KR20110051945A

KR20110051945A - Stepping motor

Info

Publication number: KR20110051945A
Application number: KR1020090108772A
Authority: KR
Inventors: 원유만
Original assignee: 엘지이노텍 주식회사
Priority date: 2009-11-11
Filing date: 2009-11-11
Publication date: 2011-05-18

Abstract

PURPOSE: A stepping motor is provided to prevent the failure of a product by combining a housing and a cage structure. CONSTITUTION: A cage(10) is united to one side of a housing(20). The cage accepts the ball bearing inside of the cage. A plurality of combining projections are formed on the surface of the case in which the case is combined. Combining holes(11) are formed coping with the combining protrusions(21). Each combining protrusion and combining hole are inserted into the combining cage.

Description

Stepping Motor {STEPPING MOTOR}

The present invention relates to a stepping motor, and more particularly, to a stepping motor capable of improving reliability by improving a coupling structure when a cage housing a housing and a ball bearing therein.

Recently, as the dimensions of the motor have become smaller and smaller, the outer diameter of the housing tends to be smaller and smaller. On the contrary, the performance of the stepping motor is required to have the same level of output as the high torque. Thus, the applied set is also sensitive in nature and responds largely to small characteristic differences in stepping motors.

1 is a view schematically showing the configuration of a stepping motor according to the related art. As shown therein, a rotor 102 forming a lead screw 101; A stator 107 formed by attaching a tooth york 105 and a housing 106 to a bobbin 104 in which a coil 103 is wound around a coil winding stacking unit in a predetermined winding form. Wow; A cage 109 for forming a groove so that the rotor 102 on the stator 107 side is supported to embed a ball 108a; An end cover 111 for allowing the cage 109 to be elastically supported; Pivot bearings 113 forming grooves so that the other shafts of the rotors 102 are fixed and having balls embedded therein; It is configured to include a bracket (114) for inserting and fixing the pivot bearing 113 while penetrating the rotor 102, the lead screw 101 is formed.

Referring to the operation of the stepping motor according to the prior art made of the configuration as follows.

The bobbin 104 wound by the stator 107 is provided up and down, and the bobbin 104 is fixed by the tooth yoke 105 and the housing 106. A part of the rotor 102 is inserted into the central hole of the stator 107, and the magnet 112 is fitted to the outer circumferential surface of the rotor 102 inserted into the stator 107 to correspond to the coil. Lose. Here, a rotor magnetic force is generated by the magnet 112 of the rotor 102 and the coil of the stator 107 so that the rotor 102 rotates.

In addition, the rotor 102 has a lead screw 101 formed on an outer circumferential surface at a portion protruding from the stator passage 107, and both ends of the rotor 102 are supported by grooves on both sides. Here, each of the grooves is to allow the rotation of the rotor 102 by embedding the ball.

The groove on one side is formed in the cage 109 on the stator 107 side, and the groove on the other side is formed on the pivot bearing 113. The pivot bearing 113 is fixed by the bracket 114, and the thrust holder 109 on the stator 107 side is fixed to the stator 107 by the end cover 111. Here, the spring 110 is provided between the end cover 111 and the cage 109, which allows the rotor 102 to be elastically supported to facilitate assembly by the cumulative tolerance of the parts. For sake.

On the other hand, Figure 2 is a view schematically showing the coupling of the internal components of the housing of the stator according to the prior art. As shown in the drawing, the bobbin 104 wound around the rotor 102 is provided up and down, and the tooth yoke 105 and the housing 106 for fixing the bobbin 104 are provided. ) Is combined. The housing 106 of the stator coupled as described above is mounted on the outer surface of the bracket 114.

In the conventional stepping motor as described above, when the housing 106 and the cage 109 are coupled, the housing 106 and the cage 109 are coupled using a tool (not shown) for welding. The welding tool is a spot welder, which uses a method of melting and joining two components, and a separate guide pin (not shown) must be used to secure coaxiality with the housing 106. .

However, as described above, the coupling by welding requires a separate welding tool, which increases the investment of equipment in the process, and has a disadvantage in that a defect is likely to occur due to the extraction force of the welding spot.

In addition, in addition to the inconvenience of using a separate guide pin, the coaxiality of the product is changed by the guide pin, which acts as a source of performance degradation due to the deviation and coaxial failure of the product.

Meanwhile, as shown in FIG. 3, a plurality of grooves 106a are formed in the outer diameter of the housing 106, and a cage 111 ′ having a clip protrusion 111b 'fitted to the groove 106a is coupled in a one-touch manner. Has been proposed. However, the method of forming the grooves 106a in the outer diameter of the housing 106 is difficult in the process on the mold, and in particular, there is a difficulty in maintaining the degree of the management dimension, and when the axial impact is applied, the cage 111 There is a problem that ') is easily separated.

In order to solve the above problems, the present invention provides a stepping motor with improved reliability by improving the coupling structure of the cage and the cage housing the ball bearing therein, thereby reducing the equipment cost in the manufacturing process and reducing the defective rate. The purpose is to.

