JPH0711882U - Coreless motor - Google Patents

Abstract

(57) [Summary] A cylindrical housing, a cylindrical magnet provided inside the housing along the axial direction, a spindle rotatably provided in the inner cylindrical portion of the magnet, and one end of the spindle. A disk-shaped rotor that is provided in the housing and that rotates together with the spindle, and a coil that is disposed in the space between the inner cylindrical surface of the housing and the outer cylindrical surface of the magnet and has one end connected to the rotor. It is an object of the present invention to provide a coreless motor that can easily improve the coaxiality of the outer diameter and the inner diameter of the magnet, can be easily assembled, can reduce the magnetic gap, and can reduce the cost. A sleeve main body formed on the inner cylindrical surface of the magnet 22, coaxial with the outer cylindrical surface of the magnet 22, and having stepped portions 23c, 23d at both ends to which bearings 24, 25 engage. 23a and the sleeve body 23a, and a locking portion 23 that is locked to the end surface of the housing 21.
A resin sleeve 23 made of b is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cylindrical housing, a cylindrical magnet provided inside the housing along the axial direction, a spindle rotatably provided on an inner cylindrical portion of the magnet, and one of the spindles. Is provided in the space between the cylindrical rotor that is provided at the end of the housing and that rotates with the spindle, and the inner cylindrical surface of the housing and the outer cylindrical surface of the magnet, and one end is connected to the rotor. The present invention relates to a coreless motor including a coil, and particularly to a coreless motor suitable for a motor having a small diameter such as a vibration motor for a pager.

[0002]

[Prior art]

 Next, a conventional example will be described with reference to the drawings. FIG. 3 is a diagram showing a cross section of an example of a conventional coreless motor.

In the figure, reference numeral 1 is a cylindrical housing made of a magnetic material. One end surface of the housing 1 is open, and a hole 1a having a cylindrical portion projecting inside the housing 1 is formed at the center of the other end surface.

Reference numeral 2 denotes a metal cylindrical support that is mounted in the housing 1 so as to be substantially aligned with the center axis of the housing 1, and is mounted in the cylindrical portion of the hole 1 a of the housing 1 by press fitting or the like. . Bearings 3 and 4 are attached to both ends of the support 2, and the bearings 3 and 4 are provided so as to penetrate the inner cylindrical portion of the support 2. One end side is a hole 1a of the housing 1. A spindle 5 disposed outside the housing 1 is rotatably supported on the other end side.

A cylindrical magnet 6 is attached to the outer cylindrical portion of the support 2 with an adhesive or the like. Between the magnet 6 and the other end surface of the housing 1, in order to prevent the magnetic flux of the magnet 6 from wrapping around the housing 1, the outer cylinder surface of the support 2 is fitted and made of a non-magnetic material. A ring-shaped spacer 7 is arranged. A magnetic circuit is formed by the magnet 6 and the housing 1.

A cylindrical rotor 9 is attached to the other end of the spindle 5 by using a retaining ring 8. The rotor 9 has a cylindrical surface that is attached to the inner cylindrical surface of the housing 1 so as to cover the magnet 6 and is disposed in the magnetic gap of the magnetic circuit formed by the magnet 6 and the housing 1. A cylindrical coil 10 is attached.

A brush holder 11 is fitted to an open surface, which is one end of the housing 1. The brush holder 11 is provided with a brush 12 connected to a lead wire 13 that supplies a current from the outside of the coreless motor.

A commutator 14 with which the brush 12 slides is provided on the rotor 9 described above. Reference numeral 15 is a coil / commutator joint portion that connects the commutator 14 and the coil 10.

A retaining ring 16 that prohibits the spindle 5 from moving in the axial direction is provided on one end side of the spindle 5 protruding to the outside of the housing 1. Next, the operation of the coreless motor having the above structure will be described. When a current is applied to the lead wire 13, the current is supplied to the coil 10 via the brush 12, the commutator 14, and the coil / commutator coupling portion 15. Since the coil 10 provided on the rotor 9 side is arranged in the magnetic gap of the magnetic circuit composed of the magnet 6 and the housing 1, the coil 10 has a thrust force (in the case of the coreless motor of this conventional example, the coil 10 is rotated). Force) and the rotor 9 rotatably supported via the bearings 3 and 4 rotates.

[0010]

[Problems to be solved by the device]

 By the way, the cylindrical magnet 6 used in the coreless motor having the above-described structure is manufactured by a so-called sintering method in which metal powder particles are heated and combined, and the outer cylinder surface of this sintered product is polished centerlessly. Be served. Therefore, the center of the inner diameter and the center of the outer diameter of the cylinder deviate from each other, that is, the concentricity varies.

