JP6873845B2 - Electric motor and motor with reducer - Google Patents

Description

The present invention relates to an electric motor and a motor with a speed reducer.

Conventionally, an electric motor including a cylindrical yoke in which a permanent magnet is fixed to an inner peripheral surface and an armature rotatably provided inside the yoke and the permanent magnet in the radial direction is known (for example,). See Patent Document 1). In such a motor, the permanent magnets have an arcuate cross section, and a plurality of permanent magnets are provided in the circumferential direction around the rotation axis of the armature. Each permanent magnet is fixed to the inner peripheral surface of the yoke by adhesion or by a magnet holder formed so as to cover the permanent magnet.

By the way, in order to reduce the size and improve the performance of the motor, a neodymium magnet or the like having a strong magnetic force may be used as the permanent magnet instead of the ferrite magnet. In such a case, the distribution of the magnetic flux density by the permanent magnet in the circumferential direction varies, and the attractive force by the permanent magnet fluctuates when the armature rotates. As a result, the cogging torque of the electric motor becomes large, which leads to an increase in operating noise.

On the other hand, as a means for suppressing the cogging torque and suppressing the operating noise, a plurality of permanent magnets provided in the circumferential direction are arranged on the inner peripheral surface of the yoke so as to be inclined with respect to the center of the yoke. There is a method of skew arrangement.

Japanese Unexamined Patent Publication No. 1-286756

However, when the permanent magnets are arranged at intervals in the circumferential direction, it may be difficult to fix the permanent magnets to the inner peripheral surface of the yoke with high positional accuracy in an inclined state.

Therefore, the present invention has been made in view of the above circumstances, and the permanent magnet is fixed to the yoke with high position accuracy to improve the performance of the motor while suppressing the cogging torque to increase the operating noise. It is an object of the present invention to provide an electric motor that can be suppressed and a motor with a speed reducer.

The present invention employs the following means in order to solve the above problems.
That is, the electric motor of the present invention has a tubular portion and a bottomed tubular yoke having a bottom wall portion formed on one end side of the tubular portion, and around the central axis of the tubular portion of the yoke. A plurality of permanent magnets are arranged at intervals in the circumferential direction of the yoke, and are arranged along the inner peripheral surface of the tubular portion of the yoke, respectively, and arranged inside the tubular portion of the yoke in the radial direction. A core fixed to a rotating shaft rotatably provided around the central axis, a coil wound around the core, and fixed to the inside of the yoke at one end of the permanent magnet in the central axis direction. On the other hand, the plurality of permanent magnets are skewed by holding each of the permanent magnets at an angle with respect to the central axis so that the other end in the central axis direction is positioned offset in the circumferential direction. The holder member includes a holder member having a magnet holding portion, the holder member includes a base portion along the bottom wall portion of the yoke, a press-fitting portion press-fitted into the inside of the yoke, and an inner peripheral surface of the yoke. The magnet holding portion, which is arranged with a gap between the two, is integrally provided, and the press-fitting portion is formed independently of the magnet holding portion, and is formed from the base portion to the inner peripheral surface of the tubular portion. It is characterized by including an arm portion extending along the arm portion and a protruding portion formed so as to project on the side of the arm portion facing the inner peripheral surface of the tubular portion .

According to such a configuration, a plurality of permanent magnets in a skew arrangement are fixed to the yoke with high accuracy by holding the permanent magnets at an angle with respect to the central axis of the yoke by the magnet holding portion of the holder member. be able to.
Further, the holder member is fixed to the yoke by press-fitting the press-fitting portion into the inside of the yoke. As a result, the holder member can be mounted by simply press-fitting it into the yoke, and assembly can be easily performed. Further, since the magnet holding portion is arranged with a gap between it and the inner peripheral surface of the yoke, it is possible to prevent the magnet holding portion from being deformed due to contact with the inner peripheral surface of the yoke and the position of the permanent magnet from being displaced. Can be done.
Further, when the protruding portion formed on the arm portion abuts on the inner peripheral surface of the tubular portion of the yoke, the arm portion is elastically deformed inward in the radial direction. As a result, the frictional force between the protruding portion and the inner peripheral surface of the tubular portion is strengthened, and the holder member can be more reliably fixed to the yoke.

