JP2012036997A - Rolling bearing unit with encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a structure by which measuring performance of a rotational speed or others can be enhanced, the sealing performance of a space where an encoder body 17b and respective rollers 3 are arranged can be sufficiently secured and which can be made at low cost.SOLUTION: The axial directional inside end surface of an outer wheel 1b is located at an end outside in the axial direction more than the axial directional inside end surface of the inner wheel 11b and the diameter size of the outer periphery (surface to be detected) of the encoder body 17b supported at the axial directional inside end of the inner wheel 11b is set to be the sizes between the inner diameter size and the outer diameter size of the axial directional inside part of the outer wheel 1b. The surrounding of the encoder body 17b is covered with the non-magnetic sealing core metal 18b outwardly fitted and fixed to the axial directional inside end of the outer wheel 1b. The distal and fringes of a plurality of seal lips 20d, 20e, 20f constituting the seal material 19a fixed to the inner diameter side part of the sealing core metal 18b are slidably contact with the outer periphery of the surface of the core metal 16 for the encoder or the outer periphery of the outer ring 22a for a constant velocity joint over an entire periphery.

Description

  The present invention relates to an improvement in a rolling bearing unit with an encoder which is used for rotatably supporting a wheel of an automobile with respect to a suspension device and measuring the rotational speed of the wheel and a load applied to the wheel.

  A rolling bearing unit is used to rotatably support the wheels of the automobile with respect to the suspension system. Moreover, in order to control an anti-lock brake system (ABS) and a traction control system (TCS), it is necessary to detect the rotational speed of a wheel. For this reason, the rolling bearing unit with a rotational speed detection device incorporating a rotational speed detection device in the rolling bearing unit can support the wheel rotatably with respect to the suspension device, and can detect the rotational speed of the wheel. In recent years, it has been widely performed.

  FIGS. 6 to 7 show what is described in Patent Document 1 as a first example of a conventional structure of a rolling bearing unit with a rotational speed detection device used for such a purpose. The first example of this conventional structure is for a drive wheel. The outer wheel 1 that is supported and fixed to a suspension device does not rotate during use, and the wheel (drive wheel) is supported and fixed together with this wheel during use. A rotating hub 2, a plurality of rolling elements 3 and 3, a pair of sealing members 4 a and 4 b, an encoder 5, a sensor 6, and a drive shaft member 7 are provided.

  Of these, the outer ring 1 includes double-row outer ring raceways 8a and 8b on the inner peripheral surface, and a stationary flange 9 on the inner end portion of the outer peripheral surface. Note that “outside” with respect to the axial direction refers to the outside in the width direction of the vehicle in the assembled state in the automobile, and is the left side of each figure except FIG. On the other hand, the right side of each figure excluding FIG. 2, which is the center side in the width direction of the vehicle in the assembled state in the automobile, is referred to as “inside” in the axial direction. This is the same throughout the present specification and claims.

  In the hub 2, the hub main body 10 and the inner ring 11 fitted on the inner end in the axial direction of the hub main body 10 are coupled to each other by a caulking portion 12 formed at the inner end in the axial direction of the hub main body 10. It consists of Such a hub 2 is disposed on the inner diameter side of the outer ring 1, and a rotation-side flange 13 is provided on a portion of the outer peripheral surface that protrudes axially outward from the inner diameter side of the outer ring 1. Double row inner ring raceways 14a and 14b are respectively provided in portions facing 8a and 8b. Of these inner ring raceways 14 a and 14 b, the inner ring raceway 14 b on the inner side in the axial direction is formed on the outer peripheral surface of the inner race 11. Further, a spline hole 15 is formed in the axial direction at the center portion in the radial direction of the hub 2.

  Further, a plurality of rolling elements 3, 3 are provided between the outer ring raceways 8a, 8b and the inner ring raceways 14a, 14b so as to be freely rollable in both rows. In the illustrated example, balls are used as the rolling elements 3 and 3, but in the case of a rolling bearing unit for a heavy vehicle, tapered rollers may be used.

  The encoder 5 is externally fixed to a portion of the outer peripheral surface of the inner ring 11 that is adjacent to the inner side in the axial direction of the inner ring raceway 14b on the inner side in the axial direction. As shown in detail in FIG. 7, the encoder 5 includes an encoder cored bar 16 made of a magnetic metal plate, which is externally fitted and fixed to the inner ring 11, and an outer diameter side cylinder of the encoder cored bar 16. And a cylindrical encoder body 17 made of a permanent magnet fixedly attached to the outer peripheral surface of the portion. N poles and S poles are alternately arranged at equal intervals in the circumferential direction on the outer peripheral surface of the encoder body 17 which is a detection surface concentric with the hub 2.

  The both sealing members 4a and 4b are located between the inner peripheral surface of the outer ring 1 and the outer peripheral surface of the hub 2, and are in an internal space where the rolling elements 3 and 3 and the encoder body 17 are installed. It closes both axial direction openings, and is assembled one by one at these opening portions. This prevents leakage of the lubricating grease sealed in the internal space into the external space and prevents foreign matters such as dust, rainwater, and muddy water from entering the internal space from the external space. Further, the sealing member 4b on the inner side in the axial direction of the sealing members 4a and 4b is made of a metal plate that is fitted and fixed to the inner end of the outer ring 1 in the axial direction, as shown in detail in FIG. It consists of an annular sealing core 18 and an annular sealing material 19 made of an elastic material fixed to the inner peripheral edge of the sealing core 18. Then, the three seal lips 20a, 20b, and 20c constituting the seal material 19 are respectively arranged on the outer peripheral surface of the inner diameter side cylindrical portion of the encoder core bar 16 and the inner surface in the axial direction of the annular portion. Slid in contact with

  Further, as shown in detail in FIG. 7, the sensor 6 is inserted and supported inside an attachment hole 21 formed in a part of the sealing metal core 18, and the tip portion serving as a detection portion is covered. It is made to face and face the outer peripheral surface of the encoder body 17 that is a detection surface. A magnetic detection element such as a Hall element or a magnetoresistive element is incorporated in the detection portion of the sensor 6.

