JP2006349073A - Bearing for electromagnetic clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for an electromagnetic clutch capable of preventing electrolytic corrosion caused by spark and failure of a rotary sensor. <P>SOLUTION: This bearing 1 for the electromagnetic clutch constituted by a rolling bearing having a rolling body 23 between an inner ring 21 and an outer ring 22 has an insulation function. The insulation function is provided, for example, between the inner ring 21 and the outer ring 22. In this case, at least one of the inner ring 21, the outer ring 22, and the rolling body 23 is made of ceramics. This bearing 1 may have the rotary sensor 30. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bearing for an electromagnetic clutch used for a car air conditioner electromagnetic clutch portion or the like.

Generally, a lock sensor is attached to an electromagnetic clutch for a car air conditioner in order to control on / off of the clutch in accordance with an engine state, a running state, and a compressor body state. By taking the output signal of this sensor into the control unit, slippage of the timing belt is detected. As the lock sensor, for example, a rotation sensor or the like provided at the casing end of the compressor or the like for detecting the rotation of the drive shaft is used.
In this type of electromagnetic clutch, a pulley in which a rotating member to be hung on a belt is fixed to an outer ring of a rolling bearing is used, and a rotatable driven member is attracted to the rotating member by an electromagnetic force of a coil (for example, Patent Document 1). As the rolling bearing that supports the rotating member, a double-row angular ball bearing or a single-row multi-point contact ball bearing is used.
Further, a rolling bearing with a built-in rotation sensor has been proposed (for example, Patent Document 2).
Japanese Unexamined Patent Publication No. 2000-170752 JP 2003-240007 A

  However, in such an electromagnetic clutch bearing, if the insulation performance is insufficient, for example, the coil current leaks to the inner and outer rings and the rolling elements, or between the rolling surfaces of the rolling elements and the outer ring, or Sparking occurs between the rolling elements and the rolling surface of the inner ring, so-called galvanic corrosion may occur and the bearing life may be shortened. Further, the spark may cause a failure of a rotation sensor built in the bearing.

An object of the present invention is to provide an electromagnetic clutch bearing capable of preventing electric corrosion, rotation sensor failure, and the like due to sparks.
Another object of the present invention is to prevent the rotation sensor from being contaminated with grease in the bearing, and to provide a rotation sensor and to have a compact configuration and a small number of assembly steps.

The electromagnetic clutch bearing of the present invention is an electromagnetic clutch bearing comprising a rolling bearing in which rolling elements are interposed between an inner ring and an outer ring, and has an insulating function.
According to this configuration, since the bearing has an insulating function, for example, even if there is a leakage from the driving coil of the electromagnetic clutch to the bearing, the bearing does not spark between the rolling surface of the inner and outer rings and the rolling element, and is caused by the spark. It is possible to prevent electric corrosion of the bearing, failure of the rotation sensor, and the like, and improve the magnetic flux leakage resistance. Alternatively, depending on the form of the insulating function of the bearing, the leakage itself from the driving coil of the electromagnetic clutch to the bearing is prevented by the insulating function.

Another electromagnetic clutch bearing according to the present invention is an electromagnetic clutch bearing comprising a rolling bearing in which rolling elements are interposed between an inner ring and an outer ring, and has an insulating function between the inner ring and the outer ring. And
Even in this configuration, for example, even if there is an electric leakage from the driving coil of the electromagnetic clutch to the bearing, the bearing does not spark between the inner and outer rings and the rolling elements, and the electric corrosion of the bearing caused by the spark, the failure of the rotation sensor, etc. It can be prevented and leakage magnetic flux resistance is improved.

