JP2014054014A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor capable of stabilizing attitude of an axis of rotation even in a configuration with a small number of bearings.SOLUTION: In a motor 10 single body, a contact state in which a commutator 24 of a rotor 20 and each of slopes 30a, 31a of an annular recess part 30 and an annular convex part 31 provided at an end frame 12 are engaged is brought by energizing a coil spring 15 to a tip side of an axis of rotation 21.

Description

  The present invention relates to a motor having a mechanism for urging a rotor in an axial direction.

  Conventionally, for example, as in the motor disclosed in Patent Document 1, a bearing that supports the base end portion and the distal end portion (output side) of the rotating shaft is fixed to the rotating shaft, while both bearings are free from the motor housing. The rotor is supported so as to be movable in the axial direction with respect to the motor housing. And the bearing of the base end side receives the urging | biasing force of urging members, such as a disk spring, and becomes a structure which presses a rotor to the axial direction front end side.

JP 2006-233082 A

  However, the fact that the rotor is supported so as to be movable in the axial direction means that the motor configured as described above has a gap due to loose fit between the bearing and the housing, and thus the rotating shaft of the rotor is inadvertently used by the motor alone. It is in a situation that tends to be inclined.

  Therefore, for example, when assembling the motor and the load device, there is a concern that the assembling workability of connecting the rotating shaft in the inclined state is deteriorated in the connecting operation of the rotating shaft of the motor and the connecting portion on the load device side. It has become. In particular, when the number of bearings used in the motor is small, such as omitting the bearing on the drive connection side with the load device, the rotating shaft tends to tilt more easily, and the assembly workability with the load device is further improved. There is concern about getting worse.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor capable of stabilizing the posture of a rotating shaft even with a configuration having few bearings.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that the rotor is rotatably accommodated in the case member, and the output portion at the tip of the rotating shaft of the rotor is externally provided through the insertion hole of the case member. And a bearing that supports the rotating shaft of the rotor is disposed on the base end side, while a bearing is omitted on the distal end side of the rotating shaft that is drivingly connected to the load device. And a urging member that urges the rotor shaft to move in the axial direction with respect to the case member, and urges the rotor toward the tip side of the rotation shaft. While the respective engaging portions provided on the rotor and the case member are in contact with each other at least in the radial direction by the urging of the urging member toward the distal end side of the rotating shaft, the output portion of the rotating shaft Connected to the load device At the time of data use, the rotary shaft is pushed proximally against the biasing force of the biasing member configured to contact between the casing member and the rotor is eliminated.

  In this invention, the base end side of the rotating shaft of the rotor is supported by the bearing, and the bearing on the tip end side of the rotating shaft that is drivingly connected to the load device is omitted, and the rotating shaft is free to move in the axial direction. In the motor alone, each of the rotor and the case member provided by the biasing of the biasing member toward the distal end side of the rotating shaft is a situation in which the posture change such as the tilting of the rotating shaft is likely to occur due to the fitted and supported configuration. It is set as the contact state which latching parts latch at least to radial direction. As a result, it is possible to suppress a change in posture such as an unexpected inclination on the rotating shaft, and the assembling workability when driving and connecting the rotating shaft (output unit) of the motor and the load device is good. When using a motor in which the output portion of the rotating shaft is drivingly connected to the load device, the rotating shaft is pushed toward the base end against the biasing force of the biasing member, and the contact state between the rotor and the case member is eliminated. Thus, no rotation loss occurs in the rotor.

  According to a second aspect of the present invention, in the motor according to the first aspect, a commutator is fixed to the tip end side of the rotating shaft of the rotor, and the commutator locking portion when the motor is a single unit. Is configured to be locked with the locking portion of the case member.

  In the present invention, a commutator fixed to the front end side of the rotating shaft is used as a part of the rotor that is locked to the case member when the motor is a single unit. That is, the commutator is generally disposed close to the case member, and since the contact portion can be easily set, it is suitable for contacting the case member as a part of the rotor.

  According to a third aspect of the present invention, in the motor according to the first or second aspect, at least one of the locking portions provided on the rotor and the case member is annularly around the rotation axis with respect to the axial direction. It has an inclined surface that is uniformly inclined, and is configured so that both are locked by the inclined surface.

  According to the present invention, at least one of the locking portions of the rotor and the case member has a slope that is uniformly inclined with respect to the axial direction and has an annular shape around the rotation axis, and the both are locked by the slope. In other words, by forming at least one of the locking portions as an inclined surface, it is easy to create a situation in which the rotor and the case member that receive the biasing force in the axial direction of the biasing member are locked in the radial direction, and the locking mode is simplified. Can be configured.