  The drive shaft member 7 includes a constant velocity joint outer ring 22 and a spline shaft 23 which is a drive shaft fixedly provided at the center of the outer end surface of the constant velocity joint outer ring 22. The spline shaft 23 is engaged with the spline hole 15 and the outer end surface of the constant velocity joint outer ring 22 is in contact with the inner end surface of the hub 2. A nut 24 is screwed onto the screw and further tightened. Thereby, the drive shaft member 7 is coupled and fixed to the hub 2 so as to be able to transmit a rotational drive force.

  When the rolling bearing unit with a rotational speed detection device configured as described above is assembled to the vehicle body, the stationary flange 9 of the outer ring 1 is coupled and fixed to a support member 25 such as a knuckle that constitutes a suspension device. The wheel is supported and fixed to the rotation side flange of the hub. When the stationary flange 9 is coupled and fixed to the support member 25, a portion that protrudes inward in the axial direction from the stationary flange 9 at the axially inner end of the outer ring 1 is the support member. The inner side surface of the stationary flange 9 is brought into contact with the side surface of the support member 25. In this state, the stationary flange 9 and the support member 25 are coupled and fixed with bolts or the like. In this state, when the hub 2 rotates together with the wheels, the N pole and the S pole existing on the detection surface of the encoder 5 alternately pass through the vicinity of the detection portion of the sensor 6. As a result, the direction of the magnetic flux flowing in the detection section of the sensor 6 changes alternately, and the output of the sensor 6 changes. The frequency at which the output of the sensor 6 changes in this way is proportional to the rotational speed of the wheel. Therefore, if the output of the sensor 6 is sent to a controller (not shown), the ABS and TCS can be controlled appropriately.

  In the case of the first example of the conventional structure as described above, it is necessary to form the mounting hole 21 in a part of the sealing core 18, which increases the processing cost. In addition, the presence of a minute gap between the inner peripheral surface of the mounting hole 21 and the outer peripheral surface of the sensor 6 may cause a decrease in sealing performance. In addition, since the encoder body 17 and the sensor 6 are arranged in a radial direction between the outer peripheral surface of the inner ring 11 and the inner peripheral surface of the outer ring 1, The diameter of the outer peripheral surface of the encoder body 17 cannot be increased too much. This is disadvantageous in improving the detection performance of the rotational speed. That is, when the number of magnetic poles arranged on the detection surface of the encoder 5 is constant, the circumferential width (magnetization area) of each magnetic pole increases as the diameter of the detection surface increases. Due to the magnetic enhancement accompanying this, the detection performance of the sensor 6 is improved. Further, when the circumferential width of each magnetic pole is constant, the larger the diameter of the detected surface, the larger the number of magnetic poles arranged on the detected surface. Will improve. On the other hand, in the case of the first example of the conventional structure described above, the diameter of the detection surface of the encoder 5 cannot be increased so much, which is disadvantageous in improving the detection performance of the rotational speed.

  Next, FIG. 8 shows what is described in Patent Document 2 as a second example of a conventional structure of a rolling bearing unit with a rotational speed detection device. In the case of the second example of the conventional structure, the sealing metal core 18a constituting the sealing member 4c supported and fixed to the inner end portion in the axial direction of the outer ring 1a is made of a nonmagnetic metal plate. A resin member 27 in which the sensor 6a is embedded is bonded and fixed to the outer surface of the sealing core 18a by insert molding. In this state, the detection portion of the sensor 6a is placed on the detection surface (the outer peripheral surface of the cylindrical encoder body 17a) of the encoder 5a that is externally fitted and fixed to the inner end portion of the inner ring 11a constituting the hub 2a. It is made to face and face through a part of the sealing core 18a.

  In the second example of the conventional structure having the above-described configuration, unlike the first example of the conventional structure, the mounting hole for the sensor 6a does not exist in a part of the sealing metal core 18a. For this reason, problems such as an increase in processing cost and a decrease in sealing performance due to the presence of the mounting hole do not occur. However, in the case of the second example of the conventional structure described above, as in the case of the first example of the conventional structure, the encoder main body 17a and the inner peripheral surface of the outer ring 1a Since the sensor 6a is arranged so as to overlap in the radial direction, the diameter of the detection surface of the encoder 5a cannot be increased too much. Therefore, it is disadvantageous in improving the performance related to rotation speed detection.

  In addition, the combination of an encoder and a sensor is not limited to the above-described rotational speed detection device, and even a load measuring device (for example, see Patent Documents 3 and 4) that has recently appeared and is being developed is applied to wheels. Used to measure load (load acting between outer ring and hub). When implementing a rolling bearing unit equipped with such a load measuring device, if the same structure as the conventional structures shown in FIGS. 6 to 8 is employed, the same problem as described above will occur.

JP 2005-42866 A JP 2008-202733 A JP 2006-317420 A JP 2008-64731 A

  The rolling bearing unit with an encoder of the present invention can improve the measurement performance of the rotational speed and the load in view of the circumstances as described above, and the inner end in the axial direction of the internal space where the encoder body and each rolling element are installed The invention was invented to realize a structure that can sufficiently secure the sealing performance of the opening and can be manufactured at low cost.

The rolling bearing unit with an encoder of the present invention includes an outer ring, a rotating body, a plurality of rolling elements, an encoder, and a sealing member.
Of these, the outer ring has a double-row outer ring raceway on the inner peripheral surface, and does not rotate while being supported by the suspension device during use.
The rotating body is disposed on the inner diameter side of the outer ring. A flange for supporting the wheel is provided on a portion of the outer peripheral surface that protrudes outward in the axial direction from the inner diameter side of the outer ring, and a double-row inner ring raceway is provided on a portion that faces both the outer ring raceways. And rotates with the wheel during use.
In addition, a plurality of rolling elements are provided between the outer ring raceways and the inner ring raceways so as to roll freely for each row.
The encoder includes an annular encoder core made of a magnetic metal material, and a cylindrical encoder body made of a permanent magnet fixed to the outer peripheral surface of the encoder core. S poles and N poles are alternately arranged in the circumferential direction on the outer peripheral surface of the encoder body. The encoder core metal is externally fixed to a part of the rotating body adjacent to the axially inner side of the inner ring raceway on the axially inner side.
The sealing member closes the axial inner end opening of the internal space in which the rolling elements and the encoder body are installed.