In the present invention, a seal is provided for sealing a portion of the bearing space between the inner ring and the outer ring that accommodates the rolling elements, and this seal is attached to the rotating side wheel of the inner ring and the outer ring, and is provided between the inner ring and the outer ring. A rotation sensor for detecting rotation is provided outside the seal in the bearing space, and the rotation sensor is attached to a detected portion provided in the seal and a fixed side wheel of the inner ring and the outer ring, and is It is good also as what consists of a sensor part which detects a detection part.
In the case of this configuration, when the bearing incorporated in the electromagnetic clutch rotates, a rotation detection signal is output from the rotation sensor, so that the rotation state of the bearing can be grasped from this output signal. When the electromagnetic clutch bearing is provided with a rotation sensor, the rotation sensor may be damaged due to a spark. However, since it has an insulating function, the spark is prevented and the failure of the rotation sensor due to the spark is prevented.
Since the rotation sensor is provided in the bearing space, the axial dimension can be shortened compared to the conventional structure in which the rotation sensor is installed outside the bearing, and the bearing can be made compact accordingly. Although the rotation sensor is disposed in the bearing space, since the rotation sensor is provided outside the seal, the rotation sensor is prevented from being contaminated by the outflow of grease in the bearing space. In addition, since the detected part of the rotation sensor is provided on the seal, the seal and the detected part can be attached to the bearing in one operation, the number of assembling steps is reduced, and the detected part is arranged. Dedicated space is not required, and further compactness can be achieved.

  In the present invention, at least one of the inner ring, the outer ring, and the rolling element may be ceramic. In the case of this configuration, an insulating function can be provided with a simple configuration in which the material is ceramics, without adding a special separate part.

The electromagnetic clutch bearing according to the present invention is an electromagnetic clutch bearing comprising a rolling bearing in which a rolling element is interposed between an inner ring and an outer ring, and has an insulating function, thereby preventing electric corrosion and rotation sensor failure caused by sparks. can do.
In the present invention, a seal is provided for sealing a portion of the bearing space between the inner ring and the outer ring that accommodates the rolling elements. The seal is attached to the rotation side wheel of the inner ring and the outer ring, and the rotation between the inner ring and the outer ring is performed. A rotation sensor for detecting the rotation is provided outside the seal in the bearing space, and the rotation sensor is attached to a detected portion provided in the seal and a fixed side wheel of the inner ring and the outer ring, and is detected. In the case where the rotation sensor is configured to be a sensor unit, the rotation sensor is prevented from being contaminated with grease in the bearing, and the rotation sensor is provided, and a compact configuration and a small number of assembly steps are required.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an example in which this electromagnetic clutch bearing 1 is used for a pulley 4 of an electromagnetic clutch 3 in a drive system of a compressor 2 in a vehicle air conditioner. A rotating member 6 of a pulley 4 is rotatably supported via a bearing 1 on the outer periphery of a cylindrical portion 5 a provided in the housing 5 of the compressor 2. The rotating member 6 is a ring-shaped member provided with a belt groove 8 on which the driving belt 7 is hung on the outer periphery. The pulley 4 includes the rotating member 6 and the bearing 1. The belt 7 is rotationally driven by, for example, an automobile engine (not shown). The belt 7 may be a timing belt (that is, a toothed belt). In this case, the belt groove 8 of the rotating member 6 is toothed, and the pulley 4 is a toothed pulley.

  The electromagnetic clutch 3 includes the pulley 4, a coil 9 that generates an electromagnetic force when energized, and a rotatable driven member 10. The rotating member 6 and the driven member 10 of the pulley 4 are driven by the electromagnetic force generated by the coil 9. And the rotation of the rotating member 6 is transmitted to the driven member 10. The coil 9 is fixed to the housing 5 and is loosely fitted in a circumferential groove 11 provided on the back surface of the rotating member 6 of the pulley 4. The rotating member 6 is preferably a magnetic material. The driven member 10 is a member in which a ring-shaped clutch plate 12 is attached to a compressor drive shaft 14 by a spring member 13 such as a plate spring, and the clutch plate 12 is made of a magnetic material. The compressor drive shaft 14 is inserted into the cylindrical portion 5a of the housing 5 and is rotatably supported by a bearing (not shown). When the coil 9 is excited, the spring member 13 is bent by electromagnetic force, the clutch plate 12 is attracted to the rotating member 6, and the driven member 10 rotates integrally with the rotating member 6. When the excitation is released, the clutch plate 12 is separated by the restoring force of the spring member 13.

