CN113644781A - Electric motor - Google Patents
Electric motor Download PDFInfo
- Publication number
- CN113644781A CN113644781A CN202110512621.8A CN202110512621A CN113644781A CN 113644781 A CN113644781 A CN 113644781A CN 202110512621 A CN202110512621 A CN 202110512621A CN 113644781 A CN113644781 A CN 113644781A
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- China
- Prior art keywords
- stator
- fixed
- disposed
- rotating shaft
- inertia ring
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K3/00—Details of windings
- H02K3/32—Windings characterised by the shape, form or construction of the insulation
- H02K3/34—Windings characterised by the shape, form or construction of the insulation between conductors or between conductor and core, e.g. slot insulation
- H02K3/345—Windings characterised by the shape, form or construction of the insulation between conductors or between conductor and core, e.g. slot insulation between conductor and core, e.g. slot insulation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids
Abstract
The invention provides a motor, which can be miniaturized in the axial direction of a rotating shaft even if an inertia ring is fixed on the rotating shaft. The motor (1) is provided with: a rotor (4) having a rotating shaft (2); a stator (6) formed in a cylindrical shape and disposed on the outer peripheral side of the rotor (4); and an inertia ring (9) fixed to the outer peripheral surface of the rotating shaft (2). The inertia ring (9) is provided with a fixed part (9a) fixed to the outer peripheral surface of the rotating shaft (2). At least a part of the fixed portion (9a) is disposed on the inner circumferential side of the stator (6) formed in a cylindrical shape.
Description
Technical Field
The present invention relates to a motor including an inertia ring fixed to a rotating shaft of a rotor.
Background
Conventionally, an inner rotor type motor including a rotor and a cylindrical stator disposed on an outer peripheral side of the rotor is known (for example, see patent document 1). In the motor described in patent document 1, the rotor includes a rotating shaft, a rotor core fixed to an outer peripheral surface of the rotating shaft, and a rotor magnet fixed to an outer peripheral surface of the rotor core. The stator includes a stator core and a stator coil wound around the stator core via an insulating member. The stator core includes a ring portion and a plurality of salient poles protruding radially inward from the ring portion. The stator coil is wound around each of the plurality of salient poles via an insulating member. The insulating member is composed of a first insulating member and a second insulating member divided in the axial direction of the stator core.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2016-208782
Disclosure of Invention
Technical problem to be solved by the invention
In the motor and the like described in patent document 1, an inertia ring may be fixed to a rotating shaft constituting a part of the rotor in order to increase the inertia moment of the rotor and suppress rotation unevenness and vibration of the rotor. The inventors of the present application have studied a technique for fixing an inertia ring to a rotating shaft in a motor described in patent document 1. However, if the inertia ring is simply fixed to the rotating shaft, the rotating shaft becomes long by the inertia ring, and therefore the motor becomes large in the axial direction of the rotating shaft.
Accordingly, an object of the present invention is to provide a motor that can be downsized in the axial direction of a rotating shaft even if an inertia ring is fixed to the rotating shaft.
Technical scheme for solving technical problem
In order to solve the above-described problems, a motor according to the present invention includes: a rotor having a rotation axis; a stator formed in a cylindrical shape and disposed on an outer peripheral side of the rotor; and an inertia ring fixed to an outer peripheral surface of the rotating shaft, the inertia ring including a fixed portion fixed to the outer peripheral surface of the rotating shaft, at least a part of the fixed portion being disposed on an inner peripheral side of the stator formed in a cylindrical shape.
In the motor of the present invention, at least a part of the fixed portion of the inertia ring is disposed on the inner circumferential side of the stator formed in a cylindrical shape. That is, in the present invention, at least a part of the fixed portion of the inertia ring overlaps a part of the stator in the radial direction of the rotor, and enters the inside of the stator in the axial direction of the rotary shaft. Therefore, in the present invention, the length of the rotating shaft can be shortened as compared with a case where the entire fixed portion of the inertia ring is arranged at a position offset from the stator in the axial direction of the rotating shaft. Therefore, in the present invention, even if the inertia ring is fixed to the rotary shaft, the motor can be downsized in the axial direction of the rotary shaft.
In the present invention, at least a part of the fixed portion of the inertia ring enters the inside of the stator in the axial direction of the rotary shaft, so that the length of the fixed portion in the axial direction of the rotary shaft can be secured while the motor is downsized in the axial direction of the rotary shaft. Therefore, in the present invention, the motor can be downsized in the axial direction of the rotating shaft, and the fixing strength of the inertia ring to the rotating shaft can be secured.