  According to a fourth aspect of the present invention, in the motor according to the third aspect, one of the engaging portions provided on the rotor and the case member is an inclined surface, and the other is a convex shape convex toward the inclined surface side. It has a curved surface, and is configured to be locked by the slope and the convex curved surface.

  In the present invention, one of the engaging portions of the rotor and the case member has a slope, and the other has a convex convex curved surface on the slope side, and the both sides are locked by the slope and the convex curved surface. Done. In other words, it can be expected that the rotating shaft of the rotor is aligned by locking with the inclined surface, but by making the other side in contact with the inclined surface a convex curved surface, the sliding resistance between both surfaces can be reduced, and the rotating shaft The alignment action is more likely to occur.

  According to a fifth aspect of the present invention, in the motor according to any one of the first to fourth aspects, one of the locking portions provided on the rotor and the case member is formed in a part of the recess. The other is formed on a part of the convex portion inserted into the concave portion.

  In the present invention, one of the engaging portions of the rotor and the case member is formed in a part of the concave part, and the other is formed in a part of the convex part inserted into the concave part. In other words, since the locking portions are locked together with the projections inserted into the recesses, the configuration in which the locking portions are provided also contributes to suppressing the increase in the size of the motor in the axial direction.

According to a sixth aspect of the present invention, in the motor according to any one of the second to third aspects of the present invention, the locking portion of the rotor is provided on the outer peripheral surface of the commutator. It is formed.
In the present invention, since the locking portion of the rotor is formed on the outer peripheral surface of the commutator, the locking portion that is locked in the radial direction can be easily formed without greatly changing the outer shape of the commutator.

  According to a seventh aspect of the present invention, in the motor according to any one of the first to sixth aspects, the bearing that supports at least the base end portion of the rotating shaft is a ball bearing, and the rotating shaft is disposed on an inner ring thereof. It is loosely fitted, and the urging member is interposed between the axially opposed surfaces of the inner ring of the ball bearing and the rotor core constituting the rotor.

  In this invention, the rotating shaft is loosely fitted to the inner ring of the ball bearing that supports at least the base end portion of the rotating shaft, and the urging member is interposed between the axially opposed surfaces of the inner ring of the ball bearing and the rotor core. As a result, the inner ring of the ball bearing can be rotated in the same manner as the rotor core that rotates together with the rotating shaft, so that it is possible to prevent the urging member interposed therebetween from being twisted or slidably contacted.

  According to an eighth aspect of the present invention, in the motor according to the seventh aspect, the biasing member is orthogonal to an axial end surface that is a surface orthogonal to the axial direction of the inner ring of the ball bearing, and orthogonal to the axial direction of the rotor core. Orthogonal bearing surface portions orthogonal to the axial direction that are in surface contact with each of the axially opposing surfaces that are surfaces to be provided are provided at both axial ends.

  In the present invention, the orthogonal bearing surface portions provided at both axial ends of the urging member are in contact with the axial end surface of the inner ring of the ball bearing and the axially opposed surface of the rotor core at surfaces orthogonal to each other in the axial direction. Thereby, since the urging force of the urging member acts in the axial direction, it becomes possible to make it difficult to tilt the rotating shaft. Moreover, suppression of the radial vibration of the rotor based on the urging of the urging member can be expected.

According to a ninth aspect of the present invention, in the motor according to any one of the first to eighth aspects, the urging member is a coil spring and is externally fitted to the rotating shaft.
In this invention, a coil spring is used as the urging member and is fitted on the rotating shaft. That is, by effectively using the inner space of the coil spring, it contributes to the suppression of the enlargement of the motor.

  A tenth aspect of the present invention is the motor according to any one of the seventh to ninth aspects, wherein the rotor core constituting the rotor has an annular portion formed by annularly connecting base end portions of the teeth portions. Having at least one core block for fixing to the rotating shaft when the virtual division is performed into a plurality of core blocks in the axial direction, and the other core block is a core for fixing to the rotating shaft It is fixed to the block, and is configured to have an opening around the rotation axis of the rotor core, and at least a part of the urging member is formed in an accommodating portion formed by the opening around the rotation axis of the rotor core. Contained in the axial direction.

  In the present invention, in the rotor core, the core block that does not have a function of directly fixing to the rotating shaft can easily form the opening for forming the housing portion around the rotating shaft. The housing is efficiently carried out, which contributes to the suppression of the increase in size of the motor.

  According to the motor of the present invention, there is an effect that the posture of the rotary shaft can be stabilized even with a configuration with a small number of bearings.