  The bearing 1 is a rolling bearing and includes an inner ring 21, an outer ring 22, and a plurality of rolling elements 23 interposed between the inner and outer rings 21 and 22, and a rotation sensor that detects relative rotation between the inner and outer rings 21 and 22. 30 is built-in. The inner ring 21 is fixed to the outer periphery of the cylindrical portion 5 a of the housing 5, and the outer ring 22 is fixed in the inner diameter hole of the rotating member 6. At least one of the inner ring 21, the outer ring 22, and the rolling element 23 is made of ceramics. For example, the rolling element 23 is made of ceramics. Thereby, an insulating function is provided between the inner ring 21 and the outer ring 22.

  As shown in FIG. 2 in an enlarged manner, this rolling bearing 1 is composed of a double row angular ball bearing. The rolling elements 23 in each row are held by a resin cage 24, and both ends of the bearing space between the inner and outer rings 21 and 22 are sealed with contact bearing seals 25 and 26. One bearing seal 26 is provided on the inner side with respect to the width surface of the inner and outer rings 21, 22, and the rotation sensor 30 is installed in a bearing space outside the bearing seal 26. A contact type external seal 27 for sealing the bearing space is provided outside the bearing space for the rotation sensor 30.

  The bearing seals 25 and 26 are attached to the outer ring 22, and the outer seal 27 is attached to the inner ring 21. Specifically, one bearing seal 25 is composed of a ring-shaped cored bar 36 and an elastic member 37 fixed to the cored bar 36, and its outer diameter side end is formed on the inner diameter surface of the outer ring 22. By fitting into the seal mounting groove 38, the outer ring 22 is mounted. The other bearing seal 26 is also composed of a ring-shaped cored bar 39 and an elastic member 40 fixed to the cored bar 39, and the outer diameter side end of the seal seal groove is formed on the inner diameter surface of the outer ring 22. By being fitted to 41, it is attached to the outer ring 22. Lips 37 a and 40 a whose tips contact the outer diameter surface of the inner ring 21 are formed at the inner diameter side ends of the elastic members 37 and 40 in the bearing seals 25 and 26.

  The outer seal 27 is composed of a ring-shaped flat cored bar 42 and an elastic member 43 fixed to the cored bar 42, and the inner diameter end side thereof is a seal mounting groove 44 formed on the inner diameter surface of the inner ring 21. The inner ring 21 is attached by fitting. A lip portion 43 a whose tip is in contact with the inner diameter surface of the outer ring 22 is formed at the outer diameter side end of the elastic member 43 in the outer seal 27.

  The rotation sensor 30 includes a detected portion 31 that rotates integrally with the outer ring 22, and a sensor portion 32 that is attached to the inner ring 21 that is a fixed side wheel and detects the detected portion 31. The detected portion 31 is made of a permanent magnet attached to the bearing seal 26.

  The sensor unit 32 is attached to the inner ring 21 via the outer seal 27. Specifically, the sensor unit 32 is configured by disposing a magnetic sensor chip 45 made of, for example, a Hall element or the like on a circuit board 46, and is provided on the inner surface of the external seal 27 so as to be integrated with the external seal 27. Has been. The signal cord 47 connected to the circuit board 46 of the sensor unit 32 is drawn out of the bearing from a cord insertion hole 48 formed in the core metal 42 of the outer seal 27, and then the code insertion hole 47 is molded with resin or the like. Sealed with a material 49. Thus, by passing the signal cord 47 through the cord insertion hole 48 of the core 42 of the outer seal 27 attached to the inner ring 21 that is the fixed side wheel, the signal cord 47 is not cut by the rotation of the outer ring 22. The signal cord 47 can be easily pulled out of the bearing. Through this signal code 47, the detection signal of the sensor unit 32 is output outside the bearing.