In the present invention, it is preferable that the rotor includes a driving magnet, and the stator includes: a driving coil; an insulating member; and a stator core having a plurality of salient pole portions around which a driving coil is wound via an insulating member, wherein a front end portion of each salient pole portion is a salient pole front end portion disposed to face an outer peripheral surface of the driving magnet, the insulating member includes a front end covering portion covering the front end portion of the salient pole from one axial side of the rotating shaft, the plurality of front end covering portions are arranged in a ring shape around an axis of the rotating shaft, and at least a part of the fixed portion is disposed on an inner peripheral side of the plurality of front end covering portions arranged in the ring shape. Since the plurality of front end covering portions arranged in a ring shape easily form a dead space on the inner peripheral side, if configured in this manner, at least a part of the fixed portion is easily arranged on the inner peripheral side of the stator.
In the present invention, it is preferable that the inertia ring is formed in a flanged cylindrical shape, and includes a fixed portion formed in a cylindrical shape and a flange portion extending in a flange shape from one end portion of the fixed portion, a part of the fixed portion is disposed on an inner circumferential side of the stator, and the flange portion is disposed at a position shifted from the stator in an axial direction of the rotating shaft. With such a configuration, the outer diameter of the flange portion can be increased while preventing interference between the flange portion and the stator. Therefore, even if the length of the inertia ring in the axial direction of the rotating shaft is shortened, the moment of inertia of the inertia ring fixed to the rotating shaft can be secured by the action of the flange portion. Therefore, even if the inertia ring is fixed to the rotary shaft, the rotary shaft can be made shorter, and as a result, the motor can be further downsized in the axial direction of the rotary shaft.
In the present invention, it is preferable that the thickness of the fixed portion formed in a cylindrical shape in the radial direction is larger than the thickness of the flange portion in the axial direction of the rotating shaft. With this configuration, since the thickness of the fixed portion in the radial direction can be increased, even if the thickness of the flange portion in the axial direction of the rotating shaft is reduced, the moment of inertia of the inertia ring fixed to the rotating shaft can be ensured. Therefore, the thickness of the flange portion in the axial direction of the rotary shaft can be reduced, and the length of the inertia ring in the axial direction of the rotary shaft can be further shortened. Therefore, even if the inertia ring is fixed to the rotating shaft, the rotating shaft can be further shortened, and as a result, the motor can be effectively downsized in the axial direction of the rotating shaft.
In the present invention, the inertia ring may include: a fixed part formed in a cylindrical shape; a flange portion extending in a flange shape from one end of the fixed portion; and a cylindrical protruding portion protruding from an outer peripheral end portion of the flange portion in an axial direction of the rotating shaft, wherein a part of the fixed portion is disposed on an inner peripheral side of the stator, and the flange portion is disposed at a position shifted from the stator in the axial direction of the rotating shaft. Even in this case, the outer diameter of the flange portion can be increased while preventing interference between the flange portion and the stator.
In the present invention, it is preferable that the stator includes a substrate to which the driving coil is electrically connected, the substrate is disposed on a side opposite to an output side of the motor with respect to the stator core in an axial direction of the rotating shaft, and the inertia ring is disposed on a side closer to the output side of the motor with respect to the stator core in the axial direction of the rotating shaft. With such a configuration, the inertia ring can be easily arranged as compared with a case where the inertia ring is arranged on the opposite side of the motor output from the stator core on which the substrate is arranged. Therefore, the degree of freedom in design of the motor can be improved, and the motor can be easily assembled.
Effects of the invention
As described above, in the motor according to the present invention, even if the inertia ring is fixed to the rotating shaft, the motor can be downsized in the axial direction of the rotating shaft.
Drawings
Fig. 1 is a sectional view of a motor according to an embodiment of the present invention.
Fig. 2 is a perspective view of the stator and the front end portion of the housing main body shown in fig. 1.
Fig. 3 is an exploded perspective view of the stator shown in fig. 1.
Fig. 4 is a perspective view of the stator core shown in fig. 3.
Fig. 5 is a perspective view of the first insulator shown in fig. 3.
Fig. 6 is a perspective view of the second insulator shown in fig. 3.
Fig. 7 (a) is a side view of the inertia ring shown in fig. 1, and fig. 7 (B) is a sectional view of the inertia ring shown in fig. 7 (a).
Fig. 8 is a sectional view of an inertia ring according to another embodiment of the present invention.
