JP2008164143A - Bearing with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a sensor to precisely measure the rotation state for the long term without damaging a body to be detected and a detecting body. <P>SOLUTION: The bearing with the sensor comprises: a pair of rotary ring 2 and static ring 4 arranged to be relatively rotatable and oppositely to each other; and the sensor 20 to measure the rotation state of the bearing. The sensor comprises: the body 22 to detected rotating in the same state as the rotary ring; the detecting body 24 to detect the rotation state of the body to be detected; and an annular sensor housing 26 to store the detecting body. The body to be detected is fixed to the rotary ring, and rotated together with the rotary ring, while the detecting body is fixed to the static ring, being stored in the sensor housing so that it is spaced oppositely to the body to be detected at a predetermined interval. The sensor housing comprises a portion 80, which is integrally formed with the sensor housing, for preventing a foreign material from entering in order to prevent the foreign material from entering the opposite portion of the body to be detected and the detecting body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a main shaft of a jet engine, a gas turbine engine, or a bearing that supports an axle of an automobile, a railcar, or the like. For example, the present invention relates to an improvement in a sensor-equipped bearing having a sensor function for measuring a sensor.

  Conventionally, for example, a bearing that supports a main shaft such as a jet engine or a gas turbine engine, or an axle such as an automobile or a railway vehicle, etc., the rotational state of the bearing (for example, rotational speed, rotational direction, rotational angle, etc.) Various types of sensor-equipped bearings having a sensor function for measuring the pressure are known. For example, Patent Document 1 discloses, as an example, a configuration of a sensor-equipped bearing having a sensor function for measuring the rotation speed and the rotation direction of an inner ring that is a rotating wheel.

  FIG. 3 shows an example of the configuration of a sensor-equipped bearing (hereinafter simply referred to as bearing D) that measures the rotational speed and direction of the inner ring, which is a rotating wheel, with a sensor. The bearing D includes a pair of rotating wheels 2 and a stationary wheel 4 arranged to face each other so as to be relatively rotatable, and a plurality of rolling elements incorporated so as to be able to roll between the rotating wheel 2 and the stationary wheel 4. A (ball) 6 and a cage 8 that rotatably holds the rolling elements (balls) 6 one by one in the pocket are provided. In this case, the inner ring is configured as a rotating wheel 2 that rotates together with a rotating shaft (not shown) of the bearing D, whereas the outer ring is configured as a stationary wheel 4 that is always maintained in a non-rotating state.

  Further, in the configuration shown in FIG. 3, the bearing D has an annular seal member 10 interposed between the inner and outer rings 2 and 4 on one side in the axial direction (lower side in the figure). Intrusion of foreign matter (for example, water and dust) from the outside of the bearing and leakage of lubricant (for example, lubricating oil and grease) from the inside of the bearing are prevented. In this case, a contact-type seal is applied as the seal member 10, and the seal member 10 is positioned so that the inner diameter portion is in contact with the inner ring 2 in a state where the outer diameter portion is fixed to the outer ring 4. ing.

  On the other hand, the bearing D is provided with a sensor 60 for measuring the rotational state (rotational speed and rotational direction) of the bearing D on the other side in the axial direction (upper side in FIG. 3). Reference numeral 60 denotes a detected body 62 that rotates in the same rotational state as the inner ring 2, a exposed body 64 that detects the rotational state of the detected body 62, a sensor housing 66 that houses the exposed body 64, and the exposed body A circuit wiring board (hereinafter referred to as a printed circuit board) for supplying power to the body 64 from a predetermined power supply device and transmitting a detection signal output from the exposed body 64 to a predetermined signal processing unit (not shown). 70.

  In this case, a multi-pole magnetized ring-shaped magnet (hereinafter referred to as an encoder 62) is applied as the detected object 62, while a magnetic state change (magnitude of magnetic field) is applied as the detected object 64. Two magnetic detection elements (hereinafter referred to as Hall IC 64) for detecting the direction and the direction (specifically, fluctuation of magnetic flux density, etc.) are provided. Note that the encoder 62 is configured as an annular magnet having a total of 100 magnetic poles, in which N poles and S poles are alternately magnetized in the circumferential direction by 50 poles on the inner peripheral surface thereof.

  The two Hall ICs 64 are accommodated in the sensor housing 66 while being connected to the printed circuit board 70, and a cover 68 (hereinafter referred to as a housing cover) to which the sensor housing 66 is fixed is attached to the outer ring 4. Thus, the outer ring 4 is fixed. The housing cover 68 has an annular shape, and its outer diameter portion is fixed to the outer ring 4. In this state, a predetermined gap is provided between the tip of the inner diameter portion and the peripheral surface portion of the rotating shaft (not shown) of the bearing D. A gap is formed. In addition, the two Hall ICs 64 are shifted by 90 ° in the electrical angle (the phase when one period of the signal sine wave is 360 °) at the timing of detecting the change in the magnetic state (providing a phase difference of 90 °). The sensor housing 66 is positioned on the printed circuit board 70.

The encoder 62 is fixed to the outer diameter portion of the encoder holder 72 so as to face the Hall IC 64 at a predetermined interval (for example, adhesion or welding), and is attached to the inner ring 2 via the encoder holder 72. The encoder holder 72 has an annular shape, and its inner diameter portion is fixed to the inner ring 2. In this state, a predetermined gap is formed between the tip of the outer diameter portion and the outer ring 4.
Thereby, the sensor 60 has a structure that rotates together with the inner ring 2 in a state where the encoder 62 faces the Hall IC 64.
JP 2004-211841 A

  By the way, in various mechanical devices in which the bearing D is incorporated, foreign matter, specifically, a small piece of magnetic material such as iron (hereinafter referred to as a magnetic material piece) is suspended in the atmosphere, and the magnetic material piece is used as an inner ring. 2 and the sensor housing 66 may enter a portion where the Hall IC 64 and the encoder 62 face each other (hereinafter referred to as a sensor portion) and adhere to the encoder 62 in some cases. As described above, since the encoder 62 is configured as an annular magnet magnetized with multiple poles (for example, 100 poles (50 N poles and 50 S poles)), the magnetic material that is a foreign substance is used. Depending on the size (length) of the piece, or depending on the size of the encoder 62, the number of magnetized magnetic poles, etc., the distance between the N pole and the S pole adjacent to each other in the circumferential direction on the magnetic material piece attached to the encoder 62 May become larger (longer) than

  As described above, when a magnetic material piece larger (longer) than the interval between the N pole and S pole adjacent in the circumferential direction adheres to the encoder 62, the magnetic circuit is short-circuited by the magnetic material piece, and the Hall IC 64 When detecting a change in the magnetic field (for example, fluctuation in the magnetic flux density of the magnetic flux), the magnetic field change becomes large only in the short circuit part, and the detected (output) magnetic field pulse is in an abnormal state (so-called pulse omission). There is a risk of becoming.