  In this embodiment, the rotation sensor 30 outputs one pulse origin signal in one rotation. As shown in FIG. 3, the detected part 31 is constituted by a magnetic pole part provided at one place in the circumferential direction of the bearing seal 26. The surface of the detected part 31 facing the sensor part 32 side is magnetized with one S pole or up to three poles in the order of N, S, N. When the characteristics of the sensor unit 32 are opposite to each other, the polarities of the sensors need to be reversed. When the S pole approaches the sensor unit 32, the pulse output from the sensor unit 32 becomes one pulse origin signal for one rotation on the positive or negative side.

  The rotation detection signal of the rotation sensor 30 is input to the control unit 35 as shown in FIG. For example, the control unit 35 takes a deviation between a reference rotation speed signal a obtained from the rotation speed of the engine and the output of the rotation sensor 30, and detects the presence or absence of slipping of the belt 7 from the deviation. Further, the control unit 35 determines the lock of the electromagnetic clutch 3 based on the deviation and performs the excitation control of the coil 9.

According to the above configuration, at least one of the inner ring 21, the outer ring 22, and the rolling element 23 of the bearing 1 is made of ceramics and an insulating function is provided between the inner ring 21 and the outer ring 22. Even if electric leakage occurs in the bearing 1, the bearing 1 does not spark, so that electric corrosion of the bearing 1 due to the spark, failure of the rotation sensor 30 and the like can be prevented, and leakage flux resistance is improved. In addition, the bearing 1 can be provided with an insulating function with a simple configuration without adding any special separate parts.
The rotation sensor 30 outputs an origin signal of 1 pulse / 1 rotation each time the bearing 1 incorporated in the electromagnetic clutch 3 rotates. By taking this output signal into the control unit 35, the rotation state of the bearing 1 can be grasped. Further, by reading the deviation between the output signal and the reference rotational speed, it is possible to detect whether the belt 7 is slipping or the like. Thereby, it can utilize for the control etc. which avoid the serious trouble by belt run out beforehand.
In addition, since the bearing 1 has both a rotation speed detection function and a bearing function in a single housing, the vehicle air conditioner equipped with the bearing 1 and the compressor 2 can be reduced in size and simplified. That is, unlike the case where a rotation sensor of a dedicated part independent of the bearing is provided and used for the above control, a dedicated installation space, a mounting part, a casing part, etc. of the rotation sensor 30 can be omitted, and the sensor mounting process is omitted. Is done.

  Further, in this bearing 1, the external seal 27 that seals the bearing space is provided outside the bearing space for the rotation sensor 30, so that muddy water and foreign matter can be prevented from entering the installation portion of the rotation sensor 30. Since the external seal 27 is a contact-type seal, the sealing performance is excellent as compared with a case where a labyrinth seal is used. Moreover, since the sensor part 32 of the rotation sensor 30 and the external seal 27 are integrated, components such as a sensor case can be omitted, and the cost can be reduced. Since the detected portion 31 of the rotation sensor 30 is provided on the bearing seal 26, the bearing seal 26 and the detected portion 32 can be attached to the bearing in one operation, and the assembly is further facilitated. It becomes. Since the rotation sensor 30 is disposed outside the bearing seal 26, the rotation sensor 30 is prevented from being contaminated by the outflow of grease in the bearing space. In this bearing, the outer ring 22 is a rotating side wheel, but the bearing seal 26 is attached to the outer ring 22, so that the grease leaks to the rotation sensor 30 side due to the centrifugal force accompanying the rotation of the outer ring 22. Is prevented.

  The bearing seal 26 provided with the detected portion 31 and the external seal 27 integrated with the sensor portion 32 are fitted and attached to seal mounting grooves 41 and 44 formed in the outer ring 22 and the inner ring 21, respectively. By managing the axial dimension between the seal mounting grooves 41 and 44, the axial gap between the detected part 31 and the sensor part 32, that is, the sensor gap of the rotation sensor 30, can be set easily and accurately. This also facilitates assembly.

