Sensor 5 Outer ring track 6 Nut 7, 7a, 7c Inner ring 8 Inner ring track 9 Rolling element 10 Cage 11 Flange 12 Mounting part 13 Seal ring 14 Detecting part 15 , 15a cylindrical portion 16, 16a circular ring portion 17 through hole 18, 18a, 18b, 18c cover 19 fitting cylindrical portion 20, 20a, 20b closing plate portion 21 step 22 main body 23 fitting cylinder 24 fitting cylindrical portion 25 inward Collar part 26 Bottom plate part 27 Cylindrical part 28 Insertion hole 29 Sensor unit 30 Harness 31 Coupling spring 32 Cylindrical part 33 Support ring 34 Encoder main body 35 Fitting cylinder part 36 Overlapping part 37 Circle part 38, 38a Shoulder part 39, 39a Synthesis Resin 40 Holder 41, 41a Connector 42 Female spline 43 Drive shaft 44 Nut 45 Step 46 Step surface 47 Caulked portion 48 Flat surface 49 Flat surface 50 Seal ring 51 Core bar 52 Seal lip 53 Cylindrical portion 54 Ring portion 55 Constant velocity joint 56 Step portion 57 Holder 58 Through hole 59 Through hole

Claims (2)

[Claims] 1. An outer ring having an outer raceway on an inner peripheral surface and not rotating during use, an inner race having an inner raceway on an outer peripheral surface and rotating during use, and between the outer raceway and the inner raceway. A plurality of rolling elements provided rotatably, a cylindrical part and a ring part, of which the characteristics of the ring part are alternately changed at equal intervals in the circumferential direction to be a detected part. An encoder fixed concentrically with the inner ring by externally fitting the cylindrical portion to an end of the inner ring, and a detected portion of the encoder is supported by a portion that does not rotate, and characteristics of the detected portion are In a rolling bearing unit with an encoder used in a state of being opposed to a detection unit of a sensor that changes an output signal in response to a change in the output signal, the encoder includes a support ring and an encoder main body. Support ring bends metal plate And a cylindrical part,
A superposed portion and a circular portion are provided, and the superposed portion is configured such that a part of the metal plate is folded back 180 degrees at the inner peripheral edge of the circular portion, and both sides of the folded portion are formed. The metal plate is formed by overlapping each other, and the cylindrical portion is formed by bending an outer peripheral edge of the overlapped portion at a right angle toward the opposite side to the circular portion, The encoder body is S
A permanent magnet in which poles and N poles are alternately arranged, and a portion of the inner side of the encoder body attached to a side surface of the circular ring portion in a state where the cylindrical portion is externally fitted to an end of the inner ring; A rolling bearing unit with an encoder, wherein an end portion of the rolling bearing unit is axially overlapped with a portion where the cylindrical portion is fitted over the entire circumference. 2. An outer race having an outer raceway on an inner peripheral surface and not rotating even when used, an inner race having an inner raceway on an outer peripheral surface and rotating during use, and between the outer raceway and the inner raceway. A plurality of rolling elements provided rotatably, a cylindrical part and a ring part, of which the characteristics of the ring part are alternately changed at equal intervals in the circumferential direction to be a detected part. An encoder fixed concentrically with the inner ring by externally fitting the cylindrical portion to an end of the inner ring, and a detected portion of the encoder is supported by a portion that does not rotate, and characteristics of the detected portion are In a rolling bearing unit with an encoder used in a state of being opposed to a detection unit of a sensor that changes an output signal in response to a change in the output signal, the encoder is formed by bending a metal plate, and a cylindrical portion is formed. , A superposed part and a ring part The overlapping portion of the metal plate is formed by connecting a part of the metal plate to the inner peripheral edge of the ring portion.
The metal plate is folded back at 0 ° and the metal plates are overlapped on both sides of the folded portion, and the cylindrical portion is formed so that the outer peripheral edge of the overlapped portion is at a right angle to the opposite side to the ring portion. A large number of through-holes are formed at positions at which the annular portion and the overlapping portion are aligned with each other at equal intervals in the circumferential direction, and the cylindrical portion is formed. In a state of being externally fitted to the end of the inner ring, a portion of each of the through-holes formed in the circular ring portion near the inner diameter, and a portion of the inner ring that is externally fitted with the cylindrical portion,
A rolling bearing unit with an encoder, which is superimposed in the axial direction.