JP2005331004A - Bearing with rotation sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a rotation sensor to be used for a bearing for rotating an outer ring, capable of preventing leakage of grease due to centrifugal force and capable of reducing dimensional limitation in the axial direction, capable of facilitating wiring for output of sensor signal and capable of stabilizing sensor output and simplifying peripheral structure. <P>SOLUTION: The bearing with a rotation sensor is provided with an encoder 14 installed in one end part of the outer ring 3 as a rotating side raceway ring, and a sensor part 15 installed in an inner ring 2 opposite to the encoder 14. The encoder 14 is formed of a core metal 17 having a function as a shield plate for preventing flow-out of the grease sealed inside the bearing and a material 16 to be detected, which is integrated with the core metal 17 and possible to be detected by the sensor part 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bearing with a rotation sensor that is used in outer ring rotation and includes a rotation sensor that also serves as a structure for preventing grease leakage due to centrifugal force.

If the bearing used for rotating the outer ring is equipped with a seal structure to protect it from the external environment, the outer ring fitting seal is adopted because the grease is biased toward the inner surface of the outer ring due to centrifugal force. Therefore, the seal lip is brought into sliding contact with the inner ring side to prevent grease leakage.
However, when a sensor function such as rotation detection is added to the bearing, the conventional seal structure rotates the seal itself as the bearing rotates, making it difficult to route the wires connected to the rotation sensor.
A general bearing with a rotation sensor includes a sealing device such as a seal at the end opposite to the sensor, but does not include a sealing device on the sensor side and cannot prevent grease leakage.

Also, as a conventional bearing with a rotation sensor, an encoder is mounted on one end of the outer ring so as to project outside the bearing, and a sensor facing the encoder is mounted on one end of the inner ring so as to project outside the bearing. (For example, Patent Document 1). With this configuration, the electric wires can be easily handled. However, since it does not have a function of preventing grease leakage and the encoder protrudes from the raceway in the axial direction, the overall axial dimension of the bearing with the rotation sensor increases.
JP 2002-295465 A

  However, in the bearing with a rotation sensor configured as described above, the rotation sensor protrudes outside the bearing, so that the rotation sensor is exposed to the external environment, not only causing performance deterioration but also increasing the axial dimension. There is a problem that downsizing of the bearing is hindered.

  The object of the present invention is to prevent grease leakage, reduce axial dimension restrictions, and facilitate the handling of electric wires for sensor signal output, thereby enabling stable sensor output and simplification of the surrounding structure. It is providing the bearing with a rotation sensor which becomes.

A bearing with a rotation sensor according to the present invention is attached to an outer ring serving as a rotation-side raceway, an inner ring serving as a fixed-side raceway, a plurality of rolling elements interposed between the inner and outer rings, and one end portion of the outer ring. In a bearing with a rotation sensor provided with an encoder and a sensor portion mounted on the inner ring so as to face the encoder, the encoder has a function as a shield plate for preventing leakage of sealed grease in the bearing And an object to be detected that is integrated with the metal core and can be detected by the sensor unit.
According to this configuration, since the encoder core also functions as a shield plate, it is possible to prevent the sealed grease from being biased toward the inner surface of the outer ring and flowing out of the bearing due to the centrifugal force caused by the rotation of the outer ring. In addition, since the rotation sensor is installed in the bearing, the axial dimension can be shortened and the bearing can be made more compact as compared with the conventional structure in which the rotation sensor is projected outside the bearing. The signal output wire connected to the sensor unit is not hindered by the rotation of the bearing because the sensor unit is mounted on the inner ring, which is the stationary raceway, and is also affected by disturbances and the like due to the rotation of the bearing. This makes it easier to route the wires. As a result, a stable sensor output can be obtained, and the peripheral structure of the bearing can be simplified.

  An elastic body may be interposed on the fitting surface of the encoder with the outer ring of the metal core. When the elastic body is interposed, the penetration of the oil in the fitting surface between the encoder core that functions as a shield plate and the outer ring is prevented, and the lubrication life is improved and the surrounding dirt due to the leaked oil is prevented.

  The encoder core may be provided with an elastic lip that contacts the outer diameter surface of the inner ring. When a contact structure is provided by providing a lip, the rotational resistance increases, but the effect of preventing grease leakage is enhanced. Therefore, it is possible to obtain an effect of preventing the rotation sensor from deteriorating or malfunctioning due to the outflow grease.

  In the present invention, the bearing with the rotation sensor may be a ball bearing. The ball bearing may be a deep groove ball bearing or an angular ball bearing, and may be a single row or a double row.