Further, in the electric motor of the present invention, it is preferable that the permanent magnet has a rectangular flat plate shape, and the magnet holding portion has magnet support surfaces along two adjacent sides of the permanent magnet.

According to such a configuration, by supporting two adjacent sides of the rectangular flat plate-shaped permanent magnets on the magnet supporting surface, the permanent magnets can be easily tilted with respect to the central axis of the yoke. And it can be held securely.

Further, in the electric motor of the present invention, a convex portion is formed on the bottom wall portion of the yoke so as to project toward the other end side of the tubular portion, and the convex portion is fitted to the base portion of the holder member. Holes or recesses are formed.

According to such a configuration, the holder member can be positioned with high accuracy with respect to the central axis of the yoke by fitting the hole or the concave portion formed in the base portion of the holder member to the convex portion of the bottom wall portion. .. As a result, the permanent magnet held by the holder member can be positioned with high accuracy with respect to the yoke.

Further, in the electric motor of the present invention, the tubular portion of the yoke has a polygonal shape having three or more corners when viewed from the central axis direction, and the press-fitting portion is a corner portion of the tubular portion. It is arranged so as to hit the inner peripheral surface of the.

According to such a configuration, by abutting the press-fitted portion of the holder member against the corner portion of the polygonal yoke, the holder member can be positioned with high accuracy and firmly in the circumferential direction around the central axis of the yoke. ..

Further, in the electric motor of the present invention, the yoke has a diameter between the outer peripheral portion of the bottom wall portion and the tubular portion from the outer peripheral portion of the bottom wall portion toward the other end side of the tubular portion. The holder member may have a curved portion that gradually rises outward in the direction, and the holder member may be positioned with respect to the yoke by having the outer peripheral portion of the base portion along the inner peripheral surface of the curved portion.

According to such a configuration, the holder member is highly accurate with respect to the yoke by aligning the outer peripheral portion of the base portion of the holder member with the curved portion between the outer peripheral portion of the bottom wall portion of the yoke and the tubular portion. And it can be positioned firmly.

Further, in the electric motor of the present invention, a reinforcing rib projecting in the thickness direction of the base portion may be integrally formed at the base portion of the holder member.

According to such a configuration, by forming the reinforcing ribs at the base of the holder member, the strength of the base can be increased and the resonance frequency of the base can be shifted. As a result, it is possible to more effectively suppress the generation of operating noise when the electric motor is operating.

Further, the motor with a speed reducer of the present invention includes a rotating shaft provided with a worm gear, an electric motor as described above that rotationally drives the rotating shaft around a central axis, a worm wheel that meshes with the worm gear, and the worm wheel. It is characterized by including a speed reducer unit including at least an output gear, which is transmitted with the rotation of the wheel and outputs a rotational force to the outside.

According to such a configuration, a plurality of permanent magnets in a skew arrangement can be fixed to the yoke with high accuracy.

According to the present invention, it is possible to fix a permanent magnet to a yoke with high positional accuracy, improve the performance of the motor, suppress cogging torque, and suppress an increase in operating noise.

It is a perspective view which shows the appearance of the motor with a reduction gear in 1st Embodiment of this invention. It is a perspective development view which shows the component structure of the motor with a reduction gear in 1st Embodiment of this invention. It is a perspective view which shows the internal structure of the motor with a reduction gear in 1st Embodiment of this invention. It is a perspective view which shows the internal structure of the yoke in 1st Embodiment of this invention. It is a perspective view which shows the shape of the yoke in 1st Embodiment of this invention. It is a perspective view which shows the state which attached the permanent magnet to the inside of the yoke in 1st Embodiment of this invention via a holder member. It is a perspective view which shows the appearance of the holder member in 1st Embodiment of this invention. It is a perspective view which looked at the holder member in 1st Embodiment of this invention from the angle different from FIG. It is a figure which shows the structure of the yoke of the electric motor in the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the holder member mounted inside the yoke in the 2nd Embodiment of this invention. It shows the resonance frequency in the first-order to fourth-order resonance modes when the holder member according to the first embodiment of the present invention is provided. It shows the resonance frequency in the first-order to fourth-order resonance modes when the holder member according to the second embodiment of the present invention is provided. It is a perspective view which shows the internal structure of the yoke in the modification of the Embodiment of this invention. It is sectional drawing along the central axis of the yoke shown in FIG.

