JP2002062305A - Combination seal ring with encoder and rolling bearing unit for wheel support incorporating this - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure both sealing performance and securing the coupling strength of the encoder 4 to the slinger 3. SOLUTION: Seal lips 11a to 11c of a rotating cylindrical portion 12 and a rotating ring portion 13 constituting a slinger 3 are provided.
The sealability is ensured by making the portion where the leading edge of the slidable contact is made a smooth surface of about 0.3 Ra. On the other hand, the portion for coupling the encoder 4 is formed as a rough surface of about 1.0 to 1.5 Ra to secure the coupling strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A combined seal ring with an encoder according to the present invention is incorporated in a rolling bearing unit that rotatably supports a wheel of an automobile with respect to a suspension device, seals the rolling bearing unit, and includes a rolling bearing. It is used to detect the rotation speed of the wheels supported by the unit.

[0002]

2. Description of the Related Art In addition to supporting the wheels of a vehicle rotatably with respect to a suspension, an anti-lock brake system (ABS) and a traction control system (TC) are provided.
In order to detect the rotational speed of the wheel in order to control S), a rolling bearing unit with an encoder as described in, for example, JP-A-64-21219 has been known. Further, a structure in which an encoder is assembled to a part of a seal ring that closes an end opening of a rolling bearing unit is also disclosed in, for example, JP-A-5-26233 and JP-A-5-238369.
JP-A-6-281018, JP-A-9-27405
No. 1, No. 11-44702, European Patent Publication EP
As described in 0 495 323 A1, etc., it is conventionally known.

When the rotational speed of a wheel is detected magnetically, an encoder whose magnetic characteristics alternately change in the circumferential direction (generally at regular intervals) is used. As such an encoder whose magnetic characteristics alternately change in the circumferential direction, an encoder in which a large number of thinned portions and solid portions are alternately formed in a magnetic material in the circumferential direction, or an S pole and N
Permanent magnets with alternating poles are used. Among them, the permanent magnet encoder has a simple structure on the sensor side, and furthermore, from the viewpoint of securing detection accuracy at low speed,
In recent years, it has been increasingly used.

In order to improve the sealing performance in a case where an annular space between the inner peripheral surface and the outer peripheral surface, each of which is cylindrical, is closed by adopting a structure in which an encoder is assembled to a part of the seal ring, It is preferable to employ a combination seal ring in which a seal ring and a slinger are combined.
In this case, the slinger is fitted and fixed to the rotating wheel, and the seal ring is fitted to the stationary wheel. Then, the seal lip forming the seal ring is slid on the peripheral surface and one side surface of the slinger, and the encoder is attached to the other side surface of the slinger.

[0005]

Conventionally, when producing a combination seal ring with an encoder as described above, the surface roughness of the slinger has been made the same over the entire surface. For this reason, it has been difficult to achieve both the securing of the coupling strength of the encoder to the slinger and the securing of the sealing performance. The reason is as follows. That is, in order to couple the encoder to the slinger, a rubber magnet is baked on the slinger or bonded with an adhesive. Whichever method is used to fix and fix the encoder to the slinger, it is desirable that the surface of the side of the slinger where the encoder is fixed and fixed has a large surface roughness (a large surface roughness value). On the other hand, the peripheral surface and the side surface of the slinger where the leading edge of the seal lip slides,
A smooth surface having a small surface roughness value is preferable for securing the sealing property. However, in the case of a slinger constituting a conventional combination seal ring with an encoder, since the entire surface has the same surface roughness as described above, it is difficult to achieve both the securing of the coupling strength of the encoder and the securing of the sealing performance. Was. The present invention has been made in view of such circumstances.

[0006]

According to the present invention, there is provided a combination seal ring with an encoder according to the present invention and a rolling bearing unit for supporting a wheel incorporating the encoder with the encoder. It is used for closing the opening end of the space existing between the rotating wheel and the peripheral surface of the rotating wheel, and detecting the rotation speed of the rotating wheel. And a seal ring fixed to the peripheral surface of the stationary wheel,
It includes a metal slinger fixed to the peripheral surface of the rotating wheel, and an encoder supported and fixed to the slinger.
Further, the seal ring includes a fixed cylindrical portion fitted and fixed to the peripheral surface of the stationary wheel, and a cored bar including a fixed circular portion bent from an edge of the fixed cylindrical portion toward the peripheral surface of the rotating wheel. And an elastic material having a seal lip attached around the entire circumference of the cored bar. Further, the slinger includes a rotating cylindrical portion fitted and fixed to the peripheral surface of the rotating wheel, and a rotating circular portion bent from an edge of the rotating cylindrical portion toward the peripheral surface of the stationary wheel, No elastic material is provided, and a portion where the leading edge of the seal lip slides on one side of the peripheral surface of the rotary cylinder and one side of the rotary ring is made a smooth surface, and the other surface of the rotary ring is The surface on which the encoder is to be supported and fixed is a rough surface having a larger surface roughness value than the peripheral surface and one side surface. The rough surface referred to in this specification refers to a surface that is rougher than a smooth surface on which the leading edge of the seal lip is slid, and also includes a case that is not necessarily as rough as a generally referred to rough surface. Further, the encoder is made of a permanent magnet in which S poles and N poles are alternately arranged in the circumferential direction, and is fixedly connected to the other side surface of the rotating ring.