  For example, the rotation sensor bearing may be a double row angular ball bearing. In the case of a double row angular contact ball bearing, since axial loads in both forward and reverse directions can be applied, for example, a belt-driven rotating component can be supported alone. Such a double-row angular contact ball bearing is equipped with a rotation sensor and has the structure of the present invention, so that grease leakage can be prevented reliably, the dimensions in the axial direction can be made compact, the wire can be easily routed, and the resulting stability can be achieved. The practical effect of obtaining the simplified sensor output and the peripheral structure is great.

  The bearing with a rotation sensor may be a single row multi-point contact ball bearing. Similarly to the double-row angular contact ball bearing, the multi-point contact ball bearing can be loaded with an axial load in both forward and reverse directions, and can independently support a rotating component driven by a belt. Therefore, the above advantages of the present invention are effectively exhibited.

  A bearing with a rotation sensor according to the present invention is attached to an outer ring serving as a rotation-side bearing ring, an inner ring serving as a stationary-side bearing ring, a plurality of rolling elements interposed between the inner and outer rings, and one end of the outer ring. In a bearing with a rotation sensor provided with an encoder and a sensor portion mounted on the inner ring so as to face the encoder, the encoder has a function as a shield plate for preventing leakage of sealed grease in the bearing And an object to be detected that can be detected by the sensor unit integrated with the metal core, thus preventing grease leakage, reducing axial dimensional constraints, and handling the wires for sensor signal output. This makes it possible to achieve stable sensor output and simplification of the peripheral structure.

  A first embodiment of the present invention will be described with reference to FIG. This rotation sensor bearing 1 is a rolling bearing, and as shown in FIG. 1A, an outer ring 3 serving as a rotation-side raceway, an inner ring 2 serving as a fixed-side raceway, and these inner and outer rings 2, 3 And a plurality of rolling elements 4 interposed between them, and a rotation sensor 13 for detecting relative rotation between the inner and outer rings 2 and 3 is incorporated.

  This bearing 1 with a rotation sensor consists of a single row ball bearing, and the rolling element 4 consisting of a ball is held by a cage 5. Both ends of the bearing space between the inner and outer rings 2 and 3 are sealed with contact bearing seals 6 and 7. One bearing seal 6 is attached to the outer ring 3. The bearing seal 6 includes a ring-shaped cored bar 8 and an elastic member 9 fixed to the cored bar 8, and an outer diameter end side of the bearing seal 6 is formed in a seal mounting groove 10 formed on the inner diameter surface of the outer ring 3. Is attached to the outer ring 3. At the inner diameter side end of the elastic member 9 in the bearing seal 6, a lip portion 9 a whose tip contacts the outer diameter surface of the inner ring 2 is formed.

  The other bearing seal 7 is attached to the inner ring 2. The bearing seal 7 is also composed of a ring-shaped cored bar 11 and an elastic member 12 fixed to the cored bar 11, and press-fitting the cored bar 11 to the outer diameter surface of the inner ring 2. 2 is attached. The metal core 11 has an L-shaped cross section including a standing plate portion 11a to which the elastic member 12 is fixed, and a cylindrical portion 11b extending from the inner diameter side end of the standing plate portion 11a to the inside of the bearing. 11 b is press-fitted to the outer diameter surface of the inner ring 2. A lip portion 12 a is formed at the outer diameter side end of the elastic member 12 in the bearing seal 7 so that the tip thereof contacts the inner diameter surface of the outer ring 3.

The rotation sensor 13 includes an encoder 14 that rotates integrally with the outer ring 3, and a sensor unit 15 that is attached to the inner ring 2 and detects the encoder 14.
The encoder 14 includes a detected body 16 that can be detected by the sensor unit 15 and a ring-shaped cored bar 17 that supports the detected body 16. The metal core 17 also functions as a shield plate that prevents the sealed grease in the bearing from flowing out. The metal core 17 has an L-shaped cross section including a cylindrical portion 17a and a standing plate portion 17b extending from the bearing inner end of the cylindrical portion 17a toward the inner diameter side. The cylindrical portion 17a is press-fitted into the inner diameter surface of the outer ring 3. The encoder 14 is attached to one end of the outer ring 3 by fitting. The inner diameter side end of the cored bar standing plate portion 17 b is disposed close to the outer diameter surface of the inner ring 2, and a non-contact seal gap 18 is formed between the cored bar standing plate portion 17 b and the outer diameter surface of the inner ring 2.
The detected body 16 is a ring-shaped member fixed to the inner peripheral surface of the cored bar cylindrical portion 17a. Here, a magnet magnetized in multiple poles in which magnetic poles N and S are alternately arranged in the circumferential direction, or It is a pulsar ring such as a magnetic ring with gear-like irregularities.