Next, the electric motor and the motor with a speed reducer according to the embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a perspective view showing the appearance of the motor 1 with a speed reducer. FIG. 2 is a perspective development view showing a component configuration of the motor 1 with a speed reducer. FIG. 3 is a perspective view showing the internal configuration of the motor 1 with a speed reducer.

(Motor with reducer)
As shown in FIGS. 1 and 2, the motor 1 with a speed reducer is used, for example, in a power window device of a vehicle (fixed object), and is provided on a casing 10 and one end side of the casing 10. It includes a motor unit (electric motor) 30 and a speed reducer unit 60 connected to the motor unit 30 and housed in the casing 10.

(casing)
As shown in FIG. 3, the casing 10 is formed with a storage recess 11 for accommodating the speed reducer unit 60 on one surface side thereof. The accommodating recess 11 is recessed from the top surface portion 10t of the casing 10 toward the back surface portion 10b facing the top surface portion 10t. The accommodating recess 11 mainly includes a shaft accommodating groove 12 for accommodating a rotating shaft 61, which will be described later, and a worm wheel accommodating portion 13.

Here, the shaft accommodating groove 12 is formed so as to extend in one direction along the bottom surface 11b (see FIG. 2) of the accommodating recess 11. Bearing accommodating recesses 15A and 15B are formed at both ends of the shaft accommodating groove 12 in the central axial direction.
The worm wheel accommodating portion 13 is formed on one side orthogonal to the axial direction of the axial accommodating groove 12.
Further, a motor accommodating portion 16 accommodating a part of the motor portion 30 is formed on the outer peripheral portion of the casing 10.
A plate-shaped cover 8 that covers the accommodating recess 11 is attached to the top surface portion 10t of the casing 10.

(Reducer section)
As shown in FIG. 2, the speed reducer unit 60 receives the rotation of the rotating shaft 61, the worm gear 62 that rotates in response to the rotation of the rotating shaft 61, the worm wheel 63 that meshes with the worm gear 62, and the rotation of the worm wheel 63. The rotating pinion gear 64, the facing member 65 that connects and shuts off the worm wheel 63 and the pinion gear 64, the lock plate 66, the shaft member 67 that rotatably supports the pinion gear 64 and the like, and the pinion gear 64 mesh with each other. It mainly includes a spar gear 71, an output gear 72 that rotates in response to the rotation of the spur gear 71, and a support shaft member 70 that rotatably supports the spur gear 71 and the output gear 72.

An annular bearings 68A and 68B are externally fitted to the rotating shaft 61 at two locations spaced apart from each other in the direction of the central axis. The bearings 68A and 68B are made of so-called rolling bearings, and are fitted into the bearing accommodating recesses 15A and 15B formed in the casing 10.
One end of the rotating shaft 61 projects toward the motor accommodating portion 16, and an armature 32 of the motor portion 30 and a commutator 35 are provided.

The worm gear 62 is fitted onto the rotating shaft 61 at the intermediate portion between the bearings 68A and 68B. The worm gear 62 is arranged in the shaft accommodating groove 12.

The worm wheel 63 is formed in a substantially disk shape, and gear teeth 63 g that mesh with the worm gear 62 are formed on the outer peripheral surface thereof. The pinion gear 64 is engaged in the radial center of the worm wheel 63.
The pinion gear 64, the worm wheel 63, the lock plate 66, and the facing member 65 are housed in the worm wheel accommodating portion 13 in a laminated state. Then, the shaft member 67 is inserted into the worm wheel accommodating portion 13 from the pinion gear 64 side. As a result, the pinion gear 64, the worm wheel 63, the lock plate 66, and the facing member 65 are rotatably supported around the shaft member 67.
When the rotary shaft 61 is rotationally driven around the central axis of the worm wheel 63 and the pinion gear 64 by the motor unit 30, the worm wheel 63 and the pinion gear 64 rotate around the shaft member 67.

The support shaft member 70 integrally includes a plate-shaped plate portion 70a and a shaft 70s extending orthogonally from one surface side of the plate portion 70a. The support shaft member 70 is provided at the opening of the housing recess 11 of the casing 10 so that the plate portion 70a straddles the shaft housing groove 12.

