JP2017034779A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To elongate life time of a bearing and reduce component cost and assembly cost in a rotary electric machine having a sensor magnet and a magnetic sensor.SOLUTION: A rotary electric machine 1 includes a case body 2, a rotation shaft 30 rotatable to the case body 2, a holder 5 arranged at an end 30a in a rotor axis direction of the rotation shaft 30, a sensor magnet 6 arranged at the holder 5, a magnetic sensor 7 for detecting a magnetic flux of the sensor magnet 6, and a first bearing 8 having an inner race 8a inserted to the rotation shaft 30 and an outer race 8b press-fit to the case body 2. A bearing position regulation section 32a for regulating the position of the inner race 8a in the rotor axis direction is arranged to the rotation shaft 30; and a bearing fixing section 50t for fixing the first bearing 8 by sandwiching, in the rotor axis direction, the inner race 8a together with the bearing position regulation section 32a, and a holder fixing section 50g to be fixed to the end 30a of the rotation shaft 30 are arranged to the holder 5.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotating electrical machine.

Conventionally, as a rotating electrical machine used for a vehicle or the like, for example, there are those disclosed in Patent Documents 1 and 2.
Patent Document 1 includes a ball bearing in which an outer ring is fitted in a bearing housing portion of a holding portion and an inner ring is loosely fitted on a rotating shaft. In Patent Document 1, the inner ring is prevented from rotating by the inner ring holding portion of the sensor magnet and the tea washer.
Patent Document 2 includes a holder that holds a sensor magnet at one end of a rotating shaft, and a magnetic sensor that is provided opposite to the one end of the rotating shaft when viewed from the sensor magnet. Is.
On the other hand, a structure in which both the inner ring and the outer ring of the bearing are press-fitted and fixed is known.

JP 2010-130879 A JP 2013-7731 A

However, in the structure in which both the inner ring and the outer ring are press-fitted and fixed, the bearing receives a load from both the inner side and the outer side, whereby the inner ring outer peripheral surface and the outer ring inner peripheral surface (hereinafter referred to as “ball contact surface”) that contact the ball. ) Is pressed against the ball, the bearing cannot realize the original slip, the friction between the ball contact surface and the ball is increased, and the ball contact surface is easily worn. There was a problem in extending the life of the bearing.
In Patent Document 1, since the outer ring is fitted and the inner ring is loosely fitted (the outer ring is press-fitted and the inner ring is inserted), the bearing is compared with the structure in which both the inner ring and the outer ring are press-fitted and fixed. However, since a new member for preventing rotation of the inner ring is required, the number of parts is increased and there is a problem in reducing the part cost.
In Patent Document 2, since the sensor magnet is fixed to one end portion of the rotating shaft via a holder, when the inner ring is not fixed to the rotating shaft, a gap generated between the inner ring and the rotating shaft Since the integral rotation of the inner ring and the rotating shaft is hindered, friction is generated between the inner ring and the rotating shaft, and the inner peripheral surface of the inner ring is likely to be worn.Therefore, there is a problem in extending the life of the bearing. It was.
In addition, due to the clearance, the rotational axis moves in the radial direction, so that the position of the sensor magnet is easily displaced with respect to the magnetic sensor, and the detection accuracy of the magnetic sensor may be impaired. In order to maintain the detection accuracy of the magnetic sensor, there is a method of adjusting the position of the magnetic sensor in accordance with the displacement of the sensor magnet. However, the adjustment process of the magnetic sensor increases and the number of assembly steps increases, so the assembly cost is reduced. There was a problem in reducing it.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to increase the life of a bearing in a rotating electrical machine including a sensor magnet and a magnetic sensor, and to reduce component costs and assembly costs.

As a means for solving the above problems, the invention described in claim 1 includes a case body, a rotation shaft that is rotatable with respect to the case body, a holder provided at one end of the rotation shaft in an axial direction, In a rotating electrical machine comprising: a sensor magnet provided in the holder; a magnetic sensor for detecting a magnetic flux of the sensor magnet; and a bearing having an inner ring inserted into the rotating shaft and an outer ring press-fitted into the case body. A bearing position restricting portion that restricts the position of the inner ring in the axial direction is provided on the rotating shaft, and the bearing is fixed to the holder by holding the inner ring in the axial direction together with the bearing position restricting portion. And a holder fixing portion that is fixed to one end portion of the rotating shaft.
According to a second aspect of the present invention, the rotating shaft is formed integrally with the shaft portion extending in the axial direction and the shaft portion, and the diameter of the rotating shaft is increased outward in the radial direction from the shaft portion. And a diameter-expanding portion that functions as a restricting portion.
According to a third aspect of the present invention, the holder includes a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft, and a base end portion of the cylindrical portion serves as the holder fixing portion. It is characterized by functioning.
According to a fourth aspect of the present invention, the holder includes a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft, and a base end portion of the cylindrical portion serves as the bearing fixing portion. It is characterized by functioning.
The invention described in claim 5 is characterized in that the holder further includes an annular protrusion that protrudes radially inward from the cylindrical portion and forms an annular shape coaxial with the rotating shaft.
The invention described in claim 6 is characterized in that a gap is formed between one end of the rotating shaft and the annular protrusion in the axial direction.
The invention described in claim 7 is characterized in that the holder fixing portion is press-fitted and fixed to one end portion of the rotating shaft.
The invention described in claim 8 is characterized in that the holder fixing portion is detachably fixed to one end portion of the rotating shaft.

