JPH05316684A - Rotating electric machine - Google Patents

Abstract

PURPOSE:To make the key of a rotary electric machine easily removable and, at the same time, to prevent the damage of a bearing put on the rotating shaft of the machine when the key is removed. CONSTITUTION:Since a key gradually comes off upward from a shaft when a tool, such as a common head screw driver, etc., is struck with a hammer after the tool is inserted into a notch 5b and the front end of the tool is pressed against the bottom section of a key 8, the key 8 gradually comes out upward from the shaft 5, the key 8 can be surely removed from the shaft 5 while the tool does not act on the shaft 5. Therefore, a bearing put on the shaft 5 is not damaged, because the impact force of the hammer is not transmitted to a bearing through the shaft 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine, and more particularly to an improvement in a structure for mounting a rotary shaft and a key provided to mount a load on the rotary shaft.

[0002]

2. Description of the Related Art In a conventional rotary electric machine, for example, an electric motor, a key groove B is formed on a rotary shaft A as shown in FIGS. 3 (a) and 3 (b) in order to mount a load on the rotary shaft. A key C that fits into the key groove B is formed, and the key C
Is press-fitted into the key groove B of the rotary shaft A and the key groove of the load component (not shown), so that the load component is coupled to the rotary shaft A. Conventionally, the key C has a chamfered portion D formed on the bottom surface on the tip side, and in order to pull it out from the key groove B of the rotary shaft A, a tool such as a flat-blade screwdriver is used, and the tip of this tool is chamfered. It is inserted from the side of the taking part D between the key groove B and the rotary shaft A, and is removed from the rotary shaft A by hitting the tool with a hammer and applying an impact force to pry the key C from the key groove B at the tip of the tool. I am trying.

[0003]

In the prior art described above, when the key C is pulled out from the key B groove of the rotary shaft, a tool such as a flat-blade screwdriver is used from the chamfered portion D provided on the key C. Since the tool is inserted between C and the rotating shaft A and the tool is hit by a hammer to pull out, the impact force when hitting the tool acts on the rotating shaft, and the impact force moves from the rotating shaft A to the rotating shaft. Acts on the bearing to be supported, and therefore
The bearing may be damaged. Further, if the chamfered portion D is formed on the bottom surface of the key C, the surface pressure of the key with respect to the rotation axis A increases, and therefore the strength of the rotation axis key groove B must be increased. Yes,
Further, if the chamfered portion D is formed, the machining process is complicated by that much, and the cost of the key increases.

In view of the above circumstances, an object of the present invention is to provide a rotary electric machine in which the key can be easily removed and the bearing of the rotary shaft is not damaged when the key is removed.

[0005]

In the rotary electric machine of the present invention, a notch is provided at the end of the key groove of the rotary shaft, the notch communicating with the bottom surface of the key fitted and fixed in the key groove.

[0006]

In the present invention, as described above, since the notch is formed at the end of the key of the shaft, a tool such as a flat-blade screwdriver is inserted along the notch, and the tip of the tool is placed at the bottom of the key. Then, when the tool is hit with a hammer in that state, the impact force directly acts on the key, and the key 8 gradually comes out above the shaft 5, so that the key does not act on the shaft as in the prior art, and the key is removed. It can be pulled out securely and easily from the shaft. Therefore, the impact force when hitting the tool does not act on the bearing via the shaft, and there is no risk of damage to the bearing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the rotating electric machine of the embodiment shown in FIG. 1, a housing 1 is formed in a cylindrical shape with both ends open, a stator 3 is attached to the housing 1, and a shaft 5 is rotatably supported. The stator 3 is attached to the inner peripheral wall of the housing 1 and has a wound coil 4. The shaft 5 is supported by bearing brackets 2a and 2b attached to both ends of the housing 1 via respective bearings, and one end of the shaft 5 passes through one bearing bracket 2b to form an output shaft. The bearing brackets 2a and 2b close the openings at both ends of the housing 1, and are provided with air holes 10a and 10b for taking the outside air into the housing 1.
Further, a rotor 6 is provided at an intermediate position of the shaft 5 so as to face the stator 3, and the rotor 6 is a secondary conductor bar,
It has an end ring and a cooling fan 7. The cooling fan 7 is composed of a plurality of blade blades provided on both end surfaces of the end ring of the rotor 6 so as to project along the axial direction, and each of the blade blades is appropriately arranged in a plane orthogonal to the axial direction of the end ring. Are arranged radially with the length and width dimensions of. Furthermore, at the end that is inserted into the outside of the shaft 5,
A key 8 is attached for attaching a load component. The key 8 is press-fitted into a key groove 5a formed in the end portion of the shaft 5 along the axial direction and a key groove (not shown) formed in a component serving as a load, so that the shaft 5
Connect the load parts to.