The spur gear 71 is formed in a substantially disk shape, and gear teeth 71g that mesh with the gear portion 64b of the pinion gear 64 are formed on the outer peripheral surface thereof.
The output gear 72 is mounted in the radial center of the spur gear. The output gear 72 integrally includes a gear-shaped gear portion 72g.
These spur gears 71 and output gears 72 are rotatably provided around the shaft 70s of the support shaft member 70.

Such a speed reducer unit 60 is housed in the housing recess 11, and is covered by a cover 8 mounted on the casing 10 except for a part of the output gear 72, as shown in FIG. The plate portion 72a and the gear portion 72g of the output gear 72 are exposed to the outside of the cover 8 through the substantially circular opening 8h formed in the cover 8. Then, a power window device or the like (not shown) is connected to the gear portion 72g.

(Motor section)
As the motor unit 30, for example, a DC motor with a brush is used, and the yoke 20 described in detail later, the permanent magnet 24 fixed to the yoke 20, and the armature 32 rotatably provided with respect to the yoke 20 are used. , A brush holder 40 holding a pair of brushes 43, 43 that are in sliding contact with a commutator 35 of the armature 32, and a brush holder 40 are mainly provided.

The armature 32 has an armature core (core) 33 and an armature coil (coil) 34.
The armature core 33 is arranged inside the yoke 20 in the radial direction with a radial gap between the armature core 33 and the permanent magnet 24. The armature core 33 is externally fitted and fixed to the outer side in the radial direction at one end of the rotating shaft 61. By winding the enamel-coated winding around the armature core 33, a plurality of armature coils 34 are formed on the outer periphery of the armature core 33.

The commutator 35 has a columnar shape and is externally fitted and fixed to the rotating shaft 61.
The brush holder 40 includes a plate-shaped support plate 41, a thermistor 42, and a pair of brushes 43 and 43 that are in sliding contact with the segment of the commutator 35. The brush holder 40 is press-fitted into the motor accommodating portion 16 provided on the outer peripheral surface of the casing 10.

(yoke)
FIG. 4 is a perspective view showing the internal configuration of the yoke 20. FIG. 5 is a perspective view showing the shape of the yoke 20.
As shown in FIGS. 4 and 5, the yoke 20 has a bottomed cylindrical shape, and has a tubular portion 21, a bottom wall portion 22, and a flange portion 23 formed on the other end side of the tubular portion 21. It has one.
The tubular portion 21 has a hexagonal shape (polygonal shape) having, for example, six corner portions 21c when viewed from the central axis direction. That is, the tubular portion 21 has six flat surface portions 21d, and square portions 21c curved with a predetermined curvature are formed between the flat surface portions 21d adjacent to each other in the circumferential direction.

As shown in FIG. 5, the bottom wall portion 22 is formed on one end side of the tubular portion 21 and is provided so as to close one end side of the tubular portion 21. The bottom wall portion 22 has a hexagonal shape corresponding to the tubular portion 21 having a hexagonal cross section.

The flange portion 23 is formed so as to extend radially outward from the other end side of the tubular portion 21. As shown in FIG. 3, the yoke 20 has a flange portion 23 abutted against an end portion of a motor accommodating portion 16 provided on the outer peripheral surface of the casing 10 and is fixed by a screw or the like (not shown).

Further, the yoke 20 is a curved portion that gradually rises radially outward from the outer peripheral portion of the bottom wall portion 22 toward the other end side of the tubular portion 21 between the outer peripheral portion of the bottom wall portion 22 and the tubular portion 21. Has 25.

FIG. 6 is a perspective view showing a state in which the permanent magnet 24 is attached to the inside of the yoke 20 via the holder member 50.
As shown in the figure, a plurality of permanent magnets 24 are provided along the inner peripheral surface 21f of the flat surface portion 21d of the tubular portion 21 in the circumferential direction around the central axis of the yoke 20. Each permanent magnet 24 has a rectangular flat plate shape. Each permanent magnet 24 is tilted with respect to the central axis of the yoke 20 by the holder member 50 so that the other end 24b in the central axis direction is offset in the circumferential direction with respect to one end 24a in the central axis direction. Is held. As a result, the permanent magnets 24 provided in the circumferential direction are in a so-called skew arrangement.