It is an axial sectional view of a motor in one embodiment. It is explanatory drawing for demonstrating the structure of a rotor core. (A) (b) is explanatory drawing for demonstrating the biasing aspect of the rotor by a coil spring. (A)-(d) is explanatory drawing for demonstrating the latching aspect of the rotor and case member in another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the case member of the motor 10 of the present embodiment includes a bottomed cylindrical yoke housing 11 and an end frame 12 that closes the opening of the yoke housing 11. A field magnet 13 is fixed to the inner peripheral surface of the cylindrical portion of the yoke housing 11. The number of magnetic poles of the magnet 13 is six. A bearing holding part 11a is formed in the bottom central part of the yoke housing 11 so as to project inward in a cylindrical shape. A ball bearing 14 is press-fitted into the inner peripheral surface of the bearing holding part 11a. A rotor 20 is rotatably accommodated inside the magnet 13, and a base end portion of a rotating shaft 21 of the rotor 20 is supported by a bearing 14.

  The rotor 20 includes a rotating shaft 21, a rotor core 22 assembled to the rotating shaft 21 so as to be integrally rotatable, a coil 23 wound around the rotor core 22, and a rectification fixed to the rotating shaft 21 and electrically connected to the coil 23. And a child 24.

  As shown in FIGS. 1 and 2, the rotor core 22 is configured by four portions in the axial direction. In this case, the first core block A, the second core block B, the third core block C, and the fourth core block D are sequentially arranged from the base end side (bearing 14 side) of the motor 10. The first to fourth core blocks A to D are provided with 18 tooth portions 22x for winding the coil 23 at equal intervals in the circumferential direction on the outer peripheral side. That is, the number of salient poles on the rotor 20 side is set to “18” with respect to the number of magnetic poles “6” of the magnet 13. Each teeth part 22x is comprised by the 1st-4th core block AD and the same shape.

  On the inner peripheral side of the rotor core 22, the base ends of the tooth portions 22 x are connected to each other in an annular shape, but the first and fourth core blocks A and D, the second core block B, and the third core block C are connected. The shapes of the annular portions 22a to 22d are different. In this case, the outer diameters of the annular portions 22a to 22d are the same, and the inner diameters are different.

  In the annular portion 22c of the third core block C, the hole on the inner peripheral side is a shaft hole 22c1 for press-fitting the rotary shaft 21, and the third core block C is configured such that the rotary shaft 21 is inserted into the shaft hole 22c1. The rotary shaft 21 is fixed by press-fitting. Incidentally, the first core block A is fixed to the second core block B, the second core block B is fixed to one side of the third core block C, and the fourth core block D is fixed to the third core block C. It is fixed to the other side. That is, the first, second, and fourth core blocks A, B, and D are not directly fixed to the rotating shaft 21 but are indirectly fixed to the rotating shaft 21 through the third core block C. The third core block C is configured by laminating a plurality of core sheets 22cx made of a magnetic metal plate in the axial direction.

  In the annular portion 22b of the second core block B, the inner peripheral hole is a receiving hole 22b1 having a slightly larger inner diameter than the shaft hole 22c1 of the third core block C. The receiving hole 22b1 of the second core block B Is used for accommodating the coil spring 15 that is externally supported by the rotary shaft 21. The second core block B is configured by laminating a plurality of core sheets 22bx made of a magnetic metal plate in the axial direction.

  The first and fourth core blocks A and D have the same shape including the tooth portion 22x and the annular portions 22a and 22d. The annular portions 22a and 22d of the first and fourth core blocks A and D have inner holes 22a1 and 22d1 having inner diameters larger than the inner holes 22b1 of the second core block B. The accommodation hole 22a1 of the core block A is used for accommodating a part of the coil spring 15 and the bearing holding portion 11a (bearing 14), and the accommodation hole 22d1 of the fourth core block D is used for accommodating a part of the commutator 24. . The first and fourth core blocks A and D are configured by laminating a plurality of core sheets 22ax and 22dx made of magnetic metal plates in the axial direction.

  The core sheets 22ax to 22dx of the first to fourth core blocks A to D are connected to each other before and after the axial lamination by six caulking fixing portions 22y provided on the annular portions 22a to 22d. Configured as The caulking fixing portion 22y is provided on the center line in the circumferential direction of every three (60 °) teeth portions 22x at the center in the width direction of the annular portions 22a and 22d of the first and fourth core blocks A and D. The second and third core blocks B and C are also provided at the same position.

