JP4269642B2 - Rolling bearing with sensor for motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rolling bearing with a sensor for detecting the number of rotations of a rotating member integrally fixed to an inner ring or an outer ring of the rolling bearing.
[0002]
[Prior art]
The sensor-equipped rolling bearing is configured by fixing a magnetic sensing sensor and a detected member such as a magnet to an outer ring or an inner ring, respectively. Examples of prior art documents disclosing sensor-equipped rolling bearings include the following.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-311212 (pages 2 and 3, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 10-311740 (pages 2 and 3, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 7-325098 (pages 2 and 3, FIG. 1)
[0004]
FIG. 6 is a view showing a sensor-equipped rolling bearing disclosed in Patent Document 1. As shown in FIG. This sensor-equipped rolling bearing is configured such that a sensor 121 embedded in a sensor carrier 123 is beaded and fixed to a concave groove 116b provided on an inner diameter surface of an outer ring via a sensor holding device 125 over the entire circumference. . Further, the detected member 120 is disposed on the radial plane portion of the L-shaped member 122 press-fitted into the inner ring outer diameter surface, and faces the sensor 121.
[0005]
[Problems to be solved by the invention]
However, when the radial dimension of the bearing is small, it is difficult to fix the sensor to the outer ring inner diameter surface via the sensor carrier. In addition, it is also difficult in terms of dimensions to fix the member to be detected to the outer surface of the inner ring via the L-shaped member.
[0006]
In order to solve this difficulty, as shown in FIG. 7 (Patent Document 2) and FIG. 8 (Patent Document 3), a step is provided on the outer diameter of the outer ring or the outer diameter of the inner ring to fix the sensor and the detected member. However, since the stepped surface cannot be centerless polished, the dimensional variation increases and it is difficult to press-fit each member.
[0007]
In general, a rolling bearing with a sensor is often arranged in the vicinity of a member that generates electrical noise such as a motor. Therefore, depending on the mounting position, the external magnetic field caused by external noise may disturb the magnetic field formed by the detected member, and the sensor may not be able to accurately detect the magnetic field formed by the detected member. .
[0008]
An object of this invention is to provide the rolling bearing with a sensor which can attach a sensor correctly also in a small-sized bearing. Another object of the present invention is to provide a sensor-equipped rolling bearing that can operate normally even in an environment where electric noise is generated by a motor or the like.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a rolling bearing with a sensor for a motor according to claim 1 of the present invention includes an inner ring, an outer ring, a rolling element interposed between the inner ring and the outer ring, a magnetic detection unit, A rolling bearing with a sensor for a motor having a magnetic sensitive sensor facing the magnetized detection unit, the magnet bearing made of a magnetic material, and a mounting member including the sensor holder , wherein the sensor holder includes the outer ring The magnet holder is fixed to the concave groove formed on the circumference along the outer diameter surface of the inner ring at equal intervals along the circumference with the number of caulking locations according to the following formula: is fixed to the radial surface, extends so as to close the bearing space to the outer side so as to function as a cover for covering the bearing space, said magnetic induction sensors, via a sensor positioning member by said sensor holder Held, the object magnetic detection portion is supported by a magnet holder in the outer diameter side, in a position axially external to the magnet holder to the bearing space, so as to face the outer diameter side of the magnetically sensitive sensor It is characterized by being arranged.
(Number of crimping points) = nZ ± X
here,
n: positive integer
Z: Number of rolling elements
X: integer greater than or equal to 2
According to the rolling bearing with a sensor for a motor of the first aspect, the mounting member that is a magnetic body functions as a magnetic shield against an external magnetic field, and reduces the influence of the external magnetic field on the magnetic detection unit and the magnetic sensor. Therefore, the detection accuracy of the magnetic sensitive sensor can be improved and accurate measurement can be performed. Further, the magnet holder functions as a cover that extends from the inner ring to the outer ring side so as to close the bearing space and covers the bearing space. Therefore, it is possible to prevent dust from entering the bearing space without providing a cover as a separate member.
The front Symbol magnet holder supports the outer diameter side of the object magnetic detection unit. Therefore, it is possible to prevent destruction of the magnetized detection unit due to the strong centrifugal force generated when the shaft rotates at a high speed.
[0011]
The front Symbol sensor holder is caulking to concave groove provided on the outer diameter surface of the front Kigairin. Therefore, without precise machining provided a difficult step portion or the like, it is possible to mount accurately the magnetically sensitive sensor outside wheel.
