JPWO2020136753A1 - Manufacturing method of motor with rotation sensor and motor with rotation sensor - Google Patents

Abstract

It has a housing 2 having a stator 3 inside, a shaft 41, a rotor 42, and a detection target portion 43, and has an outer diameter that does not interfere with the housing 2 when it is arranged at a predetermined position inside the housing 2. A rotor unit 4 and a rotation sensor 5 provided in the housing 2 are provided, and the detection target portion 43 includes a base portion 431, a shaft mounting portion 432, and an outer diameter dimension equal to or less than the outer diameter dimension of the base portion 431. It is a manufacturing method for manufacturing an electric motor 1 with a rotation sensor provided with a protruding portion 433, wherein the step of assembling the rotor unit 4 to form the configuration and the rotor unit 4 having the configuration are described. It is a method of manufacturing an electric motor 1 with a rotation sensor, which comprises a step of inserting and fixing the housing 2 from one side in the axial direction.

Description

The present invention relates to a method for manufacturing an electric motor with a rotation sensor and an electric motor with a rotation sensor.

There is a so-called "motor-electric integrated motor" that integrates an electric motor and an inverter. An example of this is an electric motor with a rotation sensor (for example, Patent Document 1).

The rotation sensor is provided, for example, so as to face a detection target portion (also referred to as a “sensor target”) provided in the rotor unit in which the rotor and the shaft of the motor are integrated. Detect rotation. An example of a rotation sensor is a magnetic sensor that detects magnetism.

Japanese Patent No. 6071850

Here, depending on the outer diameter of the detection target portion, a step of assembling the rotor unit to the casing provided with the stator and a step of attaching the detection target portion to the rotor unit after the completion of the step are required. In this case, there is a problem that the number of processes increases. Further, if the assembly step of the rotor unit and the mounting step of the detection target portion are performed separately, the mounting error of the detection target portion tends to cause variations in the mounting position of the detection target portion with respect to the rotor unit. If this happens, the detection accuracy of the rotation sensor will be affected, which is not preferable.

Therefore, it is an object of the present invention to provide a method for manufacturing an electric motor with a rotation sensor and an electric motor with a rotation sensor that can stabilize the detection accuracy of the rotation sensor while suppressing an increase in the number of steps.

The present invention is a housing having a stator arranged in the circumferential direction, a shaft extending in the axial direction, and a rotor unit configured to rotate around the axial direction of the shaft, and the fixing thereof. A rotation having a rotor located inside the diameter of the child and a detection target portion provided on the shaft, and having an outer diameter that does not interfere with the housing when placed at a predetermined position inside the housing. A child unit and a rotation sensor provided in the housing so as to face the detection target portion in the radial direction are provided. It is provided with a shaft mounting portion extending to one side in the direction and mounted on the shaft, and a protruding portion extending from the base portion to the other side in the axial direction and having an outer diameter dimension equal to or less than the outer diameter dimension of the base portion. It is a manufacturing method for manufacturing an electric motor with a rotation sensor, in which the step of assembling the rotor unit to form the configuration and the rotor unit having the configuration are inserted into and fixed to the housing from one side in the axial direction. It is a manufacturing method of an electric motor with a rotation sensor having a process.

The present invention comprises a housing having a stator arranged in the circumferential direction, a shaft extending in the axial direction, and a rotor unit configured to rotate around the axial direction of the shaft. It has a rotor located inside the diameter of the stator and a detection target portion provided on the shaft, and has an outer diameter that does not interfere with the housing when it is placed at a predetermined position inside the housing. A rotor unit and a rotation sensor provided in the housing so as to face the detection target portion in the radial direction are provided. It is provided with a shaft mounting portion extending to one side in the axial direction and mounted on the shaft, and a protruding portion extending from the base portion to the other side in the axial direction and having an outer diameter dimension equal to or less than the outer diameter dimension of the base portion. , An electric motor with a rotation sensor.

Further, in the present invention, the protruding portion is made of a magnetic material, and is composed of a plurality of salient poles provided at intervals in the circumferential direction with respect to the base portion, and the rotation sensor is outside the diameter of the protruding portion. It can be a magnetic sensor with a built-in permanent magnet installed at the position.

FIG. 1 is a radial half-sectional view showing a schematic structure of an electric motor with a rotation sensor according to the present embodiment. FIG. 2 is a perspective view showing a detection target portion (first embodiment). FIG. 3A is a schematic view showing the positional relationship between the detection target portion (first embodiment) and the rotation sensor. FIG. 3B is a graph showing changes in the output signal of the rotation sensor. FIG. 4 is a perspective view showing a detection target portion (second embodiment).