  The bearing 1 has a longer axial dimension than the bearing without the sensor due to the built-in rotation sensor 30, but the inner diameter hole of the rotating member 6 in the electromagnetic clutch 3 is larger than the axial dimension of the bearing 1. Since it is long, it does not increase the size of the rotating member 6 and the like because it is longer than the bearing without sensor.

  The bearing 1 is a double-row angular contact ball bearing. Therefore, in addition to a radial load, an axial load in both the front and rear directions can be applied. Therefore, it is possible to independently support the rotating member 6 on which an axial force acts for belt driving and clutch operation. By providing the rotation sensor 30 in such a double-row angular ball bearing, the effect of downsizing the bearing-use equipment by providing the rotation sensor is great.

  In the above embodiment, the rotation sensor 30 incorporated in the bearing 1 is for detecting the origin of a single-pulse single-phase output. However, the rotation sensor 30 may be a multi-pulse output or a multi-phase output. It may be a thing.

  FIG. 4 shows an electromagnetic clutch bearing according to another embodiment of the present invention. This bearing 1A is configured by forming the external seal 27 as follows in the electromagnetic clutch bearing 1 according to the first embodiment shown in FIG. The outer seal 27 includes a ring-shaped cored bar 42A having an L-shaped cross section and an elastic member 43 fixed to the cored bar 42A. The cylindrical portion 42Aa of the cored bar 42A is formed on the outer diameter surface of the inner ring 21. The outer seal 27 is attached to the inner ring 21 by fitting. On the outer diameter surface of the inner ring 21 to which the cylindrical portion 42Aa of the core metal 42A of the outer seal 27 is fitted, a step surface 21a that changes from the contact portion of the bearing seal 26 to an outer diameter surface having a smaller diameter than the contact portion. The tip end of the cored bar cylindrical portion 42Aa of the outer seal 27 is engaged with the stepped surface 21a, thereby positioning the outer seal 27 in the axial direction. The outer seal 27 is formed with a lip portion 43a in contact with the inner diameter surface of the outer ring 22 at the outer diameter side end of the elastic member 43, and the inner surface of the core metal 42A in the outer seal 27 (from the cylindrical portion 42Aa of the core metal 42A). The sensor portion 32 is provided on the inner surface of the flange portion 42Ab extending to the radial side, and other configurations are the same as those of the bearing 1 in FIG.

  In the sensor-equipped bearing 1A of this embodiment, the cylindrical portion 42Aa of the core metal 42A of the outer seal 27 is fitted to the outer diameter surface of the inner ring 21 as described above, and the tip of the cylindrical portion 42Aa is the stepped surface 21a of the inner ring 21. The outer seal 27 is positioned by being engaged with each other. Therefore, the axial interval between the bearing seal 26 and the external seal 27 fitted and attached to the seal attachment groove 41 of the outer ring 22 can be easily set to a predetermined interval. Therefore, the axial gap between the detected portion 31 provided on the bearing seal 26 and the sensor portion 32 integrated with the external seal 27, that is, the sensor gap of the rotation sensor 30, can be set easily and accurately, and assembly is easy. Is further promoted.

  FIG. 5 shows an electromagnetic clutch bearing 1B according to still another embodiment of the present invention. This bearing 1B is obtained by replacing the resin cage 24 in the electromagnetic clutch bearing 1A according to the embodiment shown in FIG. 4 with a steel cage 24A. Other configurations are the same as those of the bearing 1A of FIG.

  6 and 7 show an electromagnetic clutch bearing 1C according to still another embodiment of the present invention and its attached state, respectively. In this bearing 1C, in the electromagnetic clutch bearing 1A according to the embodiment shown in FIG. 4, a stepped surface 21b is formed on the inner diameter surface of one end portion of the inner ring 21 to fit the detent key 50 (FIG. 7). By engaging the locking key 50 fitted to the stepped surface 21b with a key groove 5aa formed on the outer periphery of the cylinder part 5a of the compressor housing 5, the inner ring 21 is prevented from rotating with respect to the cylinder part 5a. .

