JP3207302B2 - Linear pulse motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear pulse motor.

[0002]

2. Description of the Related Art FIG. 7 is a longitudinal sectional view of a conventional well-known cylinder type linear pulse motor.

[0003] In FIG. 7, stator cores 101, 102, 102 of a stator 100 of the cylinder type linear pulse motor are shown.
Each of 103 and 104 has a stepped ring shape whose outer peripheral edge is thickened in the thickness direction, and a plurality of stator small teeth 105 are arranged on the inner peripheral surface at a constant pitch in the axial direction. Have been. And these stator cores 101, 102,
103 and 104 are supported and framed by a frame 106.

A ring-shaped winding 106 is held in a ring-shaped groove formed by assembling the stator cores 101 and 102 with the outer peripheral edges thereof abutting each other. Similarly, the stator cores 103 and 1
A ring-shaped winding 107 is sandwiched in a ring-shaped groove formed between the wires 04.

The cylinder type linear pulse motor is composed of the stator cores 101 and 102 and the ring-shaped winding 10.
6 to form one phase, and the stator cores 103 and 1
04 and the ring-shaped winding 107 form another phase, and constitute a total of two phases. The ring-shaped permanent magnet 108 is used for the stator core 1 forming the two phases.
01 and 102 and the stator cores 103 and 104, and are magnetized in the axial direction of the mover 109.

The moving element core 110 of the moving element 109 has a cylindrical shape, and has a plurality of moving element small teeth 111 on its outer peripheral surface.
Are arranged at a constant pitch in the axial direction. The moving element 109 is fixed to the bearing 1 by the brackets 112 and 113.
It is supported movably in the axial direction via 14 and 115.

The stator small teeth 105 and the movable small teeth 111
Is in the following positional relationship. That is, the stator core 1
The stator small teeth 105 disposed on the moving child small teeth 111
The stator core 103
Are located at positions shifted in the axial direction by 2/4 of the tooth pitch as compared with the stator core 104. Further, the stator small teeth 105 provided on the stator core 102 have a tooth pitch of 1 in comparison with the stator core 104.
It is at a position shifted in the axial direction by / 4. Further, the stator small teeth 105 provided on the stator core 101 are located at positions shifted from the stator core 104 in the axial direction by 比較 of the tooth pitch.

With this configuration, the cylinder type linear pulse motor constitutes a two-phase hybrid type linear pulse motor.

However, the cylinder type linear pulse motor having the above configuration has a drawback that the thrust is low because the winding accommodating portion cannot be made large and the number of ampere conductors per phase cannot be made large. Also, the stator cores 101, 1
04 is a permanent magnet 10 rather than the stator cores 102 and 103.
8, the magnetic circuit is not uniform,
There was also a disadvantage that the thrust was different depending on the phase to be excited. Furthermore, in principle, each phase is arranged in the axial direction, so that the length of the motor in the axial direction is long. Further, since the permanent magnet 108 is on the stator 100 side,
At the same time as requiring a motor casing,
Is required to be longer than the axial length of the stator 100, so that the inertia of the moving element 109 is increased. At the same time, there is a drawback that it is difficult to achieve multiphase.

For this reason, a linear pulse motor that solves these drawbacks has already been proposed by the present inventor, and the shape of a stator iron plate forming a stator core is described below.
It is disclosed as follows. That is, on the other hand, when k is a positive integer and m is the number of phases, the stator iron plate forming the stator core has 2 km salient poles, and the salient poles are In the circumferential direction, m sets of salient poles forming the tooth tips of the stator small teeth, and m sets of salient poles forming the tooth bottoms are arranged in this order to form one set, and k sets exist. It is constituted in. (Japanese Patent Application No. 4-332762, Japanese Patent Application No. 4-340280)

On the other hand, k is an integer of 1 or more, m is the number of phases, n
Is an integer of m / 2 or less and the value closest to m / 2, the stator iron plate has km salient poles,
The tip of the salient pole facing the moving element is, when viewed from the moving element side, a set of n salient poles having a small inner radius and (mn) salient poles having a large inner radius arranged in this order. And k pairs are formed. (Japanese Patent Application 5
-100810 number)

[0012]

However, the linear pulse motor having the above configuration has the following problems. (1) In the stator iron plate, salient poles having a small inner radius and salient poles having a large inner radius are arranged in a predetermined arrangement.
When the end brackets are assembled with the inner diameter portions of the stator at both ends in the axial direction of the stator as fitting holes, the length of the end bracket fitting portion fitted into the inner diameter portion is determined by the teeth of the stator teeth. Need to be longer than the pitch,
The axial length of the motor increases. Further, in the type in which the permanent magnet is provided on the movable element, the effective length of the stator is reduced correspondingly, and as a result, the stroke length is reduced. (2) When inserting the mover into the stator or pulling it out of the stator,
Since the small teeth disposed on the stator and the moving element extend in the right-angle direction, the small teeth are engaged with each other, and the workability in assembling and disassembling is poor.