Description of the reference numerals
1 … electric motor; 2 … rotating shaft; 3 … magnet for driving; 4 … rotor; 5 … driving coil; 6 … stator; 9 … inertia ring; 9a … fixed part; 9b … flange portion; 9c … projection; 27 … insulator (insulating member); 28 … a stator core; 28b … salient pole portion; 28c … tip of the projection; 30b … front end cover portion; a 32 … substrate; t1 … radial thickness of the fixed part; t2 … thickness of flange portion; z … axial to the axis of rotation; the output side of Z1 …; z2 … outputs the opposite side.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
(integral Structure of Motor)
Fig. 1 is a sectional view of a motor 1 according to an embodiment of the present invention. Fig. 2 is a perspective view of the stator 6 and the front end portion of the housing main body 19 shown in fig. 1.
The motor 1 of the present embodiment is an inner rotor type motor. The motor 1 includes: a rotor 4 having a rotary shaft 2 and a driving magnet 3; a stator 6 having a driving coil 5 (see fig. 2); and a detection mechanism 7 for detecting the rotational speed and rotational position of the rotor 4. The motor 1 further includes a motor housing 8 that houses the rotor 4, the stator 6, and the detection mechanism 7, and an inertia ring 9 fixed to the outer peripheral surface of the rotating shaft 2. In fig. 1, the driving coil 5 is not shown.
The output-side end of the rotary shaft 2 protrudes outside the motor housing 8. The driving magnet 3 is formed in a cylindrical shape. The driving magnet 3 is fixed to the outer peripheral surface of the rotating shaft 2. The specific structure of the rotating shaft 2 will be described later. The rotor 4 may also include a rotor core formed in a cylindrical shape. In this case, the rotor core is fixed to the outer peripheral surface of the rotating shaft 2, and the driving magnet 3 is fixed to the outer peripheral surface of the rotor core.
The stator 6 is formed in a cylindrical shape. Specifically, the stator 6 is formed in a cylindrical shape. The stator 6 is disposed on the outer peripheral side of the rotor 4. Specifically, the stator 6 is disposed on the outer peripheral side of the driving magnet 3. The stator 6 is disposed such that the axis of the stator 6 formed in a cylindrical shape coincides with the axis of the rotor 4 (i.e., the axis of the rotary shaft 2). The specific structure of the stator 6 will be described later.
In the following description, the axial direction of the rotary shaft 2 (i.e., the axial direction of the rotor 4, the Z direction in fig. 1, etc.) is referred to as the "front-rear direction". The output side (the Z1 direction side in fig. 1 and the like) of the motor 1 in the front-rear direction (the axial direction of the rotary shaft 2) is referred to as the "front" side, and the opposite side (the Z2 direction side in fig. 1 and the like) to the output of the motor 1 in the front-rear direction is referred to as the "rear (rear surface)" side. In the following description, the radial direction of the rotor 4 and the stator 6 is referred to as the "radial direction", and the circumferential direction (circumferential direction) of the rotor 4 and the stator 6 is referred to as the "circumferential direction".
The detection mechanism 7 is a magnetic rotary encoder. The detection mechanism 7 includes a detection magnet 13 and a flat plate-shaped substrate 14 disposed on the rear side of the detection magnet 13. A magnetoresistive element and a hall element are mounted on the front surface of the substrate 14. The detection magnet 13 is fixed to the rear end portion of the rotary shaft 2 via a magnet holder 15. The substrate 14 is fixed to a bearing holder 21, which will be described later, constituting the motor housing 8 via a substrate holder 16.
The motor case 8 includes: a cylindrical case main body 19 that opens in the front-rear direction; a bearing holder 20 fixed to the front end of the housing body 19; a bearing holder 21 fixed to the rear end of the housing body 19; and a cover 22 covering the detection mechanism 7. A bearing 23 for rotatably supporting the rotary shaft 2 is attached to the bearing holder 20. A bearing 24 for rotatably supporting the rotary shaft 2 is attached to the bearing holder 21. The cover 22 is fixed to the rear surface of the bearing holder 21.
(Structure of the rotation shaft)
The rotary shaft 2 is formed of a metal material such as steel. The rotary shaft 2 is formed in a stepped cylindrical shape. The rotating shaft 2 includes: a magnet fixing portion 2a for fixing the driving magnet 3; a ring fixing portion 2b for fixing the inertia ring 9; a supported portion 2c supported by the bearing 23; a supported portion 2d supported by the bearing 24; and an output section 2e constituting a front end portion of the rotary shaft 2.