  FIG. 8 shows an electromagnetic clutch bearing 1D according to still another embodiment of the present invention. In the bearing 1A for the electromagnetic clutch according to the embodiment shown in FIG. 4, the bearing 1D omits the elastic member 43 of the outer seal 27, and the outer end of the flange portion 42Ab of the core 42A of the outer seal 27 is connected to the outer ring. 22 is close to the inner diameter surface. Other configurations are the same as those of the bearing 1A of FIG.

  In this bearing 1D, since the outer seal 27 consists only of the core metal 42A, the outer seal 27 does not function as a contact seal, but between the outer diameter side end of the flange portion 42Ab of the core metal 42A and the inner diameter surface of the outer ring 22. Since the labyrinth gap 51 is formed, the inside of the bearing in which the sensor portion 32 of the rotation sensor 30 is disposed and the outside of the bearing can be sealed. The flange portion 42Ab of the cored bar 42A also functions as a shield that electrically shields the inside of the bearing where the sensor portion 32 is disposed and the outside of the bearing, and is not affected by electrical disturbance. 30 can be operated correctly.

  FIG. 9 shows an electromagnetic clutch bearing 1E according to still another embodiment of the present invention. This bearing 1E replaces the bearing seal 26 with the detected portion 31 with a bearing seal 26A without the detected portion 31 in the electromagnetic clutch bearing 1A according to the embodiment shown in FIG. The detected part 31 is attached to a support member 52 disposed between the support member 52 and the support member 52. The bearing seal 26A without the detected portion has the same structure as the bearing seal 26 of the embodiment of FIG. 4 except for the presence or absence of the detected portion 31, but the lip portion 40a forms a labyrinth gap 53 with the inner diameter surface of the inner ring 21. The difference is that they face each other. The support member 52 is a ring-shaped member having an L-shaped cross section, and is attached to the outer ring 22 by fitting the cylindrical portion 52a to the inner diameter surface of the outer ring. On the inner diameter surface of the outer ring 22 to which the cylindrical portion 52a of the support member 52 is fitted, a step surface 22a that changes from the seal mounting groove 41 of the bearing seal 26 to an inner diameter surface having a larger diameter than the seal mounting groove 41 is formed. Then, the base end of the cylindrical portion 52a of the support member 52 is engaged with the stepped surface 22a, thereby positioning the support member 52 in the axial direction. Further, the detected portion 31 is provided at one place in the circumferential direction of the flange portion 52 b of the support member 52. Other configurations are the same as those in the embodiment of FIG.

  In this embodiment, a bearing seal 26A constituting a labyrinth gap 53 is used instead of the contact-type bearing seal 26 (FIG. 4), but the support disposed between the bearing seal 26A and the external seal 27 is used. Since the labyrinth gap 54 is also formed between the flange portion 52b of the member 52 and the inner diameter surface of the inner ring 21, a sufficient sealing function can be provided even in a non-contact type. Further, since the support member 52 that supports the detected portion 31 is positioned in the axial direction, the sensor gap of the rotation sensor 30 can be set easily and accurately.

  FIG. 10 shows an electromagnetic clutch bearing 1F according to still another embodiment of the present invention. In the bearing 1F, in the electromagnetic clutch bearing 1E according to the embodiment shown in FIG. 9, the bearing seal 26A is omitted, and the detected portion 31 provided on the flange portion 52b of the support member 52 has a ring shape, and its inner diameter side. A lip portion 31 a is integrally formed at the end, and a labyrinth gap 55 is formed between the lip portion 31 a and the inner diameter surface of the inner ring 21. In this case, since the lip portion 31a is integrally formed with the detected portion 31, the detected portion 31 is, for example, a rubber rubber made of a composite material in which magnetic powder is mixed with a rubber material, and is vulcanized and bonded to the support member 52. The The detected portion 31 is magnetized by, for example, magnetizing magnetic poles N and S alternately at a predetermined pitch in the circumferential direction, but only magnetizing a predetermined magnetic pole at one location in the circumferential direction. May be good. Other configurations are the same as those in the embodiment of FIG.