  The sensor unit 15 is attached to the inner ring 2 via the bearing seal 7 so as to face the detected body 16 of the encoder 14 in the radial direction. Specifically, the sensor unit 15 is configured by arranging a magnetic sensor chip 19 made of, for example, a Hall element or a magnetoresistive element on the circuit board 20, and is formed on the outer diameter surface of the cored bar cylindrical portion 11 b in the bearing seal 7. By being provided in a part in the circumferential direction, the bearing seal 7 is integrated. As a result, the rotation sensor 13 is installed in the bearing space inside the bearing seal 7, and the rotation sensor 13 and the rolling element 4 are partitioned by a cored bar standing plate portion 17 b that functions as a shield plate. In this embodiment, the length from the center of the raceway surface of the inner and outer rings 2 and 3 to the width surface on the bearing seal 6 side is made longer than the length from the width surface on the side where the rotation sensor 13 is arranged, and the bearing space of this lengthened portion is increased. The rotation sensor 13 is installed in the front. In this case, the inner and outer rings 2 and 3 have the same width dimension, and the width dimension is set to one side larger than the standard dimension.

  An electric wire 21 such as a covered cord connected to the sensor unit 15 is drawn out of the bearing from an electric wire insertion hole (not shown) formed in the cored bar standing plate portion 11a of the bearing seal 7, and thereafter the electric wire insertion hole Sealed with a molding material such as resin. Thus, by passing the electric wire 21 through the electric wire insertion hole of the core 11 of the bearing seal 7 attached to the inner ring 2 which is the fixed side raceway, the signal electric wire 21 can be easily connected without hindering the rotation of the outer ring 3. It can be pulled out of the bearing. A detection signal of the sensor unit 15 is output to the outside of the bearing through the signal wire 21.

According to the bearing 1 with the rotation sensor of this configuration, the cored metal vertical plate portion 17b of the encoder 14 prevents the encapsulated grease from being biased toward the inner diameter surface of the outer ring 3 and flowing out of the bearing due to the centrifugal force caused by the rotation of the outer ring 3. . That is, the cored bar 17 functions as a shield plate. Therefore, the lubrication life is reduced and the rotation sensor 13 is prevented from being dirty due to grease leakage.
On the end side where the rotation sensor 13 is installed, the lip portion 12a of the bearing seal 7 has a structure in contact with the inner diameter surface of the outer ring 3 which is the rotating side raceway. It functions as an intrusion prevention means for dust and water.

In addition, since the rotation sensor 13 is installed in the bearing, the axial dimension can be shortened and the bearing can be made more compact as compared with the conventional structure in which the rotation sensor is projected outside the bearing. The electric wire 21 connected to the sensor portion 15 of the rotation sensor 13 in the bearing is pulled out of the bearing through an electric wire insertion hole (not shown) of the bearing seal 7 attached to the inner ring 2 that is a stationary side raceway. The rotation of the bearing is not hindered and is not affected by disturbance or the like by the rotation of the bearing. Therefore, the electric wire 21 can be easily routed. As a result, a stable sensor output can be obtained, and the peripheral structure of the bearing 1 can be simplified.
Further, since the bearing space in which the rotation sensor 13 is installed is sealed with the bearing seal 7, the rotation sensor 13 is not exposed to the external environment, and the performance is deteriorated by being damaged by foreign matter or the like. Since it can be avoided, a stable sensor output can be obtained.

  1A shows a case where the cored bar cylindrical portion 17a of the encoder 14 is directly press-fitted into the inner diameter surface of the outer ring 3, but the elastic member 22 is interposed as shown in FIG. 1B. The cored bar cylindrical portion 17a may be press-fitted and fitted. When the elastic member 22 is interposed, the penetration of oil in the fitting surface between the metal core 17 and the outer ring 3 is prevented, and the lubrication life is improved and the effect of preventing surrounding dirt due to leaked oil is obtained.