According to the first aspect of the present invention, by providing the bearing having the inner ring inserted into the rotating shaft and the outer ring press-fitted into the case body, the bearing can receive a load only from the outside. Compared to the structure in which both are press-fitted and fixed, the inner ring outer peripheral surface and the outer ring inner peripheral surface that are in contact with the ball are less likely to be worn, so that the life of the bearing can be extended. Further, by providing a bearing position restricting portion for restricting the position of the inner ring in the axial direction on the rotating shaft, it is not necessary to separately provide a member for restricting the position of the bearing in the axial direction. In addition, by providing the holder with a bearing fixing portion that clamps the inner ring in the axial direction together with the bearing position restricting portion to fix the bearing, there is no need to separately provide a new member for preventing the inner ring from rotating. Therefore, the number of parts does not increase, and the part cost can be reduced. In addition, by providing the holder with a holder fixing portion that is fixed to one end of the rotating shaft, the position of the holder with respect to the rotating shaft is regulated in the radial direction. The detection accuracy of the sensor can be maintained. Therefore, the adjustment process of the magnetic sensor does not increase, so that the number of assembling steps is not required and the assembling cost can be reduced. Therefore, it is possible to extend the life of the bearing and reduce the part cost and the assembling cost. In addition, by providing a bearing with an inner ring inserted into the rotating shaft and an outer ring press-fitted into the case body, the bearing can receive a load only from the outside. Since the ball contact surface is less likely to wear, the motor output is reduced due to increased friction between the inner ring and the rotating shaft, and the surface with increased friction generates heat due to frictional heat. Problems such as a decrease in the adhesive strength of the resulting adhesive can be suppressed.
According to the second aspect of the present invention, the rotation shaft is formed integrally with the shaft portion extending in the axial direction and expands radially outward from the shaft portion to function as a bearing position restricting portion. Since it is not necessary to provide the bearing position restricting portion separately, the number of components does not increase and the component cost can be reduced.
According to the invention described in claim 3, the holder includes a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft, and the base end portion of the cylindrical portion functions as a holder fixing portion. Thus, the holder can be fixed to one end of the rotating shaft with a simple configuration.
According to the invention described in claim 4, the holder is provided with a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft, and the base end portion of the cylindrical portion functions as a bearing fixing portion. Thus, the bearing can be fixed with a simple configuration.
According to the fifth aspect of the present invention, the holder protrudes inward in the radial direction from the cylindrical portion, and further includes an annular protrusion that is coaxial with the rotation shaft, so that the sensor magnet can be stabilized by the annular protrusion. While being held, the sensor magnet can be positioned.
According to the sixth aspect of the present invention, in the axial direction, a gap is formed between the one end of the rotating shaft and the annular protrusion, so that the one end of the rotating shaft and the annular protrusion are brought into contact with each other. Compared with the case of making it, it can avoid that the magnetic flux of a sensor magnet flows into a rotating shaft. Further, the gap portion can function as an air escape portion necessary when the inner ring is press-fitted into the rotating shaft.
According to the seventh aspect of the present invention, the holder fixing portion is press-fitted and fixed to one end portion of the rotating shaft, whereby the position of the holder with respect to the rotating shaft can be regulated with a simple configuration. Moreover, since it is possible to prevent a gap from being formed between the holder fixing portion and one end portion of the rotating shaft, it is possible to suppress dust, water, and the like from entering the inside.
According to the eighth aspect of the invention, the holder fixing portion is detachably fixed to the one end portion of the rotating shaft, so that the holder fixing portion can be easily detached from the one end portion of the rotating shaft, and maintenance is performed. Can be improved. In addition, when attaching the holder fixing part to one end of the rotating shaft, it is possible to prevent a gap from being formed between the holder fixing part and one end of the rotating shaft, so that dust, water, etc. enter the inside. Can be suppressed.