  In this embodiment, since the bearing seal 26A in the embodiment of FIG. 9 is omitted, the number of parts does not increase even if the support member 52 of the detected portion 31 is added, and the ease of assembly is not impaired. In addition, since the labyrinth gap 55 is formed between the lip portion 31a of the detected portion 31 and the outer diameter surface of the inner ring 21, a sufficient sealing function can be provided despite the omission of the bearing seal 26A.

  FIG. 11 shows an electromagnetic clutch bearing 1G according to still another embodiment of the present invention. This bearing 1G is an electromagnetic clutch bearing 1A according to the embodiment shown in FIG. 4, in which at least one of the inner ring 21, the outer ring 22 and the rolling element 23 is made of ceramics. For example, a ceramic insulating layer 22b is provided from the surface to both width surfaces. The thickness of the insulating layer 22b is, for example, 0.15 mm to 0.45 mm. Other configurations are the same as those in the embodiment of FIG.

When the bearing 1G of this embodiment is used for the pulley 4 of the electromagnetic clutch 3 of FIG. 1, the insulating layer 22b electrically connects the rotating member 6 that is the housing of the bearing 1G and the outer ring 22 of the bearing 1G. Insulated. For this reason, for example, even if there is a leakage from the coil 9 to the inner ring 21 of the bearing 1, the bearing 1G does not spark, and the electric corrosion of the bearing 1G and the failure of the rotation sensor 30 due to the spark can be prevented.
The insulating layer 22 b may be provided on the inner ring 21 instead of being provided on the outer ring 22, or may be provided on both the outer ring 22 and the inner ring 21. For example, the rolling element 23 may be made of ceramics, and the insulating layer 22b may be provided from the outer circumferential surface of the outer ring 22 to both width surfaces.

  FIG. 12 shows an electromagnetic clutch bearing 1H according to still another embodiment of the present invention. This bearing 1H is an axial type bearing in which the bearing seal 26 and the external seal 27 are omitted in the electromagnetic clutch bearing 1 according to the embodiment shown in FIG. 2, and the detected portion 31 and the sensor portion 32 face each other in the axial direction. Instead of the rotation sensor 30, a rotation sensor 30A in which the detected part 31 and the sensor part 32 face each other in the radial direction is provided.

  Specifically, the detected portion 31 is made of a magnetic ring fixed to the inner peripheral surface of the ring-shaped cored bar 56, and the cored bar 56 is press-fitted into the stepped surface 22 a of the inner diameter surface of the outer ring 22. Is attached to the outer ring 22. The detected portion 31 in this case is a composite rubber magnet in which magnetic powder is mixed with a rubber material, and is vulcanized and bonded to the core metal 56. The detected portion 31 is magnetized by, for example, magnetizing magnetic poles N and S alternately at a predetermined pitch in the circumferential direction, but only magnetizing a predetermined magnetic pole at one location in the circumferential direction. May be good.

  The sensor unit 32 includes a ring-shaped resin sensor housing 58 fixed to the outer peripheral surface of a ring-shaped metal core 57, and a magnetic sensor chip 45 and a circuit board 46 disposed on a part of the sensor housing 58 in the circumferential direction. Composed. The sensor part 32 is attached to the inner ring 21 so as to face the detected part 31 in the radial direction by press-fitting a cored bar 57 to the stepped surface 21 a on the outer diameter surface of the inner ring 21. The magnetic sensor chip 45 and the circuit board 46 are fixed to the sensor housing 58 by a resin mold.

