JP2012075699A - Motor structure of sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor structure as a direct motor capable of reducing in its dimension when installed in a sewing machine, and preventing foreign matters such as dust from entering a motor main body from the outside when removed from the sewing machine.SOLUTION: A motor structure of a sewing machine 1 comprises a shield material 26 for covering an opening of a motor main body 18 and arranged on a sewing machine mounting side of a rotor 21 and a stator 22 inside the motor main body 18. The shield material 26 can prevent foreign matters from entering the motor main body 18 from the outside when a motor 8 is removed from the sewing machine 1.

Description

  The present invention relates to a structure of a motor for driving a sewing machine.

An electric motor such as a clutch motor or a servo motor is generally used as a drive source for driving the sewing machine. For industrial sewing machines, a method of connecting these electric motors to the main shaft of the sewing machine via a belt or gear (indirect connection) has been the mainstream, but there are problems of friction loss and noise. There is an increasing demand for a so-called direct drive system in which the main shaft of the sewing machine is directly connected (for example, see Document 1).
Document 1 discloses an example in which a direct drive motor (hereinafter referred to as a direct motor) is connected to a conventionally known overlock sewing machine. One end of the sewing machine main shaft that protrudes from the sewing machine bed and one end of the motor shaft that protrudes from the motor body are connected by a coupling to transmit the drive of the motor shaft to the sewing machine main shaft. The motor shaft is rotatably supported by the motor body, but is usually supported by a pair of bearings.

In the disclosed example of Document 1, the direct motor is attached to extend horizontally longer than the side surface of the sewing machine, and there is a problem that it takes up a lot of space due to non-work. Therefore, in order to solve this problem, a structure of a direct motor in which one bearing and a coupling are omitted and a connection method thereof are also known in the art (for example, see Document 2).
In the disclosed example of Document 2, the motor shaft is cantilevered and supported by the motor body, and the sewing machine mounting side of the motor body is open. The motor shaft is normally supported by a bearing. And compared with the example disclosed in Document 1, since the coupling and one bearing (and the motor body to which it is attached) are omitted, the width of the sewing machine when the motor is attached can be shortened.

Chinese Utility Model No. 200420050772.8 (refer to FIGS. 3 and 4 in particular) Chinese Utility Model No. 20072019227.1 (in particular, see FIGS. 1 and 2)

  Direct motors are often removed from the sewing machine, such as during maintenance of the sewing machine or when changing to another sewing machine. With the direct motor structure of Document 2, foreign matter such as dust may enter the motor body from the sewing machine mounting portion of the motor body. A stator consisting of a motor coil and a rotor consisting of a magnet are arranged inside the motor main body, and there has been a problem that the motor is damaged or burned out due to foreign matters.

  Accordingly, an object of the present invention is to provide a direct motor in which foreign matters such as dust do not enter the inside of the motor body from the outside when the sewing machine is removed from the sewing machine while reducing the size when the sewing machine is attached. .

  The motor structure of the sewing machine according to claim 1 is cantilevered by a motor main body which forms an outer shell of the motor and has an opening on the sewing machine mounting side, and one end protrudes from the motor main body and can be rotated by a bearing fixed to the motor main body at the one end side. A motor shaft having a joint portion formed at the other end, a rotor fixed to the motor shaft in the motor, and a stator disposed opposite to the rotor and fixed to the inner surface of the motor body. In the motor structure that is directly connected to the main shaft of the sewing machine at the section, the motor structure is provided with a shield material that is disposed on the sewing machine mounting side from the rotor and stator in the motor and covers the opening of the motor body.

  According to a second aspect of the present invention, there is provided the motor structure of the sewing machine according to the first aspect, wherein the shield member includes an attachment portion fixed to the motor main body and a main body formed in a disk shape covering the periphery of the motor shaft. Features.

  The motor structure of the sewing machine according to claim 3 is the invention according to claim 2, wherein the joint portion of the motor shaft is disposed so as not to protrude from the opening of the motor body, and a groove portion is formed on an outer periphery of the joint portion. The tip of the main body of the shield material is disposed.

  According to the present invention, in the structure of a motor that is directly connected to the main shaft of the sewing machine, foreign matters are mixed into the motor body from the outside when the motor is removed from the sewing machine while reducing the size when the sewing machine is attached. This can prevent the motor from being damaged or burned out.