An embodiment of the present invention will be illustrated below with reference to the drawings. The following "axial direction" corresponds to the left-right direction in FIG. 1, and the "diameter direction" corresponds to the vertical direction in FIG. 1. Further, the "circumferential direction" is a direction surrounding the axial direction.

As shown in FIG. 1, which is a schematic diagram, the motor 1 with a rotation sensor of the present embodiment includes a housing 2, a rotor unit 4, and a rotation sensor 5. Since the configuration of the motor portion is the same as the configuration of a general motor, detailed description will not be given. Incidentally, the motor 1 with a rotation sensor of the present embodiment is used to assist the rotation of the turbine by incorporating it into a turbocharger for an automobile. However, this is only an example, and the application of the motor 1 with a rotation sensor is not limited to this.

The housing 2 constitutes the exterior of the motor 1 with a rotation sensor, and has a stator 3 arranged in the circumferential direction inside. The housing 2 of the present embodiment is a substantially cylindrical body extending in the axial direction (left-right direction in FIG. 1). The right end portion in FIG. 1 is closed, and the left end portion is closed except for the portion through which the shaft 41 and the bearing 44 pass during assembly. However, this is only an example, and the configuration of the housing 2 is not limited. Since the rotor 42 rotates axially so as to face the stator 3, the radial inner surface of the stator 3 is arranged along a curved surface having a constant curvature. Inside the housing 2, a circuit board (not shown, the same applies hereinafter) for measuring, controlling, and the like related to the motor 1 with a rotation sensor is provided.

The rotor unit 4 is arranged inside the housing 2. The rotor unit 4 has a shaft 41 extending in the axial direction, a rotor 42 located inside the diameter of the stator 3, and a detection target portion (sensor target) 43 provided on the shaft 41.

The rotor unit 4 has a bearing 44. The bearing 44 is fixed to the housing 2 at two points divided in the axial direction. The bearing 44 rotatably supports the shaft 41. Therefore, the shaft 41, the rotor 42, and the detection target portion 43 are integrated and rotate around the axial direction of the shaft 41.

Further, the rotor unit 4 has an outer diameter that does not interfere with the housing 2 when it is arranged at a predetermined position inside the housing 2. Specifically, in the insertion direction of the rotor unit 4 at the time of assembly (right direction in FIG. 1), the outer diameter dimension of the portion of the rotor unit 4 located on the inner side of each bearing 44 is the outer diameter dimension of each bearing 44. It is formed smaller than the outer diameter. Since the rotor unit 4 has a shape that does not interfere with the housing 2 in this way, the rotor unit 4 in the completed state is left as it is in the axial direction (before the insertion direction) as described later. It can be fixed after being inserted into the housing 2 from the side).

The rotation sensor 5 provided in the housing 2 is provided so as to face the detection target portion 43 in the radial direction. As the rotation sensor 5, a magnetic sensor that detects by magnetism, such as one using a Hall IC, is used. Although the rotation sensor 5 is shown floating in FIG. 1, it is actually fixed to the housing 2.

The detection target portion 43 is attached to the tip end portion (right end portion in FIG. 1) of the shaft 41, and includes a base portion 431, a shaft mounting portion 432, and a protruding portion 433.

The base portion 431 has a rotationally symmetric shape with respect to the axial direction. The base portion 431 of the present embodiment is a substantially disk-shaped portion having a small axial thickness. A through hole 4311 penetrates in the axial direction at the center of the base portion 431 in the axial direction. A screw shaft 411 formed at the tip of the shaft 41 penetrates through the through hole 4311. The nut 412 and the washer 413 are passed through the screw shaft 411, and the nut 412 is screwed in so that the detection target portion 43 can be fixed to the shaft 41.

The shaft mounting portion 432 extends from the base portion 431 to one side in the axial direction (left side in FIG. 1) and is a portion mounted on the shaft 41. The shaft mounting portion 432 of the present embodiment is a substantially cylindrical portion that covers the outside diameter of the shaft 41. The inner diameter of the shaft mounting portion 432 substantially coincides with the outer diameter of the tip portion of the shaft 41. The base end portion (left end portion in FIG. 1) of the shaft mounting portion 432 abuts on the tip surface of the inner ring of the bearing 44 or the step 414 formed on the shaft 41. As a result, the detection target portion 43 can be prevented from shifting in the axial direction, and the detection target portion 43 can be reliably fixed to the shaft 41 by the above-mentioned nut screwing.