  Further, when the magnetic material piece adhering to the encoder 62 is rotated along with the rotation of the inner ring 2, the sensor unit continues to be in sliding contact with the opposing surfaces of the Hall IC 64 and the encoder 62, and friction against the opposing surface. May cause scratches. Further, in the sensor unit, when the magnetic material piece is sandwiched between the encoder 62 and the Hall IC 64, the above-described damage to the facing surface is further increased.

  The present invention has been made to solve such a problem, and its purpose is to seal a facing portion (sensor portion) between the detected body and the detecting body, and to remove foreign matter, particularly a magnetic material piece, to the facing portion. By providing a foreign matter intrusion prevention member to prevent the intrusion of the material, it can be rotated with high precision over a long period of time without damaging the detected object and the detected object (for example, the rotational speed, rotational direction or rotation of the rotating wheel). An object is to provide a sensor-equipped bearing capable of measuring an angle or the like.

  In order to achieve such an object, a sensor-equipped bearing according to the present invention includes a pair of rotating wheels and stationary wheels that are arranged to face each other so as to be relatively rotatable, and a sensor that measures the rotational state of the bearing. The sensor includes a detected body that rotates in the same rotational state as the rotating wheel, a detection body that detects the rotational state of the detected body, and an annular sensor housing that houses the detected body. Yes. In such a sensor-equipped bearing, the detected body is fixed to the rotating wheel and rotates together with the rotating wheel, while the detecting body can be opposed to the detected body at a predetermined interval. The sensor housing is fixed to the stationary wheel, and the sensor housing is formed integrally with the sensor housing in order to prevent intrusion of foreign matter into the facing portion between the detected body and the detected body. A foreign matter intrusion prevention unit is provided.

For example, when the detected object is attached to the detected object holder fixed to the rotating wheel and configured to rotate together with the rotating wheel, the foreign object intrusion prevention unit is configured to detect the detected object of the sensor housing. The sensor housing is formed so as to protrude toward the detected object holder over the entire circumference of the surface facing the holder, and the projecting end of the foreign matter intrusion prevention unit is spaced a predetermined distance from the detected object holder. And so as to face each other.
In this case, the facing distance between the protruding end of the foreign matter intrusion prevention unit and the detected object holder may be set smaller than the facing distance between the detected object and the detected object.

Further, in a state where the detected object is attached to the detected object holder fixed to the rotating wheel, the detected object is rotated together with the rotating wheel, and the sensor housing is opposed to the detected object holder and the rotating wheel at a predetermined interval. When the structure is positioned, a concave groove or convex portion is provided over the entire circumference on the surface facing the rotating wheel of the sensor housing as the foreign matter intrusion prevention portion, and the concave groove or convex portion is provided on the rotation surface. The labyrinth may be formed by adopting a structure in which a convex portion or a concave groove provided on the entire surface of the ring facing the sensor housing is opposed to and meshed with a predetermined interval.
In this case, the facing distance between the convex portion of the rotating wheel and the concave groove of the sensor housing that mesh with each other, or the facing distance between the concave groove of the rotating wheel and the convex portion of the sensor housing are both covered. What is necessary is just to set smaller than the opposing space | interval of a detection body and a detection body.
In any case described above, the foreign matter intrusion prevention unit may be positioned on the radially inner side of the bearing with respect to the detected body and the detected body.

  According to the sensor-equipped bearing of the present invention, a foreign matter intrusion prevention member for sealing a facing portion (sensor portion) between the detected body and the sensing body and preventing foreign matter, particularly a magnetic material piece, from entering the facing portion. By providing this, it is possible to effectively prevent the detected body and the detection body from being damaged by the foreign matter. Accordingly, the sensor can measure the rotational state (for example, the rotational speed, the rotational direction, or the rotational angle of the rotating wheel) with high accuracy over a long period of time.

  Hereinafter, a sensor-equipped bearing according to a first embodiment of the present invention will be described with reference to the accompanying drawings. The basic configuration of the sensor-equipped bearing according to the present embodiment is the same as that of the conventional sensor-equipped bearing (bearing D (FIG. 3)) described above. The same reference numerals are given in the drawings.

1 (a) and 1 (b) show a sensor-equipped bearing (hereinafter simply referred to as a bearing A) according to a first embodiment of the present invention. A pair of rotating wheels 2 and stationary wheels 4 arranged, and a sensor 20 for measuring the rotation state of the bearing A are provided.
In this case, the inner ring is configured as a rotating ring 2 that rotates together with a rotating shaft (not shown) of the bearing A, and the outer ring is configured as a stationary ring 4 that is always maintained in a non-rotating state. Between 2 and 4, a plurality of rolling elements (balls) 6 are incorporated so as to be capable of rolling in a state where they are rotatably held one by one in a pocket of the cage 8. On the outer peripheral surface of the inner ring 2 and the inner peripheral surface of the outer ring 4, raceway surfaces 2a and 4a for rolling the rolling elements (balls) 6 are formed over the entire circumference. In the configuration shown in FIG. 1A, as an example, the raceway surfaces 2a and 4a are positioned approximately at the center of the axial width of the bearing A, but are shifted upward or downward from the center of the axial width. Thus, the raceway surfaces 2a and 4a may be formed.
Further, as the rolling element 6, various rollers such as a cylindrical roller, a tapered roller, and a spherical roller (a barrel roller) may be applied instead of the balls as shown in FIG. 1A, and the cage 2 c. As an alternative, various types of cages such as a crown type, a basket type, and a machined type may be applied instead of the so-called corrugated type as shown in FIG.

