JP4674146B2 - Coreless motor - Google Patents

Description

  The present invention relates to a coreless motor, and more particularly to a coreless motor having a configuration in which a magnet holder is fixed in a housing.

  Japanese Patent Application Laid-Open No. H10-228561 discloses that a motor is supported rotatably by a bottom-side bearing and a head-side bearing in which both ends of a rotating shaft of the motor are fixed inside the housing.

  The motor described in Patent Document 1 is a cored motor (a coil is wound around an iron core provided on a rotating shaft), but a housing is formed by protruding a mounting portion of a bottom bearing outward. .

  Also in the coreless motor, similarly to Patent Document 1, a housing is known in which a mounting portion of a bottom bearing protrudes outward.

JP 2001-309608 A

  However, in the above-described prior art, since the magnet holder is fitted into the bottom center portion of the housing, there is a possibility that the magnet holder cannot be stably mounted unless the projecting amount to the outside of the bottom center portion is a predetermined amount. is there. For this reason, the amount of protrusion at the center of the bottom of the housing increases, and the size of the rotating shaft becomes unnecessarily long by the amount of protrusion, which limits the miniaturization of the motor.

  Accordingly, an object of the present invention is to provide a coreless motor capable of downsizing the motor and stably mounting the magnet holder.

In order to solve the above-mentioned problem, the invention described in claim 1 includes a housing, a rotating shaft disposed in the housing, a cylindrical coil body fixed to the rotating shaft and rotating integrally with the rotating shaft. A magnet and a magnet holder arranged on the inner peripheral side of the coil body, a bottom bearing arranged on the bottom side of the housing to rotatably hold the bottom side end of the rotating shaft, and a rotating shaft arranged on the head side of the housing A head-side bearing that rotatably holds the head side end of the housing, and the bottom of the housing is recessed from the outside to the inside with the center of the bottom surface protruding toward the inside of the housing, and the inner circumference side of the magnet holder is Yes and the fitted portion is provided to be fitted, the fitted portion recess has a bottom surface, the bottom surface of the recess Yes in abutment disposed bottom side bearing on the housing inner magnet holder Characterized in that it locks the bottom bearing thereby fitted into the fitting portion of the housing bottom within Ujingu.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the fitted portion of the housing bottom is formed by closing a recessed portion in which the outer surface of the housing is recessed with a cap.

  According to the first aspect of the present invention, in the housing, since the portion to be fitted with the magnet holder protrudes from the inside of the housing, there is no protrusion to the outside of the housing, so that the motor outer shape is reduced. be able to. Further, since the portion to be fitted with the magnet holder protrudes from the inside of the housing, the rotation shaft can be made shorter than the conventional one, and the weight of the rotation shaft can be reduced to reduce the weight of the entire motor.

  In addition, since the mating part with the magnet holder protrudes from the inside of the housing, it is difficult to be restricted by the external dimensions of the motor even if the fitting amount with the magnet holder is long, and the degree of freedom in design is high. By taking a long fitting amount with the magnet holder, the mounting strength of the magnet holder can be increased, and the magnet holder can be mounted stably. Moreover, since the attachment strength of the magnet holder is high, the shock resistance is excellent.

  By increasing the amount of fitting with the magnet holder in the mated part to increase the mounting strength, the magnet holder can be prevented from swinging and misaligned to prevent contact between the magnet and the coil body, with smooth drive. In addition, a long-life coreless motor can be obtained.

  According to the second aspect of the present invention, the same effects as those of the first aspect of the invention can be achieved, and dust and water pools in the recesses on the bottom outer surface of the housing can be prevented.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 is a longitudinal sectional view of a coreless motor according to the present embodiment, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a sectional view taken along the line AA showing only the housing.

  A coreless motor 1 according to the present embodiment is a motor used as a power source of an electric machine, and includes a housing 3, a rotating shaft 5, a coil body 7, a magnet 9, and a magnet holder 11.

  The housing 3 is formed into a bottomed cylindrical shape by press molding, and a head cover assembly 13 is attached to the opening side (head side). A head-side bearing 15 and a power supply terminal 17 are attached to the head cover assembly 13.

  The bottom 19 of the housing 3 is provided with a fitted portion 21 that protrudes toward the inside of the housing 3 with the outer surface of the central portion in the radial direction recessed from the outside to the inside. The fitted portion 21 has a shape in which the center portion of the bottom 19 of the housing 3 protrudes slightly outward, and a gap S is formed between the bottom end 5 a of the rotating shaft 5.

  A cylindrical sleeve 27 made of a magnetic material is fitted to the inner peripheral surface of the housing 3, and the magnetic material on the peripheral surface of the housing is thickened to prevent magnetic leakage.

  Further, a cap 31 is mounted on the bottom 19 of the housing 3 to close the outer surface recess 33 by the fitted portion 21.

  The rotating shaft 5 is rotatably held by a bottom side bearing 23 provided on the bottom side and a head side bearing 15 provided on the head side. An adapter 25 is attached to the end of the rotary shaft 5 on the head side, and a rotation output is transmitted from the adapter 25 to an external mechanism.

  The bottom bearing 23 is disposed in contact with the fitted portion 21 of the housing 3 and is latched by a latching portion 35 formed on the magnet holder 11, so that the fitted portion 21 and the magnet holder 11 are fitted. It is fixed.