FIG. 7 is a perspective view showing the appearance of the holder member 50. FIG. 8 is a perspective view of the holder member 50 as viewed from an angle different from that of FIG. 7.
As shown in FIGS. 7 and 8, the holder member 50 integrally includes a base portion 51, a press-fitting portion 52 formed so as to rise from the outer peripheral portion 51s of the base portion 51, and a magnet holding portion 53.
The base portion 51 is formed in a plate shape along the bottom wall portion 22 of the yoke 20. The base portion 51 is formed in a polygonal shape according to the shape of the bottom wall portion 22 of the yoke 20. Further, the outer peripheral portion 51s of the base portion 51 is formed so as to be along the curved portion 25 between the outer peripheral portion of the bottom wall portion 22 of the yoke 20 and the tubular portion 21.
Here, as shown in FIGS. 5 and 6, the bottom wall portion 22 of the yoke 20 is formed with a convex portion 26 projecting toward the other end side of the tubular portion 21. On the other hand, as shown in FIGS. 6 to 8, a hole or a concave portion 55 that fits into the convex portion 26 is formed in the base portion 51 of the holder member 50.

The press-fitting portion 52 is formed on an arm portion 52a extending from the base portion 51 along the inner peripheral surface 21f of the tubular portion 21 in the direction of the central axis of the tubular portion 21 and on the inner peripheral surface 21f of the tubular portion 21 in the arm portion 52a. It integrally has a protruding portion 52b formed so as to project to the opposite side.

As shown in FIG. 6, the press-fitting portion 52 is press-fitted inside the yoke 20. In the press-fitting portion 52, the protruding portion 52b formed on the arm portion 52a abuts on the inner peripheral surface 21f of the tubular portion 21 of the yoke 20, so that the arm portion 52a is elastically deformed inward in the radial direction. As a result, the frictional force between the protruding portion 52b and the inner peripheral surface 21f of the tubular portion 21 is strengthened, and the holder member 50 is more reliably fixed to the yoke 20.

Further, as shown in FIGS. 7 and 8, the press-fitting portion 52 is formed independently of the magnet holding portion 53 by forming a slit 54 between the press-fitting portion 52 and the magnet holding portion 53.
As shown in detail in FIG. 6, a plurality of such press-fitting portions 52 are provided in the circumferential direction, and each of them is arranged so as to face the inner peripheral surface 21f of the corner portion 21c of the tubular portion 21.

The magnet holding portion 53 is arranged with a gap between it and the inner peripheral surface 21f of the flat surface portion 21d of the tubular portion 21. As shown in FIGS. 7 and 8, the magnet holding portion 53 has magnet support surfaces 53f and 53g. The magnet support surfaces 53f and 53g are inclined with respect to the central axis of the yoke 20, and are formed orthogonal to each other. The magnet support surfaces 53f and 53g support the permanent magnets 24 by supporting the two sides 24e and 24f adjacent to each other in the permanent magnets 24 so that the permanent magnets 24 are inclined with respect to the central axis of the yoke 20.

In this way, the permanent magnet 24 is held by the magnet holding portion 53 of the holder member 50 at an angle with respect to the central axis of the yoke 20. As a result, the plurality of permanent magnets 24 in the skew arrangement are fixed in a state of being tilted with high accuracy.
Specifically, the permanent magnets 24 are tilted with respect to the central axis of the yoke 20 by supporting the two adjacent sides of the rectangular flat plate-shaped permanent magnets 24 with the magnet support surfaces 53f and 53g. Is held at.

(Operation of reducer motor)
When the motor unit 30 of the motor 1 with a speed reducer is driven, the worm wheel 63 rotates via the rotating shaft 61 and the worm gear 62. Then, the output gear 72 rotates together with the worm wheel 63, and a driving force for opening and closing the window glass is output from the gear portion 72g of the output gear 72 to the outside.
Here, the speed reducer unit 60 is decelerated in two stages by the meshing of the worm gear 62 and the worm wheel 63 and the meshing of the pinion gear 64 and the spur gear 71.