When attaching such a magnet to the support 2, the following method is used. The outer diameter of the magnet 6 is used as a reference, and the adhesive is applied to the outer cylindrical surface of the support 2 to adjust the outer diameter of the magnet 6 and the coaxiality of the support 2.

The outer diameter of the magnet 6 is set small in consideration of the eccentricity of the outer cylindrical surface of the magnet 6. In the case of such a method, the following problems occur.

A step of producing coaxiality between the magnet 6 and the support 2 is required. Since the outer diameter of the magnet 6 is set to be small, the magnetic gap length becomes large and the motor characteristics cannot be fully exhibited.

Further, in order to mount the magnet 6 on the housing 1, a support 2 is necessary. Further, in order to prohibit the movement of the bearings 3 and 4, the bearings 3 and 4 are formed with flanges 3 a and 4 a. Must. Therefore, it causes a cost increase.

The present invention has been made in view of the above problems, and an object thereof is to easily improve the coaxiality of the outer diameter and the inner diameter of a magnet, to easily assemble, to reduce the magnetic gap, and It is to provide a coreless motor that can reduce costs.

[0016]

[Means for Solving the Problems]

 The invention as set forth in claim 1 for solving the above-mentioned problems, a cylindrical housing, a cylindrical magnet provided along the axial direction inside the housing, and an inner cylinder portion of the magnet rotatably provided. And a cylindrical rotor fixed to one end of the spindle and rotating with the spindle, and arranged in a space between the inner cylindrical surface of the housing and the outer cylindrical surface of the magnet. A coreless motor having a coil connected to the rotor at an end thereof is formed on an inner cylindrical surface of the magnet and coaxially with an outer cylindrical surface of the magnet, and bears at both ends. And a resin sleeve formed of a sleeve body formed with a step portion for engaging with a ring and a locking portion continuous with the sleeve body and locked to an end surface of the housing.

According to a second aspect of the invention, the resin sleeve in the first aspect of the invention is formed by insert molding. According to the third aspect of the invention, a magnetic material is mixed in the resin sleeve according to the first or second aspect of the invention.

[0018]

[Action]

 In the coreless motor according to the first and second aspects of the invention, by providing the sleeve main body of the resin sleeve, the coaxiality between the outer diameter of the magnet and the inner diameter of the resin sleeve is improved, and the magnetic gap of the magnetic circuit is minimized. Can be set. Moreover, since the magnet with the resin sleeve formed thereon can be attached to the housing without the correction of the concentricity, the assembly becomes easy.

Further, since the step portion with which the bearing is engaged is provided, the flange portion of the bearing becomes unnecessary. Furthermore, the support can be eliminated by providing the locking portion of the resin sleeve.

In the coreless motor according to the third aspect of the present invention, the magnetic material is mixed in the resin sleeve to compensate for the change in the magnetic flux density flowing in the magnetic circuit and prevent the output of the coreless motor from decreasing.

[0021]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG.

In these figures, 21 is a cylindrical housing made of magnetic material. One end surface of the housing 21 is open, and a hole 21a is formed at the center of the other end surface.

Reference numeral 22 is a cylindrical magnet provided inside the housing 21 along the axial direction. On the inner cylindrical surface of the magnet 22, a resin sleeve 23 is insert-formed with a sleeve body 23a coaxial with the outer cylindrical surface of the magnet 22 and a locking portion 23b connected to the sleeve body 23a.

Stepped portions 23c and 23d are formed at both ends of the sleeve body, and bearings 24 and 25 are engaged with these stepped portions 23c and 23d to prohibit axial movement. In this embodiment, the resin sleeve 23 is mixed with a magnetic material such as zinc, iron powder and aluminum.

A magnetic circuit is formed by the magnet 22, the resin sleeve 23, and the housing 21. Bearings 24 and 25 are attached to the inner cylindrical portion of the resin sleeve 23. The bearings 24 and 25 are provided so as to penetrate the inner cylindrical portion of the resin sleeve 23, and one end portion side is the housing 21. On the other end side, a spindle 26 disposed in the housing 21 is rotatably supported.

A disc-shaped rotor 28 is attached to the other end of the spindle 26 using a retaining ring 27. The rotor 28 has a cylindrical surface, which is attached to the inner cylindrical surface of the housing 21 so as to cover the magnet 22 and is arranged in a magnetic gap of a magnetic circuit including the magnet 22 and the housing 21. A cylindrical coil 29 is attached.

