This application claims the benefit of priority to Japanese Patent Application No. 2018-069884 filed on Mar. 30, 2018. The entire contents of this application are hereby incorporated herein by reference.
The present disclosure relates to a motor.
Conventionally, in a cable in which an outer skin covers a circumference of a wire material, an outer diameter of the cable is increased by providing an anchor member on an inside of the outer skin, so that a sealing property between an inside and an outside of the motor is obtained while the cable is prevented from coming out.
A dimension of the case accommodating the cable and a substrate is increased by the cable, the anchor member, and the substrate.
In one aspect of the present disclosure, a motor includes a rotor and a stator, a substrate electrically connected to the stator, a sheet-metal cover accommodating the stator and the substrate, and a wiring electrically connected to the substrate. The cover includes a through-hole open to a wall of the cover and communicating an outside and an inside of the cover. The wiring includes a plurality of cables extending from the inside to the outside of the cover through the through-hole, and a bush with a tubular shape into which the plurality of cables are inserted, the bush being attached to the through-hole and elastically deformable. The cover includes a first cup body accommodating the stator and a second cup body accommodating the substrate. The bush is located radially between the second cup body and the substrate.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
As illustrated in
In the embodiment, a direction parallel to the center axis J is simply referred to as an “axial direction”. A direction from the first end at which the output end 3a is located toward a second end different from the first end in both the ends of the motor shaft 3 is referred to as one side in the axial direction. One side in the axial direction is a left side in
As illustrated in
The cover 5 is made of sheet metal. The first cup body 6A and the second cup body 6B are made of sheet metal. For example, the first cup body 6A and the second cup body 6B are made of a steel plate. An axial dimension of the second cup body 6B is smaller than an axial dimension of the first cup body 6A. The first cup body 6A and the second cup body 6B are equal to each other in a radial dimension. The first cup body 6A and the second cup body 6B are press-molded into a cup shape. That is, the first cup body 6A and the second cup body 6B are a press molded product. The cover 5 is a press cover.
The first cup body 6A is located on the other side in the axial direction with respect to the second cup body 6B. The second cup body 6B is positioned on one side in the axial direction with respect to the first cup body 6A. The first cup body 6A is open to one side in the axial direction. The second cup body 6B is open to the other side in the axial direction. Each of the first cup body 6A and the second cup body 6B includes a bottom wall 8, a circumferential wall 9, and a flange 10. That is, the cover 5 includes the bottom wall 8 and the circumferential wall 9 as a wall. The first cup body 6A and the second cup body 6B are disposed while openings of the circumferential walls 9 of the first cup body 6A and the second cup body 6B are opposed to each other.
The first cup body 6A and the second cup body 6B are fixed to each other while openings of the first cup body 6A and the second cup body 6B are opposed to each other in the axial direction. The flanges 10 of the first cup body 6A and the second cup body 6B are fixed to each other. An inside of the first cup body 6A and an inside of the second cup body 6B communicate with each other while the first cup body 6A and the second cup body 6B are fixed to each other.
The bottom wall 8 includes a bearing holder 18, a flat unit 8c, and a connection unit 8d. The bearing holder 18 has a bottomed tubular shape. The bearing holder 18 has the bottomed cylindrical shape centered on the center axis J. The bearing holder 18 is open toward the inside of the cover 5. The bearing holder 18 holds the bearing 7. For example, the bearing 7 is a ball bearing. The bearing 7 is fitted in and fixed to the bearing holder 18. In the cover 5, the pair of bearings 7 is disposed away from each other in the axial direction. The pair of bearings 7 is disposed at both ends in the axial direction of the cover 5. The pair of bearings 7 journals the motor shaft 3. The bearing 7 journals the motor shaft 3 about the center axis J.
A shaft insertion hole 19 axially penetrating the bottom wall 8 is made in the bottom wall 8 of the first cup body 6A. The shaft insertion hole 19 is made in the bearing holder 18 of the first cup body 6A. The shaft insertion hole 19 is a through-hole penetrating a bottom of the bearing holder 18. The motor shaft 3 is inserted into the shaft insertion hole 19. The motor shaft 3 protrudes from the inside to the outside of the cover 5 through the shaft insertion hole 19.
The flat unit 8c has an annular shape extending in the circumferential direction. The flat unit 8c has an annular plate shape centered on the center axis J. A plate surface of the flat unit 8c faces the axial direction, and spreads in a direction orthogonal to the center axis J. A radial position of the flat unit 8c is disposed outside a radial position of the bearing holder 18. The flat unit 8c surrounds the bearing holder 18 from the radial outside. The flat unit 8c is disposed at a position overlapping the bearing holder 18 when viewed in the radial direction. The flat unit 8c is connected to the circumferential wall 9. An outer edge of the flat unit 8c is connected to an end of the circumferential wall 9 on the side opposite to the opening along the axial direction.