The protruding portion 433 is a portion extending from the base portion 431 to the other side in the axial direction (right side in FIG. 1) and having an outer diameter dimension equal to or less than the outer diameter dimension of the base portion 431. In this embodiment, the diameter is the same. As described above, since the rotation sensor 5 is provided so as to face the detection target portion 43 in the radial direction, the rotation sensor 5 is provided even if the protrusion 433 is slightly displaced in the axial direction with respect to the rotation sensor 5. The radial distance between 5 and the outer peripheral surface of the protrusion 433 does not change. Therefore, it is highly compatible with the positional deviation in the axial direction. Further, the protruding portion 433 does not protrude in the outer diameter direction from the outer peripheral edge of the base portion 431. Here, for example, in the detection target portion having a shape having a radially protruding portion as shown in FIG. 5 (b) of Patent Document 1, the centrifugal force during rotation becomes large and the moment of inertia increases. There was a problem of doing it. On the other hand, the protruding portion 433 of the present embodiment is advantageous in that such a problem is unlikely to occur. Therefore, the rotation characteristics (for example, rotation acceleration characteristics) of the motor 1 with a rotation sensor can be improved. Therefore, it is advantageous when used at high rotation speed.

Hereinafter, the first and second embodiments will be illustrated and described with respect to the detection target unit 43. However, the configuration of the detection target unit 43 is not limited to these exemplified configurations. The parts that are functionally common in each embodiment are designated by the same reference numerals in the drawings, and duplicate description will be omitted.

The detection target portion 43 of the first embodiment has the shape shown in FIG. In the detection target portion 43 of the first embodiment, the protruding portion 433 is made of a magnetic material (specifically, a ferromagnet), and two salient poles provided at intervals in the circumferential direction with respect to the base portion 431. It is composed of 4331 and 4331. Specifically, two salient poles 4331 and 4331 project from the base 431 at intervals of 180 degrees in the circumferential direction. By providing the salient poles 4331 and 4331 at intervals in the circumferential direction with respect to the base 431, the presence or absence of the protruding portion 433, that is, the portion of the protruding portion 433 that has substance (the salient pole 4331) and the portion that does not (space). That is, since the parts having different forms are adjacent to each other in the circumferential direction, the change in the magnetic flux density in the rotation sensor 5 can be clarified. Therefore, reliable detection by the rotation sensor 5 is possible. Each salient pole 4331 is formed over 90 degrees in the circumferential direction. Note that FIG. 1 shows a state in which the detection target unit 43 of the first embodiment is incorporated. As shown in FIGS. 1 and 2, the detection target portion 43 of the first embodiment has a tapered shape in which the base end side is larger than the tip end side in terms of the thickness dimension in the radial direction. In the first embodiment, only the inner peripheral surface is a tapered surface. This tapered shape is advantageous in that it can withstand the shearing force applied to the base end of each salient pole 4331 at the start of rotation at the thick base end, and at the same time, it can be lighter than the one having a uniform thickness as a whole. Is. Further, since the tip portion is lightweight, the behavior that the tip portion of each salient pole 4331 opens (deforms in the out-of-diameter direction) when the detection target portion 43 rotates is reduced.

The rotation sensor 5 corresponding to the detection target portion 43 of the first embodiment is a magnetic sensor with a built-in permanent magnet provided at a position outside the diameter of the protrusion 433. The rotation sensor 5 is arranged in the positional relationship substantially shown in FIG. 3A. The relationship between the rotation angle of the rotation sensor 5 and the output is as shown in FIG. 3B. The rotation angle shown in FIG. 3B indicates the rotation angle related to the rising edge of the detection signal. That is, when the salient pole 4331 is positioned facing the rotation sensor 5, the output of the rotation sensor 5 becomes large (“H” in the figure). On the other hand, when the salient pole 4331 is not located facing the rotation sensor 5, the output of the rotation sensor 5 is small (“L” in the figure). As described above, since each salient pole 4331 is formed over 90 degrees in the circumferential direction, there is also a gap of 90 degrees in the circumferential direction between the two adjacent salient poles 4331 and 4331. Therefore, as shown in FIG. 3B, "H" and "L" appear alternately every 90 degrees. Rotation can be detected from such changes in the output value.

