JP6797435B1 - Motor structure with built-in sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat type motor having a small diameter. SOLUTION: A motor structure with a built-in sensor is formed between an outer ring-shaped wall 2A and an inner ring-shaped wall 2B formed integrally with a ring-shaped housing 2 having a U-shaped cross section, and the outer ring-shaped wall 2A and the inner ring-shaped wall 2B. The motor shaft 11 is rotatably provided via a ring-shaped space 60 formed in the above, a first bearing 27 provided inside the inner ring-shaped wall 2B, and an outer peripheral surface 11A of the motor shaft 11. The hollow shaft 50 supported by the second bearing 15 provided on the inner surface 2Aa of the outer ring-shaped wall 2A, the motor stator 32a provided on the inner surface 2Aa of the outer ring-shaped wall 2A, and the outer surface 50Aa of the hollow shaft 50. Provided and located between the motor rotor 3 located inside the motor stator 32a, the inner surface 2Ba of the inner ring-shaped wall 2B, and the outer peripheral surface 11A of the motor shaft 11, and not in contact with the motor shaft 11. It is composed of one or more sensors of the mold. [Selection diagram] Fig. 1

Description

The present invention relates to a motor structure with a built-in sensor, and in particular, by disposing a motor stator, a motor rotor, and a hollow shaft inside a ring-shaped housing, and providing a sensor between the inner ring-shaped wall of the ring-shaped housing and the motor shaft, conventionally. It relates to a new improvement for obtaining a flat type motor having a shorter axial length than the configuration and a small diameter.

Although the name of the document is not shown as this type of motor structure with a built-in sensor that has been conventionally used, the first conventional configuration manufactured in-house by the applicant is disclosed in FIG. 4 and in Patent Document 1. The second conventional configuration made can be listed as FIG.
For example, in FIG. 4, what is indicated by reference numeral 2 is a ring-shaped housing, and front lids 110 and rear lids 111 are provided at both ends of the ring-shaped housing 2.

The front lid 110 is provided with a first bearing 27, the rear lid 111 is provided with a second bearing 15, and a motor shaft 11 having a motor rotor 3 is rotatably provided between the bearings 27 and 15. Has been done.
A motor stator 32a is provided on the inner surface 2Aa of the ring-shaped housing 2, and the motor stator 32a is arranged to face the motor rotor 3 with a slight gap.

An angle sensor 100 made of a well-known encoder is provided on the outer surface 111a of the rear lid 111, and an encoder rotor 100a of the angle sensor 100 is provided on the motor shaft 11.

Further, in the second conventional configuration shown in FIG. 5, a configuration in which the magnetic absolute sensor 25 as the angle sensor is arranged outside the first bearing 27 of the motor shaft 11 of the motor main body 80 is disclosed. ..
The second conventional configuration shown in FIG. 5 is a motor with a reduction mechanism in which a flat motor body 80 and a planetary gear reduction mechanism 23 are combined along the axial direction P.
The motor body 80 mainly includes a motor shaft 11 provided inside a ring-shaped duct 35 via first and second bearings 27 and 15, a motor rotor 3 provided on the motor shaft 11, and a duct 35. It is composed of a motor stator 32a having a stator winding 32b, which is arranged on the side facing the motor rotor 3, and a magnetic absolute sensor 25 and a ring-shaped magnet 40 provided inside the motor stator 32a.

The planetary gear reduction mechanism 23 connected to the motor body 80 is mainly provided inside the case body 6, the planetary gear shaft 21 provided in the case body 6, and the planetary gear shaft 21. A planetary two-stage gear 18, a sun gear 12 provided on the motor shaft 11, a third bearing 29 for supporting the tip of the motor shaft 11, and a fourth bearing 28 outside the motor shaft 11. It is composed of an output rotating shaft 24 provided via the above.

JP-A-2015-228752

Since the conventional motor with a sensor is configured as described above, the following problems exist.
That is, in the first conventional configuration of FIG. 4, since the angle sensor 100 is provided at the rear end of the motor body 80, the axial length, that is, the thickness of the motor as a whole becomes large, and the thickness can be reduced. There was a limit.
Further, in the second conventional configuration of FIG. 5, the planetary gear reduction mechanism 23 for decelerating the rotational output of the motor body 80 is connected to the motor body 80, so that the thickness is along the axial direction P of the motor. It was difficult to reduce the thickness and diameter of the planetary gear as long as the planetary gear reduction mechanism 23 was used.
Further, the motor main body 80 also has an outer rotor type configuration in which the motor rotor 3 is provided on the outside of the ring-shaped motor stator 32a, and the first and second bearings 27 and 15 must be provided on the inside of the motor stator 32a. Instead, a sensor composed of a magnetic absolute sensor 25 and a ring-shaped magnet 40 was provided on the outside of the first bearing 27.
Therefore, it is difficult to reduce the thickness as described above, and at the same time, it is impossible to reduce the outer diameter of the motor body 80 because the sensor cannot be attached to the peripheral surface of the motor shaft 11.