A stud through-hole 23 is made in the bottom wall 8 of the second cup body 6B. The second cup body 6B includes a plurality of stud through-holes 23 axially penetrating the bottom wall 8. For example, the stud through-hole 23 is a circular hole. The stud through-hole 23 is made in the flat unit 8c of the second cup body 6B. The stud through-hole 23 axially penetrates the flat unit 8c of the second cup body 6B. The plurality of stud through-holes 23 are circumferentially made away from each other in the bottom wall 8. The plurality of stud through-holes 23 are circumferentially made at equal intervals in the flat unit 8c.
A plurality of stud bolts 22 are provided in the bottom wall 8 of the second cup body 6B. The stud bolt 22 protrudes from the bottom wall 8 of the second cup body 6B toward one side in the axial direction. The plurality of stud bolts 22 are circumferentially arranged at intervals in the bottom wall 8. In the illustrated example, four stud bolts 22 are circumferentially provided at equal intervals in the bottom wall 8. The stud bolt 22 is inserted into the stud through-hole 23, and attached to the bottom wall 8. The stud bolt 22 is press-fitted in the stud through-hole 23, and fixed to the flat unit 8c. Using the stud bolt 22, the motor 1 is attached and fixed to a device frame (not illustrated) to which the motor 1 is attached.
A screw attachment hole (not illustrated) is made in the bottom wall 8 of the second cup body 6B. The second cup body 6B includes the screw attachment hole axially penetrating the bottom wall 8. For example, the screw attachment hole is a circular hole. A plurality of screw attachment holes are made in the flat unit 8c of the second cup body 6B. The screw attachment hole axially penetrates the flat unit 8c of the second cup body 6B. The plurality of screw attachment holes are circumferentially made away from each other in the bottom wall 8. The two screw mounting holes are made. A screw member 25 (to be described later) is inserted into the screw mounting hole.
The connection unit 8d connects the bearing holder 18 and the flat unit 8c. The connection unit 8d connects tan opening of a tubular portion of the bearing holder 18 and the inner circumferential edge of the flat unit 8c. The connection unit 8d is disposed between the bearing holder 18 and the flat unit 8c. The connection unit 8d is located between the bearing holder 18 and the flat unit 8c along the radial direction. In the example of the embodiment, the connection unit 8d has a tapered tubular shape centered on the center axis J. The connection unit 8d extends toward the opening of the circumferential wall 9 along the axial direction as going from the flat unit 8c toward the radial inside. That is, the connection unit 8d of the first cup body 6A extends toward one side in the axial direction as going from the flat unit 8c toward the radial inside. The connection unit 8d of the second cup body 6B extends toward the other side in the axial direction as going from the flat unit 8c toward the radial inside.
The circumferential wall 9 has a tubular shape centered on the center axis J. The circumferential wall 9 has a cylindrical shape. The circumferential wall 9 extends axially from the outer circumferential edge of the bottom wall 8. The circumferential wall 9 is open onto the side opposite to the bottom wall 8 along the axial direction. The opening is located at the end of the circumferential wall 9 on the side opposite to the bottom wall 8 along the axial direction.
The end portion of the circumferential wall 9 on the side opposite to the opening along the axial direction is closed by the bottom wall 8.
A plurality of stator support claws 9a are provided in the circumferential wall 9 of the first cup body 6A. The stator support claw 9a protrudes from the circumferential wall 9 toward the inside of the first cup body 6A. The plurality of stator support claws 9a are circumferentially arranged at equal intervals in the circumferential wall 9. The stator support claw 9a contacts with the stator 4 disposed in the first cup body 6A from the other side in the axial direction. The stator support claw 9a supports the stator 4 toward one side in the axial direction.
As illustrated in
The bush 9b is inserted into the through-hole 17, and fixed to the circumferential wall 9. The bush 9b is attached to the through-hole 17. The bush 9b is elastically deformable. The bush 9b has a bottomed tubular shape. The bush 9b has a polygonal tubular shape. In the example of the embodiment, the bush 9b has a square tubular shape having a rectangular section. The end on the radial inside of the bush 9b is closed by the bottom. A wiring lead port 51 is open to a central portion of the bottom of the bush 9b. As illustrated in
The bush 9b extends from the inside to the outside of the cover 5 through the through-hole 17. In the bush 9b, an inner end 9c contacting with the circumferential wall 9 from the radial outside has an outer diameter larger than that of an outside 9d located on the radial outside of the inner end 9c. As illustrated in
As illustrated in
As illustrated in
As illustrated in
As illustrated in
That is, the sleeve 50c protrudes outward from both ends of the binding unit 50d along the extending direction of the cable 50a. A frictional coefficient between the sleeve 50c and the cable 50a is larger than a frictional coefficient between the sleeve 50c and the binding unit 50d. That is, the sleeve 50c and the cable 50a are difficult to move relative to each other in the direction in which the cable 50a extends.