According to a second aspect of the present invention, there is provided a wheel supporting rolling bearing unit incorporating a combined seal ring with an encoder, wherein a stationary wheel having a stationary side track on a stationary side peripheral surface and a rotating side track on a rotating side peripheral surface are provided. A rotating wheel having a wheel supported and fixed freely, a plurality of rolling elements rotatably provided between the stationary-side track and the rotating-side track, and an end of the stationary-side peripheral surface and the rotation A seal ring with an encoder according to claim 1 provided between the end portion of the side peripheral surface and the end portion.

[0008]

With the combination seal ring with the encoder of the present invention configured as described above, the gap between the peripheral surface of the stationary wheel and the peripheral surface of the rotating wheel is closed, and foreign matter is contained in the space between these peripheral surfaces. The action of preventing the grease filled in this space from leaking to the outside at the same time as preventing it from entering, and the action of detecting the rotation speed of the rotating wheel by combination with a sensor are described in the above-mentioned publications. This is the same as the case of a conventionally known combination seal ring with an encoder as described in, for example. In particular, in the case of the combination seal ring with the encoder of the present invention, since the peripheral surface of the rotating cylindrical portion and the one side of the rotating annular portion that make up the slinger make the leading edge of the seal lip slidably contact with the smooth surface, it is sufficient. Secure sealing performance. On the other hand, since the surface on the other side of the rotary ring to support and fix the encoder is a rough surface having a large surface roughness value, the coupling strength of the encoder to the slinger can be increased.

[0009]

1 and 2 show an embodiment of the present invention. First, the combination seal ring with encoder 1 shown in FIG. 1 will be described. The combined seal ring 1 with encoder 1 is made of a magnetic ring such as a steel plate or a stainless steel plate. The seal ring 2 is fitted and fixed to the end of an outer race 5 (FIG. 2). ) Is provided with a slinger 3 fitted and fixed to an end portion of the bracket, and an encoder 4 supported and fixed by the slinger 3.

The seal ring 2 comprises a metal core 7 having an L-shaped cross section and an annular shape as a whole, and an elastic member 8. The core metal 7 is made of a metal plate such as a mild steel plate and has a substantially L-shaped cross section and is formed in an annular shape. The core metal 7 is internally fixed to the inner peripheral surface of the outer ring 5 as a stationary ring by interference fitting. And a fixed circular portion 10 bent inward in the diametrical direction from the axial end edge of the fixed cylindrical portion 9 toward the outer peripheral surface of the inner ring 6 which is a rotating wheel. Also, the elastic material 8
Is attached over the entire circumference of the cored bar 7, and one or more (three in the illustrated example) seal lips 11a to
11c. Generally, the elastic member 8 is made of rubber, and is bonded to the core metal 7 by baking.

The slinger 3 is a rotary cylindrical portion 12 which is externally fitted and fixed to the outer peripheral surface of the end of the inner race 6 by interference fit.
And the rotating annular portion 1 bent radially outward from the axial end edge of the rotating cylindrical portion 12 toward the inner peripheral surface of the outer ring 5.
3 is provided. The slinger 3 is not provided with an elastic material, and has an outer peripheral surface of the rotating cylindrical portion 12 and the rotating annular portion 1.
A portion of one side surface 3 (the left side surface in FIGS. 1 and 2) in which the tip edges of the seal lips 11a to 11c are in sliding contact is a smooth surface having a surface roughness of about 0.3 Ra.