Further, in the configuration shown in FIG. 1A, the bearing A has an annular seal member 10 on one side (the lower side in the figure) in the axial direction (the vertical direction in FIG. 1A). It is interposed between 2 and 4. In this case, as an example, the seal member 10 is configured as a contact-type seal, and the seal member 10 is an annular cored bar formed by pressing or the like such that a steel plate or the like has an L-shaped cross section. A part is connected by various elastic materials (for example, resin materials such as rubber and plastic). A lip portion made of such an elastic material is formed on the inner diameter portion of the seal member 10. The seal member 10 is positioned such that its outer diameter portion is fixed to a mounting groove 4 m formed in the outer ring 4 and its inner diameter portion is in sliding contact with the seal groove 2 m formed in the inner ring 2.
As a result, the inside of the bearing A is maintained in a sealed state. For example, a lubricant (for example, lubricating oil or grease) sealed inside the bearing leaks to the outside of the bearing, or foreign matter (for example, water or It is possible to prevent dust from entering the bearing.

  In addition, since the magnitude | size, the shape, and number of the sealing member 10 are arbitrarily set by the magnitude | size of the bearing A etc., for example, it does not specifically limit here. Further, for example, by providing a plurality of lip portions at the tip of the inner diameter portion of the seal 10 and bringing the lip portions into contact with the bottom portion or the side surface portion of the seal groove 2m described above, the sealing performance of the bearing A is further improved. be able to. Further, as the seal member 10, instead of the contact type seal as shown in FIG. 1A, the outer diameter portion is fixed to the mounting groove 4m of the outer ring 2, and the inner diameter portion contacts the seal groove 2m of the inner ring 2. Non-contact type seals (for example, seals made by connecting all or part of a steel cored bar with various elastic materials (for example, resin materials such as rubber and plastic)) and non-contact type shields (For example, a shield press-formed from a thin metal plate such as a stainless steel plate or an iron plate) may be applied.

  On the other hand, the bearing A is provided with a sensor 20 on one side (upper side in the figure) in the axial direction (the vertical direction in FIG. 1A), and the sensor 20 is an inner ring 2 that is a rotating wheel. A detection object 22 that rotates in the same rotation state as the first detection object, a detection object 24 that detects the rotation state of the detection object 22, and a sensor housing 26 that houses the detection object 22.

  Here, as the sensor 20, for example, a magnetic sensor that detects a change in magnetic state (magnetic field strength or direction (specifically, fluctuation of magnetic flux density) or the like), or an optical sensor that detects reflected light with respect to irradiation light. Etc. can be arbitrarily selected and used. In this embodiment, as an example, assuming that the sensor 20 is a magnetic sensor, an annular magnet (hereinafter referred to as an encoder 22) magnetized in multiple poles is used as the detection target 22 of the magnetic sensor. In addition, a magnetic detection element (specifically, a Hall IC (hereinafter referred to as Hall IC 24)) that detects a change in magnetic state (as one example, a change in magnetic flux density) is applied as the detection body 24.

The number of magnetic poles to be magnetized in the encoder 22 may be arbitrarily set according to the rotational speed of the inner ring 2 and the detection accuracy of the Hall IC 24. However, as the number of magnetized magnetic poles increases, the Hall IC 24 has a magnetic state. It is preferable because the change can be easily detected and the measurement accuracy of the rotation state (rotation speed, rotation direction or rotation angle) of the bearing A can be increased. As an example, in the present embodiment, the inner circumferential surface of the encoder 22 is configured as an annular magnet having a total of 100 poles in which N poles and S poles are alternately magnetized in the circumferential direction by 50 poles. Assuming that
However, instead of the encoder described above, the object to be detected 22 is, for example, a gear (gear-like magnetic body, etc.), a pressed product with a window (annular magnetic body having through holes formed at predetermined intervals in the circumferential direction, etc.) ) May apply.

  In the configuration shown in FIG. 1A, a circuit wiring board (hereinafter referred to as a printed board) 30 is provided for the sensor 20, and the printed board 30 supplies power to the Hall IC 24 from a predetermined power supply device. The sensor structure is configured to supply the detection signal output from the Hall IC 24 to a predetermined signal processing unit (not shown). In this case, as an example, the printed circuit board 30 is formed in a fan-shaped plate shape, and has a structure in which the Hall IC 24 and a signal processing unit (not shown) are connected directly or via a cable (not shown).

In such a bearing A, the encoder 22 is fixed to the inner ring 2 and rotates together with the inner ring 2. In the configuration shown in FIG. 1A, as an example, the encoder 22 is fixed (for example, bonded or welded) to an outer diameter portion of a holder (hereinafter referred to as an encoder holder) 32, and the encoder holder 32 is attached to the inner ring 2. By being attached, it is fixed to the inner ring 2. In this case, the encoder holder 32 is formed in an annular shape whose inner diameter is slightly smaller than the outer diameter of the inner ring 2, whose outer diameter is smaller than the inner diameter of the outer ring 4, and larger than the outer diameter of the inner ring 2. In a state where the inner diameter portion is fixed to the inner ring 2, positioning is performed such that a predetermined gap is generated between the outer diameter portion and the inner peripheral surface of the outer ring 4. As an example, the outer diameter portion of the encoder holder 32 is raised to one side in the axial direction (the upper side in FIG. 1A), and the raised end portion is substantially flush with the end surface of the encoder 22. The launch height has been adjusted.
Thereby, the encoder 22 can rotate in the same rotational state as the inner ring 2 together with the inner ring 2 without contacting the outer ring 4.

  In this case, on the outer peripheral surface of the inner ring 2, a concave groove (hereinafter referred to as an encoder mounting portion) 2g is formed over the entire circumference at one end portion (the upper end portion in FIG. 1 (a)). The encoder holder 32 is fixed to the inner ring 2 by fitting the inner diameter portion of the encoder holder 32 to the encoder mounting portion 2g. For example, the encoder holder 32 may be bonded and fixed to the encoder mounting portion 2g by an adhesive, or may be fastened and fixed by a fastening member. Or you may fix combining various methods mentioned above arbitrarily. Further, the encoder holder 32 may be directly fitted to the outer peripheral surface, or may be bonded or fastened without forming the encoder mounting portion 2g on the inner ring 2.