The present invention has been made in view of such a point.
The object of the present invention is to solve the above-mentioned problem, and to fix the inner diameter portions of the stator at both ends in the axial direction of the stator as fitting holes, each end bracket is assembled, and to adjust the length of the fitting portion of the end bracket to the stator. An object of the present invention is to provide a linear pulse motor which can be shorter than the tooth pitch of the small teeth, and which has good workability in assembling and disassembling the stator and the moving element.

[0014]

According to an aspect of the present invention, there is provided an image forming apparatus comprising: a plurality of salient poles radially inwardly arranged at an equal pitch angle; A stator having a stator core in which a plurality of stator teeth are formed in an axial direction on a peripheral surface, and a stator core which is supported in the stator so as to be movable in the axial direction and has an outer peripheral surface on which the stator teeth are formed. A moving element having a moving element core formed with a plurality of moving element small teeth at an equal pitch in the axial direction, and a middle of the stator core, or a middle of the moving element core, A stator magnet is formed by sequentially rotating and laminating stator iron plates of the stator core at an integral multiple of an equal pitch angle of the salient poles. Wherein the stator iron plate has a small inner radius forming the tip of the stator small teeth. And poles, and the large radius of the salient poles among which form the tooth bottoms of the stator teeth, in the linear pulse motor disposed in a predetermined arrangement, are as follows.

(1) A plurality of stator iron plates having all of the salient poles formed with the same inner radius are added to a plurality of stator iron plates at both end portions in the axial direction of the stator core, and the inner diameter portions are fitted into holes. In addition, forming a fitting portion that fits into the fitting hole in the end bracket that is supported at both ends so that the mover can be moved in the axial direction via a bearing,
The moving element is fitted with each other, and at least the tooth space of the moving element small teeth is filled with a non-magnetic material to form a single cylindrical surface on the outer peripheral surface of the moving element.

(2) At both ends in the axial direction of the stator core, the inner radii of all the salient poles of the stator iron plate to be added form salient poles forming the tip of the stator teeth. Is characterized by the same inner radius.

[0017]

In the linear pulse motor constructed as described above, a plurality of stator iron plates each having all the salient poles formed with the same inner radius are added to each other at both axial ends of the stator core. And the inner diameter portion is used as a fitting hole.
The fitting portion of each end bracket can be fitted. In addition, by filling non-magnetic material into the tooth space of the small teeth of the movable element and making the outer peripheral surface of the movable element a single cylindrical surface, the stator and the movable element can be mounted and disassembled when the linear pulse motor is assembled. Can be prevented from meshing with each other.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of the linear pulse motor of the present invention, and FIG.
FIG. 2 is a transverse sectional view taken along line II-II.

In FIG. 1 and FIG. 2, five salient poles 1 are provided on a stator core 10 and a core end 10a of the stator 1.
1, 12, 13, 14, and 15 are arranged at equal pitch angles, and a plurality of stator small teeth 16 (tooth tip 16a and tooth bottom 16a) are arranged at equal pitch in the axial direction on the inner peripheral surface of the stator core 10. 16
b) is provided. In addition, these five salient poles 11,
,... 15, respectively, the stator windings W1, W2,
W3, W4 and W5 are individually wound.

The core ends 10a provided at both ends in the axial direction of the stator core 10 have inner diameter portions 10b as fitting holes, and fitting portions 17a, 18a formed on end brackets 17, 18 are provided with fitting portions 17a, 18a. It is fitted to the inner diameter portion 10b.