The present invention relates to a stepping motor including a housing in which a coil is wound around a coil wound on a coil winding stacking unit in a predetermined winding form and coupled to a tooth yoke. A cage for accommodating the ball bearing is further included, and a plurality of coupling protrusions are formed on a surface to which the case of the housing is coupled, and a coupling hole corresponding to the plurality of coupling protrusions on a surface to be coupled to the housing of the cage. Is formed, the housing and the cage is coupled to each engaging projection is inserted into the coupling hole.

In addition, in the stepping motor of the present invention, the housing and the cage, each coupling protrusion is inserted into the coupling hole, and the outer diameter of the front end of the coupling protrusion by pressing (caulking) the coupling protrusion protruding through the coupling hole is It is larger than the diameter of the engagement hole.

In addition, in the stepping motor of the present invention, the coupling hole of the cage includes a tapered portion whose internal diameter increases in the direction in which the coupling protrusion of the housing is inserted, and a portion of the tip of the coupling protrusion is located on the tapered portion.

As described above, according to the coupling structure of the housing and the cage of the stepping motor according to the present invention can be easily coupled to each other to prevent the occurrence of product defects, the cost is reduced, the manufacturing time in the process is shortened.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Now, a stepping motor according to an embodiment of the present invention will be described in detail with reference to the drawings. The same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

4 is a cross-sectional view illustrating a cage coupling structure of a stepping motor according to an exemplary embodiment of the present invention, and FIG. 5 is an enlarged view 'A' shown in FIG. 4.

The overall configuration of the stepping motor according to the embodiment of the present invention is omitted because it is similar to that shown in Figs.

The coupling structure of the housing 20 and the cage 10 of the stemming motor of this embodiment is shown in detail in FIGS. 4 and 5.

The cage 10 coupled to the outer surface of the housing 20 accommodates a ball bearing (not shown) therein. The housing 20 has a plurality of coupling holes 11 formed therein, and the coupling holes ( A plurality of engaging projections 21 are formed on the outer surface of the cage 10 corresponding to 11).

Accordingly, the housing 20 and the cage 10 are coupled to each other by the coupling protrusions 21 inserted into the coupling holes 11, and after the coupling protrusions 21 are inserted into the coupling holes 11, the coupling holes ( 11, the front end portion 21b of the coupling protrusion 21 protruding is pressed. Accordingly, as shown in FIG. 5, the outer diameter of the distal end portion 21b of the coupling protrusion 21 is larger than that of the flat portion 11b of the coupling hole 11, thereby making it difficult to eliminate each other.

At this time, the coupling hole 11 is provided with a tapered portion 11a having an inner diameter that increases in the direction in which the coupling protrusion 21 of the housing 20 is inserted, so that the tip portion 21b of the coupling protrusion 21 is tapered. It is located at (11a). That is, the front end portion 21b of the coupling protrusion 21 protruded through the coupling hole 11 is caulked by using a separate tool, and is tapered to the tapered portion 11a of the coupling hole 11. The pressing force can be applied to a predetermined portion of the inner surface of the coupling hole 11, and has a strong coupling force in the shape in which the tip portion 21b of the coupling protrusion 21 is fitted to the inclined surface of the tapered portion 11a.

Therefore, there is no need for a separate welding tool compared to the conventional method of joining by welding, and there is an advantage in that facility investment is reduced in the process, and there is an advantage of preventing the spreading force generated by the welding method.

In addition, the mold-like process is easier than the method of coupling in the clip method, there is an advantage that the cage is firmly fixed to the impact in the axial direction and the width direction.

One embodiment of the present invention described above should not be construed as limiting the technical spirit of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention as long as it will be apparent to those skilled in the art.

1 is a view schematically showing the configuration of a stepping motor according to the related art

Figure 2 schematically shows a coupling of internal components of the stator housing according to the prior art

Figure 3 is an enlarged cross-sectional view showing a cage coupling structure of a conventional stepping motor

4 is a cross-sectional view illustrating a cage coupling structure of a stepping motor according to an embodiment of the present invention.

5 is an enlarged view of 'A' shown in FIG.

Claims

In a stepping motor comprising a housing in which a coil is wound around a coil wound in a coil winding stacking unit in a predetermined winding form and coupled to a tooth yoke.

A cage coupled to one end surface of the housing and accommodating a ball bearing therein;

The coupling surface of the housing is formed with a plurality of coupling protrusions,

A coupling hole corresponding to the plurality of coupling protrusions is formed on a surface of the cage coupled with the housing.

Stepping motor to the housing and the cage is coupled to each engaging projection is inserted into the coupling hole.

The method of claim 1,

The housing and cage,

A stepping motor in which each engaging projection is inserted into the engaging hole, and the outer diameter of the tip of the engaging projection is larger than the diameter of the engaging hole by pressing the engaging projection projecting through the engaging hole.

The method of claim 2,

The coupling hole of the cage,

And a tapered portion having an increased inner diameter in a direction in which the coupling protrusion of the housing is inserted.

A stepping motor, wherein a portion of the front end of the engaging projection is located in the tapered portion.