  Regarding the widths (radial widths) Wa to Wd of the annular portions 22a to 22d of the first to fourth core blocks A to D, the diameters of the inner shaft hole 22c1, the accommodation hole 22b1, and the accommodation holes 22a1 and 22d1 are gradually increased. Compared with the increase, the width Wc of the annular portion 22c, the width Wb of the annular portion 22b, and the widths Wa and Wd of the annular portions 22a and 22d become gradually smaller. Since the annular portions 22a to 22d connect adjacent teeth portions 22x to form a magnetic circuit on the rotor core 22 side, the difference in the widths Wa to Wd of the annular portions 22a to 22d is the difference in magnetic flux density in that portion. Thus, the amount of magnetic flux to be allowed (maximum flow rate at the saturation magnetic flux density) is allowed.

  That is, the annular portions 22a and 22d of the first and fourth core blocks A and D have the highest magnetic flux density by being set to the narrowest width and are accommodated on the inner diameter side of the field magnet 13 In the first and fourth core blocks A and D (core sheets 22ax and 22dx), the annular portions 22a and 22d have a width dimension that is magnetically saturated. The annular portion 22b of the second core block B is set to be wide next, so that the magnetic flux density becomes an intermediate value, and no magnetic saturation occurs in the annular portion 22b in the second core block B (core sheet 22bx). It is a width dimension. The annular portion 22c of the third core block C has the lowest magnetic flux density by being set to the widest width, and the third core block C (core sheet 22cx) has a width dimension that does not cause magnetic saturation in the annular portion 22c. It has become. And in the rotor core 22 which combined such each core block AD, it becomes possible to flow a magnetic flux from the cyclic | annular parts 22a and 22d to the cyclic | annular parts 22b and 22c, and the average magnetic flux density of the cyclic | annular parts 22a-22d whole. The setting is configured not to be magnetically saturated.

  That is, the widths Wa to Wd of the annular portions 22a to 22d are made as small as possible without causing a magnetic influence that causes a reduction in the output of the motor 10, that is, in the radial direction of the rotor 20 and thus the motor 10. Miniaturization is achieved. A part or all of the bearing holding portion 11a (bearing 14), the coil spring 15, and the commutator 24 arranged in the axial direction are accommodated in the accommodating holes 22a1, 22b1, and 22d1 inside the annular portions 22a, 22b, and 22d from the axial direction. As a result, the motor 10 is also downsized in the axial direction.

  The rotor core 22 including the first to fourth core blocks A to D is configured such that the rotary shaft 21 is press-fitted into the shaft hole 22c1 of the third core block C, whereby the third core block C is inserted into the rotary shaft 21. Is directly fixed, and the first, second, and fourth core blocks A, B, and D are indirectly fixed. The base end portion of the rotating shaft 21 is rotatably supported by the ball bearing 14, and the outer ring 14a of the bearing 14 is press-fitted into the bearing holding portion 11a of the yoke housing 11, whereas the rotating shaft 21 is idled in the inner ring 14b. It is fitted. That is, the rotating shaft 21 (the rotor 20) is supported so as to be movable in the axial direction. And a part of tip part of this bearing 14 and the bearing holding | maintenance part 11a is inserted in the accommodation hole 22a1 of the 1st core block A, and is accommodated.

  A coil spring 15 is stretched between the axially opposed surfaces of the inner ring 14b of the ball bearing 14 and the annular portion 22c of the third core block C. The coil spring 15 is externally supported by the rotary shaft 21 and is received in the receiving holes 22a1 and 22d1 of the first and second core blocks A and B. Here, the coil spring 15 is formed with orthogonal bearing surface portions orthogonal to the axial direction at both ends in the axial direction, and the orthogonal bearing surface portions of each end portion of the inner ring 14b of the ball bearing 14 are surfaces orthogonal to the axial direction. Surface contact is made with each of the axial end surface and the axially opposed surface of the rotor core 22 (annular portion 22c of the third core block C) that is a surface orthogonal to the axial direction. The coil spring 15 uses the inner ring 14b of the ball bearing 14 as a fulcrum, and exerts its urging force on the annular portion 22c of the third core block C to press the rotor 20 toward the tip side.

  A commutator 24 is fixed to the distal end side of the rotating shaft 21. A plurality of segments 24 a are fixed to the outer peripheral surface of the commutator 24, and the terminal wires of the coils 23 wound around the tooth portions 22 x of the rotor core 22 are connected to the corresponding segments 24 a. The distal end portion of the rotating shaft 21 protruding from the commutator 24 is configured as an output portion 21a that is connected to a load and transmits a driving force. The rotating shaft 21 has a straight shape with no steps except for the output portion 21a.