  On the other hand, in the bearing A, the Hall IC 24 is accommodated in the sensor housing 26 in a state of being connected to the printed circuit board 30 so as to be opposed to the encoder 22 with a predetermined interval. A cover 28 (hereinafter referred to as a housing cover) 28 is fixed to the outer ring 4 by being attached to the outer ring 4. In the configuration shown in FIG. 1A, as an example, the outer surface of the Hall IC 24 (specifically, the surface where the Hall element is disposed (the left surface in FIG. 1)) 24a and the inner peripheral surface of the encoder 22 ( The Hall IC 24 is positioned with respect to the encoder 22 so that it can be opposed to the magnetic pole surface 22a with a predetermined interval. Hereinafter, the facing distance (distance d1 shown in FIG. 1A) between the outer surface 24a of the Hall IC 24 and the inner peripheral surface (magnetic pole surface) 22a of the encoder 22 is referred to as a sensor gap.

Note that the relative positional relationship between the Hall IC 24 and the encoder 22 is such that the Hall IC 24 (more specifically, the Hall element) and the magnetic pole surface of the encoder 22 face each other as shown in FIG. There is no particular limitation. For example, the inner surface of the Hall IC 24 (the right surface in FIG. 1A) may be opposed to the outer peripheral surface of the encoder 22, or the end surface of the Hall IC 24 (the lower surface in FIG. The end surfaces (the upper surface in the figure) may be opposed. In this case, the outer peripheral surface or end surface of the encoder 22 that is the surface facing the Hall IC 24 (more specifically, the Hall element) may be configured as a magnetic pole surface.
Further, the facing distance between the Hall IC 24 (more specifically, the Hall element) and the magnetic pole surface of the encoder 22 (in this embodiment, the inner peripheral surface), that is, the sensor gap d1, should be set as narrow as possible. However, since the specific interval is arbitrarily set according to the detection accuracy of the magnetic change of the Hall IC 24, the magnitude of the magnetic force of the encoder 22, or the size and shape of the bearing A, it is particularly here. Not limited.

The sensor housing 26 has an outer diameter smaller than the outer diameter of the outer ring 4 and larger than the inner diameter of the outer ring 4, and the inner diameter is smaller than the outer diameter of the inner ring 2 and larger than the inner diameter of the inner ring 2. It is formed in an annular shape.
In addition, the sensor housing 26 is entirely on one end surface in the axial direction (the lower end surface in FIG. 1A) so as to be in non-contact with the encoder 22 fixed to the inner ring 2 via the encoder holder 32. A concave groove (hereinafter referred to as an encoder track groove) 26m is formed over the circumference. The sensor housing 26 is not formed with the encoder raceway groove 26m, and its end face (the lower end face in FIG. 1A) is not in contact with the end face of the encoder 22 (the upper end face in the same figure). The axial height of the housing 26 (the vertical distance in the figure) may be set, or the housing cover 28 to which the sensor housing 26 is fixed may be positioned with respect to the outer ring 4.

The housing cover 28 has an outer diameter that is substantially the same as the outer diameter of the outer ring 4, and an inner diameter that is smaller than the outer diameter of the inner ring 2 and larger than the inner diameter of the inner ring 2. In a state where the diameter portion is fixed to the outer ring 4, positioning is performed so that a predetermined gap is generated between the tip of the inner diameter portion and the peripheral surface portion of the rotation shaft (not shown) of the bearing A.
As an example, in the configuration shown in FIG. 1A, the housing cover 28 is configured such that the tip of the inner diameter portion thereof is substantially flush with the inner peripheral surface of the sensor housing 26. The tip of the inner diameter portion of the housing cover 28 protrudes from the inner peripheral surface of the sensor cover 26, that is, the inner diameter of the sensor housing 26 may be larger than the inner diameter of the housing cover 28. Alternatively, the tip of the inner diameter portion of the housing cover 28 may be retracted from the inner peripheral surface of the sensor housing 26, that is, the inner diameter of the sensor housing 26 may be smaller than the inner diameter of the housing cover 28.

  In this case, on the outer peripheral surface of the outer ring 4, a concave groove (hereinafter referred to as a cover mounting portion) 4g is formed over the entire circumference at one end portion (the upper end portion in FIG. 1A). The housing cover 28 is fixed to the outer ring 4 by fitting the tip of the outer peripheral portion of the housing cover 28 to the cover mounting portion 4g. For example, the housing cover 28 may be bonded and fixed to the cover mounting portion 4g by an adhesive, or may be fastened and fixed by a fastening member. Or you may fix combining various methods mentioned above arbitrarily. Further, the housing cover 28 may be directly fitted to the outer peripheral surface, or may be bonded or fastened without forming the cover attachment portion 4g on the outer ring 4.

  Further, as an example, the housing cover 28 is configured by providing a predetermined stepped portion 28s between an inner diameter portion and an outer diameter portion, and the outer circumferential surface and one end face (see FIG. The sensor housing 26 is fixed in a state in which the upper end surface of a) is in contact with the sensor housing 26 so that the sensor housing 26 is integrated. In this case, the stepped portion 28s may be formed so that its diameter is substantially the same as the outer diameter of the sensor housing 26. As a method for fixing the sensor housing 26 and the housing cover 28, any method such as fitting, adhesion, welding, or fastening may be used.

  Here, the number of Hall ICs 24 provided in the sensor 20 may be arbitrarily set according to the accuracy required for the measurement of the rotation state (rotation speed, rotation direction, rotation angle, etc.) of the bearing A, In the present embodiment, as an example, a case where two Hall ICs 24 are provided for the sensor 20 is assumed. The two Hall ICs 24 shift the electrical angle (the phase when one period of the signal sine wave is 360 °) by 90 ° at the timing of detecting the change in the magnetic state (the phase difference of 90 ° is changed). It may be connected to the printed circuit board 30 so as to be positioned. Thus, the rotational state of the bearing A (specifically, the inner ring 2 and the encoder 22) can be detected more accurately by comparing the detection result of the magnetic change in each Hall IC 24 in consideration of the phase difference. it can. However, the sensor 20 may be configured to measure the rotational state of the bearing A with only one Hall IC 24, or may be configured to measure the rotational state of the bearing A with three or more Hall ICs 24.

