JP2657144B2 - Small 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 small motor having a claw-pole type outer stator.

[0002]

2. Description of the Related Art For example, an armature such as a small stepping motor having a PM (permanent magnet) type inner rotor and a cropole type outer stator includes a soft iron crown-shaped yoke which also serves as a coil bobbin frame as shown in FIG. A set (yoke assembly) 50 is used. The yoke assembly 50 is for a two-phase winding, and is composed of a combination of crown-shaped soft iron yokes 51a, 51b, 51c, 51d (51). Each yoke 51 has an annular flange 52 (5
2a, 52b, 52c, 52d), a plurality of pole teeth (pole pieces) 53 (53a, 53b, 53c, 53) which are cut and raised at a right angle from the inner peripheral side at the inner peripheral side, project in the axial direction, and are arranged in an annular row.
d), the outer yoke 51a is called a claw pole (pole claw) shape and is located at one end in the axial direction.
The opposing pole teeth 53a and 53b of the inner yoke 51b sandwiched between the inner yoke and the outer yoke 51d located at the other axial end and the inner yoke sandwiched inside form the N pole and the S pole of the A phase. Opposing pole teeth 53d, 53 of 51c
c forms the north pole and south pole of the B phase.

[0003] The pole teeth 5 of the outer yoke 51a (51d)
3a (53d) and the pole teeth 53b (53c) of the inner yoke 51b (51c) are housed in a mold in a state of being alternately located between the pole teeth, and as shown in FIGS. 8 (a) and 8 (b). ,
The four yokes 51 (51a, 51a) are formed by insert molding.
b, 51c, 51d) are interconnected by a resin mold to obtain an integrated cropole outer stator 60.

Here, the resin mold connection of the four yokes 51 is performed by connecting the resin layer X between the pole teeth between the pole teeth 53 adjacent in the circumferential direction and the resin layer X between the pole teeth. This is achieved by the connection with the coating resin layer Y (the resin portion is hatched in FIG. 8) which covers the outer peripheral surface of the layer X, the outer peripheral surface of the pole teeth 53, and the flange surface of the flange portion 52. And pole tooth 5
3, the armature winding 57 is formed by the winding winding portion 56.
When it is wound around, it functions as an insulating layer for electrically insulating and separating the armature winding 57 and the yoke 51. A resin terminal block 59 is also formed on the outer ends of the inner yokes 51c and 51d when the yokes 51 are connected by resin molding with the resin layers X and Y. The terminal block 59 and the coating resin layer Y are connected, and contribute to the interconnection of the four yokes 51. The end lead wire of the armature winding 57 is connected to the terminal pin 58 implanted on the terminal block 59 by soldering or the like. An inner rotor 62 in which a motor shaft 61 a is fixed to a permanent magnet 61 is attached to the rotor space of the outer pole 60 of the cropole type in such a manner as to penetrate therethrough.

[0005]

However, in the winding part 56 of the cropole outer stator 60, the flange surface of the flange part 52 (52a, 52b, 52c, 52d) is also thickly covered with the coating resin layer Y. Therefore, the wire performance of the armature winding 57 is reduced by twice the thickness of the layer. In order to ensure the electrical insulation of the coating resin layer Y, it is necessary that the layer thickness is about 0.3 to 0.5 mm, which is an obstacle to increasing the torque of a small motor.

[0006] In view of the above problems, an object of the present invention is to provide:
It is an object of the present invention to provide a small-sized motor capable of increasing the torque of a winding part by improving the structure of a cropole outer stator.

[0007]

In order to solve the above-mentioned problems, means taken in a motor according to the present invention is a winding part formed on a yoke of an armature and wound with an armature winding. In the above, the insulating layer for insulating and separating the yoke and the armature winding is constituted by a coating layer formed on the surface of the winding part.