In particular, in the rolling bearing unit with an encoder of the present invention, the inner end surface in the axial direction of the outer ring is disposed on the outer side in the axial direction with respect to the encoder body. The diameter of the detected surface of the encoder (the outer peripheral surface of the encoder body) is larger than the inner diameter of the inner end of the outer ring in the axial direction, and the outer diameter of the inner end of the outer ring in the axial direction. Is smaller than
The sealing member includes a sealing metal core and a sealing material. Of these, the sealing metal core is made of a nonmagnetic metal material in an annular shape, surrounds the periphery of the detection surface of the encoder, and partially closes the detection surface. The outer ring is supported and fixed to the inner end in the axial direction. The sealing material is formed in an annular shape by an elastic material, and is fixed to the inner diameter side portion of the sealing metal core, and the tip edge thereof extends over the entire surface of the encoder metal core. It has a seal lip in sliding contact.

In the case of carrying out the present invention, the wheel is a drive wheel, and the rotating body is formed by coupling a hub and a drive shaft member to each other. The flange and the pair of inner ring raceways each have a spline hole extending in the axial direction in the radial center, and the drive shaft member is disposed adjacent to the hub in the axial direction. And a spline shaft fixed to the outer end surface in the axial direction of the outer ring for the constant velocity joint and engaged with the spline hole, and the encoder is arranged in the axial direction of the hub. In the case of targeting a structure that is externally fitted and fixed to the end, the configuration of the invention described in claims 2 to 3 is preferably employed.
When the configuration of the invention described in claim 2 is adopted, the seal member is provided with a seal lip whose tip edge is in sliding contact with the outer circumferential surface of the constant velocity joint outer ring over the entire circumference. Let
On the other hand, when the configuration of the invention described in claim 3 is adopted, an annular slinger is externally fitted and fixed to a portion near the outer end of the constant velocity joint outer ring in the axial direction. At the same time, the seal material is provided with a seal lip whose tip edge is in sliding contact with the entire surface of the slinger.
In carrying out the invention described in claim 3, it is preferable that, as in the invention described in claim 4, the tip edge of the sealing material is the outer peripheral surface of the outer ring for the constant velocity joint. Among them, a seal lip is provided which is slidably contacted on the entire outer periphery in the axially outer portion than the portion where the slinger is fitted and fixed.
Further, when carrying out the inventions according to the third to fourth aspects, preferably, as in the invention according to the fifth aspect, the periphery of the seal lip in which the slinger is brought into sliding contact with the surface of the slinger. And the base end portion of the slinger is externally fitted to the outer ring for the constant velocity joint, and the front end portion of the slinger is made to face the surface of the sealing metal core.

  In carrying out the present invention, preferably, as in the invention described in claim 6, the encoder body protrudes outward in the radial direction and is not magnetized at a part in the radial direction of the outer end surface in the axial direction of the encoder body. Convex parts are formed over the entire circumference. At the same time, the tip edge of the convex portion is made to face and oppose the entire inner circumference of the outer ring in the axial direction.

  In carrying out the present invention, preferably, as in the invention described in claim 7, a part of the core metal for the encoder is in an internal space in which the encoder body and the rolling elements are arranged. An annular second sealing material is fixed to the existing portion. At the same time, the second seal material is provided with a seal lip whose tip edge is slidably contacted with the axially inner end surface of the outer ring.

  Further, when carrying out the present invention, preferably, as in the invention described in claim 8, of the outer peripheral surface of a portion of the sealing metal core that is close to and faces the detection surface of the encoder. In addition, a rubber layer is provided at a portion where the front end surface of the sensor is brought into contact with the sensor in use.

According to the rolling bearing unit with an encoder of the present invention configured as described above, the rotational speed and load measurement performance can be improved, and the shaft of the internal space where the detected surface of the encoder and each rolling element are installed It is possible to sufficiently secure the sealing property of the inner end opening in the direction and to manufacture at a low cost.
That is, when the number of magnetic poles arranged on the detection surface of the encoder is constant, the circumferential width (magnetization area) of each magnetic pole increases as the diameter of the detection surface increases. The detection performance of the sensor is improved by the magnetic strengthening associated with. For example, the reliability can be improved by increasing the signal voltage. Further, when the circumferential width of each magnetic pole is made constant, the larger the diameter of the detected surface, the more the number of magnetic poles arranged on the detected surface. improves. On the other hand, in the case of the present invention, the diameter dimension of the detected surface of the encoder is larger than the inner diameter dimension of the inner end portion in the axial direction of the outer ring. For this reason, in the case of the present invention, as in the conventional structures shown in FIGS. 6 to 8 described above, the diameter dimension of the detection surface of the encoder is smaller than the inner diameter dimension of the inner end portion in the axial direction of the outer ring. Compared with the existing structure, the measurement performance of the rotational speed and load can be improved.
In the case of the present invention, it is not necessary to form a mounting hole for inserting and supporting the sensor in the sealing core. For this reason, there is no problem that the sealing performance of the axially inner end opening of the internal space is lowered due to the presence of the mounting hole. Therefore, it is possible to sufficiently secure the sealing performance of the inner end opening in the axial direction of the internal space.
Furthermore, in the case of the present invention, the processing cost of the mounting hole of the sensor is not required, so that the manufacturing cost can be reduced.

  Moreover, if the structure of the invention described in claims 2 to 4 is adopted, it is based on the presence of a seal lip that constitutes the seal material in sliding contact with the outer peripheral surface of the constant velocity joint outer ring or the surface of the slinger. Thus, the sealing performance of the internal space can be improved. At the same time, it is possible to prevent foreign matter such as rain water and muddy water from entering the spline engaging portion between the spline hole and the spline shaft from the inside in the axial direction of the spline engaging portion. For this reason, the antirust effect of this spline engaging part by the grease apply | coated to this spline engaging part can be maintained for a long period of time. As a result, it is possible to prevent a problem that it is difficult to extract the spline shaft from the spline hole during inspection, repair, or the like.

  Further, if the configuration of the invention described in claim 5 is adopted, the sealing performance of the internal space and the spline engaging portion can be improved based on the presence of the slinger. At the same time, foreign matters such as stepping stones can be prevented from colliding with the seal lip slidably contacted with the surface of the slinger and the seal lip slidably contacted with the outer peripheral surface of the constant velocity joint outer ring. As a result, each of these seal lips can be prevented from being damaged.