A brush holder 31 is fitted to an open surface that is one end of the housing 21. The brush holder 31 is provided with two brushes 32 connected to a lead wire 33 for supplying a current from the outside of the coreless motor.

The rotor 28 is provided with three commutators 34 with which the brushes 32 are in sliding contact. Reference numeral 35 denotes a coil / commutator joint portion that connects the commutator 34 and the coil 30.

A retaining ring 36 that prohibits the axial movement of the spindle 26 is provided on one end side of the spindle 26 protruding to the outside of the housing 21. Next, the operation of the coreless motor having the above structure will be described. When a current is applied to the lead wire 33, the current is supplied to the coil 29 via the brush 32, the commutator 34, and the coil / commutator coupling portion 35. Since the coil 29 provided on the rotor 28 side is arranged in the magnetic gap of the magnetic circuit composed of the magnet 22, the resin sleeve 23, and the housing 21, the thrust force is applied to the coil 29 (the coreless motor of this embodiment). In this case, the rotational force) is generated, and the rotor 29 rotatably supported via the bearings 24 and 25 rotates.

According to the above configuration, the sleeve body 23 a of the resin sleeve 23 formed on the inner cylindrical surface of the magnet 22 and coaxial with the outer cylindrical surface of the magnet 22 is formed by the insert molding method. The coaxiality between the outer diameter of the magnet 22 and the inner diameter of the resin sleeve 23 is improved, and the magnetic gap of the magnetic circuit can be set to the minimum.

Even if the magnet 22 having the resin sleeve 23 formed thereon is attached to the housing 21 without the correction of the coaxiality, the coaxiality is maintained, so that the outer cylindrical surface of the support described in the conventional example is applied. It is not necessary to adjust the outer diameter of the magnet and the support coaxially by adjusting the adhesive to make assembly easier.

Further, since the bearings 24 and 25 are locked to the stepped portions 23c and 23d of the sleeve main body 23, a structure such as a collar for prohibiting the axial movement of the bearings in the bearings is unnecessary, and the cost can be reduced. You can

Further, conventionally, a support was used to attach the magnet 22 to the housing, but in the present embodiment, the cost can be reduced by using the resin sleeve 23 which can be manufactured with an inexpensive material. it can.

In this embodiment, by mixing the magnetic material in the resin sleeve 23, the change of the magnetic flux density flowing in the magnetic circuit is compensated and the output of the coreless motor is prevented from being lowered.

[0035]

[Effect of device]

 As described above, according to the present invention, the step is formed on the inner cylindrical surface of the magnet, is coaxial with the outer cylindrical surface of the magnet, and has stepped portions at both ends for engaging the bearings. By providing a resin sleeve that is connected to the sleeve body and the locking portion that is locked to the end surface of the housing, the resin sleeve is formed on the inner cylindrical surface of the magnet and is coaxial with the outer cylindrical surface of the magnet. By using a resin sleeve composed of a sleeve body that is connected to the sleeve body and a locking portion that is locked to the end surface of the housing, and supporting the spindle through a bearing that engages with the inner cylindrical portion of the resin sleeve. It is possible to realize a coreless motor in which the outer diameter and inner diameter of the magnet can be easily improved, assembly is easy, the magnetic gap can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a view showing a cross section of an example of a conventional coreless motor.

[Explanation of symbols]

 21 Housing 22 Magnet 23 Resin Sleeve 23a Sleeve Main Body 23b Locking Part 24,25 Bearing 26 Spindle 28 Rotor 29 Coil

Claims (3)

[Scope of utility model registration request] 1. A cylindrical housing (21), a cylindrical magnet (22) provided along the axial direction inside the housing (21), and an inner cylinder portion of the magnet (22). A possible spindle (26) and a cylindrical rotor (28) fixed to one end of the spindle (26) and rotating with said spindle (26)
And a coil (29) disposed in the space between the inner cylindrical surface of the housing (21) and the outer cylindrical surface of the magnet (22) and having one end connected to the rotor (28). The coreless motor comprises a magnet (22) formed on an inner cylindrical surface of the magnet (22) and formed coaxially with an outer cylindrical surface of the magnet (22), and bearings (24, 25) are engaged at both ends thereof. Step (23c,
23d) is formed on the sleeve body (23a) and the sleeve body (23a) is connected to the housing (2).
1) A coreless motor, characterized in that a resin sleeve (23) comprising a locking portion (23b) locked to the end surface of (1) is provided. 2. The coreless motor according to claim 1, wherein the resin sleeve is formed by insert molding. 3. The coreless motor according to claim 1, wherein a magnetic material is mixed in the resin sleeve.