It is a perspective view of the rotary electric machine which concerns on 1st embodiment. It is the figure which looked at the said rotary electric machine from the arrow II which follows a rotor axial direction. It is III-III sectional drawing of FIG. It is a principal part enlarged view of the rotary electric machine which concerns on 2nd embodiment, and is sectional drawing equivalent to the 1st bearing peripheral part of FIG.

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
<Overall rotating electrical machine>
1 to 3 show an example of a rotating electrical machine 1 according to the first embodiment. For example, the rotating electrical machine 1 is used for industrial robots such as factory line equipment.
The rotating electrical machine 1 includes a case body 2, a rotor 3 that is rotatable with respect to the case body 2, and a stator 4 that can generate a magnetic field for rotating the rotor 3. The rotating electrical machine 1 is a so-called inner rotor type brushless motor having a rotor 3 rotatably provided inside a stator 4.

In the figure, reference sign CL indicates the axis of the rotating shaft 30 of the rotor 3. In the figure, the symbol CP indicates the center of the rotating shaft 30. Hereinafter, a direction along the axis CL is referred to as a “rotor axial direction”, a direction orthogonal to the axis CL is referred to as a “rotor radial direction”, and a direction around the axis CL is referred to as a “rotor circumferential direction”. Here, the rotor axial direction corresponds to the “axial direction” recited in the claims.
In the figure, reference numeral V1 indicates one side in the rotor axial direction, and reference numeral V2 indicates the other side in the rotor axial direction.

  Referring to FIG. 3, the rotating electrical machine 1 includes a holder 5 provided at one end of the rotating shaft 30, a sensor magnet 6 provided in the holder 5, a magnetic sensor 7 that detects magnetic flux of the sensor magnet 6, an inner ring, and an outer ring. The bearings 8 and 9 (the 1st bearing 8 and the 2nd bearing 9) which have are further provided. Here, the first bearing corresponds to a “bearing” recited in the claims.

<Case body>
1 and 3 together, the case body 2 includes a first bracket 21 that covers one side V1 of the stator 4 in the rotor axial direction and a second bracket 22 that covers the other side V2 of the stator 4 in the rotor axial direction. A cylindrical stator case 23 that covers the outer side of the stator 4 in the radial direction of the rotor, and a magnetic sensor cover 24 that covers the magnetic sensor 7.

The first bracket 21 includes an annular main body 21a, a cylindrical outer peripheral wall 21b standing on the other side V2 in the rotor axial direction from the outer peripheral portion of the main body 21a, and a rotor axial direction from the inner peripheral portion of the main body 21a. A cylindrical inner peripheral wall 21c standing on the other side V2, and an annular convex portion 21d protruding radially inward from the inner peripheral portion of the main body portion 21a and coaxial with the rotary shaft 30.
The inner peripheral wall 21c is a portion of the first bracket 21 into which an outer ring 8b described later is press-fitted.
The annular convex portion 21d is formed with an opening portion 21h that is coaxial with the rotation shaft 30 and opens in the rotor axial direction. The diameter of the opening 21 h is larger than the outer diameter of the holder 5.
Is provided.

  The second bracket 22 includes an annular main body portion 22a, an outer peripheral wall 22b that stands on one side V1 in the rotor axial direction from the outer peripheral portion of the main body portion 22a, and one side in the rotor axial direction from the inner peripheral portion of the main body portion 22a. An inner peripheral wall 22c that stands up at V1, an annular flange portion 22d that protrudes outward in the rotor radial direction from the outer peripheral portion of the main body portion 22a, and a radial center portion of the main body portion 22a that protrudes to the other side V2 in the rotor axial direction. And a cylindrical boss 22e. The boss 22e is formed with an opening 22h that is coaxial with the rotary shaft 30 and opens in the rotor axial direction. The diameter of the opening 22 h is larger than the outer diameter of the rotating shaft 30.

  Both end portions of the stator case 23 in the rotor axial direction are sandwiched between the outer peripheral wall 21 b of the first bracket 21 and the outer peripheral wall 22 b of the second bracket 22. The radially outer surface of the stator case 23 is formed along the radially outer surface of the outer peripheral portions 21 b and 22 b of the brackets 21 and 22.

  The magnetic sensor cover 24 includes a top plate 24a that covers one side V1 in the rotor axial direction of the magnetic sensor 7, a cylindrical outer peripheral wall 24b that rises from the outer peripheral portion of the top plate 24a to the other side V2 in the rotor axial direction, The wall 24b includes a plurality (for example, three in this embodiment) of flange portions 24c that protrude outward in the rotor radial direction from the end portion on the other side V2 in the rotor axial direction. As seen from the motor shaft direction in FIG. 2, each flange portion 24 c is arranged in three-fold symmetry with respect to the center CP of the rotation shaft 30.