Further, if the configuration of the invention described in claim 6 is adopted, each of the rollers is based on the presence of a convex portion constituting the encoder body, the tip edge of which is in close proximity to the axial inner end surface of the outer ring. The lubricating grease sealed in the space where the moving body is installed can be prevented from leaking into the space where the encoder body is installed.
That is, when carrying out the present invention, it is possible to prevent the magnetic flux entering and exiting from the detected surface of the encoder from being drawn to the inner end surface in the axial direction of the outer ring (magnetic flux leaks to the outer ring). Therefore, a gap somewhat larger than the minimum gap necessary to avoid mutual contact is interposed between the axial inner end surface of the outer ring and the axial outer end surface of the encoder body ( It is preferable that the detected surface is moved away from the inner end surface in the axial direction of the outer ring in the axial direction. However, the larger this gap is, the easier it is for the lubricating grease in the space where the rolling elements are installed to leak into the space where the encoder body is installed. On the other hand, if the convex portion as described above is provided, the detected surface is moved away from the axially inner end surface of the outer ring in the axial direction, and the lubricating grease is prevented from leaking through the gap. it can.
In addition, since the said convex part is not magnetized, the malfunction that the shape of the magnetic flux entering / exiting from the said to-be-detected surface is distorted based on the presence of this convex part does not arise.

  Further, if the configuration of the invention described in claim 7 is adopted, each of the rolling elements is installed based on the presence of a seal lip that constitutes the second seal member that is in sliding contact with the axially inner end surface of the outer ring. It is possible to prevent the lubricating grease sealed in the space from leaking into the space where the encoder body is installed.

  Further, if the configuration of the invention described in claim 8 is adopted, it is possible that foreign matter such as magnetic powder enters between the outer peripheral surface of the sealing metal core and the front end surface of the sensor based on the presence of the rubber layer. Can be prevented. For this reason, the reliability regarding the measurement of a rotational speed and a load can be improved. Furthermore, fretting wear can be prevented from occurring between the outer peripheral surface of the sealing metal core and the front end surface of the sensor based on the presence of the rubber layer.

The expanded sectional view equivalent to the A section of Drawing 6 showing the 1st example of an embodiment of the invention. The figure which looked at the circumference direction part of the outer periphery side part of the metal core for sealing from the axial direction inner side. The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention. The figure similar to FIG. 1 which shows the 3rd example. The figure similar to FIG. 1 which shows the 4th example. Sectional drawing which shows the 1st example of the conventional structure of a rolling bearing unit with a rotational speed detection apparatus. The A section enlarged view of FIG. The figure similar to FIG. 7 which shows the 2nd example of the conventional structure of a rolling bearing unit with a rotational speed detection apparatus.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1, 2, and 6. FIG. The feature of this example is the structure of the encoder 5b and the sealing member 4d and the structure of the place where the encoder 5b and the sealing member 4d are assembled. The structure and operation of other parts are basically the same as those of the first example of the conventional structure shown in FIGS. For this reason, illustrations and explanations of equivalent parts are omitted or simplified, and hereinafter, the characteristic parts of this example and parts different from the first example of the conventional structure will be mainly described.

  In the case of this example, a caulking portion is not formed at the axial inner end portion of the hub body 10a constituting the hub 2b, and the drive shaft member 7a is constituted on the axial inner end surface of the inner ring 11b constituting the hub 2b. The axial outer end surface of the constant velocity joint outer ring 22a is in direct contact with each other. In the case of this example, the hub 2b and the drive shaft member 7a correspond to a rotating body. In the case of this example, the inner end surface in the axial direction of the outer ring 1b is arranged at a position slightly shifted outward in the axial direction from the inner end edge in the axial direction of the inner ring raceway 14b formed on the outer peripheral surface of the inner ring 11b. is doing. Of the outer peripheral surface of the inner ring 11b, the portion adjacent to the inner side in the axial direction of the inner ring raceway 14b, that is, the inner end portion in the axial direction of the outer peripheral surface of the inner ring 11b, than the inner end surface in the axial direction of the outer ring 1b. The encoder 5b is fitted and fixed to a portion protruding inward in the axial direction.

  The encoder 5b includes an encoder core 16a and an encoder body 17b. Of these, the encoder core 16a is made of a magnetic metal plate such as a mild steel plate or a magnetic stainless steel plate in an annular shape as a whole, and includes an outer diameter side cylindrical portion 28 and an inner diameter side cylindrical portion 29 that are concentric with each other. An annular portion 30 that connects the outer end edges in the axial direction of both the outer diameter side and inner diameter side cylindrical portions 28 and 29 is provided. Of these, the inner diameter side cylindrical portion 29 is externally fitted to the inner end portion in the axial direction of the inner ring 11b with an interference fit. The encoder body 17b is made of a rubber magnet or a plastic magnet, and is formed in a cylindrical shape as a whole, and is fixed to the outer peripheral surface of the outer diameter side cylindrical portion 28. On the outer peripheral surface of the encoder body 17b, which is a detection surface concentric with the hub 2b, N poles and S poles are alternately arranged at equal intervals in the circumferential direction. In particular, in the case of this example, the diameter dimension of the detection surface of the encoder 5b is larger than the inner diameter dimension of the inner end portion in the axial direction of the outer ring 1b, and the outer diameter of the inner end portion in the axial direction of the outer ring 1b. It is smaller than the diameter dimension. More specifically, the diameter dimension of the surface to be detected of the encoder 5b is approximately the average value of the inner diameter dimension and the outer diameter dimension of the inner end in the axial direction of the outer ring 1b {diameter dimension≈ (inner diameter dimension + outer diameter). Dimension) / 2}. For this purpose, the outer diameter of the outer diameter side cylindrical portion 28 and the radial thickness of the encoder body 17b are restricted.