As illustrated in
The stator 4 is fitted in the cover 5. The stator 4 is fitted in the first cup body 6A or the second cup body 6B. In the embodiment, the stator 4 is fitted in and fixed to the inner circumferential surface of the circumferential wall 9 of the first cup body 6A. The stator 4 is radially opposed to the rotor 2 with a gap interposed therebetween. The stator 4 is opposed to the rotor 2 from the radial outside. The stator 4 includes a stator core 26, a coil 27, and an insulating unit 28. The stator core 26 has an annular shape surrounding the radial outside of the rotor 2. The stator core 26 is radially opposed to the rotor magnet 2a with a gap interposed therebetween. The stator core 26 is opposed to the rotor magnet 2a from the radial outside.
The coil 27 is installed in the stator core 26. The coil 27 is indirectly installed in the stator core 26 with the insulating unit 28 interposed therebetween. The insulating unit 28 includes a portion disposed between the stator core 26 and the coil 27. The insulating unit 28 includes a portion radially opposed to the coil 27. That is, the insulating unit 28 is radially opposed to the coil 27. The insulating unit 28 includes an outer circumferential side insulating unit 28a located on the radial outside of the coil 27 and an inner circumferential side insulating unit 28b located on the radial inside of the coil 27. The outer circumferential side insulating unit 28a is opposed to the coil 27 from the radial outside. The inner circumferential side insulating unit 28b is opposed to the coil 27 from the radial inside. The substrate 20 is attached and fixed to the outer circumferential side insulating unit 28a.
The substrate 20 is located on one side in the axial direction of the stator 4. The substrate 20 has a disc shape. The substrate 20 has an annular plate shape centered on the center axis J. The plate surface of the substrate 20 faces in the axial direction, and spreads in the direction orthogonal to the center axis J. The motor shaft 3 extends in the axial direction on the radial inside of the substrate 20.
The substrate 20 is electrically connected to the stator 4. The substrate 20 is electrically connected to a coil lead wire (not illustrated) of the coil 27. The substrate 20 is connected to the coil lead line at the outer circumferential edge of the plate surface facing one side in the axial direction of the substrate 20. The substrate 20 is located on one side in the axial direction of the rotor magnet 2a. The substrate 20 is disposed at a position that overlaps the stator 4 and the rotor magnet 2a when being viewed from the axial direction. The substrate 20 is surrounded from the radial outside by the outer circumferential side insulating unit 28a. The substrate 20 is disposed at a position that overlaps the outer circumferential side insulating unit 28a when being viewed from the radial direction. The outer circumferential side insulating unit 28a includes a recess recessed from the upper end of the outer circumferential side insulating unit 28a toward the side of the stator 4. In the recess, the substrate 20 does not overlap the outer circumferential side insulating unit 28a when being viewed from the radial direction. In the example of the embodiment, the substrate 20 is accommodated in the second cup body 6B. That is, when viewed from the radial direction, the substrate 20 is disposed at a position overlapping the second cup body 6B.
Although not illustrated, an electronic component is mounted on the plate surface of the substrate 20. Examples of the electronic component include an integrated circuit and a capacitor. The substrate 20 is disposed while the plate surface on which the integrated circuit and the capacitor are mounted faces one side in the axial direction. The integrated circuit has a rectangular plate shape. The capacitor has a columnar shape. The capacitor extends in the axial direction. The surface facing one side in the axial direction of the capacitor is axially opposed to the bottom wall 8 of the second cup body 6B. A surface facing one side in the axial direction of the capacitor is disposed with a gap interposed between the surface facing one side in the axial direction of the capacitor and a surface facing the other side in the axial direction of the bottom wall 8. One end of the cable 50a is electrically connected on the plate surface of the substrate 20. One end of the cable 50a and the plate surface of the substrate 20 may directly be connected to each other by soldering or the like, or electrically be connected while a member such as a connector is interposed therebetween. The cable 50a extends radially from a connection point between the cable 50a and the substrate 20 along the substrate 20, and passes through the through-hole 17. That is, the cable 50a extends along the substrate 20. Consequently, the cable 50a is disposed closer to the plate surface of the substrate 20 than the flat unit 8c of the second cup body 6B. This enables the axial dimension of the second cup body 6B to be shortened. That is, the height of the entire motor can be reduced to miniaturize the motor size. The connection position between the cable 50a and the substrate 20 is radially opposed to the through-hole 17. Consequently, the length of the cable routed inside the motor is shortened to reduce the amount of members used, which leads to the cost reduction.