<Rotor>
Referring to FIG. 3, the rotor 3 includes a rotating shaft 30 that forms an axis CL, and a cylindrical magnet ring 35 (driving magnet) provided on the radially outer side of the rotating shaft 30. The rotor 3 is rotatable by receiving a magnetic field generated by the stator 4. The rotor 3 is rotatably supported by the case body 2 via the first bearing 8 and the second bearing 9.

<Rotating shaft>
The rotary shaft 30 includes a shaft portion 31 that extends in the rotor axial direction, a first diameter-expanded portion 32 that expands radially outward from the shaft portion 31, and the rotor diameter direction other side V2 of the first diameter-expanded portion 32. A second enlarged portion 33 that is adjacent to the portion and expands radially outward from the first enlarged portion 32, and is adjacent to a portion on the other side V2 of the second enlarged portion 33 in the rotor axial direction and first. A third diameter-expanded portion 34 that expands radially outward from the diameter-expanded portion 32 and contracts radially inward from the second diameter-expanded portion 33 is provided. Each enlarged diameter portion 32, 33, 34 is formed integrally with the shaft portion 31. Here, the 1st diameter expansion part 32 is corresponded to the "diameter expansion part" as described in a claim.
The shaft portion 31 (specifically, the portion of the shaft portion 31 on the one side V1 in the rotor axial direction from the first enlarged diameter portion 32) is a portion of the rotating shaft 30 into which an inner ring 8a described later is inserted. .

<Bearing position restriction section>
The first enlarged diameter portion 32 has a bearing position restricting portion 32a that restricts the position of the inner ring 8a of the first bearing 8 in the rotor axial direction. The bearing position restricting portion 32 a is a portion on one side V <b> 1 in the rotor axial direction of the first enlarged diameter portion 32, and abuts on an end portion on the other side V <b> 2 in the rotor axial direction of the inner ring 8 a of the first bearing 8. The bearing position restricting portion 32a restricts the position of the inner ring 8a described later in the rotor axial direction.

The second enlarged diameter portion 33 functions as a magnet ring support portion that supports the magnet ring 35. The radially inner side surface of the magnet ring 35 is fixed to the radially outer side surface of the second enlarged diameter portion 33 with an adhesive or the like.
The portion on the other side V2 in the rotor axial direction of the third enlarged diameter portion 34 abuts on the end portion on the one side V1 in the rotor axial direction of the inner ring of the second bearing 9.

<Bearing>
The first bearing 8 includes an inner ring 8a and an outer ring 8b. The inner ring 8 a of the first bearing 8 is inserted into the shaft portion 31 of the rotating shaft 30. The outer ring 8 b of the first bearing 8 is press-fitted into the inner peripheral wall 21 c of the first bracket 21. In the present embodiment, the inner ring 8a is inserted and the outer ring 8b is press-fitted.

The end portion on the other side V2 of the inner ring 8a in the rotor axial direction is in contact with the above-described bearing position restricting portion 32a. Thereby, the position in the rotor axial direction of the inner ring 8a is regulated.
The end portion on the one side V1 in the rotor axial direction of the outer ring 8b contacts the portion on the other side V2 in the rotor axial direction of the annular convex portion 21d.

  The second bearing 9 has a larger size than the first bearing 8. The second bearing 9 is provided on the radially inner side of the inner peripheral wall 22 c of the second bracket 22. The end of the inner ring of the second bearing 9 on the one side V1 in the rotor axial direction abuts on the other side V2 of the third enlarged diameter portion 34 of the rotating shaft 30 in the rotor axial direction. Between the end portion on the other side V2 in the rotor axial direction of the second bearing 9 and the central portion in the radial direction of the main body portion 22a of the second bracket 22 (including the portion on the one side V1 in the rotor axial direction of the boss portion 22e). Is provided with an annular washer 9w. The washer 9w is curved so as to wave along the circumferential direction of the rotor.

<Stator>
The stator 4 is disposed at a distance from the magnet ring 35 of the rotor 3 on the outer side in the rotor radial direction. 1 and 3 together, the stator 4 is fixed to the case body 2 by bolts 4a and nuts 4b. For example, the long bolt 4a is inserted into an insertion hole (not shown) formed in each flange portion 24c of the magnetic sensor cover 24, the main body portion 21a of the first bracket 21 and the main body portion 22a of the second bracket 22, The stator 4 can be fixed to the case body 2 by screwing the protruding end of the inserted bolt 4 a into the nut 4 b in the recess of the main body portion 22 a of the second bracket 22.