  In the case of this example, the minimum necessary for avoiding mutual contact between the axial inner end surface of the outer ring 1b and the radially outer end portion or intermediate portion of the axial outer end surface of the encoder body 17b. A gap slightly larger than the limit gap is interposed. As a result, the detected surface of the encoder 5b is moved away from the axially inner end surface of the outer ring 1b in the axial direction, and a large amount of magnetic flux entering and exiting from the detected surface is drawn into the axially inner end surface of the outer ring 1b. (The magnetic flux entering and exiting from the detected surface leaks to the outer ring 1b). In the case of this example, the inner peripheral edge portion of the outer end surface in the axial direction of the encoder body 17b protrudes outward in the axial direction from the outer peripheral surface of the outer cylindrical portion 28 and is magnetized. The convex part 31 which is not performed is provided over the perimeter. And the labyrinth clearance gap is formed in the part which made the front-end edge of this convex part 31 face and oppose to the inner peripheral part of the axial direction inner end surface of the said outer ring | wheel 1b over the perimeter.

  In the case of this example, the sealing member 4d is supported and fixed to the inner end in the axial direction of the outer ring 1b. The sealing member 4d includes a sealing core 18b and a sealing material 19a. Of these, the sealing core 18b is made of a non-magnetic metal plate such as a non-magnetic stainless steel plate or an aluminum alloy plate in an annular shape as a whole, and has a cylindrical peripheral wall portion 32 and a shaft of the peripheral wall portion 32. And a side wall portion 33 bent inward in the radial direction from the inner edge in the direction. A flat portion 34 that is recessed inward in the radial direction from the other portion of the peripheral wall portion 32 is provided in a portion in the circumferential direction of the inner half portion in the axial direction of the peripheral wall portion 32. Further, by providing the inclined portion 35 on the inner peripheral portion of the side wall portion 33, the inner diameter side of the side wall portion 33 is positioned on the outer side in the axial direction as compared with the outer diameter side. Such a sealing metal core 18b is configured such that the outer end in the axial direction of the peripheral wall portion 32 is externally fitted to the inner end in the axial direction of the outer ring 1b with an interference fit, thereby the inner end in the axial direction of the outer ring 1b. Is supported and fixed. In this state, the sealing core 18b surrounds the encoder body 17b and the flat portion 34 is in close proximity to the detected surface of the encoder 5b.

  The sealing material 19a is made of an elastic material such as an elastomer such as rubber, and is formed in an annular shape as a whole, and the radially inner end or intermediate portion of the side wall 33 constituting the sealing core 18b. It is fixed to. In the case of this example, the sealing material 19a has three sealing lips 20d, 20e, and 20f. Of these, the tip edges of the two seal lips 20d, 20e are attached to the outer peripheral surface of the inner diameter side cylindrical portion 29 constituting the encoder core 16a, and the tip edges of the remaining one seal lip 20f are Out of the outer peripheral surface of the constant velocity joint outer ring 22a, it is in sliding contact with the entire circumference of the inclined surface portion present near the outer end in the axial direction. Of the outer peripheral surface of the constant velocity joint outer ring 22a, at least the portion where the tip edge of the one seal lip 20f is slidably contacted is a smooth surface. In the case of this example, the outer diameter dimension in the free state of the tip edge of the one seal lip 20f is smaller than the outer diameter dimension of the peripheral wall portion 32 constituting the sealing metal core 18b (specifically, Is smaller than the diameter dimension of a circle centered on the central axis of the peripheral wall portion 32 and in contact with the outer diameter side surface of the flat portion 34. As a result, the axial direction of the peripheral wall portion 32 is not obstructed by the one seal lip 20f when the axially outer end portion of the peripheral wall portion 32 is press-fitted into the axially inner end portion of the outer ring 1b. The inner edge can be pressed by a pressing jig.

  In the case of this example, the front end surface (the flat surface, the lower end surface in FIG. 1) of the sensor 6b is brought into contact with the outer diameter side surface of the flat portion 34. Thereby, the detection part provided in the front-end | tip part of this sensor 6b is made to oppose and close to the to-be-detected surface of the said encoder 5b through the said flat part 34. FIG. In this state, the sensor 6b is supported by a part of the vehicle body that does not rotate during use, such as a part of the support member 25 that constitutes the suspension device.

According to the rolling bearing unit with an encoder of the present example configured as described above, the performance of detecting the rotational speed can be improved, and the internal space in which the encoder body 17b and the rolling elements 3 and 3 are installed can be improved. The sealability of the axially inner end opening can be sufficiently secured and can be manufactured at low cost.
That is, in the case of this example, the diameter dimension of the detection surface of the encoder 5b is larger than the inner diameter dimension of the inner end portion in the axial direction of the outer ring 1b. For this reason, as in each of the conventional structures shown in FIGS. 6 to 8 described above, the diameter of the detected surface of the encoder 5, 5a is smaller than the inner diameter of the inner end of the outer ring 1, 1a in the axial direction. Compared to the structure, the circumferential width (magnetization area) of each magnetic pole existing on the detected surface can be increased, or the number of magnetic poles existing on the detected surface can be increased. As a result, in the case of this example, it is possible to improve the rotational speed detection performance by the combination of the encoder 5b and the sensor 6b.
In the case of this example, the encoder 5b is fitted on the inner end portion of the inner ring 11b with the outer peripheral surface being a ground surface with good dimensional accuracy. For this reason, the inner peripheral surface of the inner diameter side cylindrical portion 29 constituting the encoder core metal 16a, which is a fitting surface with the ground surface, and the outer peripheral surface of the encoder main body 17b, which is a detected surface, are concentric. Thus, if the encoder body 17b is vulcanized or injection-molded, it is possible to sufficiently suppress radial deflection of the detected surface during use. Therefore, in the case of this example, the air gap (opposite distance) between the detection surface of the encoder 5b and the detection portion of the sensor 6b is only required if the dimensions of the flat portion 34 constituting the sealing core 18b are strictly controlled. Can be set sufficiently small. As a result, coupled with the large diameter size of the surface to be detected as described above, sufficient rotation speed detection performance can be ensured.

In the case of this example, it is not necessary to form a mounting hole for inserting and supporting the sensor 6b in the sealing core 18b. For this reason, there is no problem that the sealing performance of the axially inner end opening of the internal space is lowered due to the presence of the mounting hole. Therefore, it is possible to sufficiently secure the sealing performance of the inner end opening in the axial direction of the internal space.
Furthermore, in the case of this example, the manufacturing cost can be reduced because the processing cost of the mounting hole of the sensor 6b becomes unnecessary.