The present invention has been made to solve the above problems, and in particular, a motor stator, a motor rotor, and a hollow shaft are arranged inside the housing, and between the inner ring-shaped wall of the ring-shaped housing and the motor shaft. The purpose is to obtain a flat motor with a smaller diameter than before by providing a sensor in the housing and superimposing the sensor and the first bearing along the axial direction. To do.

The motor structure with a built-in sensor according to the present invention has a ring-shaped housing having a U-shaped cross section composed of an outer ring-shaped wall and an inner ring-shaped wall integrally formed with each other, and a ring-shaped housing formed between the outer ring-shaped wall and the inner ring-shaped wall. A space, a motor shaft rotatably provided via a first bearing provided inside the inner ring-shaped wall, and a third motor shaft connected to the outer peripheral surface of the motor shaft and provided on the inner surface of the outer ring-shaped wall. 2 A hollow shaft supported by a bearing, a motor stator provided on the inner surface of the outer ring-shaped wall, a motor rotor provided on the outer surface of the hollow shaft and located inside the motor stator, and an inner surface of the inner ring-shaped wall. It is located between the motor shaft and the outer peripheral surface of the motor shaft, and includes one or a plurality of sensors that are non-contact with respect to the motor shaft, and the sensor and the first bearing are of the ring-shaped housing. When viewed along the axial direction, they are configured to overlap each other and are located adjacent to each other, and the sensor is composed of a torque sensor and an angle sensor, and also includes the motor stator and the motor stator. The second bearing has a configuration in which the second bearings overlap each other and are located adjacent to each other when viewed along the axial direction of the ring-shaped housing, and the second bearing is located on the opening side of the ring-shaped housing. The configuration is provided, and the resolver rotor and torque rotor of each of the sensors are fixed to the outer peripheral surface.

Since the motor structure with a built-in sensor according to the present invention is configured as described above, the following effects can be obtained.
A ring-shaped housing having a U-shaped cross section composed of an outer ring-shaped wall and an inner ring-shaped wall integrally formed with each other, a ring-shaped space formed between the outer ring-shaped wall and the inner ring-shaped wall, and the inside of the inner ring-shaped wall. A motor shaft rotatably provided via a first bearing provided in the motor shaft, and a hollow shaft connected to the outer peripheral surface of the motor shaft and supported by a second bearing provided on the inner surface of the outer ring-shaped wall. A motor stator provided on the inner surface of the outer ring-shaped wall, a motor rotor provided on the outer surface of the hollow shaft and located inside the motor stator, an inner surface of the inner ring-shaped wall, and an outer peripheral surface of the motor shaft. It is located in between and includes one or more sensors that are non-contact with respect to the motor shaft, the sensor and the first bearing being viewed along the axial direction of the ring-shaped housing from each other. By having a structure in which the bearings are overlapped and located adjacent to each other, the structure is simple, the length in the axial direction can be shortened, and the outer diameter can be shortened. ..
Further, since the sensor is composed of both a torque sensor and an angle sensor, it is most suitable as a motor for power steering and the like.
Further, since the motor stator and the second bearing have a configuration in which they overlap each other and are located adjacent to each other when viewed along the axial direction of the ring-shaped housing, they are located in the axial direction and the outer diameter direction. Both dimensions can be reduced.
Further, in the second bearing, the second bearing is opened to the outside due to the configuration provided on the opening side of the ring-shaped housing, and the adjustment of the second bearing after production is easy.
Further, since the resolver rotor and the torque rotor of each sensor are fixed to the outer peripheral surface, the torque sensor becomes non-contact using a Hall IC or the like, and the angle sensor also makes the motor shaft magnetic. It can be made non-contact by using a body or attaching a magnetic material to the motor shaft.

It is sectional drawing of the motor structure with a built-in sensor by embodiment of this invention. It is sectional drawing which shows the other form of FIG. It is sectional drawing which shows the other form of FIG. It is sectional drawing which shows the 1st conventional structure. It is sectional drawing which shows the 2nd conventional structure.