[0012]
The concave groove is formed on a circumference along the outer diameter surface of the front Kigairin, wherein the sensor holder, that has been tightened several places pressurized at equal intervals along on the circumference. By caulking at equal intervals on the circumference, it is possible to improve mounting accuracy.
[0013]
Moreover, the number of the said crimping locations follows the following formula | equation , and it is more preferable that the number of the said crimping locations is a prime number.
(Number of crimping points) = nZ ± X
here,
n: positive integer Z: number of rolling elements X: integer greater than or equal to 2
By caulking as described above, it is possible to reduce abnormal noise or vibration that may occur in the bearing.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
[0016]
(First embodiment)
FIG. 1 is a cross-sectional view showing a first embodiment of a rolling bearing with a sensor according to the present invention. The sensor-equipped rolling bearing 10 includes an inner ring 11 fitted on a shaft, an outer ring 12 fitted on a housing, an inner ring raceway 11a and an outer ring raceway 12a formed on an outer diameter surface of the inner ring 11 and an inner diameter surface of the outer ring 12, respectively. A ball 13 that is a rolling element that rolls along, a cage 14 that holds the ball 13, and a bearing that is erected from the vicinity of one side surface of the outer ring 12 toward the inner ring 11 and formed between the inner ring 11 and the outer ring 12. And a cover 15 that covers the space. In the present embodiment, a concave groove 16 is formed at the end of the outer diameter surface 12 b of the outer ring 12 along the circumferential direction of the outer ring 12.
[0017]
A sensor portion 30 that functions as a sensor of the sensor-equipped rolling bearing 10 is provided at one end in the axial direction of the inner ring 11 and the outer ring 12. The sensor unit 30 includes a sensor holder 31 as an attachment member, a magnet holder 32 as an attachment member, a magnetic sensor 33, a magnet 34 as a magnetism detection unit, a spacer 35, a substrate 36, and a sensor positioning member. 37.
[0018]
The sensor holder 31 is an annular magnetic member having a U-shape in cross section. The sensor holder 31 is fixed by caulking one end 31 a to the concave groove 16 formed in the outer diameter surface 12 b of the outer ring 12.
[0019]
2 (a) and 2 (b) are diagrams showing one method for caulking and fixing one end 31a of the sensor holder 31 in the concave groove 16 formed in the outer diameter surface 12b of the outer ring 12. FIG. Here, in the caulking machine 100, caulking screws 101 are provided at nZ ± X locations at equal intervals along the circumferential direction of the annular sensor holder 31, that is, in an equiangular arrangement. The crimping machine 100 tightens each crimping screw 101 so that the tip 101a of the crimping screw 101 crimps and fixes the one end 31a of the sensor holder 31 to the concave groove 16b. Here, n is a positive integer, Z is the number of balls of the bearing, and X is an integer of 2 or more. That is, the number of caulking locations is preferably a prime number. As a sensor holder fixed by crimping, as shown in FIG. 2 (c), it is also possible to use a sensor holder 131 in which notches are provided at one end portion at equal intervals.
[0020]
In rolling bearings, if the inner ring raceway or the outer ring raceway has undulations having a relatively large peak height, abnormal noise may occur or the bearing may vibrate at a constant frequency. When a bearing having such undulations is incorporated in the shaft, the shaft performs a special whirling motion, which is not preferable in practice. Here, abnormal noise or vibration occurs when the number of undulations is nZ or nZ ± 1.
[0021]
The caulking may deform the outer ring or the inner ring of the bearing and generate nZ and nZ ± 1 undulations in the inner ring or the outer ring. Therefore, in this embodiment, the occurrence of vibration is prevented by setting the number of caulking points to nZ ± X (X is 2 or more) so as not to generate nZ and nZ ± 1 swells.
[0022]
The sensor holder 31 holds the magnetic sensitive sensor 33 at a predetermined location via a sensor positioning member 37 on the side surface of the U-shaped inner end portion. The magnetic sensor 33 is connected to a substrate 36 disposed on the inner back side surface of the same U-shape via a spacer 35. A signal line 38 that transmits an output signal from the magnetic sensor 33 is connected to the substrate 36.
[0023]
On the other hand, the magnet holder 32 is an annular magnetic member that is bent so that the tip portion faces the tip portion of the sensor holder 31. In the present embodiment, the magnet holder 32 is press-fitted and fixed to the outer diameter surface end portion 11 b of the inner ring 11. The magnet holder 32 extends from the inner ring 11 toward the outer ring 12 so as to close the bearing space, and also functions as a cover that covers the bearing space.