As described above, the motor portion 30 and the motor 1 with a speed reducer according to the first embodiment described above have a tubular portion 21 and a bottom wall portion 22 formed on one end side of the tubular portion 21. A plurality of the shaped yoke 20 and the tubular portion 21 of the yoke 20 are arranged at intervals in the circumferential direction around the central axis, and each is permanently arranged along the inner peripheral surface 21f of the tubular portion 21 of the yoke 20. The magnet 24, the armature core 33 arranged on the radial inside of the tubular portion 21 of the yoke 20, and fixed to the rotating shaft 61 rotatably provided around the central axis, and the armature wound around the armature core 33. Each of the permanent magnets 24 is fixed to the inside of the coil 34 and the yoke 20 so that the other end 24b in the central axis direction is offset in the circumferential direction with respect to one end 24a in the central axis direction of the permanent magnet 24. The holder member 50 has a magnet holding portion 53 in which a plurality of permanent magnets 24 are skewed by holding the magnets at an angle with respect to the central axis.

According to such a configuration, the magnet holding portion 53 of the holder member 50 holds the permanent magnets 24 at an angle with respect to the central axis of the yoke 20, so that a plurality of permanent magnets 24 in a skew arrangement can be held with high accuracy. Can be fixed to the yoke 20. Therefore, it is possible to fix the permanent magnet 24 to the yoke 20 with high positional accuracy, improve the performance of the motor unit 30, suppress the cogging torque, and suppress the increase in the operating noise.

Further, the permanent magnet 24 has a rectangular flat plate shape, and the magnet holding portion 53 has magnet support surfaces 53f and 53g along two adjacent sides of the permanent magnet 24.
According to such a configuration, the permanent magnet 24 can be easily and surely held in a state of being inclined with respect to the central axis of the yoke 20.

Further, the holder member 50 is arranged with a gap between the base portion 51 along the bottom wall portion 22 of the yoke 20, the press-fitting portion 52 press-fitted inside the yoke 20, and the inner peripheral surface 21f of the yoke 20. The magnet holding portion 53 and the magnet holding portion 53 are integrally provided.
According to such a configuration, the holder member 50 is fixed to the yoke 20 by press-fitting the press-fitting portion 52 into the yoke 20. As a result, the holder member 50 can be mounted by simply press-fitting it into the yoke 20, and assembly can be easily performed. Further, since the magnet holding portion 53 is arranged with a gap between it and the inner peripheral surface 21f of the yoke 20, the magnet holding portion 53 is deformed by the contact with the inner peripheral surface 21f of the yoke 20, and the permanent magnet 24 It is possible to prevent the position from shifting.

Further, the press-fitting portion 52 is formed independently of the magnet holding portion 53, and has an arm portion 52a extending from the base portion 51 along the inner peripheral surface 21f of the tubular portion 21 and the inside of the tubular portion 21 in the arm portion 52a. A projecting portion 52b formed so as to project to the side facing the peripheral surface 21f is provided.
According to such a configuration, the protruding portion 52b formed on the arm portion 52a abuts on the inner peripheral surface 21f of the tubular portion 21 of the yoke 20, so that the arm portion 52a is elastically deformed inward in the radial direction. As a result, the frictional force between the protruding portion 52b and the inner peripheral surface 21f of the tubular portion 21 is strengthened, and the holder member 50 can be more reliably fixed to the yoke 20.

Further, the motor portion 30 has a convex portion 26 formed on the bottom wall portion 22 of the yoke 20 and projects toward the other end side of the tubular portion 21, and fits the convex portion 26 on the base 51 of the holder member 50. A hole or recess 55 is formed.
According to such a configuration, the holder member 50 is fitted to the convex portion 26 of the bottom wall portion 22 with the hole or the concave portion 55 formed in the base portion 51 of the holder member 50 so that the holder member 50 can be attached to the central axis of the yoke 20. Can be positioned with high accuracy. As a result, the permanent magnet 24 held by the holder member 50 can be positioned with high accuracy with respect to the yoke 20.

Further, the tubular portion 21 of the yoke 20 has a polygonal shape having three or more corner portions 21c when viewed from the central axis direction, and the press-fit portion 52 is formed on the inner peripheral surface 21f of the corner portion 21c of the tubular portion 21. Arranged to be located.
According to such a configuration, by arranging the press-fitting portion 52 of the holder member 50 at the corner portion 21c of the polygonal yoke 20, the holder member 50 can be placed with high accuracy in the circumferential direction around the central axis of the yoke 20. And can be firmly positioned.