According to the motor structure with a built-in sensor according to the present invention, the motor stator, the motor rotor, and the hollow shaft are arranged inside the ring-shaped housing, and the sensor is provided between the inner ring-shaped wall of the ring-shaped housing and the motor shaft. It is possible to obtain a flat type motor with a short axial length and a small diameter.

Hereinafter, a preferred embodiment of the motor structure with a built-in sensor according to the present invention will be described with reference to the drawings.
The same parts as those of the conventional example of FIG. 4 will be described with the same reference numerals.
In the form of FIG. 1, what is indicated by reference numeral 2 is a ring-shaped housing whose overall shape is formed in a ring shape, and the ring-shaped housing 2 has a smaller diameter than the large-diameter outer ring-shaped wall 2A and the outer ring-shaped wall 2A. The inner ring-shaped walls 2B of the above are integrally formed with each other. Further, the outer ring-shaped wall 2A and the inner ring-shaped wall 2B form a U-shape in cross section.
A ring-shaped motor stator 32a having a stator winding 32b is provided on the inner surface 2Aa of the outer ring-shaped wall 2A, and the inner ring-shaped wall 2B has a tubular shape via only one first bearing 27. The motor shaft 11 is rotatably provided.

The inner surface 2Aa of the outer ring-shaped wall 2A is provided with only one second bearing 15 located adjacent to or near the motor stator 32a, and the inside of the second bearing 15 has an overall shape. A first shaft portion 50A having a tubular shape, extending along the axial direction P, and having a large diameter, and a second shaft shorter and smaller in diameter along the axial direction P than the first shaft portion 50A. A hollow shaft 50 composed of a portion 50B is arranged.
The motor stator 32a and the second bearing 15 are superposed on each other when viewed along the axial direction P of the ring-shaped housing 2.
On the outer surface 50Aa of the first shaft portion 50A, a motor rotor 3 made of a ring-shaped magnet is rotatably provided together with the hollow shaft 50 with respect to the motor stator 32a via a slight gap G.

The second shaft portion 50B of the hollow shaft 50 is connected to the outer peripheral surface 11A of the motor shaft 11, and when the motor shaft 11 is rotated, the hollow shaft 50 and the motor rotor 3 are configured to rotate together. There is.

A well-known angle sensor 100 and a well-known torque sensor 102, which are one or a plurality of sensors, are provided as sensors between the inner surface 2Ba of the inner ring-shaped wall 2B and the outer peripheral surface 11A of the motor shaft 11.
The resolver shown in FIG. 1 is suitable for the angle sensor 100, but an encoder, a Hall IC, or the like can be used, and by arranging the angle sensor 100 in the inner diameter direction (concentric circles) of the motor rotor 3, the axial length can be used. It is configured so that the increase of can be suppressed. The angle sensor 100 is made of a well-known resolver, the resolver stator 100A is provided on the inner ring-shaped wall 2B, and the resolver rotor 100B is provided on the outer peripheral surface 11A of the motor shaft 11.

Further, the torque sensor 102 is basically a well-known and widely used magnetostrictive torque sensor, but other configurations can be adopted as long as it is a non-contact type.
Further, the central shaft P1 of the motor shaft 11 coincides with the central shaft of the ring-shaped housing 2, and the outer ring-shaped wall 2A, the hollow shaft 50, and the inner ring-shaped wall 2B are coaxially arranged with respect to the motor shaft 11. There is.
The torque sensor 102 has a well-known configuration. A hole IC 102A is provided on the inner surface 2Ba of the inner ring-shaped wall 2B, and a torque rotor 102B made of a well-known magnetostrictive material is provided on the motor shaft 11 for torque input. The state of the torque rotor 102B that twists accordingly is detected by the hall IC 102A. Although the sensors 100 and 102 are configured as a pair, only one of the sensors 100 and 102 may be used.

Therefore, the motor stator 32a, the motor rotor 3, and the hollow shaft 50 are arranged in the ring-shaped space 60 formed between the outer ring-shaped wall 2A and the inner ring-shaped wall 2B.
When the sensors 100 and 102 and the first bearing 27 are viewed along the axial direction P of the ring-shaped housing 2, they overlap each other and are located adjacent to each other, so that the ring-shaped housing 2 can be made thinner. It can be seen that it contributes to the reduction in diameter.
The second bearing 15 is provided on the opening 61 side of the ring-shaped housing 2, and a part of a plurality of well-known parts (resolver rotor 100B, torque rotor 102B) constituting the sensors 100 and 102 is formed on the outer peripheral surface. It is fixed to 11A.