[0024]
A magnet 34 is disposed at the tip of the magnet holder 32 at a position facing the magnetic sensor 33. With this arrangement, the sensor holder 31 and the magnet holder 32 hold the magnetic sensitive sensor 33 and the magnet 34 at positions where they are not exposed to the outside. Here, since the sensor holder 31 and the magnet holder 32 are made of a magnetic material, the sensor holder 31 and the magnet holder 32 function as a magnetic shield for preventing changes in the magnetic field caused by electrical noise from being transmitted to the magnetic sensor 33 and the magnet 34.
[0025]
FIG. 3 is a sectional view showing the magnetic sensor 33 and the sensor positioning member 37. The sensor positioning member 37 is an annular member disposed on the sensor holder 31. The sensor positioning member 37 is disposed so as to be concentric with the rotation center of the shaft. In the sensor positioning member 37 of the present embodiment, three recesses 37a for positioning and fixing the magnetic sensitive sensor 33 are formed on the outer diameter surface, and the magnetic sensitive sensor 33 is inserted and fixed in each recess 37a. . In the present embodiment, the magnetic sensitive sensors 33 are arranged on the same circumference at predetermined angular intervals with respect to the center of the sensor positioning member 37, that is, the rotation center of the shaft 7. The number of the magnetic sensitive sensors 33 to be attached can be changed to an arbitrary number according to the application of the sensor-equipped rolling bearing, and the number of the recesses 37a formed on the sensor positioning member 37 is also arbitrarily changed according to the number of sensors. Is possible. The configuration of the present embodiment is a configuration for detecting the phase angle of each phase of the three-phase motor. In order to detect the rotational speed of the shaft, it is sufficient to have at least one sensor, and the rotational direction is also detected. For this purpose, two sensors are sufficient.
[0026]
FIG. 4 is a cross-sectional view showing the structure of the magnet 34. The outer surface of the magnet 34 is fixed to the magnet holder 32, and faces the magnetic sensor 33 and the sensor positioning member 37. In the present embodiment, the magnet 34 is formed by annularly connecting eight N poles 34a and eight S poles 34b having the same shape on the same circumference so that the N poles 34a and the S poles 34b are alternately arranged. It is configured. Similar to the sensor positioning member 37, the magnet 34 is arranged so as to be concentric with the rotation center of the shaft, and rotates with the rotation of the inner ring 11. Since the magnet 34 is concentric with the sensor positioning member 37, the distance when the magnet 34 and each magnetic sensitive sensor 33 face each other does not change regardless of the rotational position of the magnet 34. Each N pole 34 a and S pole 34 b are arranged so that the magnetic flux density becomes stronger in the direction of the magnetic sensor 33. It should be noted that the number of magnetic poles of the magnet 34 can be changed to an arbitrary number according to the usage status of the rolling bearing with sensor, similarly to the number of the magnetic sensitive sensors 33.
[0027]
The magnetic sensor 33 detects the strength of the magnetic field formed by each magnetic pole of the magnet 34 that rotates with the rotation of the shaft, and outputs it as an electrical signal. The output electrical signal is sent to the substrate 36 through the signal line 39, subjected to a predetermined process, and then output to the measuring device installed outside through the signal line 38. The measuring device obtains information such as the rotational speed, the rotational direction, and the three-phase phase angle based on the received electrical signal.
[0028]
As described above, in the rolling bearing with sensor 10 of the present embodiment, the sensor holder 31 that holds the magnetic sensor 33 is fixed by caulking the concave groove 16 formed on the outer diameter surface of the outer ring 12 at a plurality of locations. Further, a magnet holder for holding the magnet 34 is press-fitted and fixed to the end of the inner ring 11. Therefore, it is possible to arrange the magnetic sensor 33 and the magnet 34 at accurate positions without providing a step having a large variation in dimensions.
[0029]
Further, since the sensor holder 31 and the magnet holder 32 made of a magnetic material shield the external magnetic field, there is no fear that a change in the external magnetic field affects the magnetic sensor 33 and the magnet 34. Therefore, accurate measurement can be performed without being affected by changes in the external magnetic field.
The magnet holder 32 extends from the inner ring 11 to the outer ring 12 so as to close the bearing space, and functions as a cover that covers the bearing space. Therefore, it is possible to prevent dust from entering the bearing space without providing a cover as a separate member.