That is, the present invention uses a pair of yokes having a plurality of pole teeth which are cut and raised from the inner peripheral side of the flange portion, project in the axial direction, and are arranged in an annular row, and a pair of yokes is provided between the pole teeth of one of the yokes. A cropole outer stator formed by interconnecting and integrating the yokes with a mold resin in a state where the pole teeth of the other opposing yoke are located with each other, and wound around the outer periphery of the pole teeth of the yoke In a small motor provided with an armature winding, an inter-tooth resin layer filled in a thickness gap between circumferentially adjacent pole teeth, an outer peripheral surface of the inter-tooth resin layer, It is characterized in that the outer peripheral surface of the teeth and the flange surface of the flange portion are covered, and the two-piece yoke and the insulating coating layer for electrically insulating the armature winding are provided.

In the case of a small motor having a multi-phase armature winding in which the flanges of the yoke are in contact with each other and are connected in the axial direction, at least one contact surface of the flanges that come into contact with each other is provided. It is preferable that a resin supply passage communicating from the inner peripheral end of the flange to the terminal block on the outer peripheral side is formed.

[0010]

In the motor according to the present invention, the insulating layer formed on the surface of the armature winding side of the yoke for insulating and separating the yoke side from the armature winding has a thick coating formed when the yoke is connected to the mold. Not a resin layer but a thin coating layer that covers the outer peripheral surface of the inter-tooth resin layer, the outer peripheral surface of the pole teeth, and the flange surface of the flange formed at the time of mold connection. The wire performance of the armature winding is significantly increased. Therefore, a small motor with high torque can be provided.

Forming an insulating coating layer instead of forming a resin layer on the flange surface of the flange portion results in a structure in which the inner and outer peripheral sides of the yoke are not connected by the resin layer when the mold is connected. Therefore, a resin terminal block cannot be formed on the outer peripheral side of the flange of the yoke. Therefore, in the present invention, a resin supply passage capable of supplying the resin from the inner peripheral end toward the outer peripheral side is formed on the contact surface of at least one of the flanges that come into surface contact with each other among the flanges of the yoke. When the plurality of yokes are molded and integrated with the resin on the inner peripheral side, they are integrated from the inner peripheral side of the yoke through the oil supply passage formed on the contact surface of the flange portion. The side is supplied with resin. Therefore, the resin-made terminal block can be simultaneously formed at the time of resin-molding the yoke without adding another step. After the mold is connected, the resin also remains in the oil supply passage, so that the connecting force between the contacting flanges is increased. Therefore, it is possible to provide a small motor having a high torque and a multi-phase armature winding.

[0012]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic sectional view schematically showing the structure of a main part of a stepping motor according to an embodiment of the present invention, FIG. 2 is a schematic perspective view schematically showing the structure of the armature, and FIG. It is a perspective view which shows the structure of the yoke which comprises a yoke assembly. FIG. 4A is a side view showing the arrangement of the yokes in the yoke assembly of the stepping motor, and FIG.
FIG. 4 is a plan view showing a configuration of a resin supply passage formed in the flange portion.

In these figures, a cropole stepping motor 10 of the present embodiment is a
1a, and a second bearing 12 on the case open end side.
Bearings 13, and these bearings 12, 1
3, a motor shaft 15 is supported, and a magnet 14 is fixed to the motor shaft 15. Also,
An armature 20 is arranged around the magnet 14, and a yoke assembly (yoke assembly) of the armature 20 is provided.
An armature winding 22 is wound around 30, and an end 221 of the armature winding 22 is formed of a CP wire 4 fixed to a resin terminal block 23 formed on the outer peripheral side of the yoke assembly 30. It is connected to the terminal 24 of the book.