The front end of the supported portion 2c is connected to the rear end of the output portion 2 e. The front end of the ring fixing portion 2b is connected to the rear end of the supported portion 2 c. The magnet fixing portion 2a is disposed on the rear side of the ring fixing portion 2 b. The supported portion 2d is disposed on the rear side of the magnet fixing portion 2 a. The outer diameter of the supported portion 2c is larger than the outer diameter of the output portion 2 e. The ring fixing portion 2b has an outer diameter larger than that of the supported portion 2 c. The magnet fixing portion 2a has an outer diameter larger than that of the ring fixing portion 2 b.
Between the ring fixing portion 2b and the magnet fixing portion 2a, there is formed a positioning portion 2f for positioning the inertia ring 9 in the front-rear direction. The front end of the positioning portion 2f is connected to the rear end of the ring fixing portion 2b, and the rear end of the positioning portion 2f is connected to the front end of the magnet fixing portion 2 a. The outer diameter of the positioning portion 2f is larger than the outer diameter of the ring fixing portion 2 b. In addition, the outer diameter of the positioning portion 2f is smaller than the outer diameter of the magnet fixing portion 2 a.
(Structure of stator)
Fig. 3 is an exploded perspective view of the stator 6 shown in fig. 1. Fig. 4 is a perspective view of the stator core 28 shown in fig. 3. Fig. 5 is a perspective view of the first insulator 30 shown in fig. 3. Fig. 6 is a perspective view of the second insulator 31 shown in fig. 3. In fig. 3, illustration of the driving coil 5 and the substrate 32 is omitted.
The stator 6 includes an insulator 27 as an insulating member and a stator core 28 around which the driving coil 5 is wound via the insulator 27, in addition to the driving coil 5. The stator 6 includes a plurality of terminal pins 29 around which end portions of the driving coil 5 are wound and fixed, and a substrate 32 (see fig. 1) soldered and fixed to the terminal pins 29.
The stator core 28 is a laminated core formed by laminating thin magnetic plates made of a magnetic material. The stator core 28 is formed by combining and integrating a plurality of divided core segments divided in the circumferential direction. The stator core 28 of the present embodiment is formed of 12 divided cores. The stator core 28 includes an outer circumferential ring portion 28a formed in an annular shape and a plurality of salient pole portions 28b (see fig. 4) protruding radially inward from the outer circumferential ring portion 28 a. The outer peripheral ring portion 28a constitutes the outer peripheral surface of the stator core 28. The stator core 28 of the present embodiment includes 12 salient pole portions 28 b.
The plurality of projecting pole portions 28b are formed at equal angular intervals. That is, the plurality of projecting pole portions 28b are arranged at a constant interval in the circumferential direction. The distal end of the projecting pole portion 28b is a projecting pole distal end 28c disposed to face the outer peripheral surface of the driving magnet 3. The inner surface of the salient-pole tip portion 28c in the radial direction is formed in an arc shape with the axial center of the stator 6 as the center of curvature when viewed from the front-rear direction. The width of the projecting pole portion 28b in the front-rear direction is larger than the length of the driving magnet 3 (the length in the front-rear direction).
The insulator 27 is made of an insulating material such as resin. The insulator 27 is attached to each salient pole portion 28b, and the stator 6 includes the same number (i.e., 12) of insulators 27 as the salient pole portions 28 b. The insulator 27 is constituted by a first insulator 30 and a second insulator 31 divided in the front-rear direction, and the insulator 27 is formed by combining the first insulator 30 and the second insulator 31. In the present embodiment, the first insulator 30 is disposed on the front side, and the second insulator 31 is disposed on the rear side.
The first insulator 30 includes a covering portion 30a (see fig. 5) covering the protruding electrode portion 28b from the front side. The covering portion 30a includes a front end covering portion 30b that covers the tip end portion 28c of the salient electrode from the front side. That is, the insulator 27 includes a front end covering portion 30b that covers the protruding electrode front end portion 28c from the front side. The plurality of front end covering portions 30b are arranged in a ring shape around the axial center of the rotary shaft 2. Specifically, a plurality of (12) tip end covering portions 30b are arranged in an annular shape around the axial center of the rotary shaft 2. That is, the plurality of front end covering portions 30b are arranged in a ring shape around the axial center of the rotary shaft 2 when viewed from the front-rear direction.