  In the above-described embodiment, the materials of the sensor housing 26, the housing cover 28, and the encoder holder 32 are not particularly mentioned, but the change in the magnetic state that occurs when the encoder 22 rotates does not be affected. It is preferable to use a predetermined material (for example, a nonmagnetic material or a magnetic material coated with a nonmagnetic material).

  By positioning the encoder 22 and the Hall IC 24 with respect to the inner and outer rings 2, 4 as described above, the sensor 20 is in a state where the encoder 22 faces the Hall IC 24, specifically, the inner peripheral surface (magnetic pole surface) of the encoder 22. ) 22a can be configured to rotate together with the inner ring 2 in a state where the outer surface (hall element arrangement surface) 24a of the Hall IC 24 is opposed.

That is, in the bearing A, when the inner ring 2 is rotated, the encoder 22 is also rotated at the same time, and the positions of the magnetic poles (N pole and S pole) with respect to the Hall IC 24 are alternately and continuously changed. At this time, the magnetic flux passing through the Hall IC 24 (more specifically, the magnetic flux density of the magnetic flux) continuously changes, and the change or the like of the encoder 22 is detected by detecting the change by the Hall IC 24. be able to. The printed circuit board 30 converts the change in magnetic flux density detected by the Hall IC 24 into an electrical signal, and transmits the electrical signal (data) to a signal processing unit (not shown). The amount of variation such as the position and angle of the encoder 22 is calculated and processed so that the bearing A (specifically, the inner ring 2 to which the encoder 22 is fixed) is rotated (for example, rotational speed, rotational direction or rotational angle). ) Can be measured.
In this case, the printed circuit board 30 (Hall IC 24) of the sensor 20 and a signal processing unit (not shown) are connected by a predetermined signal cable (not shown), and the above-described electrical signal is signaled through the signal cable. It is transmitted (output) to a processing unit (not shown).

  Further, in the bearing A according to the present embodiment, as shown in FIGS. 1A and 1B, the sensor housing 26 includes a facing portion between an encoder 22 as a detection target and a Hall IC 24 as a detection target. Specifically, a foreign matter (for example, iron or the like) to a facing portion (hereinafter referred to as a sensor portion) between the inner peripheral surface (magnetic pole surface) 22a of the encoder 22 and the outer surface (Hall element arrangement surface) 24a of the Hall IC 24. In order to prevent intrusion of small pieces of magnetic material (hereinafter referred to as magnetic material pieces), a foreign matter intrusion prevention portion (hereinafter referred to as a sensor seal portion) 80 formed integrally with the sensor housing 26 is provided. ing.

  The sensor seal portion 80 is provided over the entire circumference with respect to the surface 26a of the sensor housing 26 facing the encoder holder 32 (the end surface on the encoder holder 32 side (the lower end surface of FIGS. 1A and 1B)) 26a. Projecting toward the holder 32 is formed. The sensor housing 26 in which the sensor seal portion 80 is formed has a protruding end portion (that is, a peripheral edge portion (hereinafter referred to as a seal peripheral portion)) 80a of the sensor seal portion 80 in the encoder holder 32 (specifically, its surface). (The upper surface in FIGS. 1 (a) and (b)) 32a) is positioned so as to face a predetermined distance. Hereinafter, the facing distance (the distance d2 shown in FIGS. 1A and 1B) between the seal peripheral portion 80a of the sensor seal portion 80 and the surface 32a of the encoder holder 32 is referred to as a seal gap.

In the configuration shown in FIGS. 1A and 1B, the sensor seal portion 80 has a cylindrical shape whose diameter is substantially the same as the outer diameter of the inner ring 2, and is 1 with respect to the end surface 26 a of the sensor housing 26. Only one is formed.
In this case, as an example, the sensor seal portion 80 is formed in a cylindrical shape having the same diameter from the connection portion with the end surface 26a of the sensor housing 26 to the seal peripheral portion 80a. 26 may have a conical shape in which the diameter is gradually increased or reduced from the connection portion with the end face 26a to the seal peripheral edge 80a. Further, the vertical cross-sectional shape of the sensor seal portion 80 may be a flat shape as shown in FIGS. 1A and 1B, a concave curved shape, a convex curved shape, or a wave shape. . Furthermore, the vertical cross-sectional shape of the sensor seal portion 80 may be formed in a substantially L shape, a substantially J shape, or the like by bending the seal peripheral portion 80a in the diameter increasing direction or the diameter reducing direction.

In the configuration shown in FIGS. 1A and 1B, as an example, the seal peripheral portion 80a of the sensor seal portion 80 is processed into a flat surface parallel to the surface of the encoder holder 32. The shape of the peripheral edge portion 80a is not particularly limited to a flat surface shape, and can be an arbitrary shape.
For example, as in the first modification of the present invention shown in FIG. 1C, the seal peripheral edge 80a may be processed into a convex curved surface, or the second modification of the present invention shown in FIG. It is good also as a structure which processed the seal | sticker peripheral part 80a into the pyramid shape like an example. In the first modification shown in FIG. 1 (c) and the second modification shown in FIG. 1 (d), the bearing A according to this embodiment is excluded except for the shape of the seal peripheral portion 80a of the sensor seal portion 80. , And the sensor seal 80.

Note that one end portion of the inner peripheral surface of the sensor housing 26 (the lower end portion of FIGS. 1A and 1B) is chamfered over the entire circumference so as not to come into contact with the inner ring 2 and has a corner. The sensor seal portion 80 is formed continuously with the chamfered portion.
The method for forming the sensor seal portion 80 with respect to the sensor housing 26 is not particularly limited. For example, the sensor seal portion 80 may be formed simultaneously with the sensor housing 26 by casting or injection molding, or the sensor housing after molding. The sensor seal portion 80 may be formed by cutting the end surface 26a of the 26. Further, the number of sensor seal portions 80 provided in the sensor housing 26 is not limited to one as shown in FIGS. 1A and 1B, and may be two or more.

  In this embodiment, the facing distance between the seal peripheral edge 80a of the sensor seal 80 and the encoder holder 32 (specifically, the surface 32a), that is, the seal gap d2, is the facing distance between the encoder 22 and the Hall IC 24, that is, the sensor. It is set smaller than the gap d1.