  The stator 4 includes a cylindrical stator core 40, an insulating bobbin 41 provided in a slot 40 h of the stator core 40, and a conductive coil 42 wound around the bobbin 41.

  The terminal portion of the coil 42 is pulled out to one side V1 in the rotor axial direction, and is an annular printed circuit board 45 disposed in a space 21s inside the first bracket 21 (a space between the outer peripheral wall 21b and the inner peripheral wall 21c). Connected to. The printed circuit board 45 has a function of supplying electric power from the outside to the coil 42 via the harness 46 and the like.

<Holder>
Referring to FIG. 3, the holder 5 has a cylindrical shape that is coaxial with the rotary shaft 30 and surrounds one end 30 a of the rotary shaft 30, and protrudes radially inward from the rotor axial center of the cylindrical portion 50. And an annular protrusion 51 having an annular shape coaxial with the rotary shaft 30. One end 30 a of the rotating shaft 30 is separated from the annular protrusion 51. A gap 51 s is formed between the one end 30 a of the rotating shaft 30 and the annular protrusion 51 in the rotor axial direction. The shape of the annular protrusion 51 is not limited to an annular shape, and a notch may be formed in a part of the annular protrusion 51.

<Holder fixing part>
The base end portion 50 a of the cylinder portion 50 (the end portion on the other side V <b> 2 in the rotor axial direction) has a holder fixing portion 50 g that fixes the holder 5 to the one end portion 30 a of the rotating shaft 30. The holder fixing portion 50 g is an inner peripheral portion of the base end portion 50 a of the cylindrical portion 50 and abuts on the outer peripheral portion of the one end portion 30 a of the rotating shaft 30.

The base end portion 50 a of the cylindrical portion 50 is press-fitted and fixed to the one end portion 30 a of the rotating shaft 30. Thereby, the holder 5 is fixed so as to be rotatable integrally with the rotor 3.
For example, the forming material of the holder 5 is austenitic stainless steel such as SUS303, SUS304, and SUS316, which is nonmagnetic and has a small difference in thermal expansion coefficient from the rotating shaft 30 (for example, iron material). Thereby, the stress at the time of press-fitting and fixing the holder 5 can be allowed, and the tightening allowance between the rotating shaft 30 and the holder fixing portion 50g at a high temperature can be secured. As long as such an effect can be achieved, the material for forming the holder 5 is not limited to the austenitic stainless steel, and other stainless steel, aluminum, brass, or the like may be used.

<Bearing fixing part>
The base end portion 50 a of the cylindrical portion 50 has a bearing fixing portion 50 t that fixes the first bearing 8. The bearing fixing portion 50t is a portion on the other side V2 in the rotor axial direction of the base end portion 50a of the cylindrical portion 50, and abuts on an end portion on the one side V1 in the rotor axial direction of the inner ring 8a of the first bearing 8. The bearing fixing portion 50t, together with the bearing position restricting portion 32a, fixes the first bearing 8 by sandwiching the inner ring 8a in the rotor axial direction.

<Sensor magnet housing>
A tip end portion 50 b (end portion on one side V <b> 1 in the rotor axial direction) of the cylinder portion 50 surrounds the sensor magnet 6. The sensor magnet 6 is placed on one surface 51f of the annular protrusion 51 (the surface on the one side V1 in the rotor axial direction). The tip portion 50 b of the cylindrical portion 50 and the annular protrusion 51 in the holder 5 form a sensor magnet housing portion 52 that houses the sensor magnet 6.

<Sensor magnet>
The sensor magnet 6 has a disk shape coaxial with the rotary shaft 30. For example, the assembly procedure of the sensor magnet 6 is performed by the procedure of housing the sensor magnet 6 in the sensor magnet housing portion 52 after fixing the holder 5 to the one end 30 a of the rotating shaft 30. The sensor magnet 6 is press-fitted and fixed to the distal end portion 50 b of the cylindrical portion 50. Thereby, the sensor magnet 6 is fixed to the rotor 3 together with the holder 5 so as to be integrally rotatable.

  The sensor magnet 6 includes a pair of N-pole magnetized portions and S-pole magnetized portions (both not shown) so that the magnetic poles are switched in the circumferential direction. The sensor magnet 6 changes the magnetic field as the rotor 3 rotates.

<Magnetic sensor>
The magnetic sensor 7 is disposed to face the sensor magnet 6 with a gap in the rotor axial direction. The magnetic sensor 7 is provided in the central portion in the radial direction of a disk-like circuit board 70 disposed in a space 24s (a space surrounded by the top plate 24a and the outer peripheral wall 24b) inside the magnetic sensor cover 24. The circuit board 70 is connected to an external power source (not shown) via a harness 71 and the like.