1 is a schematic front view of an overlock sewing machine to which a motor according to a first embodiment of the present invention is attached. It is a fracture | rupture front view which shows the principal part when the motor of FIG. 1 is removed. It is a fracture | rupture front view which shows the principal part of the motor of FIG. Broken front view of the motor of the second embodiment Broken front view of the motor of the third embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. A motor 8 is attached to the right side surface of the bed 2 of the sewing machine 1 via a bracket 9. The bracket 9 is fixed to the bed 2 with screws 19 and includes screw holes 9a and 9a. A bearing 5 is fixed to the bed 2, and the main shaft 4 is rotatably supported by the bearing 5. One end of the main shaft 4 protrudes from the bed 2 to the outside. A fan 12 and a collar 13 are extrapolated to the projecting end of the main shaft 4. A screw 15 is screwed to the one end of the main shaft 4 via a washer 14. The circumferential edge of the washer 14 is in contact with the end of the collar 13. By tightening the screw 15 with respect to the main shaft 4, the fan 12 is held between the bearing 5 and the collar 13, and the left and right positions of the fan 12 are determined.

  The motor 8 includes a motor body 18 that forms an outer shell of the motor 8. The motor body 18 is formed in a cylindrical shape extending left and right, and a bearing 23 (bearing) is fixed to the right side wall of the motor body 18, and the surface facing the right side wall, that is, the sewing machine mounting side of the motor body 18 is opened. Yes. A flange portion 18 c is formed in a flange shape at the opening end of the motor body 18. The flange portion 18c is provided with screw holes 18b, 18b penetrating left and right. A through hole 18a that passes through the motor body 18 in the vertical direction is provided in the vicinity of the flange 18c at the top of the motor body 18.

  A motor shaft 11 is horizontally disposed in the motor body 18, and a shaft portion 11 d of the motor shaft 11 is supported by the bearing 23 so as to be rotatable around the shaft. As shown in FIGS. 1 to 3, one end of the shaft portion 11 d protrudes from the motor body 18, and the pulley 10 is fixed to the protruding end of the shaft portion 11 d with a screw 7. A joint portion 11a is provided on the other end side (sewing machine mounting side) of the shaft portion 11d. The shaft portion 11d and the joint portion 11a are on the same axis. The joint portion 11a is formed in a hollow cylindrical shape having an opening on the left side, that is, on the side where the sewing machine is attached. The inner diameter of the joint portion 11a is such that the attachment collar 13 is inserted into the main shaft 4 with almost no gap. Further, the joint portion 11 a is disposed so as not to protrude from the opening on the sewing machine attachment side of the motor body 18. Further, the joint portion 11a is provided with a screw hole 11b at a position that can be concentric with the through hole 18a of the motor body 18. With the above configuration, the motor shaft 11 is cantilevered by the bearing 23, and the width of the motor 8 when it is attached to the sewing machine 1 is shortened as in the case of Document 2. A rotor 21 made of a magnet is fixed around the shaft portion 11d, and the rotor 21 rotates with the motor shaft 11. A stator 22 made of a motor coil is disposed on the inner surface of the motor body 18 so as to face the rotor 21 and is fixed.

  The motor 8 is fixed to the bracket 9 with screws 20 and 20 through screw holes 18b and 18b of the flange portion 18c and screw holes 9a and 9a of the bracket 9. Further, the main shaft 4 having the collar 13 fixed thereto is fitted to the joint portion 11 a of the motor shaft 11. The collar 13 is provided with a screw hole 13a at a position that can be concentric with the screw hole 11b of the joint portion 11a. A contact surface 4 a is formed at the one end of the main shaft 4. The screw 16 is configured such that the tip of the screw 16 hits the face 4a through the screw hole 11b of the joint portion 11a and the screw hole 13a of the collar 13, and the joint portion 11a is fixed to the main shaft 4. The motor shaft 11 is connected and fixed to the main shaft 4 so as to be on the same axis as the main shaft 4. In the state where the motor 8 is attached to the sewing machine 1, a screw plug 17 is screwed into the through hole 18 a of the motor body 18. The joint 11a can be removed from the main shaft 4 by removing the screw plug 17 from the through hole 18a, inserting a tool such as a screwdriver into the motor body 18 from the through hole 18a, and loosening the screw 16.

  The present invention is characterized in that, in the motor structure of the sewing machine having the above-described configuration, the shield material 26 that covers the opening of the motor body 18 is arranged on the sewing machine mounting side with respect to the rotor 21 and the stator 22 inside the motor body 18. And The shield material 26 is connected to the outer periphery of the main body 26a, which is formed in a disc shape covering the periphery of the motor shaft 11, and extends horizontally from the outer periphery to the inner periphery of the mounting portion 26b. The reinforcing member 27 is attached. The main body 26 a and the mounting portion 26 b are integrally formed of an elastic synthetic rubber or the like, and the shield material 26 is fixed to the motor main body 18 by the press-contacting of the mounting portion 26 b to the inner surface of the motor main body 18. The reinforcing member 27 is made of metal having a cross-sectional “L” shape along the main body 26a and the attachment portion 26b of the shield material 26, and is for maintaining the shapes of the main body 26a and the attachment portion 26b. As shown in FIG. 2, the main body 26a is bent in the shape of a cross section "" in the middle of the motor shaft 11, and the tip of the motor shaft 11 side is a side surface of a groove portion 11c formed around the joint portion 11a. 11cb. Further, the tip of the main body 26a on the motor shaft 11 side is not in contact with the bottom surface 11ca of the groove 11c.