The second insulator 31 includes a covering portion 31a (see fig. 6) covering the protruding electrode portion 28b from the rear side. The covering portion 31a includes a front end covering portion 31b covering the tip end portion 28c from the rear side. That is, the insulator 27 includes a front end covering portion 31b covering the protruding electrode front end portion 28c from the rear side. Like the plurality of tip covering portions 30b, the plurality of tip covering portions 31b are arranged in a ring shape around the axial center of the rotating shaft 2. Specifically, a plurality of (12) tip end covering portions 31b are arranged in an annular shape around the axial center of the rotary shaft 2. That is, the plurality of front end covering portions 31b are arranged in a ring shape around the axial center of the rotary shaft 2 when viewed from the front-rear direction.
The terminal pin 29 is fixed to the second insulator 31. Specifically, two terminal pins 29 are fixed to one second insulator 31. The terminal pin 29 protrudes toward the rear side. The driving coil 5 is wound around the salient pole portion 28b via the insulator 27. Specifically, the driving coil 5 is wound around the salient pole portion 28b via the covering portions 30a and 31 a. The distal end covering portions 30b and 31b function to prevent the driving coil 5 from unwinding radially inward. One end of the driving coil 5 is wound around and fixed to one of the two terminal pins 29 fixed to the second insulator 31, and the other end of the driving coil 5 is wound around and fixed to the other of the two terminal pins 29.
The substrate 32 is a rigid substrate formed in a flat plate shape. As described above, the board 32 is soldered to the terminal pins 29. The driving coil 5 is electrically connected to the substrate 32 via the terminal pin 29. The substrate 32 is disposed such that the thickness direction of the substrate 32 coincides with the front-rear direction. As shown in fig. 1, the base plate 32 is disposed behind the stator core 28. That is, the substrate 32 is disposed on the opposite side of the stator core 28 from the output of the motor 1 in the axial direction of the rotary shaft 2. The substrate 32 is disposed behind the driving magnet 3.
(Structure of inertia ring)
Fig. 7 (a) is a side view of the inertia ring 9 shown in fig. 1, and fig. 7 (B) is a sectional view of the inertia ring 9 shown in fig. 7 (a).
The inertia ring 9 is formed of a high-density metal material such as steel. The inertia ring 9 is formed in a flanged cylindrical shape, and includes a cylindrical fixed portion 9a fixed to the outer circumferential surface of the rotating shaft 2, and a flange portion 9b extending in a flange shape from one end of the fixed portion 9 a. The ring fixing portion 2b of the rotary shaft 2 is inserted through the inner peripheral side of the fixed portion 9a, and the fixed portion 9a is fixed to the outer peripheral surface of the ring fixing portion 2 b. The fixed portion 9a has an outer diameter smaller than an inner diameter of the stator 6 formed in a cylindrical shape. The fixed portion 9a has an outer diameter larger than the inner diameter of the driving magnet 3 and smaller than the outer diameter of the driving magnet 3. The length (length in the front-rear direction) of the fixed portion 9a is shorter than the length (length in the front-rear direction) of the ring fixing portion 2 b.
The axis of the fixed part 9a formed in a cylindrical shape coincides with the axis of the rotary shaft 2. The flange portion 9b is radially outwardly expanded from the distal end portion of the fixed portion 9 a. The flange portion 9b is formed in an annular shape and a flat plate shape. The flange portion 9b has an outer diameter larger than an inner diameter of the stator 6. The flange portion 9b has an outer diameter larger than that of the bearing 23. The flange portion 9b has an outer diameter smaller than that of the stator 6. The thickness t1 (see fig. 7B) in the radial direction of the cylindrical fixed portion 9a is greater than the thickness t2 (see fig. 7B) in the front-rear direction of the flange portion 9B.
In the present embodiment, the inertia ring 9 is fixed to the ring fixing portion 2b by the fixed portion 9a being shrink fitted to the ring fixing portion 2 b. The rear end surface of the inertia ring 9 fixed to the ring fixing portion 2b (i.e., the rear end surface of the fixed portion 9a) is in surface contact with a step formed at the boundary portion of the ring fixing portion 2b and the positioning portion 2 f. Since the ring fixing portion 2b is disposed on the front side of the magnet fixing portion 2a, the inertia ring 9 is disposed on the front side of the driving magnet 3. The inertia ring 9 is disposed on the front side of the stator core 28. That is, the inertia ring 9 is disposed on the output side of the motor 1 with respect to the stator core 28 in the axial direction of the rotary shaft 2.