Here, as shown in FIG. 3, the yoke assembly 30 includes four first to fourth yokes 31, 32, 3
3 and 34, and which of the yokes 31 and 3
2,3334 are also annular flanges 310,320,330,34.
0 has a plurality of pole teeth 311, 321, 331, and 341 protruding in the axial direction and raised and arranged in an annular row.
Flanges 310, 320, 330, 3 having a thickness of about 0.5 mm
Forty to five pole teeth 311, 321, 331, 341 protrude at regular intervals in a direction perpendicular to the flanges 310, 320, 330, 340. Also, the flanges 310, 320, 33
Notches 315, 325, 335 and 345 used for positioning and the like are formed on the outer peripheral edge of 0 and 340, respectively. Here, in a state where the first to fourth yokes 31 to 34 constitute the yoke assembly 30, FIG.
As shown in FIG. 3, among the first to fourth yokes 31 to 34, the first yoke 31 (outer yoke) and the second yoke 32 (inner yoke) are the pole teeth 31 of one of the yokes.
, The other yoke pole teeth 311,
321 are positioned with respect to each other and the third yoke 33
The (inner yoke) and the fourth yoke 34 (outer yoke) are made such that the pole teeth 331 and 341 of one yoke and the pole teeth 331 and 341 of the other yoke are positioned with respect to each other. A heat-resistant polar interdental resin layer 2 having a thickness of about 0.3 mm, such as a nylon resin contained therein.
5 are interconnected. This interdental resin layer 25
As shown in FIG. 5 and FIG. 6, the gap between the pole teeth 311 and 321 adjacent to each other in the circumferential direction or the gap between the pole teeth 331 and 341 is also filled. 31
1, 321, 331, 341 do not bulge outward from the outer peripheral surface level. Here, the flange 3 of the second yoke 32
The contact surface 320a, 330a, which is the back side, of the 20 and the flange portion 330 of the third yoke 33 is in a state of being in surface contact with each other.

Further, a part of the resin layer 25 is
0 is a support portion 25a that protrudes from the end surface of the stepping motor 10 and fixes the second bearing 13.
, The armature 20 and the motor shaft 15 can be housed in the motor case 11 in an integrated state. Therefore, even if there is no end cap attached to the open end side of the motor case 11, the motor shaft 15
Is supported on the armature 20 side, so that it can be operated as it is, and the size of the gap between the armature 20 and the magnet 14 can be easily set to a predetermined condition. Is high.

In the yoke assembly 30 having such a structure, the flange portion 310 of the first yoke 31 and the pole teeth 311
The first (A-phase) winding portion 40 for winding the armature winding 22 is defined by the flange portion 320 and the pole teeth 321 of the second yoke 32. Of the fourth yoke 34 and the collar 330 of the fourth yoke 34
A second (B-phase) winding winding portion 41 that winds the armature winding 22 is defined by the 40 and the pole teeth 341. In addition, of the first to fourth yokes 31 to 34, the flange portions 32 of the second yoke 32 and the third yoke 33 are provided.
Flat portions 323 and 333 are formed on the outer peripheral ends of the reference numerals 0 and 330, and the second yoke 32 and the third yoke 33 are connected to each other in a state where the flat portions 323 and 333 coincide with each other. The terminal block 23 made of resin is formed by utilizing the thick portions of the flat portions 323 and 333.

In the armature 20 having such a configuration, the armature winding 22 is a bare copper wire, while the first to fourth yokes 31 to 34 are all made of soft iron. In order to wind the armature winding 22 around the first winding winding section 40 and the second winding winding section 41, it is necessary to ensure electrical insulation between them. In order to ensure this electrical insulation, conventionally, when the first to fourth yokes 31 to 34 are connected by molding with a resin layer, a coating resin layer is also formed on the surface of the winding part. However, in the stepping motor 10 of this example, the first and second
A thin insulating coating layer 42, which is baked after spraying a fluorine resin or the like onto the surfaces of the winding winding portions 40, 41, for example,
By forming an insulating coating layer 42 having a thickness of about 30 to 50 μm and using the insulating coating layer 42 as an insulating layer for insulating the yoke 30 and the armature winding 22, the first and second insulating coating layers are formed. The winding results of the winding portions 40 and 41 are large. In addition, at the time of resin mold connection before applying the insulating coating layer 42, the inter-tooth resin layer 25 is packed in the thickness gap between circumferentially adjacent pole teeth. The insulating coating layer 42 can be formed on the substrate.