The heat sink 21 is disposed on one side in the axial direction of the substrate 20. The heat sink 21 contacts thermally with the integrated circuit. The heat sink 21 is fixed to the cover 5. As illustrated in
In the embodiment, the elastic modulus of the sleeve 50c is smaller than the elastic modulus of the coated portion of the cable 50a, and the sleeve 50c is soft, so that a contact area between the plurality of cables 50a passing through the sleeve 50c and the sleeve 50c is secured. The frictional force between the sleeve 50c and the cable 50a is increased, and the cable 50a is difficult to move in the sleeve 50c. The sleeve 50c and the cable 50a are bundled by the binding unit 50d, so that the sleeve 50c and the cable 50a further contact with each other. Because the sleeve 50c has a diameter larger than that of the wiring lead port 51 and is opposed to the wiring lead port 51 from the inside of the cover 5, the sleeve 50c is caught by the wiring lead port 51 when the cable 50a is pulled, and the cable 50a is prevented from coming out of the cover 5. The cable 50a is also prevented from slipping out of the sleeve 50c. Even if the cable 50a is strongly pulled, the sleeve 50c contacting with the wiring lead port 51 absorbs the impact to prevent the damage of the cable 50a. Even if the binding unit 50d is tightened too much during the manufacturing of the motor, the soft sleeve 50c functions as a cushioning member to prevent the damage of the cable 50a.
In the embodiment, the sleeve 50c contacts with all the plurality of cables 50a, so that the cable 50a can further be prevented from coming out. The length of the sleeve 50c in the direction in which the cable 50a extends is longer than the length of the binding unit 50d, and the binding unit 50d is located inside the both the ends of the sleeve 50c. That is, the sleeve 50c can be lengthened, so that the contact area between the sleeve 50c and the cable 50a can be enlarged to further prevent the cable 50a from coming out. When the sleeve 50c contacts with the wiring lead port 51, the sleeve 50c is easily elastically deformed and easily functions as the cushioning member against the pull of the cable 50a.
In the embodiment, the frictional coefficient between the sleeve 50c and the cable 50a is larger than the frictional coefficient between the sleeve 50c and the binding unit 50d. That is, the frictional coefficient between the sleeve 50c and the cable 50a is increased, so that the cable 50a can further prevented from coming out. Further, the cable 50a extends while being curved between the wiring lead port 51 and the substrate 20.
That is, because the cable 50a is bent in the cover 5, the connection state between the cable 50a and the substrate 20 is maintained well even if the cable 50a is pulled.
In the embodiment, the wiring lead port 51 is disposed in the elastically deformable bush 9b, so that a sealing property of the wiring lead port 51 can be enhanced. Because the wiring lead port 51 is a flat cross shape including the first slit 51a and the second slit 51b, the pre-binding individual cables 50a passes easily through the wiring lead port 51 during the manufacturing. After the assembly of the motor, the sleeve 50c having the diameter larger than that of cable 50a hardly comes out from the wiring lead port 51. The length of the first slit 51a is smaller than the outer diameter of the sleeve 50c, so that the sleeve 50c hardly slips out of the wiring lead port 51.
The bush 9b includes the flange 9f, so that the bush 9b hardly comes out of the through-hole 17. Thus, the sealing property of the bush 9b is improved, and the bush 9b stably prevents the cable 50a from coming out. Because the sleeve 50c is the heat-shrinkable tube, the contact area between the sleeve 50c and the cable 50a is enlarged.
The present disclosure is not limited to the embodiment. For example, as will be described below, the configuration or the like can be changed without departing from the scope of the present disclosure.
In the embodiment, the wiring lead port 51 of the bush 9b has the flat cross shape. However, the present disclosure is not limited to this configuration. For example, the wiring lead port 51 may have a slit shape that is open to the bottom of the bush 9b and reaches the outer circumferential edge of the flange 9f. The wiring lead port 51 may be a flattened rectangular shape or the like. The through-hole 17 may be made in the bottom wall 8, and the bush 9b may be provided in the bottom wall 8. During assembly of the motor, a wedge member may be inserted from the inside of the cover 5 into the wiring lead port 51. Consequently, when the cable 50a is pulled, the wedge member is drawn into the wiring lead port 51 to further prevent the cable 50a from coming out. As illustrated in
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
Number | Date | Country | Kind |
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2018-069884 | Mar 2018 | JP | national |