As shown in fig. 1, a part of the fixed portion 9a is disposed on the inner peripheral side of the stator 6 formed in a cylindrical shape (inside the stator 6 in the radial direction). That is, a part of the fixed portion 9a overlaps the stator 6 in the radial direction, and enters the inner circumferential side of the stator 6 in the front-rear direction. Specifically, a part of the fixed portion 9a is disposed on the inner peripheral side of the plurality of tip covering portions 30b arranged in a ring shape (inside the plurality of tip covering portions 30b in the radial direction). That is, a part of the fixed portion 9a overlaps with the plurality of front end covering portions 30b in the radial direction, and enters the inner peripheral side of the plurality of front end covering portions 30b in the front-rear direction.
More specifically, a part of the rear end side of the fixed portion 9a is disposed on the inner peripheral side of the plurality of front end covering portions 30b arranged in a ring shape. The rear end surface of the fixed portion 9a is disposed at a position forward of the rear end of the front end covering portion 30b (i.e., the front end surface of the projecting electrode front end portion 28 c). The flange 9b is disposed on the front side of the stator 6. That is, the flange portion 9b is disposed at a position shifted from the stator 6 in the front-rear direction. The flange portion 9b is disposed between the stator 6 and the bearing 23 in the front-rear direction.
(main effect of the present embodiment)
As described above, in the present embodiment, a part of the fixed portion 9a of the inertia ring 9 is disposed on the inner circumferential side of the stator 6 formed in a cylindrical shape, and enters the inner circumferential side of the stator 6 in the front-rear direction. Therefore, in the present embodiment, the length of the rotary shaft 2 can be shortened as compared with the case where the entire fixed portion 9a is disposed at a position forward of the stator 6. Therefore, in the present embodiment, even if the inertia ring 9 is fixed to the rotary shaft 2, the motor 1 can be downsized in the front-rear direction.
In addition, in the present embodiment, since a part of the fixed portion 9a enters the inside of the stator 6 in the front-rear direction, the length of the fixed portion 9a in the front-rear direction can be secured while the motor 1 is downsized in the front-rear direction. Therefore, in the present embodiment, the fixing strength of the inertia ring 9 to the rotary shaft 2, which is fixed to the rotary shaft 2 by shrink fitting, can be secured while the motor 1 is downsized in the front-rear direction.
In the present embodiment, although the dead space is easily formed on the inner peripheral side of the plurality of front end covering portions 30b arranged in a ring shape, a part of the fixed portion 9a of the inertia ring 9 is disposed on the inner peripheral side of the plurality of front end covering portions 30b arranged in a ring shape. Therefore, in the present embodiment, a part of the fixed portion 9a can be easily arranged on the inner peripheral side of the stator 6.
In the present embodiment, the inertia ring 9 is formed in a flanged cylindrical shape, and includes a cylindrical fixed portion 9a and a flange portion 9b, and the flange portion 9b is disposed on the front side of the stator 6. Therefore, in the present embodiment, the outer diameter of the flange portion 9b can be increased while preventing interference between the flange portion 9b and the stator 6. Therefore, in the present embodiment, even if the length of the inertia ring 9 in the front-rear direction is shortened, the moment of inertia of the inertia ring 9 fixed to the rotary shaft 2 can be secured by the flange portion 9 b. Therefore, in the present embodiment, even if the inertia ring 9 is fixed to the rotary shaft 2, the rotary shaft 2 can be further shortened, and as a result, the motor 1 can be further downsized in the front-rear direction.
In the present embodiment, the thickness t1 in the radial direction of the fixed portion 9a is greater than the thickness t2 in the front-rear direction of the flange portion 9b, and the thickness t1 in the radial direction of the fixed portion 9a is relatively thick. Therefore, in the present embodiment, even if the thickness t2 in the front-rear direction of the flange portion 9b is made small, the moment of inertia of the inertia ring 9 fixed to the rotary shaft 2 can be ensured. Therefore, in the present embodiment, the thickness t2 of the flange portion 9b can be made thinner, and the length of the inertia ring 9 in the front-rear direction can be further shortened. Therefore, in the present embodiment, even if the inertia ring 9 is fixed to the rotary shaft 2, the rotary shaft 2 can be further shortened, and as a result, the motor 1 can be effectively downsized in the front-rear direction.