[0030]
The magnet 34 is located on the outer diameter side of the sensor, and the outer diameter side of the magnet 34 is supported by the magnet holder 32. Accordingly, the magnet 34 is prevented from being broken by a strong centrifugal force generated when the shaft rotates at a high speed.
[0031]
In addition, since the number of caulking locations is nZ ± X (X is 2 or more), it is possible to suppress the occurrence of nZ or nZ ± 1 waviness on the raceway surface of the bearing due to deformation caused by caulking. It becomes. Therefore, it is possible to provide a highly accurate rolling bearing with a sensor that does not generate abnormal noise or vibration.
[0032]
The sensor-equipped rolling bearing 10 according to the present embodiment can be used as a shaft bearing used in automobiles, railway vehicles, steel manufacturing facilities, machine tools, and the like, and can detect the rotational speed of the shaft of each device.
[0033]
(Second Embodiment)
FIG. 5 is a cross-sectional view showing a second embodiment of the sensor-equipped rolling bearing according to the present invention. The sensor-equipped rolling bearing 50 includes an inner ring 51 fitted on a shaft, an outer ring 52 fitted on a housing, an inner ring raceway 51a and an outer ring raceway 52a formed on the outer diameter surface of the inner ring 51 and the inner diameter surface of the outer ring 52, respectively. A ball 53 that is a rolling element that rolls along, a cage 54 that holds the ball 53, and a bearing that is erected from the vicinity of one side surface of the outer ring 52 toward the inner ring 51 and formed between the inner ring 51 and the outer ring 52. And a cover 55 that covers the space. In the present embodiment, a concave groove 51 b is formed in the vicinity of one end of the outer diameter surface 51 b of the inner ring 51 along the circumferential direction of the inner ring 51.
[0034]
A sensor portion 60 that functions as a sensor of the sensor-equipped rolling bearing 50 is provided at one end in the axial direction of the inner ring 51 and the outer ring 52. The sensor unit 60 includes a sensor holder 61 as an attachment member, a magnet holder 62 as an attachment member, a magnetic sensor 63, a magnet 64 as a magnetism detection unit, a spacer 65, a substrate 66, and a sensor positioning member. 67.
[0035]
The sensor holder 61 is an annular magnetic member having an L shape. One end of the sensor holder 61 is press-fitted and fixed in a concave groove 52 c formed along the circumferential direction on the inner diameter surface of the end portion 52 b of the outer ring 52. A sensor positioning member 67 is attached to the other end of the L-shaped sensor holder 61 in parallel to the axial direction. The sensor positioning member 67 holds the magnetic sensitive sensor 63 at a predetermined location. The magnetic sensitive sensor 63 is connected to a substrate 66 disposed on the inner side surface of the same L shape via a spacer 65. A signal line 68 for transmitting an output signal from the magnetic sensor 63 is connected to the substrate 66 to the outside.
[0036]
On the other hand, the magnet holder 62 is an annular magnetic member that is bent so that the tip portion faces the tip portion of the sensor holder 61. In the present embodiment, one end portion 62 a of the magnet holder 62 is caulked and fixed to a concave groove 51 b formed in the circumferential direction along the outer diameter surface of the inner ring 51. The number of caulking points is nZ ± X (X is 2 or more) in order to prevent the occurrence of vibration. The magnet holder 62 extends from the inner ring 51 toward the outer ring 52 so as to close the bearing space, and also functions as a cover that covers the bearing space.
[0037]
A magnet 64 is disposed at the tip of the magnet holder 62 at a position facing the magnetic sensor 63. With this arrangement, the sensor holder 61 and the magnet holder 62 hold the magnetic sensitive sensor 63 and the magnet 64 at positions where they are not exposed to the outside. Here, since the sensor holder 61 and the magnet holder 62 are made of a magnetic material, the sensor holder 61 and the magnet holder 62 function as a magnetic shield for preventing a change in magnetic field caused by electrical noise from being transmitted to the magnetic sensor 63 and the magnet 64.
[0038]
The configurations of the magnetic sensor 63 and the magnet 64 are the same as those of the magnetic sensor 33 and the magnet 34 of the first embodiment.
