JPH0279745A - Structure of motor housing and manufacture thereof - Google Patents

Abstract

PURPOSE:To use a motor housing in common regardless of the magnitude of rotational speed by setting the inside diameter of a bearing groove in response to the size of a certain bearing having a large outside diameter for revolution at low speed and interposing a collar member to a bearing having a small outside diameter for revolution at high speed. CONSTITUTION:A front bearing groove 26 formed to a from housing 12 is shaped previously in large size D1 for revolution at low speed. A bearing in large size, size D1, is used in a motor for revolution at low speed. A front bearing 30 having an outside diameter smaller than D1 is employed while interposing a collar member 32 on the outer ring side in a motor for revolution at high speed. Accordingly, the bearing groove 26 is formed in conformity with the size of the bearing for revolution at low speed having large size in the front housing 12, and a bearing section is constituted while interposing the collar member 32 in the bearing for revolution at high speed having the small outside diameter when the bearing groove 26 is used for revolution at high speed, thus employing a motor housing for both low speed and high speed without increasing cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a housing structure for a motor that can be used in both high-speed rotation bearings and low-speed rotation bearings, and a method for manufacturing the same.

[Conventional technology]

In general, bearing design is subject to the so-called I)+n value, which is the average value of the inner diameter and outer diameter of the bearing multiplied by the rotational speed. That is, as the rotational speed increases, the average diameter drop of the bearing must be reduced. The design of a bearing that supports the output shaft of a motor is also subject to limitations on the Down value. Conventionally, both low-speed motors and high-speed motors have shared one type of output shaft from the viewpoint of cost reduction.

[Problem to be solved by the invention]

However, in the above case, although the inner diameter of the bearing is the same,
The outer diameter differs between low-speed and high-speed bearings, and the outer diameter of high-speed bearings must be set small. Therefore, different types of motor housings are prepared to accommodate and hold the bearings. I needed to. Furthermore, even if the motor housing were to be shared, it would be necessary to use a custom-made high-speed bearing with a thicker outer ring, resulting in higher costs.

Therefore, in order to solve this problem, the present invention aims to provide a motor housing structure that can be used in common regardless of the rotational speed used and does not increase the cost of bearings, and a method for manufacturing the same. shall be.

[Means to solve the problem]

In view of the above objects, the present invention provides a central housing that accommodates a rotor, an O; an annular body forming a part of a rear housing that covers a rear end of the central housing and having a central hole having an inner diameter slightly larger than the outer diameter of the rotor; a disc body that is in close contact with the central hole and that cooperates with the annular body to configure the rear housing and accommodates a rear bearing that supports the rear end side of the output shaft; The inner diameter of the bearing groove that accommodates the front bearing is set to correspond to the dimensions of a bearing with a large outer diameter for low-speed rotation, and a collar member is set for a bearing with a small outer diameter for high-speed rotation. To provide a structure of a motor housing that can be used with an interposed motor housing.

Further, after the front housing, the central housing, and the annular body are integrally fixed by screw members, a holding jig for holding the integral housing assembly is inserted through the central hole of the annular body, and the integral housing assembly is assembled. The three-dimensional body is attached to a processing machine, and then the bearing groove of the front housing and the inner peripheral part of the annular body that is in close contact with the disk body are machined integrally, thereby forming the bearing groove of the front housing. and a motor housing according to claim 1, characterized in that when a disc body supporting the rear end side of the output shaft is mounted on the annular body, concentricity with a bearing center within the disc body is increased. Provides a method for manufacturing.

[For production]

After the front housing and the annular body are integrally fixed to the central housing with a screw member, the bearing groove of the front housing and the inner circumference of the annular body that forms a part of the rear housing are machined integrally. Increase the concentricity of the bearing. Bearings are housed in the bearing grooves of the motor housing manufactured in this way to support the front and rear of the output shaft.In the front housing, the bearing grooves are formed to match the dimensions of the large low-speed rotation bearings, and When used for rotation, a high-speed rotation bearing with a small outer diameter is interposed with a collar member to form a bearing portion. In this way, the motor housing according to the present invention can be used for both low-speed and high-speed applications without increasing costs, and there is no need to prepare multiple types of housings depending on the rotational speed used.

〔Example〕

The present invention will be described in more detail below based on embodiments shown in the accompanying drawings. The front side of a cylindrical central housing 10 with a stator 22 fixed therein is covered by a front housing 12. Further, the rear side is covered by two members constituting the rear housing, that is, an annular body 14 and a disc body 16. The front housing 12 and the disc body 16 are arranged to face the stator 22 fixed to the central housing 10, and support the front or rear part of the output shaft 20, which is fixed integrally with the rotor 18, using a bearing 30 or a bearing 30, respectively. It is supported by a bearing 28. Reference number 36 indicates the terminal box, and reference number 38
indicates a cooling fan.

-a, the front bearing of the output shaft of the motor receives a larger radial load than the rear bearing due to the load. Therefore, only the front bearing uses a larger external dimension bearing with higher radial load resistance than the rear bearing, but the bearing for low speed rotation cannot be used for high speed rotation, and a smaller sized bearing is required.