In the present embodiment, the inertia ring 9 is disposed at a position on the front side of the stator core 28. That is, in the present embodiment, the inertia ring 9 is disposed on the front side of the stator core 28 on which the base plate 32 is not disposed, instead of the rear side of the stator core 28 on which the base plate 32 is disposed. Therefore, in the present embodiment, the inertia ring 9 is easier to dispose than when the inertia ring 9 is disposed on the rear side of the stator core 28. Therefore, in the present embodiment, the degree of freedom in designing the motor 1 can be improved, and the motor 1 can be easily assembled.
(other embodiments)
The above embodiment is an example of the best mode of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.
In the above embodiment, as shown in fig. 8, the inertia ring 9 may include a cylindrical protrusion 9c protruding in the front-rear direction from the outer peripheral end portion of the flange portion 9 b. In this case, the protruding portion 9c may protrude forward from the outer peripheral end portion of the flange portion 9B as shown in fig. 8 (a), or may protrude rearward from the outer peripheral end portion of the flange portion 9B as shown in fig. 8 (B). The inertia ring 9 may include a protrusion 9c protruding forward from the outer peripheral end of the flange 9b and a protrusion 9c protruding rearward from the outer peripheral end of the flange 9 b.
In this case as well, the rear end of the fixed portion 9a is disposed on the inner peripheral side of the stator 6, and the flange portion 9b is disposed on the front side of the stator 6. Further, when the protruding portion 9c protrudes forward from the outer peripheral end portion of the flange portion 9b, the length of the protruding portion 9c in the front-rear direction is set so as not to interfere with the bearing holder 20 and the protruding portion 9 c. When the protruding portion 9c protrudes rearward from the outer peripheral end portion of the flange portion 9b, the length of the protruding portion 9c in the forward and rearward direction is set so that the stator 6 and the protruding portion 9c do not interfere with each other.
In the above embodiment, the rear end surface of the fixed portion 9a may be arranged at the same position as the rear end of the front end covering portion 30b (i.e., the front end surface of the distal end portion 28 c) in the front-rear direction. In the above embodiment, the rear end surface of the fixed portion 9a may be disposed on the rear side of the rear end of the front end covering portion 30b (i.e., the front end surface of the distal end portion 28 c). That is, a part of the rear end side of the fixed portion 9a may be disposed on the inner peripheral side of the plurality of tip covering portions 30b arranged in a ring shape and the inner peripheral side of the plurality of salient-electrode tip portions 28c arranged in a ring shape.
In the above embodiment, the inertia ring 9 may be disposed behind the stator core 28. In this case, the flange portion 9b is radially outwardly expanded from the rear end portion of the fixed portion 9 a. Even in this case, a part of the fixed portion 9a is disposed on the inner peripheral side of the stator 6. For example, the distal end portion of the fixed portion 9a is disposed on the inner peripheral side of the plurality of distal end covering portions 31b arranged in a circular ring shape around the axial center of the rotary shaft 2.
In the above embodiment, the thickness t1 in the radial direction of the fixed portion 9a and the thickness t2 in the front-rear direction of the flange portion 9b may be equal, and the thickness t1 may be smaller than the thickness t 2. In the above embodiment, the inertia ring 9 may not include the flange portion 9 b. That is, the inertia ring 9 may be formed in a simple cylindrical shape. In this case, the whole of the fixed portion 9a may be disposed on the inner peripheral side of the plurality of front end covering portions 30b arranged in a ring shape. That is, the whole of the fixed portion 9a may be disposed on the inner peripheral side of the stator 6. The fixed portion 9a may be formed in a shape other than a cylinder.
In the above embodiment, the inertia ring 9 may be fixed to the ring fixing portion 2b by press-fitting the ring fixing portion 2b into the fixed portion 9a, or the inertia ring 9 may be fixed to the ring fixing portion 2b by bonding the fixed portion 9a to the ring fixing portion 2 b. In the above embodiment, a plurality of (12) first insulators 30 may be formed integrally. Similarly, a plurality (12) of second insulators 31 may be integrally formed. In the above embodiment, the rotor 4 may include the driving coil 5, and the stator 6 may include the driving magnet 3.
Claims (6)
1. An electric motor, comprising:
a rotor having a rotational axis; a stator formed in a cylindrical shape and disposed on an outer peripheral side of the rotor; and an inertia ring fixed to an outer circumferential surface of the rotation shaft,
the inertia ring has a fixed portion fixed to an outer peripheral surface of the rotating shaft,
at least a part of the fixed portion is disposed on an inner peripheral side of the stator formed in a cylindrical shape.