  In the case of this example, the seal material 19a is used for a constant velocity joint in addition to the two seal lips 20d and 20e slidably in contact with the outer peripheral surface of the inner diameter side cylindrical portion 29 constituting the encoder core metal 16a. One seal lip 20f is provided to be slidably brought into contact with the outer peripheral surface of the outer ring 22a near the outer end in the axial direction. For this reason, the sealing performance of the internal space can be improved as compared with the structure having only the two sealing lips 20d and 20e. Further, based on the presence of the one seal lip 20f, the spline engagement portion is connected to the spline engagement portion between the spline hole 15 of the hub 2b and the spline shaft 23 (see FIG. 6) of the drive shaft member 7a. It is possible to prevent foreign substances such as rainwater and muddy water from entering from the inside in the axial direction. For this reason, the antirust effect of this spline engaging part by the grease apply | coated to this spline engaging part can be maintained for a long period of time. As a result, it is possible to prevent a problem that it becomes difficult to pull out the spline shaft 23 from the spline hole 15 during inspection, repair, or the like.

  Further, in the case of this example, the tip edge of the convex portion 31 provided on the inner peripheral edge portion of the outer end surface in the axial direction of the encoder body 17b extends over the entire inner periphery portion of the inner end surface in the axial direction of the outer ring 1b. The labyrinth gap is formed in the portion opposed to each other by making it face and face each other. For this reason, the surface to be detected is moved away from the axially inner end surface of the outer ring 1b in the axial direction, and the lubricating grease sealed in the space in which the rolling elements 3 and 3 are installed causes the encoder main body 17b to move. Leakage into the installed space can be suppressed. In the case of this example, since the convex portion 31 is not magnetized, there is a problem that the shape (distribution) of the magnetic flux entering and exiting from the detected surface is distorted based on the presence of the convex portion 31. It never happens.

  In the case of this example, with respect to the peripheral wall portion 32 constituting the sealing core 18b, only the flat portion 34 sandwiched between the sensor 6b and the encoder 5b is the detected surface of the encoder 5b. The other part is in a state slightly away from the detected surface. For this reason, the magnetic flux reaching the outside is weakened at the portion of the peripheral wall portion 32 that is separated from the flat portion 34, and the magnetic material such as iron powder or iron pieces is less likely to adhere to the outer peripheral surface of the portion. Therefore, it is possible to sufficiently suppress the occurrence of so-called rust, which is formed by oxidizing the attached magnetic material.

[Second Example of Embodiment]
FIG. 3 shows a second example of an embodiment of the present invention corresponding to claims 1 to 5 and 8. In the case of this example, a small diameter step portion 36 is formed on the outer peripheral surface of the inner end portion in the axial direction of the outer ring 1c. And the axial direction outer end part of the surrounding wall part 32 is externally fitted by this interference fitting to this small diameter step part 36 among the sealing metal cores 18b which comprise the sealing member 4e. In this state, the sealing member 4e is positioned in the axial direction by abutting the axial outer end edge of the peripheral wall portion 32 against the step surface existing at the base end portion of the small diameter step portion 36. Yes. Further, in the case of this example, a locking groove 37 is formed over the entire circumference in the axially intermediate portion of the small diameter step portion 36, and an O-ring 38 is mounted in the locking groove 37. The O-ring 38 is compressed between the bottom surface of the locking groove 37 and the inner peripheral surface of the outer peripheral end portion of the peripheral wall portion 32, so that the outer peripheral end portion of the peripheral wall portion 32 and the small diameter portion are compressed. The fitting part with the step part 36 is sealed.

In the case of this example, the encoder core bar 16b constituting the encoder 5c includes an annular spacer 39 bent at a right angle inward in the radial direction from the axial inner end of the inner diameter side cylindrical portion 29. . The spacer portion 39 is brought into contact with the inner end surface of the inner ring 11b in the axial direction, thereby positioning the encoder 5c in the axial direction. Further, in the case of this example, the spacer 39 is sandwiched between the axial inner end surface of the inner ring 11b and the axial outer end surface of the constant velocity joint outer ring 22a.
In the case of this example, by appropriately selecting the material, heat treatment, surface treatment, etc. of the encoder core bar 16b provided with the spacer 39, the inner end face in the axial direction of the inner ring 11b and the like The fretting wear is prevented from occurring between the outer peripheral surface 22a of the fast joint and the axial direction outer end surface.

  In the case of this example, a thin rubber layer 40 is vulcanized and bonded to a portion of the outer diameter side surface of the flat portion 34 constituting the sealing metal core 18b where the tip surface of the sensor 6b comes into contact. During use, the tip surface of the sensor 6b is brought into contact with the outer diameter side surface of the rubber layer 40, so that magnetic powder or the like is placed between the tip surface of the sensor 6b and the outer diameter side surface of the flat portion 34. Prevents foreign objects from entering. Thereby, the reliability regarding rotation speed detection is improved. Furthermore, fretting wear is prevented from occurring between the front end surface of the sensor 6b and the outer diameter side surface of the flat portion 34 based on the presence of the rubber layer 40.

  In the case of this example, a slinger 41 is fitted and fixed to a portion near the outer end in the axial direction of the outer ring 22a for the constant velocity joint and a portion whose outer peripheral surface is a cylindrical surface. The slinger 41 is made of a metal plate having excellent corrosion resistance, such as a stainless steel plate, and is formed into an annular shape as a whole with a crank-shaped cross section. The outer diameter side cylindrical portion 42 and the inner diameter side cylindrical portion 43 are concentric with each other. An annular portion 44 that connects the axial inner end edge of the outer diameter side cylindrical portion 42 and the axial outer end edge of the inner diameter side cylindrical portion 43 is provided. Of these, the inner diameter side cylindrical portion 43 is externally fitted into a portion near the outer end in the axial direction of the outer ring 22a for the constant velocity joint with a cylindrical outer surface. In this state, the axial outer end edge of the outer diameter side cylindrical portion 42 is the axis of the portion of the peripheral wall portion 32 constituting the sealing metal core 18b that is out of the flat portion 34 in the circumferential direction. It is made to face and oppose the inner edge in the direction. As a result, a labyrinth gap is formed in the portion opposed to each other.