  As a result, even if a large foreign substance (specifically, a magnetic material piece) having the same size as or larger than the sensor gap d1 floats, the magnetic material piece can be blocked by the sensor seal portion 80. it can. When the magnetic material piece is smaller than the sensor gap d1 and further smaller than the seal gap d2, the magnetic material piece may enter the sensor portion from the seal gap d2. In this case, the encoder The configuration may be such that 22 is magnetized to 100 poles (for example, 100 poles (50 N poles and 50 S poles)) and the interval between the N poles and S poles adjacent in the circumferential direction is narrowed. . That is, in this case, the size (length) of the magnetic material piece that has entered the sensor unit does not become larger than the interval between the N pole and the S pole adjacent in the circumferential direction, and the magnetic material attached to the encoder 22 It is possible to prevent the magnetic circuit from being short-circuited by the piece.

  As described above, the relative positional relationship between the Hall IC 24 and the encoder 22 is not particularly limited as long as the Hall IC 24 (specifically, the Hall element) and the magnetic pole surface of the encoder 22 face each other. Regardless of whether the IC 24 and the encoder 22 are positioned, the sensor seal 80 needs to be positioned radially inward of the bearing A with respect to the encoder 22 and the Hall IC 24. In other words, since the sensor housing 26 and the housing cover 28 have sufficient sealing performance in the sensor portion on the radially outer side of the bearing A, the sensor seal portion 80 is located on the radially inner side of the bearing A from the encoder 22 and the Hall IC 24. It is possible to substantially seal the sensor unit from the outside of the bearing A.

Thus, since the sensor seal portion 80 is provided in the bearing A according to this embodiment, in various mechanical devices in which the bearing A is incorporated, foreign matter, specifically, a magnetic material is present in the atmosphere. Even when the piece floats, the magnetic material piece can be blocked by the sensor seal portion 80 between the inner ring 2 and the sensor housing 26. As a result, the magnetic material piece can be reliably prevented from entering the sensor portion, and the magnetic circuit piece adhering to the encoder 22 can be effectively prevented from being short-circuited. As described above, the encoder 22 is magnetized in multiple poles (for example, 100 poles (50 N poles and 50 S poles)), and the N poles and S poles adjacent in the circumferential direction are arranged. By narrowing the interval, a short circuit of the magnetic circuit due to the magnetic material pieces adhering to the encoder 22 can be surely prevented, and a change in the magnetic state when the encoder 22 is rotated can be increased. Therefore, it is possible to easily increase the accuracy of detecting magnetic changes.
Further, since the magnetic material piece can be reliably prevented from entering the sensor portion, it is possible to effectively prevent the encoder 22 and the Hall IC 24, particularly the sensor portion, from being damaged by the magnetic material piece. As a result, the rotation state of the bearing A (for example, the rotation speed, rotation direction, or rotation angle of the rotating wheel) can be measured over a long period of time.

  The sensor seal 80 is not limited to the configuration according to the first embodiment described above (FIGS. 1A and 1B). For example, the second embodiment of the present invention shown in FIG. Even with the configuration according to this embodiment and the configuration according to the third embodiment of the present invention shown in FIG. 2B, the same effects as those of this embodiment can be obtained. In the second embodiment shown in FIG. 2 (a) and the third embodiment shown in FIG. 2 (b), the structure of the sensor seal portion 80, specifically, the structure of the sensor housing 26 and the inner ring 2 ( Since the bearing configuration is the same as that of the bearing A according to the first embodiment described above (FIGS. 1A and 1B), except for the shape of the mutually facing surfaces, The same reference numerals are given above and the description thereof is omitted.

  FIG. 2A shows a sensor-equipped bearing (hereinafter simply referred to as a bearing B) according to a second embodiment of the present invention. In the bearing B, an encoder 22 is an encoder fixed to the inner ring 2. The sensor housing 26 rotates with the inner ring 2 while being attached to the holder 32, and the sensor housing 26 is positioned to face the encoder holder 32 and the inner ring 2 with a predetermined interval. And in the sensor housing 26, as a sensor seal portion 80, a concave groove (hereinafter referred to as a seal concave groove) on the entire surface of the opposed surface (end surface (lower end surface of FIG. 2A)) 26a with respect to the inner ring 2 is provided. 80d is provided, and the projecting protrusion 80d is provided on the entire surface of the surface 2s (end surface (the lower end surface of FIG. 2A)) facing the sensor housing 26 of the rotating wheel 2 with respect to the sensor housing 26. A labyrinth is formed by engaging with 2d (hereinafter referred to as an inner ring convex portion) with a predetermined interval therebetween.

  In the configuration shown in FIG. 2A, the inner ring convex portion 2 d protrudes from the end surface 2 s of the inner ring 2 toward the end surface 26 a of the sensor housing 26 in a cylindrical shape whose diameter is slightly larger than the inner diameter of the sensor housing 26. Only one is formed. In this case, as an example, the inner ring convex portion 2d is formed in a cylindrical shape having the same diameter from the connecting portion with the end surface 2s of the inner ring 2 to the protruding end portion (that is, the peripheral portion (hereinafter referred to as the inner ring convex peripheral portion)). However, for example, the inner ring convex portion 2d may have a conical shape whose diameter is gradually expanded or reduced from the connecting portion with the end surface 2s of the inner ring 2 to the inner ring convex peripheral portion. Further, the longitudinal sectional shape of the inner ring convex portion 2d may be a rectangular shape as shown in FIG. 2A, or may be a convex curve shape or a wave shape.

On the other hand, the seal concave groove 80d is continuous along the circumferential direction of the end surface 26a of the sensor housing 26 in an annular shape, and is continuous over the entire circumference at both ends of the bottom portion, and rises in the direction of the end surface 26a. As a groove having a rectangular shape in a longitudinal sectional view formed by a pair of wall portions facing each other, only one groove is provided on the end surface 26a so as to be opposed to the inner ring convex portion 2d.
The inner ring convex portion 2d and the seal concave groove 80d are opposed to each other with a predetermined interval between the inner ring convex peripheral edge and inner and outer peripheral surfaces of the inner ring convex portion 2d, and the bottom and wall of the seal concave groove 80d. However, the sizes of the inner ring convex portion 2d and the seal concave groove 80d may be adjusted to each other so as to engage with each other in a non-contact state.

