JP2023014680A - Housing, stator unit, motor and manufacturing method of stator unit - Google Patents

Abstract

[Problem] To reduce compressive stress when joining a stator and a housing. [Solution] The housing 22 has a cylindrical shape, and the stator is joined to the inner peripheral surface 22A. A groove 31 for filling with brazing material is formed in the inner peripheral surface 22A of the housing 22. The groove 31 has a spiral shape. A supply port 32 that communicates with the groove 31 and supplies brazing material to the groove 31 is formed in an end face 22B of the housing 22 in the insertion direction D of the stator. The housing 22 has a flow path for circulating a coolant. [Selected Figure] Figure 3

Description

The present invention relates to a housing, a stator unit, a motor, and a method of manufacturing the stator unit.

In some motor structures, a housing is joined to the outer peripheral surface of a stator that holds windings. As a method for joining the stator and the housing, shrink fitting, metal-to-metal joining by aluminum plating (aluminum plating method), and the like are used. For example, as a structure for suppressing deformation of the stator at the time of joining by shrink fitting or press fitting, a structure is disclosed in which a weld provided on the stator and a flange provided on the housing are arranged at positions corresponding to each other. (Patent Document 1).

JP 2014-82935 A

When the stator and housing are joined by shrink fitting, aluminum plating, or the like, compressive stress is generated in the stator due to the stress load due to the interference fit and the difference in coefficient of thermal expansion between the stator and the housing. Such compressive stress should be reduced as much as possible, since it may cause deterioration of the performance of the motor.

Therefore, one of the problems to be solved by the present invention is to provide a housing, a stator unit, a motor, and a method of manufacturing a stator unit that can reduce compressive stress when joining the stator and the housing.

According to one aspect of the present invention, there is provided a housing having a cylindrical shape and having an inner peripheral surface to which a stator is joined, wherein a groove for filling a brazing material is formed in the inner peripheral surface. is.

Another aspect of the present invention is a stator unit including a stator and a housing, wherein a groove for filling a brazing material is formed in the inner peripheral surface of the cylindrical housing, and the outer peripheral surface of the stator and the inner peripheral surface of the housing are formed. It is characterized in that the peripheral surface is brazed with a brazing material filled in the groove.

Another aspect of the present invention is a motor including the stator unit.

According to another aspect of the present invention, there are provided a step of inserting a stator into a cylindrical housing, a step of supplying a brazing filler metal into a groove formed in an inner peripheral surface of the housing, and a step of placing the stator and the housing relative to each other. and a step of melting the brazing material by frictional heat generated by rotating the stator unit.

FIG. 1 is an exploded perspective view showing an example of the configuration of the motor according to the embodiment. FIG. 2 is a partially see-through perspective view showing an example of the configuration of the stator unit according to the embodiment. FIG. 3 is a perspective view showing an example of the structure of the housing according to the embodiment; 4 is a sectional view taken along line IV-IV in FIG. 3, showing an example of the structure of the housing according to the embodiment. FIG. 5 is a flow chart showing an example of a method for manufacturing the stator unit according to the embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configurations of the embodiments described below and the actions and effects brought about by the configurations are examples, and the present invention is not limited to the following descriptions.

FIG. 1 is an exploded perspective view showing an example of the configuration of a motor 1 according to an embodiment. A motor 1 according to this embodiment has a stator unit 11 , windings 12 , a rotor 13 , bearings 14 and 15 and a shaft 16 .

The stator unit 11 is a member that holds the windings 12 . The stator unit 11 has a cylindrical shape, and the windings 12 are fixed to the inner circumference of the stator unit 11 . The winding 12 is connected to a power supply via wiring, and generates a magnetic field according to power (current) supplied from the power supply. The rotor 13 is a cylindrical member made of a conductor and contains permanent magnets. The rotor 13 is inserted inside the stator unit 11 along the insertion direction D, is rotatably supported by bearings 14 and 15 , and rotates according to the magnetic field generated by the windings 12 . The shaft 16 is a cylindrical member extending along the insertion direction D, rotates together with the rotor 13, and transmits rotational force to a predetermined mechanism. The configuration shown in FIG. 1 is an example, and the configuration of the motor 1 is not limited to this.

FIG. 2 is a partially see-through perspective view showing an example of the configuration of the stator unit 11 according to the embodiment. A stator unit 11 according to this embodiment includes a stator 21 and a housing 22 . In FIG. 2, a portion of the housing 22 is shown transparently.

The stator 21 is a tubular member, and is made of a material containing, for example, electromagnetic steel as a main component. Winding 12 is arranged so as to be in contact with end surface 21A of stator 21 in insertion direction D. As shown in FIG. A plurality of recesses 21C extending along the insertion direction D are formed on the outer peripheral surface 21B of the stator 21 . The stator 21 functions together with the windings 12 as a member that generates a magnetic field.

The housing 22 is a tubular member, and is made of a material containing aluminum as a main component, for example. 22 A of inner peripheral surfaces of the housing 22 are joined to the outer peripheral surface 21B of the stator 21 . The housing 22 has functions such as protecting the stator 21 and the windings 12 and cooling the stator 21 (promoting heat dissipation).

In the stator unit 11 according to this embodiment, the stator 21 and the housing 22 are joined by brazing. The structure of the housing 22 for effectively joining the stator 21 and the housing 22 by brazing will be described below.

FIG. 3 is a perspective view showing an example of the structure of the housing 22 according to the embodiment. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, showing an example of the structure of the housing 22 according to the embodiment.