  An end frame 12 is attached to the opening of the yoke housing 11 in which the rotor 20 and the like are accommodated. From the insertion hole 12a provided in the center part of the end frame 12, the output part 21a provided in the front-end | tip part of the rotating shaft 21 is protruded outside.

  A brush device 25 is provided on the inner side surface of the end frame 12. The brush device 25 includes a rectangular cylindrical holder portion 26, and a rectangular parallelepiped brush 27 is accommodated so as to be able to advance and retract in the radial direction. The brush 27 receives the urging force of the spring 28 at its rear end surface, and comes into pressure contact with the segment 24 a on the outer peripheral surface of the commutator 24. Then, power is supplied to the coil 23 of the rotor 20 through the brush 27 and the commutator 24, and a magnetic field for rotation is generated in the rotor 20.

Next, the operation of the motor 10 of this embodiment will be described.
In the configuration of the motor 10 of the present embodiment in which the inner ring 14b of the ball bearing 14 and the rotating shaft 21 are loosely fitted, and the bearing 14 is provided only at the base end portion of the rotating shaft 21, the rotating shaft 21 is inadvertently constituted by the motor 10 alone. 3 (a), the coil spring 15 is used and the commutator 24 is brought into pressure contact with the end frame 12 by its urging force so that the rotating shaft 21 is unexpectedly inclined. It has come to be suppressed.

  The contact portion between the commutator 24 and the end frame 12 will be described in detail. An annular recess 30 that is recessed in the axial direction around the rotation shaft 21 is formed on the end face of the commutator 24. An annular inclined surface 30 a that is uniformly inclined with respect to the rotation shaft 21 is formed at the opening edge on the radially outer side of the recess 30. The inclined surface 30a forms a linear cross-sectional surface that gradually expands from the bottom side to the opening side of the recess 30 (as it approaches the end frame 12). The inclined surface 30a has a line-symmetric shape with the rotating shaft 21 in the axial section. On the other hand, an annular convex portion 31 is formed around the insertion hole 12a of the end frame 12 so as to project toward the concave portion 30 at a position facing the annular concave portion 30 in the axial direction. The annular convex portion 31 has a trapezoidal cross section, and the slope 31a on the radially outer side is inclined to the slope 30a of the annular concave portion 30 that is uniformly inclined with respect to the rotary shaft 21 (having a line symmetrical shape with the rotary shaft 21 in the axial cross section). Opposite the axial direction.

  Then, based on the axial biasing of the coil spring 15, the insertion of the annular projection 31 of the end frame 12 into the annular recess 30 of the commutator 24 and the slope 30 a of the annular recess 30 of the commutator 24 and the end frame 12 are performed. The inclined surface 31a of the annular convex part 31 is in pressure contact with each other. Thereby, the movement of the commutator 24 in the radial direction with respect to the end frame 12 is restricted, and the posture change such as the inclination of the rotating shaft 21 does not occur. In particular, in the motor 10 of the present embodiment, the bearing on the commutator 24 side is omitted, and the rotating shaft 21 is cantilevered only by the bearing 14 at the base end portion, and the posture of the rotating shaft 21 is likely to change. Therefore, it is particularly effective to stabilize the posture of the rotating shaft 21 by urging the coil spring 15.

  In addition, each of the contact portions between the rotor 20 and the end frame 12 has inclined surfaces 30a and 31a that are annularly inclined around the rotation shaft 21 with respect to the axial direction, and both contact with each other with the inclined surfaces 30a and 31a. Therefore, the movement of the rotor 20 in the radial direction can be more reliably restricted by the locking of the inclined surfaces 30a and 31a, and the rotation shaft 21 can be positioned. Moreover, the alignment effect | action of the rotating shaft 21 can also be anticipated by the contact by the inclined surfaces 30a and 31a.

  In addition, the coil spring 15 that generates an urging force is accommodated in the accommodating holes 22a1 and 22b1 formed inside the annular portions 22a and 22b of the rotor core 22, and is rotated while suppressing the enlargement of the motor 10 in the axial direction. The posture of the shaft 21 is stabilized.

  As described above, since the motor 10 alone is configured to suppress the posture change such as the unexpected inclination of the rotating shaft 21, the assembling property at the time of assembling the motor 10 (the rotating shaft 21) with the load device 40 is improved. To contribute. Further, since the rattling of the rotor 20 is suppressed by the urging of the coil spring 15, it is possible to expect an effect of preventing the occurrence of problems due to the rattling when the motor 10 alone is transported.