  The sensor housing 58 of the sensor portion 32 is formed with a ring-shaped flange portion 58a that protrudes closer to the bearing width surface side portion than the installation portion of the detected portion 31 on the inner diameter surface of the outer ring 22. Thus, a labyrinth gap 59 having an inverted Z-shaped cross section is formed between the installation portion of the detected portion 31 of the outer ring 22 and the sensor portion 32 of the inner ring 21. Other configurations are the same as those in the first embodiment of FIG.

  In this embodiment, since the bearing seal 26 and the external seal 27 in the embodiment of FIG. 2 are omitted, the number of parts can be omitted. Further, in the installation portion of the rotation sensor 30A in the bearing internal space, a labyrinth gap 59 is formed between the installation portion of the detected portion 31 of the outer ring 22 and the sensor portion 32 of the inner ring 21, so that the bearing seal 26 and the outer seal are provided. In spite of the omission of 27, the installation portion of the rotation sensor 30A can be sufficiently sealed.

  FIG. 13 shows an electromagnetic clutch bearing 1J according to still another embodiment of the present invention. This bearing 1J is obtained by exposing the rotation sensor 30A to the outside of the bearing 1J in the electromagnetic clutch bearing 1H according to the embodiment shown in FIG. The cored bar 57 to which the sensor unit 32 is fixed has a Z-shaped cross-sectional shape, and a small-diameter cylindrical part 57a is press-fitted into the inner diameter surface of the inner ring 21 and protrudes off the shaft from the width surface of the inner ring 21. The sensor part 32 is fixed to the outer diameter surface of 57b. The cored bar 56 to which the detected part 31 is fixed has a cylindrical part 56a and a flange part 56b extending from one end to the outer diameter side, and the detected part 31 is fixed to the inner diameter surface thereof. Yes. The test portion 31 is attached to the outer ring 21 by press-fitting the cylindrical portion 56a of the core metal 56 to the inner diameter surface of the outer ring 22, and the flange portion 56a of the core metal 56 and the sensor housing 58a in the sensor portion 32 are connected. It is made to oppose to an axial direction.

  In this embodiment, since the rotation sensor 30A is exposed outside the bearing, the width dimension of the bearing 1J can be shortened. Further, since the bearing seal 26 and the external seal 27 are omitted, the number of parts can be omitted. Further, since the labyrinth gap 50 is formed between the detected portion 31 and the sensor portion 32 facing the detected portion 31, the rotation sensor 30A also serves as a seal member, and the detected portion 31 and the sensor in the rotation sensor 30A. It is also possible to prevent foreign matter from entering between the portion 32.

It is sectional drawing of the electromagnetic clutch provided with the electromagnetic clutch bearing which concerns on 1st Embodiment of this invention. It is sectional drawing of the bearing. It is a front view of the bearing. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing which shows the state which attached the same bearing to the electromagnetic clutch. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention. It is sectional drawing of the electromagnetic clutch bearing which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A-1H, 1J ... Electromagnetic clutch bearing 21 ... Inner ring 22 ... Outer ring 22b ... Insulating layer 23 ... Rolling elements 30, 30A ... Rotation sensor

Claims (4)

  An electromagnetic clutch bearing comprising a rolling bearing having a rolling element interposed between an inner ring and an outer ring and having an insulating function.   An electromagnetic clutch bearing comprising a rolling bearing having a rolling element interposed between an inner ring and an outer ring, wherein the bearing has an insulating function between the inner ring and the outer ring.   3. A seal according to claim 1, wherein a seal is provided for sealing a portion of the bearing space between the inner ring and the outer ring that accommodates the rolling elements, and the seal is attached to a rotating side wheel of the inner ring and the outer ring. A rotation sensor for detecting rotation between the outer ring and the outer ring is provided outside the seal in the bearing space, and the rotation sensor is provided on a detected portion provided in the seal and a fixed side wheel of the inner ring and the outer ring. A bearing for an electromagnetic clutch comprising a sensor portion that is attached and detects the detected portion.   The electromagnetic clutch bearing according to claim 3, wherein at least one of the inner ring, the outer ring, and the rolling element is ceramic.

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