Housing, rotating electrical machine using the same, and method of manufacturing housing of rotating electrical machine

An object is to assemble a housing to a mating bracket with high accuracy and to improve the reliability of a rotating electrical machine. A housing of a rotating electrical machine according to the present invention is a housing of a rotating electrical machine that accommodates a stator of the rotating electrical machine and is supported by a support member, the housing including: a first tab that forms a first through-hole through which a first screw passes; and a second tab that forms a second through-hole through which a second screw passes and forms a fitting portion that fits with a position adjustment member, wherein the first tab is formed such that a first facing surface facing the support member of the first tab is farther from the support member than a second facing surface facing the support member of the second tab.

TECHNICAL FIELD

The present invention relates to a housing, a rotating electrical machine using the housing, and a method of manufacturing the housing of the rotating electrical machine.

BACKGROUND ART

Higher output is required for a motor for an automobile, a generator, or a drive motor, and, for higher output, size of a rotating electrical machine is also increased. In this manner, it is becoming important to improve the reliability in a case where a rotating electrical machine is fixed to a support member.

For example, when a stator core is fixed to a fitted housing, a first tab, on which only a hole of a bolt is formed, and a second tab, on which both a bolt hole and a knock hole for dowel pin are formed, are provided (PTL 1).

However, the technique described in PTL 1, in which tightening and fixing with a bolt are performed after positioning with a dowel pin is performed, does not describe a problem regarding lowering in attaching accuracy and positioning accuracy due to variations at the time the first tab and the second tab are formed.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

An object of the present invention is to assemble a housing to a mating bracket with high accuracy and to improve the reliability of a rotating electrical machine.

Solution to Problem

A housing of a rotating electrical machine according to the present invention is a housing of a rotating electrical machine that accommodates a stator of the rotating electrical machine and is supported by a support member, the housing including: a first tab that forms a first through-hole through which a first screw passes; and a second tab that forms a second through-hole through which a second screw passes and forms a fitting portion that fits with a position adjustment member, wherein the first tab is formed such that a first facing surface facing the support member of the first tab is farther from the support member than a second facing surface facing the support member of the second tab.

Advantageous Effects of Invention

According to the present invention, a housing can be assembled to a mating bracket with high accuracy, and the reliability of a rotating electrical machine can be improved.

DESCRIPTION OF EMBODIMENTS

FIG.1is an exploded perspective view of a rotating electrical machine100according to the present embodiment.

The rotating electrical machine100is configured with a rotor200, a stator300, and a housing400. In particular, higher output is required for a motor for an automobile, a generator, or a drive motor, and, for higher output, size of a rotating electrical machine is also increased.

The rotor200is configured with a plurality of rotor cores and a permanent magnet. A plurality of the rotor cores are aligned in a rotation axis direction and skewed with each other.

The stator300is formed of a divided core, and is configured with a coil wound around the core. The outer periphery of stator300is fixed to the inner periphery of the housing400by shrink fitting.

The housing400has a large plate thickness in order to withstand the vibration caused by a vehicle along with an increase in size of the rotating electrical machine100.

On the other hand, the housing400is manufactured by drawing to improve the productivity. However, with the increase in a plate thickness, the manufacture by drawing is becoming difficult.

FIG.2is an external perspective view of the rotating electrical machine100according to the present embodiment.

The housing400includes two first tabs410facing each other across the rotor200and two second tabs420facing each other across the rotor200. Each of the two first tabs410forms a first through-hole411through which a first screw601described later passes. Each of the two second tabs420forms a second through-hole421through which the second screw602passes, and a fitting portion422that fits with a position adjustment member701.

FIG.3is a schematic side view showing a state in which the housing400according to a comparative example is fixed to a support member500.

The housing400is supported on the support member500by the first screw601and the second screw602. Positioning of the housing400and the support member500is performed by the position adjustment member701. The support member500forms a fitting portion501that fits with the position adjustment member701. The position adjustment member701is also referred to as a dowel pin.

The first tab410has a first facing surface415facing the support member500, and the second tab420has a second facing surface425facing the support member500. The first tab410of the housing400according to the comparative example is formed such that the first facing surface415is closer to the support member500than an edge of the housing400or the second facing surface425.

In this case, the first facing surface415of the first tab410comes into contact with the support member500, and the housing400becomes in an inclined state. Then, the second facing surface425is in an inclined state with respect to the support member500. In such a state, between the housing400and the support member500, the fitting portion422of the second tab420and the fitting portion501of the support member500are positioned by the position adjustment member701.