  The magnetic sensor 7 is for detecting the rotation angle of the rotating shaft 30 of the rotor 3. The magnetic sensor 7 detects the rotation angle by detecting a change in the magnetic field of the sensor magnet 6 accompanying the rotation of the rotor 3. For example, the magnetic sensor 7 uses a Hall IC.

  As described above, the embodiment described above includes the case body 2, the rotary shaft 30 that is rotatable with respect to the case body 2, the holder 5 that is provided at one end 30 a of the rotary shaft 30 in the rotor axial direction, A sensor magnet 6 provided in the holder 5, a magnetic sensor 7 for detecting the magnetic flux of the sensor magnet 6, a first bearing 8 having an inner ring 8a inserted into the rotating shaft 30 and an outer ring 8b press-fitted into the case body 2, In the rotary electric machine 1 having the above structure, the rotary shaft 30 is provided with a bearing position restricting portion 32a for restricting the position of the inner ring 8a in the rotor axial direction, and the holder 5 holds the inner ring 8a together with the bearing position restricting portion 32a in the rotor axial direction. The bearing fixing portion 50t for fixing the first bearing 8 and the holder fixing portion 50g fixed to the one end 30a of the rotating shaft 30 are provided.

  According to this configuration, by providing the first bearing 8 having the inner ring 8a inserted into the rotating shaft 30 and the outer ring 8b press-fitted into the case body 2, the first bearing 8 receives a load only from the outside. Compared with the structure in which both the inner ring and the outer ring are press-fitted and fixed, the inner ring outer peripheral surface and the outer ring inner peripheral surface that are in contact with the ball are less likely to be worn, and thus the life of the bearing can be extended. In addition, by providing the rotary shaft 30 with the bearing position restricting portion 32a that restricts the position of the inner ring 8a in the rotor axial direction, there is no need to separately provide a member that restricts the position of the first bearing 8 in the rotor axial direction. Further, by providing the holder 5 with a bearing fixing portion 50t that clamps the inner ring 8a in the axial direction of the rotor together with the bearing position restricting portion 32a to fix the first bearing 8, a new member for preventing rotation of the inner ring 8a is separately provided. There is no need to provide it. Therefore, the number of parts does not increase, and the part cost can be reduced. Further, since the holder 5 is provided with the holder fixing portion 50g fixed to the one end portion 30a of the rotating shaft 30, the position of the holder 5 with respect to the rotating shaft 30 is regulated in the rotor radial direction. Therefore, the detection accuracy of the magnetic sensor 7 can be maintained. Therefore, the adjustment process of the magnetic sensor 7 does not increase, so that the number of assembling steps is not required and the assembling cost can be reduced. Therefore, it is possible to extend the life of the bearing and reduce the part cost and the assembling cost. Further, by providing the first bearing 8 having the inner ring 8a inserted into the rotary shaft 30 and the outer ring 8b press-fitted into the case body 2, the first bearing 8 receives a load only from the outside, and the inner ring and the outer ring. Since the ball contact surface is less likely to be worn and the like compared to the structure in which both of them are press-fitted and fixed, the motor output is reduced due to the increase in friction between the inner ring 8a and the rotating shaft 30, and the friction is reduced. Problems such as a decrease in adhesive strength of the adhesive caused by the increased surface generating heat due to frictional heat can be suppressed.

  Further, in the above embodiment, the rotating shaft 30 is formed integrally with the shaft portion 31 extending in the rotor axial direction and the shaft portion 31 and expands radially outward from the shaft portion 31 so as to be a bearing position restricting portion 32a. Since it is not necessary to separately provide the bearing position restricting portion, the number of components does not increase, and the component cost can be reduced.

  Moreover, in the said embodiment, the holder 5 is provided with the cylinder part 50 which makes the cylindrical shape coaxial with the rotating shaft 30, and encloses the outer periphery of the rotating shaft 30, and the inner peripheral part of the base end part 50a of the cylinder part 50 is a holder. By functioning as the fixing portion 50g, the holder 5 can be fixed to the one end portion 30a of the rotating shaft 30 with a simple configuration.

  Moreover, in the said embodiment, the holder 5 is provided with the cylinder part 50 which makes the cylindrical shape coaxial with the rotating shaft 30, and encloses the outer periphery of the rotating shaft 30, and the other end of the base end part 50a of the cylinder part 50 in the rotor axial direction. Since the portion V2 functions as the bearing fixing portion 50t, the bearing can be fixed with a simple configuration.