When the yoke assembly 30 having such a structure is employed, the surface of the first and second winding portions 40 and 41 is not covered with a thick resin layer, so that resin is supplied to the outer peripheral side of the yoke assembly 30. When the first to fourth yokes 31 to 34 are molded and connected with the inter-tooth resin layer 25, the terminal block 23 cannot be formed at the same time. Here, there is a method in which the terminal block is provided in another step, but the number of manufacturing steps is increased, and the cost is increased. Therefore, in the yoke assembly 30 of the present embodiment, as shown in FIG.
On the side of 20a, two groove-shaped resin supply passages 324 are formed, while the contact surface 3 of the flange 330 of the third yoke 33 is formed.
Also, two groove-shaped resin supply passages 334 are formed on the side of 30a, and as shown in FIG.
And the third yoke 33 with the contact surfaces 3 of the flanges 320 and 330.
When 20a and 330a are connected to be in surface contact,
The resin supply passage 324 and the resin supply passage 334 overlap each other, so that two resin supply passages 35 having an opening cross section of about 0.3 to 0.4 mm square can be formed. For this reason, since the inner peripheral side and the outer peripheral side of the yoke assembly 30 are in communication with each other via the resin supply passage 35, the first to fourth yokes 31 to 34 are connected to the inner peripheral side as described later. When molding with the interdental resin layer 25, the resin supplied to the inner peripheral side of the yoke assembly 30 is guided to the outer peripheral side via the resin supply passage 35, so that the terminal block 23 is formed without any trouble. ing.

After the mold is connected, the resin also remains in the oil supply passage 35.
The connection force between the flange portions 32 and 33 that come into contact with each other is increased.

Next, a method of manufacturing the armature 20 of the stepping motor 10 having such a configuration will be described with reference to FIGS.

FIG. 5 is a process sectional view schematically showing a process of molding the yoke of the stepping motor, and FIG.
FIG. 6 is an explanatory view showing a state in which a coating layer is formed after the yoke of the stepping motor is molded and an armature winding is wound, and FIG. 6B is a schematic cross-sectional view thereof.

First, of the first to fourth yokes 31 to 34 shown in FIG. 3, as shown in FIGS.
The first yoke 31 and the second yoke 32 are connected to each pole tooth 31.
1 and 321 are arranged in an insert type with a predetermined gap between the other side, while the third yoke 33 and the fourth
And one of the pole teeth 331, 341 is arranged in a insertion type having a predetermined gap between the other side,
Further, the second yoke 32 and the third yoke 33 are
A predetermined jig is used to fix the contact surfaces 320a and 330a of the substrates 20 and 330 to each other.

Next, as schematically shown in FIG.
Alternatively, the fourth yokes 31 to 34 are housed in the hollow interior of the mold 36 in a connected state. Here, in FIG. 5, the space between the mold 36 and the first to fourth yokes 31 to 34 is indicated by hatching, and the resin is supplied to the hatched area. That is, a gate 361 for supplying resin is provided on the inner peripheral side of the yoke assembly 30, and the resin (indicated by an arrow A) supplied from the gate 361 is supplied to the inner peripheral side of the yoke 30 in FIGS. 6 (a) and 6 (b) are filled so as to form the interdental resin layer 25 and the first to fourth resin layers 25 are formed.
Are molded and the two resin supply passages 35 formed between the flange portions 320 and 330 of the second and third yokes 32 and 33 are supplied to the outer peripheral side along the arrow B. 1, 2 and 6 (a),
The terminal block 23 shown in FIG. As a result, in the yoke set 30 molded by the inter-tooth resin layer 25, the first to fourth yokes 31 to 34
Each of the pole teeth 311, 321, 331, 341 is fixed with a predetermined gap by the inter-tooth resin layer 25 in a region shown by oblique lines in FIG. Is set exactly. On the other hand, the space defined by the flange portions 310, 320, 330, and 340 becomes the first and second winding portions 40, 41.