The configuration of FIG. 1 described above shows the main form of the present invention, and FIGS. 2 and 3 show other forms of the form of FIG.
Since the configurations of FIGS. 2 and 3 are almost the same as the configurations of FIG. 1 described above, only the parts different from the configuration of FIG. 1 will be described, the same parts will be designated by the same reference numerals, and the description thereof will be omitted. ..
The difference between the configurations of FIGS. 2 and 3 with respect to the configuration of FIG. 1 is that the orientation of the opening 61 of the ring-shaped housing 2 is opposite.
Further, the only difference in the configuration of FIG. 3 from the configuration of FIG. 2 is that the positions of the sensors 100 and 102 and the first bearing 27 are exchanged.
The configurations of the sensors 100 and 102 are the same in FIGS. 1 to 3, the angle sensor 100 uses a well-known resolver, and the resolver stator 100A is provided on the inner surface 2Ba of the inner ring-shaped wall 2B. , The resolver rotor 100B is provided on the outer peripheral surface 11A of the motor shaft 11.
As the torque sensor 102, a well-known magnetostrictive torque sensor is adopted.
Therefore, in each of the sensors 100 and 102, a part of each component (resolver rotor 100B, torque rotor 102B) constituting each of the sensors 100 and 102 is fixed to the outer peripheral surface 11A of the motor shaft 11, so that each sensor 100 The resolver stator 100A and the hole IC 102A of the and 102 are configured in a non-contact state with respect to the resolver rotor 100B and the torque rotor 102B.
By arranging a pair of bearings 27, 15 between the ring-shaped housing 2 and the motor shaft 11 as shown in FIGS. 1 to 3, it is possible to limit the shaft shake of the motor shaft 11.
Further, the configuration of the present embodiment of FIGS. 1, 2 and 3 can be applied to any of the radial gap method and the axial gap method.

The motor structure with a built-in sensor according to the present invention has a motor stator, a motor rotor, and a hollow shaft arranged inside the ring-shaped housing, and a sensor is provided between the inner ring-shaped wall of the ring-shaped housing and the motor shaft. It is possible to obtain a flat type motor having a short axial length and a small diameter motor.

2 Ring-shaped housing 2A Outer ring-shaped wall 2B Inner ring-shaped wall 2Aa, 2Ba Inner surface 3 Motor rotor 11 Motor shaft 11A Outer peripheral surface 15 2nd bearing 27 1st bearing 32a Motor stator 32b Stator winding 50 Hollow shaft 50A 1st shaft 50B 2nd shaft Part 50Aa Outer surface 60 Ring-shaped space 61 Opening 100 Angle sensor 100A Resolver stator 100B Resolver rotor 102 Torque sensor P Axial direction P1 Central axis

Claims (5)

A U-shaped ring-shaped housing (2) having a U-shaped cross section composed of an outer ring-shaped wall (2A) and an inner ring-shaped wall (2B) integrally formed with each other, and the outer ring-shaped wall (2A) and the inner ring-shaped wall (2B). A motor shaft (11) rotatably provided via a ring-shaped space (60) formed between the two, a first bearing (27) provided inside the inner ring-shaped wall (2B), and the motor. A hollow shaft (50) connected to the outer peripheral surface (11A) of the shaft (11) and supported by a second bearing (15) provided on the inner surface (2Aa) of the outer ring-shaped wall (2A), and the outer ring shape. A motor stator (32a) provided on the inner surface (2Aa) of the wall (2A) and a motor rotor (3) provided on the outer surface (50Aa) of the hollow shaft (50) and located inside the motor stator (32a). ), The inner surface (2Ba) of the inner ring-shaped wall (2B), and the outer peripheral surface (11A) of the motor shaft (11), and are non-contact type with respect to the motor shaft (11). With one or more sensors (100, 102),
The sensor (100, 102) and the first bearing (27) are configured to overlap each other and are located adjacent to each other when viewed along the axial direction (P) of the ring-shaped housing (2). Motor structure with built-in sensor. The sensor built-in motor structure according to claim 1, wherein the sensors (100, 102) are composed of a torque sensor (102) and an angle sensor (100). The motor stator (32a) and the second bearing (15) are configured to overlap each other and are located adjacent to each other when viewed along the axial direction (P) of the ring-shaped housing (2). The motor structure with a built-in sensor according to claim 1 or 2. The sensor-built-in motor structure according to any one of claims 1 to 3, wherein the second bearing (15) is provided on the opening (61) side of the ring-shaped housing (2). The invention according to any one of claims 1 to 4, wherein the resolver rotor (100B) and the torque rotor (102B) of the sensors (100, 102) are fixed to the outer peripheral surface (11A). Motor structure with built-in sensor.

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