Further, the encoder 4 is made of a rubber magnet in which S poles and N poles are alternately arranged in the circumferential direction.
That is, the encoder 4 is formed by forming a rubber magnet in which ferrite powder is mixed in rubber into a ring shape, and is magnetized in the axial direction (the left-right direction in FIG. 1). The magnetization directions are changed alternately and at equal intervals in the circumferential direction. Therefore, S-poles and N-poles are alternately arranged at equal intervals on the side surface of the encoder 4 in the circumferential direction. Such an encoder 4 is provided on the other side surface (the right side surface in FIGS. 1 and 2) of the rotary ring 13 with the seal lip 11a.
By using this surface, a rubber material mixed with ferrite powder is molded on a surface located on the side opposite to 11c, thereby supporting the surface. Such an encoder 4
The other side surface has a surface roughness of about 1.0 to 1.5 Ra (rougher than the outer peripheral surface and one side surface) in order to secure a coupling strength between the outer peripheral surface and the one side surface. ) The surface is rough.

The encoder-equipped seal ring 1 constructed as described above is incorporated in a rolling bearing unit 14 as shown in FIG. 2, for example.
4 makes it possible to detect the rotation speed of the wheel rotatably supported by the suspension device. The rolling bearing unit 14 shown in FIG. 2 supports drive wheels (rear wheels of FR and RR vehicles, front wheels of FF vehicles, and all wheels of 4WD vehicles) with respect to a suspension system. Constituting such a rolling bearing unit 14,
The outer ring 5, which is a stationary wheel, has multiple rows of outer ring tracks 15, 15 on the inner peripheral surface, which is the stationary peripheral surface. An outer flange-shaped mounting portion 16 for supporting and fixing the outer ring 5 to a suspension device is provided at an intermediate portion of the outer peripheral surface of the outer ring 5.

The hub 17 and the inner ring 6 which are rotating wheels are arranged concentrically with the outer ring 5 inside the outer ring 5. The hub 17 and the inner ring 6 are combined to form a rotating wheel.
And on the outer peripheral surface of the inner ring 6, the outer ring raceway 15,
Inner ring races 18, 18, which are rotation-side races, and are opposed to 15.
Is formed. A spline hole 19 is formed in the center of the hub 17. A spline shaft attached to a constant velocity joint (not shown) is inserted into the spline hole 19 in a state where the spline shaft is assembled to a vehicle. Then, the hub 17 and the inner ring 6 are sandwiched from both sides in the axial direction between the outer end surface of the housing provided in the constant velocity joint and the nut screwed to the tip of the spline shaft. The opening at the outer end of the hub 17 is closed by fitting a cover (not shown) after the screw tightening operation of the nut. Also, the hub 1
The outer ring 5 (outside means a part that is outward in the width direction when assembled to a car, and left in FIG. 2)
A flange 22 for supporting a wheel is provided at a portion protruding from an outer end opening of the vehicle. A wheel (not shown) is connected and fixed to the flange 22 by a stud (not shown) fixed to the flange 22. Therefore, the hub 17
As the automobile runs, it rotates together with the wheels.

Further, between each of the outer raceways 15, 15 and each of the inner raceways 18, 18, there are provided balls 20, 2 which are rolling elements.
A plurality of 0s are provided for each column. Each of these balls 2
0 and 20 are rotatably held by retainers 21 and 21 in a state of being spaced apart from each other in the circumferential direction. Therefore, the hub 17 is rotatably supported inside the outer ring 5. In the case of a heavy-duty rolling bearing unit for an automobile, tapered rollers may be used instead of the balls 20 and 20 as the rolling elements.

Further, a seal ring 23 is fitted and fixed to the outer end of the outer ring 5, and the leading edge of a seal lip constituting the seal ring 23 is slidably contacted with the outer peripheral surface of the intermediate portion of the hub 17. Outer peripheral surfaces of the hub 17 and the inner ring 6 and the outer ring 5
Of the space 24 existing between the inner peripheral surface and the inner peripheral surface of the space 24. The combined seal ring with encoder 1 configured as described above is provided at the inner end portion of the rolling bearing unit 14 configured as described above at the inner peripheral surface of the inner end of the outer ring 5 and the outer peripheral surface of the inner end of the inner ring 6. The space 24 is assembled so as to close the inner end opening. That is, the fixed cylindrical portion 9 is internally fixed to the inner end of the outer ring 5 by interference fit, and the rotating cylindrical portion 12 is externally fixed to the inner end of the inner ring 6 by interference fit. In this state, the leading edges of the seal lips 11a, 11b, and 11c are arranged on the outer peripheral surface of the rotating cylindrical portion 12 and the outer peripheral surface of the rotating annular portion 13, as shown in FIG. And slide over it. Further, a detection unit of a sensor (not shown) supported on a fixed portion such as the outer ring 5 or a part of the suspension device is opposed to the inner surface of the encoder 4 via a minute gap.