Next, as shown by dotted lines in FIGS. 6A and 6B, the surfaces of the first and second winding portions 40 and 41 of the yoke assembly 30, ie, the resin layer 25 between the pole teeth. , Outer peripheral surfaces of pole teeth 311, 321, 331, 341 and flange 3
Fluoro resin is sprayed thinly and evenly on the flange surfaces of 2,33 and then baked and solidified to a thickness of about 30.
An insulating coating layer 42 having a thickness of about 50 μm is formed.

Next, as shown by dashed lines in FIGS. 6A and 6B, the armature winding 22 is wound around the first and second winding winding portions 40 and 41 of the yoke assembly 30. Then, the end 221 is wound around the terminal 24 fixed to the terminal block 23 to be processed. As a result, the armature 20 shown in FIG. 2 is formed.

After that, as shown in FIG. 1, the armature 20 is housed in the motor case 11 with the magnet 14 fixedly penetrating the motor shaft 15 inside the yoke assembly 30.

As described above, in the stepping motor 10 of the present embodiment, the yoke assembly 30 and the armature winding 22 are insulated and separated from each other at the first and second winding portions 40 and 41 of the yoke assembly 30. The insulating layer is composed of a thin insulating coating layer 42 applied to the surface thereof.
In the yoke 30, the capacity of the first and second winding portions 40 and 41 is increased by about 1.5 times as compared with the conventional one, and the armature winding 22 that can be wound there is provided. Is greatly increased. Therefore, the output torque of the stepping motor 10 can be increased with the yoke set 30 having the same size, while the armature 2 can be increased with the same output torque.
0 can be downsized, that is, the stepping motor 10 can be downsized.

Here, when the insulating layer is constituted by the coating layer 42, the yoke assembly 30 is formed when the yoke assembly 30 is resin-molded.
Of the first and second winding portions 40 and 41 cannot be supplied to the terminal block 23 during molding.
Cannot be formed at the same time, but in the stepping motor 10 of the present embodiment, the flange portions 310, 320, 33 of the first to fourth yokes 31 to 34 constituting the yoke assembly 30.
Since the resin supply passages 324 and 334 (resin supply passage 35) are provided on the contact surfaces of the flange portions 320 and 330 that come into surface contact with each other, the yoke 30 is molded when the yoke assembly 30 is molded. From the inner peripheral side of the resin supply passage 35
The resin can be supplied to the outer peripheral side via the. Therefore, there is no problem in forming the resin layer 25 and the terminal block 23 at the same time, and only one resin molding process is required.

Further, in the stepping motor 10 of this embodiment, as shown in FIG. 5, the pole teeth 311, 321, 33 of the first to fourth yokes 31 to 34 are formed at the time of resin molding.
Since the outside of 1,341 is in contact with the mold 36,
The polar teeth 311, 321, 331 and 341 are not deformed by the molding pressure or the like at the time of resin injection and molding, and the polar teeth 311, 321, 331 and 34 are not deformed.
The size of the gap set between 1 does not change. Accordingly, an armature in which the pole teeth 311, 321, 331, and 341 are arranged with high accuracy can be formed, so that the performance of the stepping motor 10, such as step accuracy, is improved.

As a material for forming the coating film layer, an inorganic coating film layer may be employed irrespective of the organic coating film layer as long as it has insulating properties and heat resistance. Here, as the coating layer, for example, a layer used as a solid coating lubricant or the like can be used. Further, the motor including the yoke having the above structure is not limited to the PM stepping motor, but may be applied to, for example, a synchronous motor.