  In FIG. 1 (A), the inner diameter side end of the core metal upright plate portion 17b of the encoder 14 is brought close to the outer diameter surface of the inner ring 2 in a non-contact state, and the space between the core metal vertical plate portion 17b and the inner ring outer diameter surface is reached. As shown in FIG. 1C, a lip portion 17c made of an elastic member is provided on the inner diameter side end of the cored bar standing plate portion 17b, and this lip portion 17c is provided on the outer diameter surface of the inner ring 2. You may make it contact. In this way, by bringing the lip portion 17c into contact with the outer diameter surface of the inner ring 2, it is possible to reliably prevent the sealing grease from flowing out from the core metal upright plate portion 17b, and the rotation sensor 13 is deteriorated in function due to the outflow grease. Or dysfunction is also prevented.

  FIG. 2 shows a bearing 1A with a rotation sensor according to still another embodiment of the present invention. In the first embodiment shown in FIG. 1 (A), this rotation sensor-equipped bearing 1A omits the bearing seals 6 and 7 and the sensor portion 15 at both ends of the bearing, and only the encoder 14A is mounted in the bearing. Is. The encoder 14A of this example has a ring-like shape magnetized in multiple poles in which the magnetic poles N and S are alternately arranged in the circumferential direction on the surface of the upright portion 17b of the metal core 17 having an L-shaped cross section facing the outside of the bearing. This is an axial type in which a detection object 16 made of a magnet is fixed. A rotation sensor 13A is configured by the encoder 14A and the sensor unit 15 that is arranged outside the bearing and is opposed to the detected body 16 of the encoder 14A in the axial direction so as to detect the detected body 16. Other configurations are the same as those in the first embodiment.

Also in the bearing 1A with the rotation sensor of this configuration, the sealed grease is biased toward the inner diameter surface of the outer ring 3 due to the centrifugal force caused by the rotation of the outer ring 3 and flows out of the bearing from the installation side of the rotation sensor 13A. This is prevented by the plate portion 17b functioning as a shield plate.
Even in this configuration, most of the rotation sensor 13A is arranged in the bearing, so that the axial dimension can be shortened compared to the structure of the conventional example in which the entire rotation sensor projects outside the bearing, This makes it possible to reduce the size of the bearing. Moreover, since the sensor part 15 of the rotation sensor 13A is installed independently from the bearing 1A, the routing of the signal wire connected to the sensor part 15 does not become a problem.

  FIG. 3 shows a bearing 1B with a rotation sensor according to still another embodiment of the present invention. This bearing 1B with a rotation sensor is obtained by applying the configuration of the first embodiment shown in FIG. 1A to a double-row angular ball bearing. The configurations of the bearing seals 6 and 7 and the rotation sensor 13 are the same as those in the first embodiment.

  Since this rotation sensor-equipped bearing 1B is a double-row angular contact ball bearing, in addition to the radial load, an axial load in both the front and rear directions can be applied. Therefore, it is possible to independently support a rotating member on which an axial force acts for belt driving or clutch operation. By providing the rotation sensor 13 in such a double-row angular ball bearing, the effect of reducing the size and preventing the leakage of grease can be increased by providing the rotation sensor and also using the encoder core 17 as a shield plate.

  FIG. 4 shows a bearing 1C with a rotation sensor according to still another embodiment of the present invention. This rotation sensor bearing 1C is a single-row multipoint contact ball bearing, and is a four-point contact ball bearing. That is, the rotation sensor-equipped bearing 1 </ b> C has contact angles θ <b> 1 and θ <b> 2 in both forward and reverse directions, and is a bearing that contacts the inner and outer rings 2 and 3 at four points. Each of the raceway surfaces of the inner and outer rings 2 and 3 has, for example, a Gothic arch-shaped cross-sectional shape. The inner ring 2 is a single product in this example, but it may be divided into two parts arranged in the axial direction at the bottom of the raceway surface. The rotation sensor 13 is the same as that of the bearing 1 with the rotation sensor shown in FIG.

  In the case of the rotation sensor-equipped bearing 1C of this embodiment, it is possible to apply an axial load in both forward and reverse directions as in the double-row angular ball bearing, and the axial width of the entire bearing can be narrow. Therefore, also in this embodiment, the effect of downsizing and prevention of grease leakage due to the use of a rotation sensor and the use of the encoder core 17 as a shield plate is great.

  FIG. 5 shows an example in which the rotation sensor bearing 1B shown in FIG. 3 is used for the pulley 34 of the electromagnetic clutch 33 in the drive system of the compressor 32 in the vehicle air conditioner. A rotating member 36 of a pulley 34 is rotatably supported on the outer periphery of a cylindrical portion 35a provided in the housing 35 of the compressor 32 via a bearing 1B with a rotation sensor. The rotating member 36 is a ring-shaped member provided with a belt groove 38 that hangs a driving belt 37 on the outer periphery. The pulley 34 includes the rotating member 36 and a bearing 1B with a rotation sensor. The belt 37 is rotationally driven by, for example, an automobile engine (not shown). The belt 37 may be a timing belt (that is, a toothed belt). In this case, the belt groove 38 of the rotating member 36 is toothed, and the pulley 34 is a toothed pulley.