  As described above, since the motor shaft 11 is cantilevered by the bearing 23, when the motor 8 is mounted with the same shaft center of the main shaft 4 of the sewing machine 1 and the motor shaft 11 being displaced, There is a risk of rotating eccentrically in the portion 11a. That is, the joint portion 11a may move while moving in the vertical direction with respect to the axial direction. However, as in the above-described embodiment, the main body 26a receives a load caused by the above-described vertical shake from the joint portion 11a. In addition, the shield material 26 is prevented from being worn or damaged. Even if the main body 26a and the joint portion 11a come into contact with each other, the main body 26a can be expanded and contracted using the bent portion of the main body 26a as a fulcrum, thereby reducing the load received by the above-described shaking of the joint portion 11a. As a second embodiment, as shown in FIG. 4, the main body 26a is bent toward the pulley end toward the front end of the motor shaft 11 from the middle thereof, and the front end of the main body 26a on the motor shaft 11 side is turned to the opening end of the joint portion 11a. You may make it contact the side surface 11cb of the groove part 11c formed by the circumference. Also in the second embodiment, it is desirable that the tip of the main body 26a on the motor shaft 11 side is not in contact with the bottom surface 11ca of the groove 11c.

  In the motor structure of the sewing machine having the above-described configuration, the shield member 26 that covers the opening of the motor body 18 is disposed on the sewing machine mounting side with respect to the rotor 21 and the stator 22 inside the motor body 18. It is possible to prevent foreign matter from entering the motor main body 18 from the opening of the motor main body 18 when being removed from the motor 1. Accordingly, it is possible to prevent the motor 8 from being damaged or burned out due to foreign matter mixed into the motor body 18.

  The present invention is not limited to the first embodiment and the second embodiment. As described above, in order to protect the durability of the shield material 26, it is desirable not to receive a load with respect to the shake of the motor shaft 11 in the vertical direction. Therefore, as shown in FIG. It is also possible to employ a structure in which the joint portion 11a of the motor shaft 11 is not contacted. The main body 26a of the shield material 26 is formed in a disk shape extending in the vertical direction from the mounting portion 26b and covering the periphery of the motor shaft 11. The tip of the main body 26a on the motor shaft 11 side is inserted and arranged in a non-contact state in a groove portion 11c formed around the joint portion 11a. With such a configuration, a gap is formed between the shield material 26 and the joint portion 11, but the path that is formed by this gap and that leads to the motor body 18 becomes complicated, and foreign matter enters the motor body 18. It becomes difficult to mix.

DESCRIPTION OF SYMBOLS 1 Sewing machine 2 Bed 4 Main shaft 4a Contact surface 5 Bearing 8 Motor 9 Bracket 11 Motor shaft 11a Joint part 11b Screw hole 11c Groove part 11d Shaft part 13 Collar 13a Screw hole 14 Washer 17 Screw plug 18 Motor body 18a Through-hole 18c Flange part 23 (bearing)
26 Shielding material 26a Body 26b Mounting portion 27 Reinforcing member

Claims (3)

A motor body that forms an outer shell of the motor and opens on the sewing machine mounting side;
A motor shaft having one end protruding from the motor body and cantilevered with a bearing fixed to the motor body on the one end side, and a joint portion formed on the other end;
A rotor fixed to the motor shaft in the motor;
A stator disposed opposite to the rotor and fixed to the inner surface of the motor body,
In the motor structure that is directly connected to the main shaft of the sewing machine at the joint,
A motor structure for a sewing machine, comprising a shield member disposed on a sewing machine mounting side from a rotor and a stator in the motor and covering the opening of the motor body. The shield material is
A mounting portion fixed to the motor body;
The sewing machine motor structure according to claim 1, further comprising a disk-shaped main body that covers the periphery of the motor shaft. The joint portion of the motor shaft is arranged so as not to protrude from the opening of the motor body,
A groove is formed on the outer periphery of the joint,
The motor structure of the sewing machine according to claim 2, wherein a tip of the main body of the shield material is disposed in the groove.

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