Further, in the motor portion 30, the yoke 20 is radially outward from the outer peripheral portion of the bottom wall portion 22 toward the other end side of the tubular portion 21 between the outer peripheral portion of the bottom wall portion 22 and the tubular portion 21. It has a curved portion 25 that gradually rises. The holder member 50 is positioned with respect to the yoke 20 so that the outer peripheral portion 51s of the base portion 51 is along the inner peripheral surface 21f of the curved portion 25.
According to such a configuration, the holder member is formed by aligning the outer peripheral portion 51s of the base portion 51 of the holder member 50 with the curved portion 25 between the outer peripheral portion of the bottom wall portion 22 of the yoke 20 and the tubular portion 21. The 50 can be positioned with respect to the yoke 20 with high accuracy and firmness.

(Second Embodiment)
Next, a second embodiment of the electric motor and the motor with a speed reducer according to the present invention will be described. In the second embodiment described below, the configuration of the base 51 of the holder member 50 is different from that of the motor unit 30 shown in the first embodiment described above. Therefore, the same components as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted.

FIG. 9 is a diagram showing a configuration of a yoke of an electric motor according to a second embodiment of the present invention. FIG. 10 is a perspective view showing the configuration of a holder member mounted inside the yoke.
As shown in FIG. 9, a plurality of permanent magnets 24 are held on the inner peripheral surface 21f of the tubular portion 21 of the yoke 20 so as to be inclined with respect to the central axis of the tubular portion 21 via the holder member 50B. Has been done.
As shown in FIG. 10, the holder member 50B has a gap between the base portion 51B along the bottom wall portion 22 of the yoke 20, the press-fitting portion 52 press-fitted inside the yoke 20, and the inner peripheral surface 21f of the yoke 20. A magnet holding portion 53, which is arranged so as to be separated from each other, is integrally provided.

In this embodiment, the base portion 51B of the holder member 50B is integrally formed with a reinforcing rib 57 projecting in the thickness direction of the base portion 51B. The reinforcing rib 57 extends radially outward from a plurality of annular ribs 58 formed concentrically on the radial outer side of the hole or recess 55 formed in the base portion 51B and the annular rib 58 on the inner side in the radial direction. It includes a plurality of radial ribs 59.

According to such a configuration, by forming the reinforcing rib 57 on the base portion 51B of the holder member 50B, the strength of the base portion 51B can be increased and the resonance frequency of the base portion 51B can be shifted.

FIG. 11 shows the resonance frequencies in the first to fourth resonance modes when the holder member 50 according to the first embodiment described above is provided. Further, FIG. 12 shows the resonance frequencies in the first to fourth resonance modes when the holder member 50B according to the second embodiment described above is provided.
As shown in FIGS. 11 and 12, the resonance frequency of the base 51B in the second embodiment (see FIG. 12) deviates from the resonance frequency of the base 51 in the first embodiment (see FIG. 11). It can be confirmed that there is.

As described above, in the above-mentioned motor portion 30, the reinforcing rib 57 projecting in the thickness direction of the base portion 51B is integrally formed with the base portion 51B of the holder member 50B.
According to such a configuration, by forming the reinforcing rib 57 on the base portion 51B of the holder member 50B, the strength of the base portion 51B can be increased and the resonance frequency of the base portion 51B can be shifted. As a result, it is possible to effectively suppress the generation of operating noise when the motor unit 30 is operating.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and includes various modifications to the above-described embodiments without departing from the spirit of the present invention.
For example, as shown in FIGS. 13 and 14, the bottom wall portion 22 of the yoke 20 may be provided with an annular convex portion 29 for holding the bearing 68C that rotatably supports the end portion of the rotating shaft 61.
In this case, the holder member 50C can be positioned by fitting the annular convex portion 29 into the hole or the concave portion 55 formed in the base portion 51C of the holder member 50C.

Further, in the above-described embodiment, the case where the permanent magnet 24 has a rectangular flat plate shape has been described. However, the permanent magnet 24 is not limited to a flat plate shape. For example, the permanent magnet 24 may have a curved shape along the inner peripheral surface 21f of the tubular portion 21 of the yoke 20. For such a curved permanent magnet 24, the permanent magnet 24 is fixed to the yoke 20 with high position accuracy by using the holder members 50, 50B, and 50C as shown in the first and second embodiments described above. can do.