  On the other hand, when the motor 10 is used to assemble the motor 10 to the load device 40, the output portion 21a at the tip of the rotating shaft 21 and the connecting portion 40a on the load device 40 side are connected, and the tip side of the rotating shaft 21 is connected to the load device 40. Supported on the side. At the time of this connection, as shown in FIG. 3B, the rotating shaft 21 is slightly pushed in against the urging force of the coil spring 15 from the load device 40 side, whereby the end frame 12 and the commutator 24 are pushed. This eliminates the rotation loss in the rotor 20.

Next, characteristic effects of the present embodiment will be described.
(1) A configuration in which the proximal end side of the rotating shaft 21 of the rotor 20 is supported by the bearing 14 and the bearing on the distal end side of the rotating shaft 21 that is drivingly connected to the load device 40 is omitted, and the rotating shaft 21 is in the axial direction. However, in the motor 10 alone, the coil spring 15 is biased toward the distal end side of the rotating shaft 21 while the posture of the rotating shaft 21 is likely to change. The commutator 24 of the rotor 20 and the annular recess 30 provided on the end frame 12 and the inclined surfaces 30a, 31a of the annular projection 31 are brought into contact with each other. As a result, an unexpected change in posture such as an inclination of the rotating shaft 21 is suppressed, and the assembly workability when the rotating shaft 21 (output unit 21a) of the motor 10 and the load device 40 are drivingly connected is improved. be able to. Further, by omitting the bearing on the tip end side of the rotating shaft 21, reduction in the number of parts of the motor 10, reduction in weight, reduction in the axial direction, and the like are achieved.

  (2) A commutator 24 fixed to the distal end side of the rotating shaft 21 is used as a part of the rotor 20 that is engaged with the end frame 12 when the motor 10 is used alone. That is, the commutator 24 is generally disposed close to the case member of the motor 10 such as the end frame 12, and the contact portion can be easily set, and therefore is suitable for being brought into contact with the case member as a part of the rotor 20.

  (3) The commutator 24 of the rotor 20 and the engaging portions of the end frame 12 have inclined surfaces 30a and 31a that are inclined uniformly with respect to the axial direction and have an annular shape around the rotating shaft 21, and the inclined surfaces 30a and 31a. Thus, both of them are locked. In other words, the locking by the inclined surfaces 30a and 31a makes it easy to create a situation in which the rotor 20 and the end frame 12 receiving the axial biasing force of the coil spring 15 are locked in the radial direction. 30a and 31a can be simply configured. Moreover, the alignment effect | action of the rotating shaft 21 can also be anticipated by the contact by the inclined surfaces 30a and 31a.

  (4) The engaging portion of the commutator 24 of the rotor 20 is formed in a part of the annular recess 30 on the end face of the commutator 24, and the engaging portion of the end frame 12 is an annular protrusion inserted into the annular recess 30. 31 is formed in a part. That is, since the convex portions 31 are inserted into the concave portions 30 and the inclined surfaces 30a and 31a formed on a part of the convex portions 31 are engaged with each other, the increase in the axial direction of the motor 10 is suppressed even in the configuration in which the engaging portions are provided. Can contribute.

  (5) The base end of the rotating shaft 21 is loosely fitted to the inner ring 14b of the ball bearing 14, and the coil spring 15 as an urging member is fitted to the rotating shaft 21, and the inner ring 14b of the ball bearing 14 and the rotor core 22 (first It is interposed between the axially facing surfaces of the three core blocks C and the annular portion 22c). Thereby, since the inner ring 14b of the ball bearing 14 can also rotate like the rotor core 22 that rotates together with the rotating shaft 21, it is possible to prevent the coil spring 15 interposed therebetween from being twisted or slidably contacted.

  (6) The orthogonal bearing surface portions provided at both ends in the axial direction of the coil spring 15 are in contact with the axial end surface of the inner ring 14b of the ball bearing 14 and the axially opposed surface of the rotor core 22 at surfaces orthogonal to each other in the axial direction. To do. Thereby, since the urging force of the coil spring 15 acts in the axial direction, it is possible to make it difficult to tilt the rotating shaft 21, which contributes to stabilization of the posture of the rotating shaft 21. Moreover, suppression of the radial vibration of the rotor 20 based on the fluctuation of the coil spring 15 can be expected.

  (7) The coil spring 15 is externally fitted to the rotating shaft 21 and the inner space of the coil spring 15 is effectively used, which can contribute to the suppression of the enlargement of the motor 10. Further, since the coil spring 15 is configured to come into contact with the inner ring 14 b of the ball bearing 14, the coil spring 15 having a small coil diameter can be used, which can contribute to the suppression of the enlargement of the motor 10.