There has been a problem that, when the second facing surface425is inclined with respect to the support member500, the fitting portion422is inclined with respect to the support member500, and the position adjustment member701cannot be fitted to the fitting portion422, which makes positioning difficult. Alternatively, a hole diameter of the fitting portion422of the second tab420can be increased to enable fitting even when the second tab420is inclined, so that the position adjustment member701can be fitted. However, in this case, another problem that the positioning accuracy is deteriorated occurs.

FIGS.4(a) to4(f)show a method of manufacturing the housing400according to the comparative example.

When manufacturing the housing400, in order to improve productivity, the housing400is manufactured from a roll material obtained by rolling through a drawing process in the order fromFIG.4(a)toFIG.4(f).

As shown inFIG.4(a), a roll material810passes is finished to a predetermined size by allowing a plate-like material to pass between a plurality of rotating rolls.

As shown inFIG.4(b), the blank material820is punched by pressing the roll material810into a predetermined shape.

As shown inFIGS.4(c) and4(d), a drawing material830is processed into a pot shape by drawing the blank material820. A trimming material840has a substantially cylindrical shape after a bottom portion831and an outer peripheral portion832of the drawing material830are trimmed.

As shown inFIGS.4(d) and4(e), a tab planarizing process material850is formed by pressing a tab intermediate material841by a first jig851and a second jig852and planarized.

As shown inFIG.4(f), a housing final shape860is completed by performing the planarizing process through the tab planarizing process.

It is known that the rolled material shown inFIGS.4(a) to4(f)has different properties in a rolling direction and in a direction (for example, 45° direction, 90° direction) at an angle to the rolling direction. This anisotropic phenomenon also affects an amount of springback after bending.

For this reason, in the tab planarizing process material850shown inFIG.4(e), springback appears in various manners as shown in the housing final shape860, even if all the tabs are pressed under the same conditions, and a distance between the first facing surface415and the support member500and a distance between the second facing surface425and the support member500are different. It is difficult to make these distances the same, and the manufacturing variation as shown inFIG.3may occur.

In view of the above, a method of manufacturing the housing according to the present embodiment will be described hereinafter.

The steps shown inFIGS.4(a) and4(b)are the same as the steps of the comparative example.FIG.5(a)is a bottom view and a cross-sectional view showing a third step of the method of manufacturing the housing400according to the present embodiment.FIG.5(b)is a bottom view and a cross-sectional view showing a fourth step of the method of manufacturing the housing400according to the present embodiment.

The drawing material830is processed into a cylindrical shape by drawing the blank material820. At this time, the drawing material830is formed, so that a distance from the support member500becomes larger from a connecting portion836connecting a main body834and a flange portion835corresponding to the first tab410and the second tab420formed later along a direction toward a tip837of the main body.

As shown inFIG.5(c), the tab planarizing process material850is formed by pressing the tab intermediate material841by the first jig851and the second jig852and planarized. However, at this time, only the second tab420is planarized.

As shown inFIG.5(d), the housing final shape860is completed by performing the planarizing process through the tab planarizing process. The first tab410is formed so that a distance from the support member400becomes larger along a direction from the connection portion441to a tip452of a main body430because the first tab410is not planarized. In this manner, the first facing surface415can be formed farther from the support member500than the second facing surface425.

FIG.6is a schematic side view showing a state in which the housing400by the manufacturing method according to the present embodiment is fixed to the support member500.

The first facing surface415of the first tab410facing the support member500is formed farther from the support member500than the second facing surface425facing the support member500of the second tab420. In this manner, the second facing surface425can be made substantially parallel to the support member500, and the position adjustment member701and the fitting portion422can be fitted without the need of increasing the hole diameter of the fitting portion422, and positioning accuracy can be improved.

Further, after the housing400is positioned on the support member500, the first tab410can be bent and assembled by tightening the first screw601, and the reliability against the vibration of a vehicle can be improved.

FIG.7is an enlarged view around the first tab410shown inFIG.6.

Around the first tab410of the housing400is configured with the connection portion441connecting the main body430forming storage space of the housing400and the first tab410, and a first tab main body450forming the first through-hole411.

The first tab main body450forms a surface451that has a flush surface442with an edge431of the main body430of the housing400. The first tab main body450is formed such that a distance from the support member500increases along a direction from the connection portion441to the tip452of the first tab main body450.

REFERENCE SIGNS LIST