Further, in the above-described embodiment, the case where the motor 1 with a speed reducer is applied to the power window device has been described. However, the motor 1 with a speed reducer is not limited to these, and the motor 1 with a speed reducer includes various devices such as a drive source for a wiper arm of a vehicle, a drive source such as a window regulator, a sunroof, and an electric seat, and electrical components other than the vehicle. It is also applicable to.
Further, the motor unit 30 is not limited to the motor 1 with a speed reducer, and can be used for various other purposes. That is, the speed reducer unit 60 is not provided, and the motor unit 30 alone can be used by being incorporated into various devices and the like.

In addition to this, as long as the gist of the present invention is not deviated, the configurations listed in the above-described embodiments can be selected or changed to other configurations as appropriate.

1 ... Motor with reducer 8 ... Cover 20 ... Yoke 21 ... Cylindrical part 21c ... Corner part 21f ... Inner peripheral surface 22 ... Bottom wall part 24 ... Permanent magnet 24a ... One end part 24b ... Ending part 25 ... Curved part 26 ... Convex part 30 ... Motor part (electric motor)
33 ... Armature core (core)
34 ... Armature coil (coil)
50, 50B, 50C ... Holder member 51, 51B, 51C ... Base 51s ... Outer circumference 52 ... Press-fitting part 52a ... Arm part 52b ... Protruding part 53 ... Magnet holding part 53f, 53g ... Magnet support surface 55 ... Hole or recess 57 ... Reinforcing rib 60 ... Reducer section 61 ... Rotating shaft 62 ... Worm gear 63 ... Worm wheel 72 ... Output gear

Claims (7)

A bottomed tubular yoke having a tubular portion and a bottom wall portion formed on one end side of the tubular portion, and a bottomed tubular yoke.
A plurality of permanent magnets arranged at intervals in the circumferential direction around the central axis of the tubular portion of the yoke, and arranged along the inner peripheral surface of the tubular portion of the yoke, respectively.
A core arranged inside the tubular portion of the yoke in the radial direction and fixed to a rotating shaft rotatably provided around the central axis.
The coil wound around the core and
Each of the permanent magnets is centered so that the other end of the permanent magnet is located inside the yoke and the other end of the permanent magnet is offset in the circumferential direction with respect to one end in the central axis direction. A holder member having a magnet holding portion for skewing a plurality of the permanent magnets by holding the permanent magnets at an angle with respect to the shaft.
Equipped with a,
The holder member
A base along the bottom wall of the yoke and
A press-fitting portion that is press-fitted inside the yoke,
The magnet holding portion, which is arranged with a gap between the yoke and the inner peripheral surface of the yoke, is integrally provided.
The press-fitting part is
An arm portion that is formed independently of the magnet holding portion and extends from the base portion along the inner peripheral surface of the tubular portion.
A protruding portion formed in the arm portion so as to project to the side facing the inner peripheral surface of the tubular portion,
An electric motor characterized by being equipped with. The magnet holding portion is
The permanent magnet has a rectangular flat plate shape,
The electric motor according to claim 1, wherein the magnet holding portion has magnet support surfaces along two adjacent sides of the permanent magnet. A convex portion is formed on the bottom wall portion of the yoke so as to project toward the other end side of the tubular portion.
The electric motor according to claim 1 or 2 , wherein a hole or a concave portion that fits into the convex portion is formed in the base portion of the holder member. The tubular portion of the yoke has a polygonal shape having three or more corners when viewed from the central axis direction.
The press-fitting part, an electric motor according to any one of claims 1 to 3, characterized in that it is arranged so as to abut against the inner peripheral surface of the corner portion of the tubular portion. The yoke has a curved portion that gradually rises radially outward from the outer peripheral portion of the bottom wall portion toward the other end side of the tubular portion between the outer peripheral portion of the bottom wall portion and the tubular portion. And
The holder member is any one of claims 1 to 4 , wherein the outer peripheral portion of the base portion is positioned along the inner peripheral surface of the curved portion so as to be positioned with respect to the yoke. The described electric motor. To the base of the holder member, the electric motor according to any one of claims 1 to 5 in which the reinforcing rib is characterized in that it is formed integrally to protrude in the thickness direction of the base. A rotating shaft with a worm gear and
The electric motor according to any one of claims 1 to 6 , which rotationally drives the rotating shaft around a central axis.
A motor with a reduction gear including at least a worm wheel that meshes with the worm gear and an output gear that transmits the rotation of the worm wheel and outputs a rotational force to the outside.

Images