The detection target portion 43 of the second embodiment has the shape shown in FIG. The basic shape is the same as that of the first embodiment. The protruding portion 433 of the second embodiment has a complementary portion 4332 that fills the space between the two salient poles 4331 and 4331 in the circumferential direction, which is the same as that of the first embodiment. Therefore, the protruding portion 433 of the second embodiment has a substantially cylindrical shape. The complementary portion 4332 is made of a non-magnetic material or a magnetic material having a weaker magnetism than the magnetic material constituting the salient pole 4331. By providing the complementary portion 4332 to make the protruding portion 433 substantially cylindrical, the wind noise generated during rotation can be suppressed. Therefore, it is possible to contribute to reducing the noise of the motor 1 with a rotation sensor. In addition, since wind damage can be suppressed, it is also advantageous in that the rotational resistance can be reduced. Here, for example, as shown in FIG. 5 (b) of Patent Document 1, there is a problem of wind noise and wind damage in the detection target portion having a shape having a portion protruding in the radial direction. On the other hand, the protrusion 433 of the second embodiment is advantageous because such a problem does not occur. The rotation sensor 5 corresponding to the detection target unit 43 of the second embodiment is a magnetic sensor with a built-in permanent magnet as in the first embodiment.

Next, a method of manufacturing the motor 1 with a rotation sensor will be described. First, a process of assembling a circuit board including a stator 3 and a rotation sensor 5 to a housing 2 and performing necessary electrical wiring to complete a fixed-side unit is carried out. The rotation sensor 5 may be provided separately from the circuit board. Then, in parallel with the step or after the step, a step of completing the rotor unit 4 (that is, a step of assembling the rotor unit 4 to form the above configuration) is carried out. Next, a step of inserting and fixing the completed rotor unit 4 into the housing 2 from one side in the axial direction (left side shown in FIG. 1) is carried out. The rotor unit 4 is fixed by fixing the bearing 44 included in the rotor unit 4 to the inner surface of the housing 2.

As described above, since the rotor unit 4 has an outer diameter that does not interfere with the housing 2 when it is arranged at a predetermined position inside the housing 2, the rotor unit 4 is simply moved in the axial direction. The rotor unit 4 can be fixed to the housing 2. When this fixing step is completed, the positional relationship between the rotation sensor 5 and the detection target portion 43 is determined. Therefore, for example, the process can be simplified as compared with the case where only the process of assembling only the detection target unit 43 is required later. Further, since the mounting position of the detection target portion 43 with respect to the rotor unit 4 is unlikely to vary, it is possible to suppress the influence on the detection accuracy of the rotation sensor 5. This manufacturing method is thus advantageous.

The configuration and operation of the embodiment are summarized below. In the embodiment, a housing 2 having a stator 3 arranged in the circumferential direction, a shaft 41 extending in the axial direction, and a rotor unit 4 configured to rotate around the axial direction of the shaft 41. It has a rotor 42 located inside the diameter of the stator 3 and a detection target portion 43 provided on the shaft 41, and is arranged at a predetermined position inside the housing 2. A rotor unit 4 having an outer diameter that does not interfere with the housing 2 and a rotation sensor 5 provided in the housing 2 so as to face the detection target portion 43 in the radial direction are provided. 431 having a rotationally symmetric shape with reference to the axial direction, a shaft mounting portion 432 extending from the base 431 to one side in the axial direction and mounted on the shaft 41, and extending from the base portion 431 to the other side in the axial direction. It is a manufacturing method for manufacturing an electric motor 1 with a rotation sensor, which includes a protrusion 433 whose outer diameter dimension is equal to or less than the outer diameter dimension of the base portion 431, and is configured by assembling the rotor unit 4. This is a method for manufacturing an electric motor 1 with a rotation sensor, which comprises a step of inserting and fixing the rotor unit 4 having the above configuration to the housing 2 from one side in the axial direction.

In the embodiment, the housing 2 having the stator 3 arranged in the circumferential direction, the shaft 41 extending in the axial direction, and the rotor unit configured to rotate around the axial direction of the shaft 41 are configured. No. 4, which has a rotor 42 located inside the diameter of the stator 3 and a detection target portion 43 provided on the shaft 41, and rotates around the axis of the shaft 41. The rotor unit 4 has an outer diameter that does not interfere with the housing 2 when it is arranged at a predetermined position inside the housing 2, and the rotor unit 4 is radially opposed to the detection target portion 43 in the housing 2. The detection target portion 43 is provided with a rotation sensor 5 provided with the base portion 431 having a rotationally symmetric shape with reference to the axial direction, and a shaft extending from the base portion 431 to one side in the axial direction and mounted on the shaft 41. The motor 1 with a rotation sensor is provided with a mounting portion 432 and a protruding portion 433 extending from the base portion 431 to the other side in the axial direction and having an outer diameter dimension equal to or less than the outer diameter dimension of the base portion 431.