  (8) Since the core blocks A and B that do not have the function of being directly fixed to the rotating shaft 21 can easily form the receiving holes 22a1 and 22b1 around the rotating shaft 21, the coil spring 15 that is externally fitted to the rotating shaft 21 and the like Can be efficiently accommodated, and the motor 10 can be prevented from being enlarged.

In addition, you may change embodiment of this invention as follows.
The accommodation of the coil spring 15 in the rotor core 22 may be part of the axial direction as well as the whole. In addition to the coil spring 15, other urging members such as a disc spring may be used. Further, the coil spring 15 and other urging members may not be accommodated in the rotor core 22, and may be accommodated in the bearing holder 11, for example.

  The configuration (shape) including the accommodating portion of the rotor core 22 is not limited to this. For example, the rotor core 22 is virtually divided into four core blocks A to D to have a shape corresponding to each block, but the number of divisions and the shape of each block may be changed as appropriate. The number of teeth portions 22x of the rotor core 22 and the widths Wa to Wd of the annular portions 22a to 22d may be appropriately changed.

-Although the opening of the rotor core 22 is for forming the motor component housing portion, it may have an opening provided for the purpose of reducing the weight or improving the cooling performance.
-Although the outer ring 14a of the ball bearing 14 is press-fitted (fixed) to the bearing holding part 11a and loosely fitted to the inner ring 14b and the rotary shaft 21, the outer ring 14a may be loosely fitted to the bearing holding part 11a. Also, for example, regardless of whether the outer ring 14a is press-fitted or loosely fitted into the bearing holding part 11a, a protrusion that abuts the outer ring 14a in the axial direction is provided at the bottom of the bearing holding part 11a, and the outer ring 14a is positioned in the axial direction Good. That is, when the reaction force of the urging force of the coil spring 15 on the rotor core 22 acts on the inner ring 14b, the inner ring 14b is pushed closer to the bottom side of the bearing holding portion 11a than the outer ring 14a. It is easy to secure a space for preventing contact with the bottom of 11a. Further, although the bearing 14 is a ball bearing, a bearing other than the ball bearing may be used.

  Although contact is made between the slopes 30a and 31a provided on the annular recess 30 of the commutator 24 and the annular projection 31 of the end frame 12, the contact mode is not limited to this. The contact between the two may be a contact in the radial direction or a contact in the axial direction, and may be a line contact or a point contact instead of a surface contact.

  For example, in FIG. 4A, the annular protrusion 32 of the end frame 12 (formed in a triangular shape in the cross section) has an annular slope 32a on the radially outer opening edge of the annular recess 30 of the commutator 24. A convex curved surface 30b is formed on the inclined surface 32a of the convex portion 32. The convex curved surface 30b is engaged with the inclined surface 32a and the convex curved surface 30b. In other words, the centering action of the rotary shaft 21 of the rotor 20 can be expected by the locking by the inclined surface 32a, but the opposite surface that contacts the inclined surface 32a is the convex curved surface 30b, and the contact area is reduced to reduce both surfaces 32a, 30b. The sliding resistance can be reduced, and the centering action of the rotating shaft 21 can be more easily generated.

  In FIG. 4B, an inclined surface 24b is formed on the outer peripheral surface (tip peripheral portion) on the tip end side of the commutator 24, more specifically, on the main body portion of the commutator 24 protruding in the axial direction from the segment 24a. And is configured to be engaged with the end frame 12 side. Therefore, without greatly changing the outer shape of the commutator 24, the engaging portion for engaging the rotor 20 with the end frame 12 in the radial direction can be easily formed as the inclined surface 24b (taper) of the outer peripheral corner portion.

  A slope 33a on the end frame 12 side that is engaged with the slope 24b of the commutator 24 is formed in a part of the housing recess 33 into which the tip of the commutator 24 is inserted. Since a part of the tip of the commutator 24 is accommodated in the accommodating recess 33, it is possible to contribute to the suppression of the axial enlargement of the motor 10.

  4C, the annular convex portion 34 having a triangular cross section of the end frame 12 is fitted to the annular concave portion 35 having a concave triangular shape of the commutator 24 and is locked by two inclined surfaces on the radially outer side and the inner side. It is an aspect.

  4D, the annular convex portion 36 having a rectangular cross section of the end frame 12 is fitted into the annular concave portion 37 having a rectangular cross section of the commutator 24, and the radially opposing surfaces 36a of the convex portion 36 and the concave portion 37 are shown. , 37a are engaged with each other. In this case, the opposing surfaces in the axial direction of the convex portion 36 and the concave portion 37 may be brought into pressure contact with each other.