2. The motor according to claim 1,
the rotor is provided with a driving magnet,
the stator includes: a driving coil; an insulating member; and a stator core having a plurality of salient pole portions around which the driving coil is wound via the insulating member,
the distal end of the salient pole portion is a salient pole distal end portion disposed to face the outer peripheral surface of the driving magnet,
the insulating member includes a tip end covering portion that covers the tip end portion of the protruding electrode from one side in the axial direction of the rotating shaft,
the plurality of front end covering sections are arranged in a ring shape with the axis of the rotating shaft as the center,
at least a part of the fixed portion is disposed on an inner peripheral side of the plurality of front end covering portions arranged in a ring shape.
3. The motor according to claim 1 or 2,
the inertia ring is formed in a cylindrical shape with a flange, and includes the fixed portion formed in a cylindrical shape and a flange portion extending in a flange shape from one end portion of the fixed portion,
a part of the fixed portion is disposed on an inner peripheral side of the stator,
the flange portion is disposed at a position offset from the stator in an axial direction of the rotating shaft.
4. The motor according to claim 3,
the thickness of the fixed portion formed in a cylindrical shape in the radial direction is larger than the thickness of the flange portion in the axial direction of the rotating shaft.
5. The motor according to claim 1 or 2,
the inertia ring includes: the fixed portion formed in a cylindrical shape; a flange portion extending in a flange shape from one end of the fixed portion; and a cylindrical projecting portion projecting from an outer peripheral end portion of the flange portion in an axial direction of the rotary shaft,
a part of the fixed portion is disposed on an inner peripheral side of the stator,
the flange portion is disposed at a position offset from the stator in an axial direction of the rotating shaft.
6. The motor according to claim 2,
the stator includes a substrate to which the driving coil is electrically connected,
the base plate is disposed closer to the opposite side of the output of the motor than the stator core in the axial direction of the rotating shaft,
the inertia ring is disposed closer to an output side of the motor than the stator core in an axial direction of the rotating shaft.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020-083114 | 2020-05-11 | ||
| JP2020083114A JP2021180536A (en) | 2020-05-11 | 2020-05-11 | motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113644781A true CN113644781A (en) | 2021-11-12 |
Family
ID=78415875
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110512621.8A Pending CN113644781A (en) | 2020-05-11 | 2021-05-11 | Electric motor |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2021180536A (en) |
| CN (1) | CN113644781A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1069594A (en) * | 1965-01-26 | 1967-05-17 | Ferranti Ltd | Improvements relating to gyroscopes |
| JPH08205511A (en) * | 1995-01-30 | 1996-08-09 | Tec Corp | Pm stepping motor |
| US20070252486A1 (en) * | 2006-04-28 | 2007-11-01 | Nidec Sankyo Corporation | Motor and manufacturing method therefor |
| CN103812246A (en) * | 2012-11-05 | 2014-05-21 | 日本电产三协株式会社 | Motor and motor manufacturing method |
| CN204334209U (en) * | 2014-09-19 | 2015-05-13 | 安川电机（沈阳）有限公司 | Motor and motor control system |
| CN206673776U (en) * | 2016-04-28 | 2017-11-24 | 日本电产株式会社 | Rotating driving device |
| JP2018046613A (en) * | 2016-09-13 | 2018-03-22 | 日本電産サンキョー株式会社 | Motor and pump device |
-
2020
- 2020-05-11 JP JP2020083114A patent/JP2021180536A/en active Pending
-
2021
- 2021-05-11 CN CN202110512621.8A patent/CN113644781A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1069594A (en) * | 1965-01-26 | 1967-05-17 | Ferranti Ltd | Improvements relating to gyroscopes |
| JPH08205511A (en) * | 1995-01-30 | 1996-08-09 | Tec Corp | Pm stepping motor |
| US20070252486A1 (en) * | 2006-04-28 | 2007-11-01 | Nidec Sankyo Corporation | Motor and manufacturing method therefor |
| CN103812246A (en) * | 2012-11-05 | 2014-05-21 | 日本电产三协株式会社 | Motor and motor manufacturing method |
| CN204334209U (en) * | 2014-09-19 | 2015-05-13 | 安川电机（沈阳）有限公司 | Motor and motor control system |
| CN206673776U (en) * | 2016-04-28 | 2017-11-24 | 日本电产株式会社 | Rotating driving device |
| JP2018046613A (en) * | 2016-09-13 | 2018-03-22 | 日本電産サンキョー株式会社 | Motor and pump device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2021180536A (en) | 2021-11-18 |
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