In the case of the combination seal ring 1 with the encoder of the present invention, which is constructed as described above and is assembled to the rolling bearing unit 14 as described above, the outer peripheral surface and the rotation of the rotary cylindrical portion 12 constituting the slinger 3 are described. Since a portion of one side surface of the circular ring portion 13 in which the leading edges of the seal lips 11a to 11c are slidably contacted is a smooth surface, sufficient sealing performance can be ensured. In addition, a portion to be a smooth surface of the outer peripheral surface of the rotating cylindrical portion 12 and one side surface of the rotating circular ring portion 13 is sufficient as long as at least the tip edges of the seal lips 11a to 11c are in sliding contact. For example, the rotating cylinder 1
Since the leading edge of any of the seal lips does not slidably contact a continuous portion between the outer peripheral surface 2 and one side surface of the rotating circular ring portion 13, the value of the surface roughness does not necessarily need to be reduced.

On the other hand, since the other surface of the rotary ring portion 13 on which the encoder 4 is supported and fixed is a rough surface having a large surface roughness value, the coupling strength of the encoder 4 to the slinger 3 is large. Can be increased. Therefore, even if the encoder 4 is used for a long period of time, the encoder 4 can be prevented from being separated from the slinger 3, and the durability of the combined seal ring 1 with the encoder and the wheel supporting rolling bearing unit incorporating the encoder can be prevented. And the reliability of rotation speed detection can be maintained for a long period of time. Note that the inner peripheral surface of the rotary cylindrical portion 12 only needs to have such a surface roughness that the fitting surface can be sealed in a state of being fitted and fixed to the inner end of the inner ring 6.

[0019]

The combination seal ring with encoder and the rolling bearing unit for supporting a wheel incorporating the same according to the present invention are constructed and operated as described above. The reliability of the rotation speed detection by the device can be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a partially enlarged cross-sectional view showing one example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the rolling bearing unit is assembled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combination seal ring with encoder 2 Seal ring 3 Slinger 4 Encoder 5 Outer ring 6 Inner ring 7 Core metal 8 Elastic material 9 Fixed cylindrical part 10 Fixed circular part 11a, 11b, 11c Seal lip 12 Rotating cylindrical part 13 Rotating circular part 14 Rolling Bearing unit 15 Outer ring raceway 16 Mounting part 17 Hub 18 Inner ring raceway 19 Spline hole 20 Ball 21 Cage 22 Flange 23 Seal ring 24 Space

Claims (2)

[Claims] 1. A combined seal ring with an encoder for closing an open end of a space existing between a peripheral surface of a stationary wheel and a peripheral surface of a rotary wheel and detecting a rotational speed of the rotary wheel. A seal ring fixed to the peripheral surface of the stationary wheel, a metal slinger fixed to the peripheral surface of the rotating wheel, and an encoder supported and fixed to the slinger. A fixed cylindrical portion fitted and fixed to the peripheral surface of the stationary wheel and a cored bar composed of a fixed circular portion bent from the edge of the fixed cylindrical portion toward the peripheral surface of the rotating wheel;
An elastic member having a seal lip attached over the entire circumference of the cored bar, wherein the slinger has a rotating cylindrical portion fitted and fixed to a peripheral surface of the rotating wheel; A rotating circular portion bent from the end edge toward the peripheral surface of the stationary wheel, without an elastic material, and a tip of the seal lip on the peripheral surface of the rotating cylindrical portion and one side surface of the rotating circular portion. A portion where the edge is brought into sliding contact is made a smooth surface, and a surface to be supported and fixed by the encoder on the other side surface of the rotating ring portion is a rough surface having a larger surface roughness value than the peripheral surface and one side surface. The encoder is made of a permanent magnet in which S poles and N poles are alternately arranged in the circumferential direction, and is fixedly connected to the other side surface of the rotating ring portion. Combination seal ring. 2. A stationary wheel having a stationary track on a stationary peripheral surface, a rotating wheel having a rotating track on a rotating peripheral surface and capable of supporting and fixing wheels, and a stationary track and a rotating track. 2. The encoder according to claim 1, wherein the plurality of rolling elements are provided so as to be freely rotatable between the end and the end of the stationary side peripheral surface and the end of the rotating side peripheral surface. 3. Rolling bearing unit for wheel support incorporating a combined seal ring with encoder consisting of a seal ring.