  The commutator 24 and the end frame 12 are brought into contact as a part of the rotor 20, but may be brought into contact with a part of the rotor other than the commutator, such as a motor that does not use the commutator 24.

  The case member of the motor 10 includes the bottomed cylindrical yoke housing 11 and the end frame 12 that closes the opening thereof, but is not limited thereto, and may be changed as appropriate.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 12 ... End frame (case member), 12a ... Insertion hole, 14 ... Ball bearing (bearing), 14b ... Inner ring, 15 ... Coil spring (biasing member), 20 ... Rotor, 21 ... Rotating shaft, 21a ... output part, 22 ... rotor core, 22a-22d ... annular part, 22a1, 22b1 ... accommodating hole (accommodating part), 22x ... teeth part, 24 ... commutator, 24b ... slope (locking part), 30, 35, 37 ... annular recess (concave part), 31, 32, 34, 36 ... annular convex part (convex part), 33 ... accommodating recess (concave part), 30a, 31a, 32a, 33a, 34a, 35a ... slope (locking part), 30b ... convex curved surface (locking portion), 36a, 37a ... opposing surface (locking portion), 40 ... load device, A to D ... core block.

Claims (10)

A rotor in which a rotor is rotatably accommodated inside a case member, and an output portion at the front end of the rotating shaft of the rotor is projected to the outside through an insertion hole of the case member,
While the bearing that supports the rotating shaft of the rotor is disposed on the base end side thereof, the distal end side of the rotating shaft that is drivingly connected to the load device is configured with the bearing omitted, and the case member A urging member that supports the rotation shaft of the rotor so as to be movable in the axial direction, and urges the rotor toward the tip side of the rotation shaft,
In the motor alone, the engaging portions provided on the rotor and the case member are in contact with each other at least in the radial direction by the urging of the urging member toward the tip side of the rotating shaft, while the rotation When using a motor in which the output portion of the shaft is drivingly connected to the load device, the rotating shaft is pushed toward the proximal end against the urging force of the urging member, and the contact state between the rotor and the case member is A motor characterized by being configured to be eliminated. The motor according to claim 1,
A commutator is fixed to the front end side of the rotating shaft of the rotor, and the engaging portion of the commutator is configured to engage with the engaging portion of the case member when the motor is a single unit. A motor characterized by The motor according to claim 1 or 2,
At least one of the respective locking portions provided on the rotor and the case member has a slope that is annularly inclined with respect to the axial direction around the rotation axis, and is configured so that both are locked by the slope. Motor characterized by that. The motor according to claim 3, wherein
One of the engaging portions provided on the rotor and the case member is a slope, and the other has a convex curved surface on the slope side, and both are engaged by the slope and the convex curved surface. A motor characterized by being configured to stop. The motor according to any one of claims 1 to 4,
One of the engaging portions provided on the rotor and the case member is formed in a part of the concave part, and the other is formed in a part of the convex part inserted into the concave part. In the motor according to any one of claims 3 and 5 dependent on claim 2 and claim 2,
The motor is characterized in that a locking portion of the rotor is formed on an outer peripheral surface of the commutator. The motor according to any one of claims 1 to 6,
The bearing that supports at least the base end of the rotating shaft is a ball bearing, and the rotating shaft is loosely fitted to the inner ring thereof.
The motor, wherein the biasing member is interposed between axially opposed surfaces of an inner ring of the ball bearing and a rotor core constituting the rotor. The motor according to claim 7, wherein
The biasing member is axially in surface contact with each of an axial end surface that is a surface orthogonal to the axial direction of the inner ring of the ball bearing and an axially opposed surface that is a surface orthogonal to the axial direction of the rotor core. A motor comprising orthogonal orthogonal seating surface portions at both axial ends. The motor according to any one of claims 1 to 8,
The motor according to claim 1, wherein the biasing member is a coil spring and is externally fitted to the rotating shaft. The motor according to any one of claims 7 to 9,
The rotor core constituting the rotor has an annular portion formed by annularly connecting the base end portions of the teeth portion, and when virtually divided into a plurality of core blocks in the axial direction, at least one of the rotor shafts The other core block is fixed to the core block for fixing to the rotating shaft, and is configured to have an opening around the rotating shaft in itself.
A motor characterized in that at least a part of the urging member is accommodated in an axial direction in an accommodating portion formed by an opening around a rotation axis of the rotor core.