Therefore, in the present invention, the front shaft bearing 26 is formed to have a large dimension DI for low-speed rotation using the manufacturing method described later, and a bearing with a large outer diameter dimension, that is, the dimension D1, is used in a motor for low-speed rotation. However, in a high-speed rotation motor, a bearing 30 having an outer diameter smaller than the dimension DI is used by interposing a collar member 32 on the outer ring side. This collar member 32 is attached to the front housing 1 by adhesive or shrink fitting.
It is fixed integrally with 2. Furthermore, for cost reduction and other reasons, the same type of output shaft 20 is commonly used for the low-speed motor and the high-speed motor.

Next, a method of manufacturing a housing assembly according to the present invention will be described. Central housing lO, each consisting of a cast part
The front housing 12 and the annular body 14 forming a part of the rear housing are integrally fixed by screw members (not shown). At this time, the front bearing groove 26 of the front housing 12 and the annular body 14
The inner circumferential surface 24 of each is cast to a size that leaves a machining allowance. The stator 22 is fixed to the central housing 10 in advance, and an opening mandrel jig is inserted from the rear of the housing assembly, and the mandrel is pushed out and brought into contact with the inner peripheral surface of the stator 22, whereby the housing assembly is completed. The solid body is opened and fixed to a mandrel, and the rear part of the opened mandrel is gripped and fixed to a chuck of a lathe, for example.

In this state, while rotating the housing assembly consisting of the front housing 12, the central housing 10, the annular body 14, and the stator 22, the front shaft portion 26 of the front housing 12 is cut to a precise dimension D1. Further, the rear part of the open mandrel used here has an outer diameter that is sufficiently smaller than the inner diameter of the stator 22. Therefore, it is also possible to cut the inner circumferential surface 14 of the annular body 14 to a predetermined dimension D2, which in turn makes it possible to form the inner circumferential surface 24 and the front bearing groove 26 concentrically. .

On the other hand, the disc body 16, which cooperates with the annular body 14 to constitute the rear housing, is formed in a separate process so that it can come into close contact with the inner circumferential surface 24 of the annular body 14. Further, a rear bearing groove 27 is formed concentrically with the central axis of the disc body 16. The outer diameter dimension of this disc body 16 and the dimension D2 of the inner circumferential surface 24 of the annular body 14 are dimensions that allow the rotor 18 to be inserted when assembling the motor. A small dimension is desirable, so dimension D2 is set slightly larger than the outer diameter of rotor 18.

After the front bearing groove 26 and the inner circumferential surface 24 of the annular body 14 are formed concentrically by the above method, the rotor 18 and the rear bearing are integrally formed with the collar member 32, the front bearing 30, and the output shaft 20. 28 and the disk body 16 are assembled in sequence,
A high-speed motor is completed. The only difference is that in the low-speed motor, a bearing with a large outer diameter DI is used instead of the front bearing 30 and the collar member 32. The present invention employs an integrated housing processing method that increases the accuracy of the output when the motor is assembled and the concentricity of the front and rear bearings of the force shaft 2o, which causes resonance even in high-speed rotation motors. It becomes possible to provide a highly reliable motor that does not cause damage.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the housing can be made common to both low-speed motors and high-speed motors, regardless of the rotational speed of the motor, and the concentricity of the front and rear bearings can be improved. Since accuracy can be improved, it is possible to provide a highly reliable motor at low cost.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view schematically showing an example of a motor having a motor housing structure according to the present invention. 10... Central housing, 12... Front housing,
14... Annular body, 16... Disc body, 18
... Rotor, 28... Rear bearing, 30.
...Front bearing, 32...Collar member.

Claims (1)

[Scope of Claims] 1. A central housing that accommodates a rotor, a front housing that accommodates a front bearing that supports an output shaft integrated with the rotor and that covers the front end of the central housing, and a front housing that covers the front end of the central housing; an annular body constituting a part of a rear housing that covers the rear end, and having a central hole having an inner diameter slightly larger than the outer diameter of the rotor;
a disc body that is in close contact with the central hole of the annular body and that cooperates with the annular body to constitute the rear housing and accommodates a rear bearing that supports the rear end side of the output shaft; In the front housing, the inner diameter of the bearing groove that accommodates the front bearing is set to correspond to a bearing with a large outer diameter for low-speed rotation, and is set to correspond to a bearing with a small outer diameter for high-speed rotation. , a structure of a motor housing that can be used with a collar member interposed therebetween. 2. After the front housing, the central housing, and the annular body are fixed together with screw members, a holding jig for holding the integral housing assembly is inserted through the central hole of the annular body to secure the integral housing assembly. Attach the solid to the processing machine,
Next, the bearing groove of the front housing and the inner peripheral portion of the annular body that is in close contact with the disc body are integrally machined,
This increases the degree of concentricity between the bearing groove of the front housing and the bearing center within the disc body when the disc body bearing the rear end side of the output shaft is mounted on the annular body. A method of manufacturing a motor housing according to claim 1.