  By forming the inner ring convex portion 2d and the seal concave groove 80d in such a non-contact state, a labyrinth structure is formed between the sensor seal portion 80, that is, the sensor housing 26 and the inner ring 2. be able to. At this time, the opposing distance between the inner ring convex peripheral edge and inner and outer peripheral surfaces of the inner ring convex portion 2d and the bottom and wall of the seal concave groove 80d, that is, the labyrinth gap (hereinafter referred to as the labyrinth gap) is It is set smaller than the distance between the Hall IC 24 and the sensor gap d1.

  As a result, even when a large foreign substance (specifically, a magnetic material piece) approximately the same size or larger than the sensor gap d1 floats, the magnetic material piece is blocked by the labyrinth of the sensor seal portion 80. be able to. When the magnetic material piece is smaller than the sensor gap d1 and further smaller than the labyrinth gap, the magnetic material piece may enter the sensor unit from the labyrinth gap. What is necessary is just to set it as the structure which magnetized the multi-pole (for example, 100 poles (50 N poles and 50 S poles)), and narrowed the space | interval of the N pole and S pole which adjoin the circumferential direction. That is, in this case, the size (length) of the magnetic material piece that has entered the sensor unit does not become larger than the interval between the N pole and the S pole adjacent in the circumferential direction, and the magnetic material attached to the encoder 22 It is possible to prevent the magnetic circuit from being short-circuited by the piece.

  The method for forming the inner ring convex portion 2d for the inner ring 2 and the method for forming the sensor seal portion 80 (specifically, the seal concave groove 80d) for the sensor housing 26 are not particularly limited. For example, casting or injection molding The inner ring convex portion 2d may be formed simultaneously with the inner ring 2, or the sensor seal portion 80 (seal concave groove 80d) may be formed simultaneously with the sensor housing 26. Further, the inner ring convex portion 2d may be formed by cutting the end surface 2s of the molded inner ring 2 or cutting the end surface 26a of the molded sensor housing 26. Thus, the sensor seal portion 80 (seal concave groove 80d) may be formed. Further, the number of inner ring convex portions 2d provided in the inner ring 2 and the number of sensor seal portions 80 (seal concave grooves 80d) provided in the sensor housing 26 are such that the inner ring convex portions 2d and the seal concave grooves 80d mesh with each other. If possible, the number is not limited to one as in the configuration shown in FIG. 2A, and may be two or more.

As described above, the relative positional relationship between the Hall IC 24 and the encoder 22 is not particularly limited as long as the Hall IC 24 (specifically, the Hall element) and the magnetic pole surface of the encoder 22 face each other. Regardless of whether the IC 24 and the encoder 22 are positioned, the labyrinth formed by the sensor seal portion 80, that is, the inner ring convex portion 2d and the seal concave groove 80d, is more in the bearing B than the encoder 22 and the Hall IC 24. Must be positioned radially inward. In other words, since the sensor housing 26 and the housing cover 28 have sufficient sealing performance in the sensor portion at the outer side in the radial direction of the bearing B, the sensor seal portion 80 (labyrinth) is disposed closer to the bearing B than the encoder 22 and the Hall IC 24. By positioning inward in the radial direction, the sensor portion can be substantially sealed from the outside of the bearing B.
Since other effects are the same as those of the bearing A according to the first embodiment of the present invention described above, description thereof is omitted.

  On the other hand, FIG. 2B shows a sensor-equipped bearing (hereinafter simply referred to as a bearing C) according to a third embodiment of the present invention. In the bearing C, the encoder 22 is fixed to the inner ring 2. The sensor housing 26 is positioned so as to face the encoder holder 32 and the inner ring 2 at a predetermined interval while rotating together with the inner ring 2 while being attached to the encoder holder 32. In the sensor housing 26, a projecting portion (hereinafter referred to as a seal convex shape) is provided as a sensor seal portion 80 on a surface 26a facing the inner ring 2 (end surface (lower end surface in FIG. 2B)) 26a. 80e, and the seal convex portion 80e is a concave shape provided on the entire surface of the surface 2s (end surface (lower end surface in FIG. 2B)) of the rotating wheel 2 facing the sensor housing 26. The labyrinth is formed by engaging with a groove (hereinafter referred to as an inner ring concave groove) 2e with a predetermined distance therebetween.

  In the configuration shown in FIG. 2B, the seal convex portion 80e has a cylindrical shape whose diameter is the same as the inner diameter of the sensor housing 26, and the end surface 2s of the inner ring 2 from the inner diameter side end portion of the end surface 26a of the sensor housing 26. Only one is formed so as to protrude toward the front. In this case, as an example, the seal convex portion 80e is formed in a cylindrical shape having the same diameter from a connection portion with the end surface 26a of the sensor housing 26 to a protruding end portion (that is, a peripheral portion (hereinafter referred to as a seal convex peripheral portion)). However, for example, the seal convex portion 80e may have a conical shape whose diameter is gradually increased or reduced from the connection portion with the end surface 26a of the sensor housing 26 to the seal convex peripheral portion. Further, the vertical cross-sectional shape of the seal convex portion 80e may be a rectangular shape as shown in FIG. 2B, or may be a convex curve shape or a wave shape.

On the other hand, the inner ring concave groove 2e is formed in an annular shape along the circumferential direction of the end surface 2s of the inner ring 2 and continuously on both ends of the bottom portion, and rises in the direction of the end surface 2s. As a groove having a rectangular shape in a longitudinal section formed by a pair of opposing wall portions, only one groove is provided on the end surface 2s so as to be able to face the seal convex portion 80e.
The seal convex portion 80e and the inner ring concave groove 2e are opposed to each other with a predetermined interval between the seal convex peripheral edge and inner and outer peripheral surfaces of the seal convex portion 80e and the bottom and wall of the inner ring concave groove 2e. However, the sizes of the seal convex portion 80e and the inner ring concave groove 2e may be adjusted to each other so as to engage with each other in a non-contact state.