On the other hand, the moving element 2 in the stator 1 is supported by the brackets 17 and 18 through bearings 19 and 20 so that the moving element 2 has the same axis as the stator core 10 and is movable in the axial direction. . The movable element 2 is provided with magnetic pole cores 22a and 22b on a shaft 21 and a ring-shaped permanent magnet 23 sandwiched between the magnetic pole cores 22a and 22b and magnetized in the axial direction. I have. And the magnetic pole core 22
a, a plurality of movable teeth 24 at the same pitch in the axial direction facing the stator teeth 16.
(The tooth tip 24a, the tooth bottom 24b, and the tooth groove 24c) are arranged, and the arrangement is as shown in FIG.

In the outer peripheral surface of the moving element 2, a tooth groove portion 24c including at least a tooth bottom portion 24b of the moving element small teeth 24.
A non-magnetic material 25 is provided on the outer peripheral portion of the permanent magnet 23.
And the outer peripheral surface of the mover 2 forms a single cylindrical surface.

FIG. 3 shows an example of the stator iron plate 30 forming the stator core 10. 3, the salient poles P1 and P3 of the stator iron plate 30 are
6 are salient poles having a small inner radius forming the tooth tip portion 16a, and salient poles P2, P4, and P5 are salient poles having a large inner radius forming the tooth bottom 16b of the stator small teeth 16.

The circumferential arrangement of each of the salient poles P1 to P5 includes salient poles P1, P3 forming the tooth tip 16a and salient poles P2, forming the tooth bottom 16b.
As shown in FIG. 3, salient poles P4 and P5, which partially form the tooth bottom 16b, are continuously arranged with P4 and P5, as shown in FIG.

For this reason, the salient poles P1 and P3 forming the tooth tip 16a are disposed at an angle of 144 degrees, and the stator core 10
It is formed by stacking while rotating by 144 degrees for each sheet.

FIG. 4 shows an example of a stator iron plate 31 forming the core ends 10a at both ends of the stator core 10. The core end 10a is composed of a plurality of sheets (this embodiment). In this case, three (3) stator iron plates 31 are added. In FIG. 4, all the salient poles P of the stator iron plate 31 are shown.
1, P2,..., P5 have the same inner radius, and have the same inner radius as the salient poles forming the tooth tips 16a of the stator small teeth 16, and an inner diameter portion 10b as a fitting hole is formed. Therefore, when finishing the inner diameter of the stator core 10, the tip 16a and the inner diameter portion 10b as a fitting hole can be simultaneously processed.

FIG. 5 shows the salient poles 11, which are formed when the stator iron plates 30 are stacked while rotating twice the pitch angle of the salient poles (72 degrees), that is, 144 degrees.
The appearance (shape) of the small stator teeth 16 of 12, 13, 14 and 15 is viewed from the side of the moving element 2. A hatched portion indicates a portion having a small inner radius, that is, a tooth tip portion 16a and an inner diameter portion 10b as a fitting hole, and a non-hatched portion indicates a tooth bottom portion 16b. Incidentally, when the t ₀ to the thickness of the stator iron plates 30 and 31,
The tooth pitch of the stator small teeth 16 is 5t ₀ , and the tooth tip 16a
Has a tooth thickness of 2t ₀ , and the length of the inner diameter portion 10b as a fitting hole is 3t _{0 in} this embodiment.

FIG. 6 shows the inner diameter portion 1 as a fitting hole.
The appearance (shape) of the stator small teeth 16 when 0b is not provided is viewed from the side of the mover 2. From FIG. 6, when the stator inner diameter portions at both ends of the stator core 10 are used as fitting holes, each of the salient poles 11, 12,.
In order to hold the end brackets 17, 18, the fitting portions 17 of the end brackets 17, 18 are required.
a, 18a is set to the tooth pitch 5t ₀ of the stator small teeth 16.
Need to be longer.

However, according to the present embodiment, the end brackets 17 and 18 are provided at both ends of the stator core 10 with the core end portions 10a having the inner diameter portions 10b as fitting holes. Fitting part 17
a, 18a, the tooth pitch 5 of the stator small teeth 16
It can be shorter than t _{0, and} the core length (length in the axial direction) of the stator core 10 can be effectively used.

The tooth space 24c of the movable element small teeth 24
Is filled with a non-magnetic material, so that the stator teeth 16
When the motor is assembled and disassembled, the movable element small teeth 24 can be prevented from meshing with each other, and workability can be improved.

In this embodiment, the inner radius of the inner diameter portion 10b of the stator iron plate 31 forming the core end portion 10a is determined by the number of teeth of the stator teeth 16 of the stator iron plate 30 forming the stator core 10. Although the inner radius is set to be the same as the inner radius of the salient pole forming the tip portion 16a, it is of course possible to make the inner radius larger than that.