  In the above embodiment, the holder 5 protrudes radially inward from the cylindrical portion 50 and further includes an annular protrusion 51 that is coaxial with the rotary shaft 30, so that the sensor magnet 6 is stabilized by the annular protrusion 51. The sensor magnet 6 can be positioned while being held.

  In the above embodiment, the gap 51s is formed between the one end 30a of the rotating shaft 30 and the annular protrusion 51 in the rotor axial direction, so that the one end 30a of the rotating shaft 30 and the annular protrusion 51 are formed. As compared with the case where the sensor magnet 6 is brought into contact, it is possible to avoid the magnetic flux of the sensor magnet 6 from flowing through the rotating shaft 30. Further, the gap 51s can function as an air escape portion required when the inner ring 8a is press-fitted into the rotary shaft 30.

  Moreover, in the said embodiment, the holder fixing | fixed part 50g is press-fitted and fixed to the one end part 30a of the rotating shaft 30, Therefore The position of the holder 5 with respect to the rotating shaft 30 can be controlled with a simple structure. In addition, since it is possible to prevent a gap from being formed between the holder fixing portion 50g and the one end portion 30a of the rotating shaft 30, it is possible to prevent dust and water from entering the inside.

<Second embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 4 is an enlarged view of a main part of the rotating electrical machine according to the second embodiment, and is a cross-sectional view corresponding to the periphery of the first bearing 8 in FIG. 3.
The second embodiment is different from the first embodiment in that the holder fixing portion 251a is detachably fixed to the one end portion 230a of the rotating shaft 230. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

<Rotating shaft>
The rotating shaft 230 is adjacent to the shaft portion 31, the first enlarged diameter portion 32, the second enlarged diameter portion 33, the third enlarged diameter portion 34, and one end portion 30 a of the axial portion 31 and has a diameter larger than that of the axial portion 31. And a reduced diameter portion 231 that is reduced inward in the direction. The reduced diameter portion 231 is formed integrally with the shaft portion 31 together with the respective enlarged diameter portions 32, 33, and 34. In addition, in FIG. 4, illustration of the 2nd enlarged diameter part 33 and the 3rd enlarged diameter part 34 is abbreviate | omitted.

  The reduced diameter portion 231 has a male screw portion 231a for detachably fixing the holder 205. The male screw portion 231a is a portion on the one side V1 in the rotor axial direction of the reduced diameter portion 231, and a spiral groove is formed in the outer peripheral portion by screw processing.

<Holder>
The holder 205 has a cylindrical shape coaxial with the rotation shaft 230 and surrounds the one end portion 230a of the rotation shaft 230. The holder 205 projects radially inward from the central portion of the cylinder portion 250 in the rotor axial direction, and the rotation shaft 230. And a female screw forming portion 251 having a coaxial cylindrical shape.
One end 230 a of the rotating shaft 230 is separated from the sensor magnet 6. A gap 251 s is formed between the one end 230 a of the rotating shaft 230 and the sensor magnet 6 in the rotor axial direction.

<Holder fixing part>
The female screw forming portion 251 of the cylindrical portion 250 has a holder fixing portion 251a that detachably fixes the holder 205 to one end portion 230a of the rotating shaft 230. The holder fixing portion 251a is an inner peripheral portion of the female screw forming portion 251 of the cylindrical portion 250, and a spiral groove is formed by screw processing. The holder fixing portion 251a functions as a female screw portion and is screwed and fixed to the male screw portion 231a of the rotating shaft 230. As a result, the holder 205 is fixed so as to rotate integrally with the rotor 203.

  A base end portion 250 a of the cylinder portion 250 (an end portion on the other side V <b> 2 in the rotor axial direction) is fitted to the one end portion 30 a of the shaft portion 31 of the rotating shaft 230. The inner peripheral portion 250 g of the base end portion 250 a of the cylindrical portion 250 is slightly separated from the outer peripheral portion of the one end portion 30 a of the shaft portion 31 of the rotating shaft 230. That is, the base end portion 250 a of the cylindrical portion 250 is not press-fitted and fixed to the one end portion 30 a of the shaft portion 31 of the rotating shaft 230. As a result, the holder 205 can be attached to and detached from the one end 230 a of the rotating shaft 230.

<Bearing fixing part>
The base end portion 250 a of the cylindrical portion 250 has a bearing fixing portion 250 t that fixes the first bearing 8. The bearing fixing portion 250t is a portion on the other side V2 in the rotor axial direction of the base end portion 250a of the cylindrical portion 250, and abuts on the end portion on the one side V1 in the rotor axial direction of the inner ring 8a of the first bearing 8. The bearing fixing portion 250t fixes the first bearing 8 by holding the inner ring 8a in the rotor axial direction together with the bearing position restricting portion 32a.