  In the case of this example, two seal lips 20g and 20h are added as components of the sealing material 19b constituting the sealing member 4e. The leading edge of one of the seal lips 20g is formed on the inner surface in the axial direction of the annular ring portion 30 constituting the encoder core 16b, and the leading edge of the other sealing lip 20h is formed on the slinger 41. The ring portion 44 is in sliding contact with the entire outer circumference in the axial direction. This improves the sealing performance of the internal space in which the rolling elements 3 and the encoder main body 17c are installed, and the spline engagement portion (see FIG. 6) between the spline hole 15 and the spline shaft 23.

  In the case of this example, the slinger 41 is arranged so as to cover the periphery of the other seal lip 20h, and the labyrinth gap is provided between the slinger 41 and the sealing core 18b. Is formed. For this reason, the sealing performance of the internal space and the spline engaging portion can be improved. At the same time, foreign matters such as stepping stones can be prevented from colliding with the seal lip 20h slidably in contact with the surface of the slinger 41 and the seal lip 20f slidably in contact with the outer peripheral surface of the outer ring 22a for the constant velocity joint. As a result, the seal lips 20f and 20h can be prevented from being damaged.

  In the case of this example, between the axial outer end edge of the outer diameter side cylindrical portion 42 constituting the slinger 41 and the axial inner end edge of the flat portion 34 constituting the sealing core 18b. A gap larger than the labyrinth gap exists in a state of opening outward in the axial direction. However, the tip of the sensor 6b is arranged at a portion facing the opening of the large gap. For this reason, in the case of this example, the front end portion of the sensor 6b functions as a blocking member for suppressing foreign matter from entering the slinger 41 through the large gap.

  In the case of this example, the convex portion 31 (see FIG. 1) is not provided on the outer end surface of the encoder body 17c, but this convex portion 31 may be provided. Other configurations and operations are the same as those in the first example of the embodiment shown in FIGS.

[Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the invention corresponding to claims 1 to 5 and 8. In the case of this example, by making the diameter of the outer diameter side cylindrical portion 42a constituting the slinger 41a smaller than in the case of the second example of the embodiment described above, the axial direction of the outer diameter side cylindrical portion 42a. The outer end edge is closely opposed to the outer peripheral portion of the inner side surface in the axial direction of the side wall 33 constituting the sealing core 18b over the entire circumference. Thus, by forming a labyrinth gap over the entire circumference between the slinger 41a and the sealing core 18b, the foreign matter intrusion preventing effect based on the presence of the slinger 41a is achieved in the second embodiment. It is higher than the case of the example. Other configurations and operations are the same as those in the second example of the embodiment shown in FIG.

[Fourth Example of Embodiment]
FIG. 5 shows a fourth example of an embodiment of the present invention corresponding to claims 1, 3 and 7. In the case of this example, the flat portion 34 (see FIGS. 1 and 2) is not provided in a part of the peripheral wall portion 32a constituting the sealing core 18c, and the entire peripheral wall portion 32a is simply cylindrical. Thereby, in the case of this example, by increasing the diameter dimension of the detected surface of the encoder 5d close to the inner diameter dimension of the peripheral wall portion 32a (the outer diameter dimension of the inner end portion in the axial direction of the outer ring 1b), The detected surface is closely opposed to the inner peripheral surface of the peripheral wall portion 32a over the entire periphery. In the case of this example, the performance relating to the rotational speed detection is further improved by further increasing the diameter of the surface to be detected in this way. At the same time, by reducing the area where the space where the magnetic flux entering and exiting from the detected surface exists and the inner end surface of the outer ring 1b face in the axial direction, the magnetic flux entering and exiting from the detected surface enters the outer ring 1b. It is difficult to leak. Further, the outer diameter of the annular portion 30a constituting the encoder core 16c is increased, and the seal constituting the second seal member 45 fixed to the radially intermediate portion of the outer circumferential surface of the annular portion 30a. The tip edge of the lip 20k is brought into sliding contact with the inner end surface of the outer ring 1b over the entire circumference. As a result, the space between the rolling elements 3 and the space where the encoder body 17d is installed are blocked. In the case of the illustrated example, the inclination direction of the seal lip 20k constituting the second seal material 45 is set to a direction in which it is easy to prevent water from entering the space where the rolling elements 3 and 3 are installed. When the present invention is implemented, the direction can be reversed, that is, the direction in which it is easy to prevent the lubricating grease from leaking into the space where the encoder body 17d is installed.

  In the case of this example, the tip surface of the sensor 6c is in close contact with the outer peripheral surface of the peripheral wall portion 32a as a partial cylindrical concave surface that matches the outer peripheral surface of the peripheral wall portion 32a. In the case of this example as well, a rubber layer can be provided on a portion of the outer peripheral surface of the peripheral wall portion 32a that is in contact with the tip surface of the sensor 6c. In this case, if the thickness of the rubber layer is changed in the circumferential direction, and the outer side surface of the rubber layer (the surface on which the tip surface of the sensor 6c abuts) is flat, the tip surface of the sensor 6c. Can also be flat.

In the case of this example, the slinger 41b fitted and fixed to the portion near the outer end in the axial direction of the outer ring 22a for the constant velocity joint includes only the inner diameter side cylindrical portion 43 and the annular portion 44.
In the case of this example, the sealing material 19c constituting the sealing member 4f is provided with a sealing lip 20m having a bifurcated tip at the outer diameter side portion, and the bifurcated leading edge of the sealing lip 20m is connected to the slinger. The outer circumferential surface of the annular portion 44 constituting 41b is in sliding contact with the entire circumference.
Other configurations and operations are the same as those in the above-described embodiments.

The present invention is not limited to the rolling bearing unit with an encoder used for detecting the rotational speed, but can also be applied to the rolling bearing unit with an encoder used for measuring the load described above.
The present invention is not limited to a rolling bearing unit with an encoder for driving wheels, but can be applied to a rolling bearing unit with an encoder for driven wheels. In the case of a rolling bearing unit with an encoder for a driven wheel, there is no drive shaft member that is coupled and fixed to a hub that rotates together with the wheel, so only this hub corresponds to a rotating body.