  The electromagnetic clutch 33 includes the pulley 34, a coil 39 that generates an electromagnetic force when energized, and a rotatable driven member 40. The rotating member 36 and the driven member 40 of the pulley 34 are driven by the electromagnetic force generated by the coil 39. And the rotation of the rotating member 36 is transmitted to the driven member 40. The coil 39 is fixed to the housing 35 and is loosely fitted in a circumferential groove 41 provided on the back surface of the rotating member 36 of the pulley 34. The rotating member 36 is preferably a magnetic material. The driven member 40 is a member in which a ring-shaped clutch plate 42 is attached to a compressor drive shaft 44 by a spring member 43 such as a plate spring, and the clutch plate 42 is made of a magnetic material. The compressor drive shaft 44 is inserted into the cylindrical portion 35a of the housing 35 and is rotatably supported by a bearing (not shown). When the coil 39 is excited, the spring member 43 is bent by electromagnetic force, the clutch plate 42 is attracted to the rotating member 36, and the driven member 40 rotates integrally with the rotating member 36. When the excitation is released, the clutch plate 42 is released by the restoring force of the spring member 43.

  The rotation detection signal of the rotation sensor 13 is input to the control unit 55 as shown in FIG. For example, the control unit 55 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 13, and detects the presence or absence of slipping of the belt 37 from the deviation. Further, the control unit 55 performs lock determination of the electromagnetic clutch 33 based on the deviation and performs excitation control of the coil 39.

  According to the above configuration, a rotation detection signal is output each time the rotation sensor-equipped bearing 1B incorporated in the electromagnetic clutch 33 rotates. By taking this output signal into the control unit 55, the rotation state of the bearing 1B with the rotation sensor 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 37 is slipping or the like. Thereby, it can utilize for the control etc. which avoid the serious trouble by belt run out beforehand.

  By using the rotation sensor bearing 1B of the above-described embodiment for the pulley 34 of the electromagnetic clutch 33, the grease leakage prevention, reduction of axial dimensional constraints, and easy handling of electric wires for sensor signal output. As a result, the advantage that the stable sensor output and the peripheral structure can be simplified can be effectively exhibited.

(A) is sectional drawing of the bearing with a rotation sensor concerning 1st Embodiment of this invention, (B) is principal part sectional drawing which shows the other example of the same bearing, (C) is another example of the same bearing It is principal part sectional drawing which shows these. It is sectional drawing of the bearing with a rotation sensor concerning other embodiment of this invention. It is sectional drawing of the bearing with a rotation sensor concerning other embodiment of this invention. It is sectional drawing of the bearing with a rotation sensor concerning other embodiment of this invention. It is sectional drawing of the electromagnetic clutch provided with the bearing with a rotation sensor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A-1C ... Bearing 2 with a rotation sensor 2 ... Inner ring 3 ... Outer ring 4 ... Rolling body 14 ... Encoder 15 ... Sensor 16 ... Detected body 17 ... Core metal 17c ... Lip part 22 ... Elastic member

Claims (6)

  An outer ring serving as a rotation-side raceway, an inner ring serving as a fixed-side raceway, a plurality of rolling elements interposed between the inner and outer races, an encoder mounted on one end of the outer ring, and facing the encoder In the bearing with a rotation sensor provided with the sensor portion mounted on the inner ring, the encoder is integrated with a core metal that functions as a shield plate that prevents the sealed grease from flowing out of the bearing. A bearing with a rotation sensor, comprising: a detection object that can be detected by the sensor unit;   2. The bearing with a rotation sensor according to claim 1, wherein an elastic body is interposed on a fitting surface of the encoder with the outer ring of the metal core.   3. The bearing with a rotation sensor according to claim 1, wherein an elastic body lip that contacts an outer diameter surface of the inner ring is provided on the core metal of the encoder.   The bearing with a rotation sensor according to any one of claims 1 to 3, wherein the bearing is a ball bearing.   The bearing with a rotation sensor according to any one of claims 1 to 3, wherein the bearing is a double-row angular ball bearing.   The bearing with a rotation sensor according to any one of claims 1 to 3, wherein the bearing is a single-row multipoint contact ball bearing.

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