A notch 5b is provided at the outer end of the key groove 5a of the shaft 5. This notch 5b
2 is tapered off at an appropriate angle at the outer end of the key groove 5a, as shown in FIGS.
It is designed to communicate with the bottom surface of the key 8 fitted and fixed in the key groove 5a, and the tip of a tool such as a flat-blade screwdriver is pressed against the key 8 through the notch 5b.
By hitting the tool toward the key 8, the key 8 can be pulled out from the shaft 5.

As described above, when the notch 5b is formed at the outer end of the key groove 5a of the shaft 5, the notch 5b is formed.
Insert a tool such as a flat-blade screwdriver along with, press the tip of the tool against the bottom surface of the key 8, and hit the tool with a hammer in that state, the impact force directly acts on the key 8,
Since the key 8 gradually comes out above the shaft 5, it does not act on the shaft 5 as in the prior art, and the key 8 can be reliably and easily removed from the shaft 5. Therefore, the impact force when hitting the tool does not act on the bearing via the shaft 5, and the bearing is not damaged. Further, the following effects are obtained as compared with the conventional technique. That is, since the notch 5b is formed in a tapered shape that widens from the middle position of the key groove 5a to the outer end portion, when a tool is inserted into the notch 5b,
Since the tool can be guided so that the tip of the tool inevitably hits the bottom surface of the key 8, the impact force when hitting the tool surely acts only on the key 8 and the workability is good. Further, since the key 8 is not provided with the chamfered portion as in the prior art, the transmission torque can be received on the entire surface of the key 8 and the strength of the key 8 can be maintained. Moreover, if the notch 5b is formed in the key groove 5a, the number of man-hours for processing the key is reduced by that much, and the cost of the key can be prevented from increasing.

[0010]

As described above, according to the present invention, the notch is formed at the end of the key groove in the shaft, and the notch is utilized so that the impact force at the time of removing the key causes the rotation shaft to move. Since the key is pulled out from the key groove so that it does not act on the bearing through the key, the key can be pulled out securely and easily, and there is a risk of damage to the bearing due to no impact force acting on the bearing. No need to consider the bearing every time the key is removed, and the strength of the key can be maintained by receiving the transmission torque over the entire surface of the key without cutting the key.
This has the effect of further increasing reliability.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of a rotating electric machine according to the present invention.

FIG. 2 is an enlarged sectional view (a) and a front view (b) of a partially broken view showing a mounted state of a key.

FIG. 3 is an enlarged explanatory view (a) and a front view (b) for explaining a state in which a key used in a conventional electric motor is partially broken.

[Explanation of symbols]

5 ... Shaft, 5a ... Key groove, 5b ... Notch, 8 ... Key.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Minor Eda, 7-1, 1-1 Narashino Higashi Narashino, Narashino City, Chiba Prefecture (72) Narashino Factory, Hitachi, Ltd. (72) Asami Watanabe 7-1 Higashi Narashino, Narashino City, Chiba Prefecture Issue Hitachi Keiyo Engineering Co., Ltd. (72) Inventor Noriyuki Kumamoto 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Keiyo Engineering Co., Ltd.

Claims (1)

[Claims] 1. A rotary electric machine comprising a key groove formed on a rotary shaft and having a key fitted and fixed in the key groove, wherein a key fitted and fixed in the key groove is provided at an end of the key groove of the rotary shaft. A rotary electric machine having a notch communicating with the bottom surface.