<Sensor magnet housing>
A distal end portion 250 b (end portion on one side V <b> 1 in the rotor axial direction) of the cylindrical portion 250 surrounds the sensor magnet 6. The sensor magnet 6 is placed on one surface 251f (the surface on the one side V1 in the rotor axial direction) of the female screw forming portion 251. The distal end portion 250 b of the cylindrical portion 250 and the female screw forming portion 251 in the holder 205 form a sensor magnet housing portion 252 that houses the sensor magnet 6.

  For example, the outer peripheral portion 250c of the distal end portion 250b of the cylindrical portion 250 is subjected to processing such as hexagonal or two-way processing. Thereby, since the said outer peripheral part 250c can be easily hold | gripped using a tool etc., the attachment or detachment of the holder 205 to the one end part 230a of the rotating shaft 230 can be performed easily.

  As described above, according to the second embodiment, the holder fixing portion 251a is detachably fixed to the one end portion 230a of the rotating shaft 230, so that the holder fixing portion 251a is detached from the one end portion 230a of the rotating shaft 230. It can be easily detached and maintenance can be improved. Further, when attaching the holder fixing portion 251a to the one end portion 230a of the rotating shaft 230, it is possible to prevent a gap from being formed between the holder fixing portion 251a and the one end portion 230a of the rotating shaft 230. Or the like can be prevented from entering the inside.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  Moreover, in the said embodiment, it is provided with the 1st enlarged diameter part 32 which functions as the bearing position control part 32a which is integrally formed with the axial part 31, and expands in diameter direction outer side rather than the axial part 31. However, the present invention is not limited to this, and a sealing material separate from the shaft portion 31 may be provided to function as a bearing position restricting portion.

  In the first embodiment, the one end 30 a of the rotating shaft 30 is separated from the annular protrusion 51. However, the present invention is not limited to this, and the one end 30 a of the rotating shaft 30 may be brought into contact with the annular protrusion 51. .

  In the second embodiment, the holder fixing portion 251a is detachably fixed to one end portion of the rotating shaft 230. The male screw portion and the female screw portion are screwed together. It is good also as a structure attached using fastening members, such as a screw | thread, or a plunger.

  In addition, it is possible to appropriately replace the components in the above-described embodiments with known components without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Case body 5 Holder 6 Sensor magnet 7 Magnetic sensor 8 First bearing (bearing)
8a Inner ring 8b Outer ring 30,230 Rotating shaft 31 Shaft part 32 First diameter enlarged part (diameter enlarged part)
32a Bearing position restricting portion 50 Tube portion 50g Holder fixing portion 50t, 250t Bearing fixing portion 51 Annular protrusion 51s Air gap portion 251a Holder fixing portion CL Rotor axial direction (axial direction)

Claims (8)

The case body,
A rotating shaft that is rotatable with respect to the case body;
A holder provided at one end in the axial direction of the rotating shaft;
A sensor magnet provided in the holder;
A magnetic sensor for detecting the magnetic flux of the sensor magnet;
In a rotating electrical machine comprising an inner ring inserted into the rotating shaft and a bearing having an outer ring press-fitted into the case body,
A bearing position restricting portion for restricting the position of the inner ring in the axial direction is provided on the rotating shaft,
The holder is provided with a bearing fixing portion that fixes the bearing by holding the inner ring in the axial direction together with the bearing position restricting portion, and a holder fixing portion that is fixed to one end portion of the rotating shaft. Rotating electric machine. The rotation axis is
A shaft portion extending in the axial direction;
The diameter-enlarging portion that is formed integrally with the shaft portion and expands radially outward from the shaft portion and functions as the bearing position restricting portion. Rotating electric machine. The holder has a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft,
The rotating electrical machine according to claim 1, wherein a base end portion of the cylindrical portion functions as the holder fixing portion. The holder has a cylindrical portion that is coaxial with the rotating shaft and surrounds the outer periphery of the rotating shaft,
The rotating electrical machine according to any one of claims 1 to 3, wherein a base end portion of the cylindrical portion functions as the bearing fixing portion.   5. The rotating electrical machine according to claim 3, wherein the holder further includes an annular protrusion that protrudes radially inward from the cylindrical portion and forms an annular shape that is coaxial with the rotating shaft.   The rotating electrical machine according to claim 5, wherein a gap is formed between one end of the rotating shaft and the annular protrusion in the axial direction.   The rotating electrical machine according to any one of claims 1 to 6, wherein the holder fixing portion is press-fitted and fixed to one end portion of the rotating shaft.   The rotating electrical machine according to any one of claims 1 to 6, wherein the holder fixing portion is detachably fixed to one end portion of the rotating shaft.

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