[0032]

As described above, the small motor according to the present invention does not have a structure in which the surface of the armature winding side of the yoke is insulated with a thick coating resin layer, but has a plate thickness between adjacent pole teeth. The present invention is characterized in that the outer peripheral surface of the inter-tooth resin layer in which the gap is filled, the outer peripheral surface of the pole teeth, and the flange surface of the flange are covered with an insulating coating layer. Therefore, the following effects are obtained.

[0033] Since the surface of the yoke on the armature winding side is covered with a thin coating layer, the wire performance of the armature winding is particularly remarkably increased in a small motor as compared with the related art. Therefore, a small motor with high torque can be provided.

A structure in which a resin supply passage capable of supplying a resin from an inner peripheral end toward an outer peripheral side is formed on a contact surface of at least one of the flanges that come into surface contact among the flanges of the yoke. Then, at the time of resin mold connection, the resin is supplied to the outer peripheral side from the inner peripheral side of the yoke via the oil supply passage formed on the contact surface of the flange portion, so that no additional process is added,
A resin terminal block can be simultaneously formed on the outer periphery of the flange when the yoke is molded with the resin. After the mold is connected, the resin also remains in the oil supply passage, so that the connecting force between the contacting flanges is increased. Therefore, it is possible to provide a small motor having a high torque and a multi-phase armature winding.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view schematically illustrating a structure of a main part of a stepping motor according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view schematically showing a structure of an armature of the stepping motor shown in FIG.

FIG. 3 is a perspective view showing a structure of a yoke constituting a yoke assembly of the stepping motor shown in FIG.

FIG. 4A is a side view showing the arrangement of yokes in the yoke assembly of the stepping motor shown in FIG. 1, and FIG.
FIG. 4 is a plan view showing a configuration of a resin supply passage formed in the flange portion.

FIG. 5 is a process cross-sectional view when the yoke assembly of the stepping motor shown in FIG. 1 is molded.

6A is an explanatory view showing a state in which a coating film is formed and a state in which an armature winding is wound after molding the yoke of the stepping motor shown in FIG. 1, and FIG. It is sectional drawing.

FIG. 7 is a perspective view showing a structure of a yoke constituting a yoke assembly of a conventional stepping motor.

FIG. 8A is a partial sectional view showing a structure of an armature of a conventional stepping motor, and FIG. 8B is a sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Stepping motor 14 ... Magnet 15 ... Motor shaft 20 ... Armature 22 ... Armature winding 23 ... Terminal block 24 ... Terminal 25 ... Inter-tooth resin layer 30 ... Yoke assembly 31 ... First yoke 32 ... Second Yoke 33: Third yoke 34: Fourth yoke 35, 324, 334: Resin supply passage 36: Die 40: First winding part 41: Second winding part 42: Insulation coating Film layers (insulating layers) 310, 320, 330, 340: annular flange portions 311, 321, 331, 341: pole teeth (tooth pieces) 323, 333: flat portions 320a, 330a: contact surface

Claims (2)

(57) [Claims] 1. A pair of yokes, each of which has a plurality of pole teeth protruding in the axial direction and being arranged in an annular row, cut and raised from the inner peripheral side of a flange portion, and one of the yokes facing the other between the pole teeth of the other yoke is used. A claw-pole outer stator formed by interconnecting and integrating the yokes with a mold resin in a state where the pole teeth of the yoke are positioned with respect to each other, and an armature winding wound around the outer periphery of the pole teeth of the yoke In a small motor with
An inter-tooth resin layer filled in a thickness gap between circumferentially adjacent pole teeth, an outer peripheral surface of the inter-tooth resin layer, an outer peripheral surface of the pole tooth, and a flange surface of the flange portion A small motor comprising: a pair of yokes; and an insulating coating layer for electrically insulating the armature windings. 2. A small-sized motor according to claim 1, having a multi-phase winding winding portion in which the flange portions of the yoke are in contact with each other and connected in the axial direction. A small motor characterized in that a resin supply passage communicating from an inner peripheral end of a flange portion to a terminal block on an outer peripheral side is formed on one contact surface.