DESCRIPTION OF SYMBOLS 1, 1a-1c Outer ring 2, 2a-2b Hub 3 Rolling element 4a-4f Seal member 5, 5a-5d Encoder 6, 6a-6b Sensor 7, 7a Drive shaft member 8a, 8b Outer ring track 9 Stationary side flange 10, 10a Hub body 11, 11a, 11b Inner ring 12 Caulking portion 13 Rotating flange 14a, 14b Inner ring raceway 15 Spline hole 16, 16a-16c Encoder core 17, 17a-17d Encoder body 18, 18a-18c Sealing core 19, 19a to 19c Sealing material 20a to 20m Seal lip 21 Mounting hole 22, 22a Constant velocity joint outer ring 23 Spline shaft 24 Nut 25 Support member 26 Mounting hole 27 Resin member 28 Outer diameter side cylindrical portion 29 Inner diameter side cylindrical portion 30, 30a Circle Ring part 31 Convex part 32, 32a Peripheral wall part 33 Side wall part 34 Flat part 35 Inclined portion 36 Small diameter step portion 37 Locking groove 38 O-ring 39 Spacer portion 40 Rubber layer 41, 41a Slinger 42, 42a Outer diameter side cylindrical portion 43 Inner diameter side cylindrical portion 44 Annular portion 45 Second seal material

Claims (8)

An outer ring, a rotating body, a plurality of rolling elements, an encoder, and a sealing member;
Of these, the outer ring has a double row outer ring raceway on the inner peripheral surface, and does not rotate while being supported by the suspension device during use.
The rotating body is disposed on the inner diameter side of the outer ring, and a flange for supporting a wheel on a portion of the outer peripheral surface that protrudes outward in the axial direction from the inner diameter side of the outer ring, Each having a double-row inner ring raceway in a portion opposed to and rotating with the wheel during use,
Each of the rolling elements is provided between the outer ring raceway and the inner ring raceway so as to be freely rollable for each row.
The encoder includes an annular encoder core made of a magnetic metal material, and a cylindrical encoder body made of a permanent magnet fixed to the outer peripheral surface of the encoder core, and is a detected surface. The S pole and the N pole are alternately arranged in the circumferential direction on the outer peripheral surface of the encoder body, and the core metal for the encoder is a part of the rotating body and the shaft of the inner ring raceway on the inner side in the axial direction. It is fitted and fixed to the part adjacent to the inner side in the direction,
The sealing member closes an axially inner end opening of an internal space where the rolling elements and the encoder body are installed.
In rolling bearing unit with encoder,
An inner end surface in the axial direction of the outer ring is disposed on the outer side in the axial direction from the encoder body, and a diameter dimension of the detected surface of the encoder is larger than an inner diameter dimension of the inner end portion in the axial direction of the outer ring, and The outer diameter of the outer ring is smaller than the outer diameter of the inner end,
The sealing member includes a sealing metal core and a sealing material, and the sealing metal core is formed in an annular shape from a nonmagnetic metal material, and surrounds the detected surface of the encoder. The seal member is supported and fixed to the inner end portion in the axial direction of the outer ring with a part facing and close to the detection surface, and the sealing material is formed in an annular shape by an elastic material, and the sealing core It is fixed to the inner diameter side portion of the gold, and has a seal lip whose tip edge is in sliding contact with the entire surface of the core metal for the encoder,
Rolling bearing unit with encoder. The wheels are drive wheels;
The rotating body is formed by coupling a hub and a drive shaft member to each other, and the hub includes the flange and the pair of inner ring raceways on an outer peripheral surface and an axial center on a radial center portion. The drive shaft member is fixed to an outer ring for a constant velocity joint disposed adjacent to an inner side in the axial direction of the hub and an outer end surface in the axial direction of the outer ring for the constant velocity joint. A spline shaft that engages with the spline hole and the spline;
The encoder is fixedly fitted to the inner end of the hub in the axial direction,
The seal material includes a seal lip whose tip edge is in sliding contact with the outer peripheral surface of the constant velocity joint outer ring over the entire circumference.
The rolling bearing unit with an encoder according to claim 1. The wheels are drive wheels;
The rotating body is formed by coupling a hub and a drive shaft member to each other, and the hub includes the flange and the pair of inner ring raceways on an outer peripheral surface and an axial center on a radial center portion. The drive shaft member is fixed to an outer ring for a constant velocity joint disposed adjacent to an inner side in the axial direction of the hub and an outer end surface in the axial direction of the outer ring for the constant velocity joint. A spline shaft that engages with the spline hole and the spline;
The encoder is fixedly fitted to the inner end of the hub in the axial direction,
An annular slinger is fitted and fixed to a portion near the outer end in the axial direction of the outer ring for the constant velocity joint,
The sealing material includes a sealing lip whose tip edge is in sliding contact with the entire surface of the slinger.
The rolling bearing unit with an encoder according to claim 1.   The seal material includes a seal lip whose tip edge is slidably contacted with the entire outer periphery of the outer peripheral surface of the constant velocity joint outer ring on the outer periphery in the axial direction from the portion where the slinger is fitted and fixed. A rolling bearing unit with an encoder according to claim 3.   The slinger is disposed in a state of covering the periphery of the seal lip that is in sliding contact with the surface of the slinger, and a base end portion is fitted on the outer ring for the constant velocity joint, and a distal end portion is disposed on the sealing core. The rolling bearing unit with an encoder according to any one of claims 3 to 4, wherein the rolling bearing unit has an encoder close to and opposed to the gold surface.   A convex portion that protrudes outward in the axial direction and is not magnetized is formed over the entire circumference on a part of the outer radial surface of the encoder body in the radial direction, and the tip edge of the convex portion is formed in the axial direction of the outer ring. The bearing unit with an encoder according to any one of claims 1 to 5, wherein the bearing unit is closely opposed to the inner end surface over the entire circumference.   An annular second sealing material is fixed to a part of the core metal for the encoder, which is present in an internal space where the encoder main body and the rolling elements are arranged, and the second sealing material is The bearing unit with an encoder according to any one of claims 1 to 6, comprising a seal lip whose tip edge is slidably contacted with the inner end surface in the axial direction of the outer ring.   The rubber layer is provided in the part which the front-end | tip surface of a sensor contact | abuts in the outer peripheral surface of the part which adjoined and opposed the to-be-detected surface of the said encoder in a part of said core metal for sealing. The rolling bearing unit with an encoder described in any one of? 7.

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