CN1077346C

CN1077346C - Armature core of DC motor

Info

Publication number: CN1077346C
Application number: CN95109340A
Authority: CN
Inventors: 古西启一
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1995-08-10
Filing date: 1995-08-10
Publication date: 2002-01-02
Anticipated expiration: 2015-08-10
Also published as: CN1142703A

Abstract

The present invention relates to an armature core of a DC motor. A plurality of lightening holes extending in an axial direction are arranged between an inserted hole of a shaft and the bottom of a groove, wherein the ratio B/A of the spacing B between the bottom of the groove and the lightening holes and the minimum width A of a gear is not smaller than 1.5 or larger than 3.0. Thus, the present invention can effectively reduce the weight of the armature core, and avoid torque form dropping simultaneously.

Description

The armature core of DC motor

The present invention relates to the armature core of the DC motor used in a kind of for example engine starter.

Fig. 4 is the perspective view of the armature of disclosed the sort of traditional DC motor among the Japanese publication 61-26454.Among the figure, axle 2 is with pack into the core of cylindrical armature core 1 of the mode that is pressed into cooperation.The outer peripheral edge portion of armature core 1 has many axially extended grooves 4.Coil 3 embeds in these grooves 4, is connected with commutator 5 respectively.

Fig. 5 is the front view of traditional electrical armature core 1.Tooth 6 is equipped with respectively between two grooves 4 that adjoin each other.The core of armature core 1 has the shaft insertion hole 7 that inserts axle 2 usefulness.

Above-mentioned traditional armature core 1 is made of many taggers of banking up vertically, thereby very heavy.Everybody is in the weight of making great efforts to manage to alleviate as far as possible armature core.

In order to address the above problem, the purpose of this invention is to provide the armature core that a kind of effectively weight reduction can be avoided the DC motor that torque reduces simultaneously again.

According to DC motor armature core provided by the present invention many axially extended grooves are arranged, for embedding the coil usefulness that is arranged radially on the outer peripheral edge portion unshakable in one's determination, be formed with tooth between each abutting groove respectively, core unshakable in one's determination has shaft insertion hole.Have axially extended lightening hole between the shaft insertion hole of DC motor armature core and the trench bottom, the ratio of the minimum widith A of spacing B between wherein said trench bottom and the lightening hole and tooth is got 1.5≤B/A≤3.0.

Fig. 1 is the front view of the DC motor armature core of one embodiment of the invention.

Fig. 2 is the graph of relation that the size of lightening hole influences torque.

Fig. 3 is the graph of relation that the size of lightening hole influences armature core weight.

Fig. 4 is the perspective view of an example of traditional DC motor armature.

Fig. 5 is the front view of the armature core of Fig. 4.

Below referring to description of drawings one embodiment of the present of invention.Fig. 1 is the front view of the DC motor armature core of one embodiment of the invention.Referring to Fig. 1, the outer peripheral edge portion of present embodiment armature core 11 radially has many axially extended grooves 12.Be formed with tooth 13 respectively between two abutting grooves 12.The core of armature core 11 is formed with shaft insertion hole 14, and axle 2 (Fig. 4) are promptly in the mode patchhole 14 with interference fit.

Four lightening hole 15a to 15d are opened in the radially outer position of shaft insertion hole, promptly between shaft insertion hole 14 and groove 12 bottoms, pass armature core 11 vertically.The cross section of each lightening hole 15a to 15d limits (being fan-shaped basically) by isocentric circular arc.

These lightening holes 15a to 15d has been arranged, can alleviate the weight of armature core 11.Yet, if the spacing B between groove 12 bottoms and the lightening hole 15a to 15d reduces because of the cross section expansion of weight hole 15a to 15d, will make that the cross section of magnetic circuit reduces in the armature core, especially can reduce the torque of DC motor.

Fig. 2 is that the size to lightening hole 15a to 15d influences the graph of relation that the situation of torque experimentizes and drawn.B/A on the horizontal axis represents the ratio of the minimum widith A of spacing B between groove 12 bottoms and the lightening hole 15a to 15d and tooth 13, the T/T on the vertical axis ₀Then represent the torque T when torque T when motor has lightening hole 15a to 15d and motor do not have lightening hole 15a to 15d ₀Ratio.

As can be seen from Figure 2, B/A is less than 1.5 scope the time, and torque reduces and sharply descends with B/A's.For example, the value of B/A equals at 1 o'clock, and torque reduces by 10%, thereby makes motor lose practicality.On the other hand, the value of B/A preferably 1.5 or more than, this be since the torque decline scope quite little.

Fig. 3 is that the size to lightening hole 15a to 15d influences the relation curve that the situation of armature weight experimentizes and drawn.Represented the same among B/A on the horizontal axis and Fig. 2, the W/W on the vertical axis ₀Then represent the weight W when weight W when armature core 11 has lightening hole 15a to 15d does not have lightening hole 15a to 15d to armature core 11 ₀Ratio.

As can be seen from Figure 3, for alleviating the weight of armature core 11, the B/A value preferably get 3.0 or below.If B/A is just little from the benefit that weight reduction obtained greater than 3.0.

In sum, when offering lightening hole 15a to 15d, getting B/A is 1.5≤B/A≤3.0, can alleviate the weight of armature core effectively, avoids torque to descend simultaneously.Especially, when the B/A value was 2.0 left and right sides, actual effect was best.

For example, if the armature core 11 of present embodiment is applied on the DC motor of automotive engine starter, then the fuel cost efficient of automobile can improve because of armature core 11 weight savings.In addition, because the moment of inertia of armature diminished, thereby the impact of the gear ring (not shown) of the pinion (not shown) that can reduce starter and engine when meshing.In addition, armature since when rotating vibrations reduce, thereby can avoid wearing and tearing such as bearing.

Describe although the foregoing description is the DC motor with regard to engine starter, armature core of the present invention also can be used for the DC motor of other purposes.

In addition, though the number of the lightening hole 15a to 15d that is offered in the foregoing description is 4, in fact the number of lightening hole is not specifically limited.

Have, the shape of lightening hole cross section is not limited to those shapes that contains circular arc again.

Also have, although lightening hole is not specifically limited in the size of peripheral direction, the spacing on peripheral direction still should be enough big between the lightening hole 15a to 15d but respectively adjoin, so that the rotation of axle 2 is passed to whole armature core 11, accepts the coordinate force that is pressed into of axle 2 simultaneously.In addition, for the size between lightening hole 15a to 15d and the shaft insertion hole 14, also need to do same consideration.

Claims

1. the armature core of a DC motor, its outer peripheral edge portion radially offers many axially extended grooves, for the usefulness that embeds coil, form tooth respectively between each groove that adjoins each other, core unshakable in one's determination has shaft insertion hole, have axially extended lightening hole between described shaft insertion hole and described each trench bottom, it is characterized in that, the spacing B between described trench bottom and the described lightening hole gets 1.5≤B/A≤3.0 to the ratio of the minimum widith A of described tooth.

2. DC motor armature core according to claim 1 is characterized in that the cross section of a plurality of lightening holes is all limited by isocentric circular arc separately.

3. DC motor armature core according to claim 1 is characterized in that the B/A value is about 2.0.