According to the method or the configuration, the motor 1 with a rotation sensor can be easily assembled, and the positional relationship between the housing 2 which is a casing and the rotor unit 4 is unlikely to vary.

The protrusion 433 is made of a magnetic material, and is composed of a plurality of salient poles 4331 provided at intervals in the circumferential direction with respect to the base 431. The rotation sensor 5 has a diameter of the protrusion 433. It can be a magnetic sensor with a built-in permanent magnet installed at an external position.

According to this configuration, by providing a plurality of salient poles 4331 in the protruding portion 433 at intervals in the circumferential direction with respect to the base portion 431, reliable detection is possible depending on the presence or absence of the protruding portion 433 (protruding pole 4331). ..

As described above, in the above embodiment, the motor 1 with a rotation sensor can be easily assembled, and the positional relationship between the housing 2 which is the casing and the rotor unit 4 is unlikely to vary. Therefore, the detection accuracy of the rotation sensor 5 can be stabilized while suppressing the increase in the process.

Although the present invention has been described above by taking up one embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

For example, in the detection target unit 43 of the first embodiment, the number of salient poles 4331 is not limited to two, but the number may be one or more. However, if the weight is biased in the circumferential direction, it causes vibration. Therefore, it is preferable to use two or more salient poles 4331 instead of one. When the number of salient poles 4331 is one, it is preferable to provide the complementary portion 4332 as in the second embodiment in order to suppress the bias of the weight in the circumferential direction.

Further, although the outer peripheral surface of the protruding portion 433 in the detection target portion 43 is parallel to the axial direction in the first embodiment, the outer peripheral surface may be a tapered surface as well as the inner peripheral surface.

Further, as shown in FIGS. 1 and 2, each salient pole 4331 of the first embodiment has a shape that gradually becomes thinner toward the tip side, and has no step in the middle. However, the present invention is not limited to this, and a step can be provided in the middle.

Further, the protruding portion 433 can be reinforced by fitting a resin ring separate from the detection target portion 43 or applying a resin coating to the outer diameter position of the protruding portion 433.

Further, in the above-described embodiment, the rotation sensor is provided so as to face the detection target portion in the radial direction, but in some cases, the rotation sensor may be provided so as to face the axial direction.

1 Motor with rotation sensor 2 Housing 3 Stator 4 Rotor unit 41 Shaft 42 Rotor 43 Detection target part 431 Base part 432 Shaft mounting part 433 Protrusion part 4331 Protruding pole 434 Permanent magnet 5 Rotation sensor

Claims (3)

A housing with a stator placed in the circumferential direction,
A shaft extending in the axial direction, a rotor unit configured to rotate around the axial direction of the shaft, a rotor located inside the diameter of the stator, and a detection provided on the shaft. A rotor unit having a target portion and having an outer diameter that does not interfere with the housing when placed at a predetermined position inside the housing.
A rotation sensor provided in the housing so as to face the detection target portion in the radial direction is provided.
The detection target portion extends from the base portion having a rotationally symmetric shape with reference to the axial direction, a shaft mounting portion extending from the base portion to one side in the axial direction and mounted on the shaft, and extending from the base portion to the other side in the axial direction. It is a manufacturing method for manufacturing a motor with a rotation sensor, which is provided with a protruding portion having an outer diameter dimension equal to or less than the outer diameter dimension of the base.
The process of assembling the rotor unit to form the configuration and
A step of inserting and fixing the rotor unit having the above configuration into the housing from one side in the axial direction.
A method of manufacturing an electric motor with a rotation sensor. A housing with a stator placed in the circumferential direction,
A shaft extending in the axial direction, a rotor unit configured to rotate around the axial direction of the shaft, a rotor located inside the diameter of the stator, and a detection provided on the shaft. A rotor unit having a target portion and having an outer diameter that does not interfere with the housing when placed at a predetermined position inside the housing.
A rotation sensor provided in the housing so as to face the detection target portion in the radial direction is provided.
The detection target portion extends from the base portion having a rotationally symmetric shape with reference to the axial direction, a shaft mounting portion extending from the base portion to one side in the axial direction and mounted on the shaft, and extending from the base portion to the other side in the axial direction. An electric motor with a rotation sensor having a protrusion whose outer diameter is equal to or less than the outer diameter of the base. The protruding portion is made of a magnetic material, and is composed of a plurality of salient poles provided at intervals in the circumferential direction with respect to the base portion.
The motor with a rotation sensor according to claim 2, wherein the rotation sensor is a magnetic sensor with a built-in permanent magnet provided at a position outside the diameter of the protrusion.

Images