  The labyrinth structure is formed between the sensor seal portion 80, that is, the sensor housing 26 and the inner ring 2, by configuring the seal convex portion 80 e and the inner ring concave groove 2 e to mesh with each other in this non-contact state. be able to. At this time, the opposing spacing between the seal convex peripheral edge and inner and outer peripheral surfaces of the seal convex portion 80e and the bottom and wall of the inner ring concave groove 2e, that is, the labyrinth gap (hereinafter referred to as the labyrinth gap) It is set smaller than the distance between the Hall IC 24 and the sensor gap d1.

  Further, the method of forming the sensor seal portion 80 (specifically, the seal convex portion 80e) with respect to the sensor housing 26 and the method of forming the inner ring concave groove 2e with respect to the inner ring 2 are not particularly limited, but for example, casting or injection molding The sensor seal portion 8 (seal convex portion 80e) may be formed at the same time as the sensor housing 26, or the inner ring concave groove 2e0 may be formed at the same time as the inner ring 2. Further, the sensor seal portion 8 (seal convex portion 80e) may be formed by cutting the end surface 26a of the sensor housing 26 after molding, or the end surface 2s of the inner ring 2 after molding. Then, the inner ring concave groove 2e may be formed by cutting or the like. Furthermore, the number of sensor seal portions 8 (seal convex portions 80e) provided in the sensor housing 26 and the number of inner ring concave grooves 2e provided in the inner ring 2 are such that the seal convex portions 80e and the inner ring concave grooves 2e mesh with each other. If possible, the number is not limited to one as shown in FIG. 2B, and may be two or more.

  As described above, the relative positional relationship between the Hall IC 24 and the encoder 22 is not particularly limited as long as the Hall IC 24 (specifically, the Hall element) and the magnetic pole surface of the encoder 22 face each other. Regardless of whether the IC 24 and the encoder 22 are positioned, the labyrinth formed by the sensor seal portion 80, that is, the seal convex portion 80e and the inner ring concave groove 2e, is more in the bearing C than the encoder 22 and the Hall IC 24. Must be positioned radially inward. In other words, since the sensor housing 26 and the housing cover 28 have sufficient sealing performance in the sensor portion on the radially outer side of the bearing C, the sensor seal portion 80 (labyrinth) is positioned more than the encoder 22 and the Hall IC 24 in the bearing C. By positioning inward in the radial direction, the sensor portion can be substantially sealed from the outside of the bearing B.

  In addition, about an effect, since it is the same as that of the bearing A which concerns on 1st Embodiment of this invention mentioned above, and the bearing B which concerns on 2nd Embodiment, description is abbreviate | omitted.

It is a figure which shows the structural example of the bearing with a sensor which concerns on 1st Embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is an expanded sectional view of a foreign material penetration | invasion prevention part (sensor seal part), (c) is an enlarged cross-sectional view of the foreign matter intrusion prevention portion (sensor seal portion) of the sensor-equipped bearing according to the first variation of the present invention, and (d) is a view of the sensor-equipped bearing according to the second variation of the present invention. The expanded sectional view of a foreign material intrusion prevention part (sensor seal part). It is a figure which shows the structural example of the bearing with a sensor which concerns on other embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view of the bearing with a sensor which concerns on 2nd Embodiment, (b) is 3rd Embodiment. The longitudinal cross-sectional view of the bearing with a sensor which concerns on. The longitudinal cross-sectional view which shows the structural example of the conventional bearing with a sensor.

Explanation of symbols

2 Rotating wheel (inner ring)
4 Stationary wheel (outer ring)
20 Sensor 22 Object to be detected (encoder)
24 Detector (Hall IC)
26 Sensor housing 28 Housing cover 30 Circuit wiring board (printed circuit board)
32 Encoder holder 80 Foreign matter intrusion prevention part (sensor seal part)
80a Foreign matter intrusion prevention part protruding end (seal peripheral part)
A Sensor bearing d1 Encoder-Hall IC facing distance (sensor gap)
d2 Sensor seal-encoder facing distance (seal gap)

Claims (6)

A pair of rotating wheels and stationary wheels arranged so as to be capable of relative rotation, and a sensor for measuring the rotation state of the bearing,
The sensor includes a detection body that rotates in the same rotation state as the rotating wheel, a detection body that detects the rotation state of the detection body, and an annular sensor housing that houses the detection body. A bearing,
The detected body is fixed to the rotating wheel and rotates together with the rotating wheel, whereas the detected body is accommodated in the sensor housing so as to be able to face the detected body at a predetermined interval. Fixed to the stationary wheel,
The sensor housing is provided with a foreign matter intrusion prevention portion formed integrally with the sensor housing in order to prevent the foreign matter from entering the opposite portion between the detected body and the detected body. Bearing with sensor.   The detected object is attached to the detected object holder fixed to the rotating wheel and is rotated together with the rotating wheel, and the foreign object intrusion preventing portion is connected to the detected object holder of the sensor housing. The sensor housing is formed so as to project toward the detected object holder over the entire circumference, and the sensor housing has a protruding end portion of the foreign matter intrusion prevention portion spaced apart from the detected object holder by a predetermined distance. The sensor-equipped bearing according to claim 1, wherein the bearing is positioned so as to face each other.   3. The sensor-attached device according to claim 2, wherein a facing interval between the protruding end portion of the foreign matter intrusion prevention unit and the detected body holder is set to be smaller than a facing distance between the detected body and the detected body. bearing.   The detected object is attached to the detected object holder fixed to the rotating wheel and rotates together with the rotating wheel, and the sensor housing is opposed to the detected object holder and the rotating wheel at a predetermined interval. As the foreign matter intrusion prevention portion, a concave groove or a convex portion is provided over the entire surface of the sensor housing facing the rotary wheel, and the concave groove or convex portion is provided on the rotary wheel. 2. The labyrinth is formed by engaging a convex portion or a concave groove provided on the entire surface of the surface facing the sensor housing with a predetermined distance therebetween. Bearing with sensor.   The opposing distance between the convex part of the rotating wheel and the concave groove of the sensor housing that meshes with each other, or the opposing distance between the concave groove of the rotary wheel and the convex part of the sensor housing is the same as the detected object. The sensor-equipped bearing according to claim 4, wherein the sensor-equipped bearing is set to be smaller than an opposing distance to the detection body.   The sensor-equipped bearing according to any one of claims 1 to 5, wherein the foreign matter intrusion prevention unit is positioned radially inward of the bearing relative to the detected body and the detection body.

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