  The coil body 7 is formed in a cylindrical shape, and is disposed on the outer peripheral side of the magnet 9 with a gap from the magnet 9. The coil body 7 is fixed to the rotating shaft 5 and rotates together with the rotating shaft 5. The coil body 7 is supplied with power from a brush 28 via a commutator 24.

  The magnet 9 is fixed to the outer periphery of the magnet holder 11. The magnet holder 11 has a substantially cylindrical shape, and is formed with a step portion 29 in which the inner peripheral diameter of the bottom side end portion is reduced. The bottom side end portion of the magnet holder 11 is in contact with the inner surface of the bottom 19 of the housing 3 and is fitted to the outer peripheral surface of the fitted portion 21 at the stepped portion 29.

  Next, the operation and effect of the coreless motor 1 according to the present embodiment will be described. When the coreless motor 1 is assembled, the bottom bearing 23 is locked to the locking portion 35 provided on the bottom side of the magnet holder 11 with the magnet 9 fixed to the outer periphery, and the bottom side of the magnet holder 11 is formed on the housing 3. The housing 3 is mounted by fitting into the fitting portion 21. Then, after the bottom end of the rotating shaft 5 to which the coil body 7 is fixed is inserted into the bottom bearing 23, the head cover assembly is mounted on the head side of the rotating shaft 5 and fixed to the housing 3.

  When a current is supplied to the brush 28, the coreless motor is driven by the commutator 24 that is in sliding contact with the brush 28, and the coil body 7 is rotated by the electromagnetic force generated between the magnet 9 and the coil body 7. Rotate with 5

  According to the coreless motor 1 according to the present embodiment, the housing 3 is formed with the fitted portion 21 with the magnet holder 11 protruding from the inside of the housing 3, so that it is compared with the case of protruding outward. Thus, the length of the housing 3 in the rotation axis direction can be shortened, and the coreless motor 1 can be downsized.

  Since the fitted portion 21 with the magnet holder 11 protrudes from the inside of the housing 3, the size of the rotating shaft 5 can be shortened to reduce the weight of the rotating shaft 5 and the overall weight of the coreless motor can be reduced. it can.

  Since the portion 21 to be fitted with the magnet holder 11 protrudes from the inside of the housing 3, even if the fitting amount with the magnet holder 11 is long, it is difficult to be restricted by the dimension in the rotation axis direction, and the design is free. The strength of the magnet holder 11 and the rotating shaft 5 can be increased while the degree is high. Thus, impact resistance can be improved by increasing the attachment strength of the magnet holder 11 and the rotating shaft 5. In addition, when an impact resistance experiment of the coreless motor 1 according to the present embodiment was performed, there was no abnormality in the inclination of the rotating shaft 5 even when an impact of 10G was applied.

  In particular, by making the fitting amount between the magnet holder 11 and the fitted portion 21 long, it is possible to reduce the shake and displacement of the magnet holder 11 and the rotating shaft 5, thereby preventing contact between the magnet 9 and the coil body 7. It is possible to obtain a smooth and long-life motor drive.

  Since the recess 33 corresponding to the fitted portion 21 of the housing 3 is closed with the cap 31, it is possible to prevent dust and water pools from being generated in the recess formed on the outer surface of the housing.

  Since the magnetic sleeve 27 is disposed on the peripheral surface of the housing 3, the thickness of the housing 3 can be reduced.

  By attaching the magnetic sleeve 27 to the inner peripheral surface of the housing 3, water or the like can be prevented from entering between the magnetic sleeve 27 and the housing 3 as compared with the case where the magnetic sleeve 27 is attached to the outer peripheral surface of the housing 3. Further, generation of rust and rust juice can be prevented, and joining means such as welding can be made unnecessary.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

  The to-be-fitted part 21 is not limited to a columnar projecting shape, but may be a prismatic shape, and the shape is not limited.

  A plurality of fitted portions 21 may be provided.

It is a longitudinal cross-sectional view of the coreless motor which concerns on this Embodiment. It is AA sectional drawing of FIG. It is AA sectional drawing of FIG. 1 which takes out and shows only a housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coreless motor 3 Housing 5 Rotating shaft 7 Coil body 9 Magnet 11 Magnet holder 15 Head side bearing 21 Fit part 23 Bottom side bearing 31 Cap

Claims (2)

A housing, a rotating shaft disposed in the housing, a cylindrical coil body fixed to the rotating shaft and rotating integrally with the rotating shaft, a magnet and a magnet holder disposed on the inner peripheral side of the coil body, and a housing A bottom side bearing that is disposed on the bottom side of the rotary shaft and rotatably supports the bottom side end of the rotary shaft, and a head side bearing that is disposed on the head side of the housing and rotatably holds the head side end of the rotary shaft. the projected toward the inside housing bottom to the recessed inward central portion of the bottom surface from the outside, Yes and the fitted portion is provided with an inner circumferential side of the magnet holder is fitted, the fitted portion recess has a bottom surface, this is the bottom surface of the recess Yes in abutment disposed bottom side bearing on the housing inner magnet holder match fitted in the fitted portion of the housing bottom in the housing Coreless motor, characterized in that it locks the bottom bearing with.
  The coreless motor according to claim 1, wherein a recessed portion in which an outer surface of the housing is recessed is closed with a cap at a fitting portion of the housing bottom.

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