[0039]
As described above, in the rolling bearing with sensor 50 of the present embodiment, the sensor holder 61 that holds the magnetic sensitive sensor 63 is press-fitted and fixed to the end portion of the inner ring 51 . Further, the magnet holder 62 that holds the magnet 34 is fixed by caulking one end 62 a to a concave groove 51 b formed on the outer diameter surface of the inner ring 51 at a plurality of locations. Therefore, it is possible to arrange the magnetic sensor 33 and the magnet 34 at accurate positions without providing a step having a large variation in dimensions.
[0040]
Further, since the sensor holder 61 and the magnet holder 62 made of a magnetic material shield the external magnetic field, there is no fear that a change in the external magnetic field affects the magnetic sensor 63 and the magnet 64. Therefore, accurate measurement can be performed without being affected by changes in the external magnetic field.
Further, the magnet holder 62 extends from the inner ring 51 to the outer ring 52 side so as to close the bearing space, and functions as a cover that covers the bearing space. Therefore, it is possible to prevent dust from entering the bearing space without providing a cover as a separate member.
[0041]
The magnet 64 is positioned on the outer diameter side of the magnetic sensor 63, and the outer diameter side of the magnet 64 is supported by the magnet holder 62. Therefore, the magnet 64 is prevented from being broken by a strong centrifugal force generated when the shaft rotates at a high speed.
[0042]
In addition, since the number of caulking locations is nZ ± X (X is 2 or more), it is possible to suppress the occurrence of nZ or nZ ± 1 waviness on the raceway surface of the bearing due to deformation caused by caulking. It becomes. Therefore, it is possible to provide a highly accurate rolling bearing with a sensor that does not generate abnormal noise or vibration.
[0043]
In addition, the rolling bearing 50 with a sensor of this embodiment can be used as a bearing of a shaft used in an automobile, a railway vehicle, a steel manufacturing facility, a machine tool, or the like, and can detect the rotational speed of the shaft of each device.
[0044]
Further, the same effect can be obtained by crimping and fixing the sensor holder 61 and the magnet holder 62 to the inner ring 51 and the outer ring 52, respectively.
【The invention's effect】
As described above, according to the rolling bearing with a sensor of the present invention, it is possible to accurately attach the sensor to the bearing even in a small-sized bearing. Further, according to the rolling bearing with sensor of the present invention, it is possible to operate normally even in an environment where electric noise is generated by a motor or the like.
FIG. 1 is a sectional view showing a rolling bearing with a sensor according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a method for caulking a sensor holder.
FIG. 3 is a cross-sectional view showing a magnetically sensitive sensor and a sensor positioning member.
FIG. 4 is a cross-sectional view showing the structure of a magnet.
FIG. 5 is a cross-sectional view showing a sensor-equipped rolling bearing according to a second embodiment of the present invention.
6 is a view showing a rolling bearing with a sensor of Patent Document 1. FIG.
7 is a view showing a rolling bearing with a sensor of Patent Document 2. FIG.
8 is a view showing a sensor-equipped rolling bearing of Patent Document 3. FIG.
[Explanation of symbols]
10, 50 Rolling bearings 11, 51 Inner ring 12, 52 Outer ring 30, 60 Sensor part 31, 61 Sensor holder 32, 62 Magnet holder 33, 63 Magnetosensitive sensor 34, 64 Magnet

Claims (2)

In a rolling bearing with a sensor for a motor , comprising: an inner ring; an outer ring; a rolling element interposed between the inner ring and the outer ring; a magnetic detection unit; and a magnetic sensor facing the magnetic detection unit.
A mounting member including a magnet holder and a sensor holder made of a magnetic material,
The sensor holder is caulked and fixed by a number of caulking locations according to the following formula at equal intervals along the circumference in a concave groove formed on the circumference along the outer diameter surface of the outer ring,
The magnet holder is fixed to the outer diameter surface of the inner ring, and extends so as to close the bearing space on the outer ring side so as to function as a cover that covers the bearing space,
The magnetic sensitive sensor is held by the sensor holder via a sensor positioning member,
The magnetized detection portion is supported by a magnet holder on the outer diameter side thereof, and is disposed at a position on the outer side in the axial direction of the magnet holder with respect to the bearing space so as to face the outer diameter side of the magnetic sensor. A rolling bearing with a sensor for a motor .
(Number of crimping points) = nZ ± X
here,
n: positive integer
Z: Number of rolling elements
X: integer greater than or equal to 2 The rolling bearing with a sensor for a motor according to claim 1, wherein the number of the crimping portions is a prime number.

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