The technique of the present invention is not limited to the technique in the above-described embodiment, but may be implemented by means of other modes having the same function. Can be changed or added.

[0033]

As is apparent from the above description, according to the linear pulse motor of the present invention, all the salient poles have the same inner radius at both ends in the axial direction of the stator core. A plurality of stator iron plates are stacked, the inner diameter portion is formed in a fitting hole, and the movable member is axially movable via a bearing in an end bracket that is supported at both ends. Forming a fitting portion that fits into the hole to fit each other, and the outer peripheral surface of the mover has a single cylindrical surface in which at least the tooth grooves of the mover small teeth are filled with a non-magnetic material. The end brackets are assembled with the inner diameter portions of the stator at both ends in the axial direction of the stator as fitting holes, and the length of the fitting portions of the end brackets is set to the tooth pitch of the stator teeth. Can be shorter. At the same time, when the mover is inserted into or pulled out of the stator, the small teeth of the stator and the small teeth of the mover are prevented from meshing with each other, so that the stator and the mover are assembled. The workability of disassembly is improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a linear pulse motor according to the present invention.

FIG. 2 is a cross-sectional view taken along line II-II of FIG.

FIG. 3 is a plan view of a stator iron plate forming a stator core.

FIG. 4 is a plan view of a stator iron plate forming a core end;

FIG. 5 is a development view of a stator tooth portion formed when the stator iron plate of FIG. 3 is rotated and stacked by an integral multiple of an equal pitch angle of salient poles (144 degrees), as viewed from the mover side.

FIG. 6 is a developed view of the stator small tooth portion in a case where an inner diameter portion as a fitting hole is not provided in FIG.

FIG. 7 is a longitudinal sectional view of a conventional cylinder type linear pulse motor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 stator 2 mover 10 stator core 10a core end 10b inner diameter portion (fitting hole) 11, 12,... 15 salient pole 16 stator small teeth 16a tooth tip 16b tooth bottom 17, 18 end bracket 17a, 18a fitting portion 21 shaft 22a, 22b magnetic pole core 23 permanent magnet 24 mover small teeth 24c tooth groove 25 nonmagnetic material 30, 31 stator iron plate P1, P2,... P5 salient pole

Continuation of the front page (56) References JP-A-64-19959 (JP, A) JP-A-49-116514 (JP, A) JP-A-1-64943 (JP, U) JP-A-50-48914 (JP) , U) Actual opening 1975-84608 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 41/02-41/035 H02K 1/00-1/16 H02K 1/18 -1/26 H02K 1/28-1/34 H02K 5/00-5/26 H02K 15/00-15/02 H02K 15/04-15/16

Claims (2)

(57) [Claims] 1. A plurality of salient poles radially inwardly arranged at an equal pitch angle, and a plurality of stator teeth are formed on an inner circumferential surface of the salient poles in an axial direction. A stator having a stator core, and a plurality of movable elements which are supported in the stator so as to be movable in the axial direction and which are opposed to the stator teeth on the outer peripheral surface at a constant pitch in the axial direction. A stator having a rotor core having teeth formed thereon, and a permanent magnet axially magnetized and sandwiched between the stator core and the middle of the stator core; Is formed by sequentially rotating and laminating the stator iron plate of the stator core at an angle that is an integral multiple of the equal pitch angle of the salient poles,
In the stator iron plate, salient poles having a small inner radius forming the tooth tips of the stator teeth and salient poles having a large inner radius forming the tooth roots of the stator teeth are arranged in a predetermined arrangement. In the linear pulse motor to be arranged, at the axial end portions of the stator core, a plurality of the stator iron plates in which all the salient poles are formed with the same inner radius are added, and the inner diameter portion thereof is Along with being formed in a fitting hole, the mover can be axially moved via a bearing,
The end brackets supported at both ends are formed with a fitting portion that fits into the fitting hole, and are fitted to each other, and the outer peripheral surface of the mover has at least a tooth groove portion of the mover small teeth. A linear pulse motor characterized in that it is filled with a non-magnetic material to form a single cylindrical surface. 2. Inner radii of all salient poles of the stator iron plate to be accumulated are provided at both ends in the axial direction of the stator core,
2. The linear pulse motor according to claim 1, wherein the inner radius of the salient pole forming the tip of the stator tooth is the same.