As shown in FIGS. 3 and 4, the inner peripheral surface 22A of the housing 22 according to this embodiment is formed with a spiral groove 31 for filling with a brazing material. By rotating the stator 21 and the housing 22 relative to each other with the brazing material filled in the grooves 31 to generate frictional heat, the brazing material in the grooves 31 is melted, and the stator 21 and the housing 22 are separated. They can be joined by brazing. As a result, the stator 21 and the housing 22 can be joined together without generating a large compressive stress on the stator 21 .

The shape of the groove 31 is not limited to the shape shown in FIGS. Any shape may be used as long as a sufficient bonding strength can be obtained. In FIGS. 3 and 4, one connected helical groove 31 is illustrated, but it may be, for example, a helical shape divided into a plurality of parts.

Further, as shown in FIG. 3, a supply port 32 that communicates with the groove 31 is formed in the annular end surface 22B in the insertion direction D of the housing 22 . The brazing material can be supplied into the groove 31 from the supply port 32 . By forming the supply port 32 in this manner, the groove 31 can be filled with the brazing material after the stator 21 is inserted into the housing 22 . Note that FIG. 3 illustrates a configuration in which one supply port 32 is formed in the end surface 22B, but the form of the supply port 32 is not limited to this. For example, a plurality of supply ports 32 may be formed in the end surface 22B.

Further, as shown in FIG. 4, a flow path 41 for circulating the coolant may be formed inside the body of the housing 22 . The flow path 41 communicates with a mechanism for circulating the coolant through a predetermined pipe. By forming such a flow path 41, the effect of cooling the stator 21 can be improved.

A method of manufacturing the stator unit 11 having the configuration described above will be described below.

FIG. 5 is a flow chart showing an example of a method for manufacturing the stator unit 11 according to the embodiment.

First, an insertion step (S11) is performed to insert the stator 21 into the interior of the housing 22 (the space inside the inner peripheral surface 22A). Through the insertion process, the inner peripheral surface 22A of the housing 22 and the outer peripheral surface 21B of the stator 21 are brought into close contact with each other. At this time, since the stator 21 and the housing 22 are joined by brazing as will be described later, there is no need for a high pressure force unlike conventional shrink fitting. By using such an insertion process, it is possible to reduce the stress load applied to the stator 21 because it is not necessary to assemble by interference fit.

After that, a brazing material supply step (S12) is performed to fill the grooves 31 of the housing 22 with the brazing material. In this embodiment, powdery or granular brazing material is supplied from the supply port 32 of the housing 22 . The material of the brazing filler metal should not be particularly limited, but zinc-tin alloys, zinc-aluminum alloys, and the like can be used, for example. The melting point of the brazing material may be a temperature at which the brazing material can be melted by frictional heat between the stator 21 and the housing 22, and is preferably 400° C. or less, for example. The state of the brazing filler metal is not limited to powder or granules, and may be a paste having an appropriate viscosity.

After that, a friction melting step (S13) is performed in which the brazing material filled in the grooves 31 is melted by frictional heat generated by rotating the stator 21 and the housing 22 relative to each other. At this time, the rotation operation (rotational speed, etc.) is performed so that the frictional heat exceeds the melting point of the brazing filler metal.

After that, a cooling step (S14) is performed to join the stator 21 and the housing 22 by cooling and solidifying the brazing material. As a result, the stator 21 and the housing 22 are firmly joined with the brazing material.

As described above, according to the present embodiment, the grooves 31 for filling the brazing material are formed in the inner peripheral surface 22A of the housing 22, and the brazing material filled in the grooves 31 by frictional heat between the stator 21 and the housing 22 is dissolved. As a result, the stress load due to the interference fit and the compressive stress caused by the difference in coefficient of thermal expansion can be reduced, and the stator 21 and the housing 22 can be firmly joined.

Although the embodiments of the present invention have been described above, the above-described embodiments and modifications thereof are merely examples, and are not intended to limit the scope of the invention. The novel embodiments and modifications described above can be embodied in various forms, and various omissions, replacements, and modifications can be made without departing from the spirit of the invention. The embodiments and modifications described above are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1 motor 11 stator unit 12 winding 13 rotor 14, 15 bearing 16 shaft 21 stator 21A end surface 21B outer peripheral surface 21C recess 22 housing 22A inner peripheral surface 22B end surface 31 groove 32 supply port 41 flow path D insertion direction

Claims (13)

A housing having a cylindrical shape and having a stator joined to its inner peripheral surface,
a groove for filling the brazing material is formed on the inner peripheral surface;
housing. the groove has a helical shape,
A housing according to claim 1. A supply port for supplying the brazing filler metal to the groove is formed in an end face of the stator in the insertion direction, and communicates with the groove.
3. A housing according to claim 2. Having a flow path for circulating the refrigerant,
A housing according to any one of claims 1-3. A stator unit including a stator and a housing,
A groove for filling a brazing filler metal is formed on the inner peripheral surface of the cylindrical housing,
The outer peripheral surface of the stator and the inner peripheral surface of the housing are brazed with the brazing material filled in the grooves,
stator unit. the groove has a helical shape,
A stator unit according to claim 5. A supply port communicating with the groove and for supplying the brazing filler metal to the groove is formed in an end face of the housing in the insertion direction of the stator.
A stator unit according to claim 6. The housing comprises a flow path for circulating a coolant,
A stator unit according to any one of claims 5-7. A motor comprising the stator unit according to any one of claims 5 to 8. a step of inserting the stator inside the cylindrical housing;
supplying a brazing material to a groove formed in the inner peripheral surface of the housing;
a step of melting the brazing material by frictional heat generated by relatively rotating the stator and the housing;
A method of manufacturing a stator unit comprising: the groove is helical in shape,
A method of manufacturing a stator unit according to claim 10 . The melting point of the brazing material is 400° C. or less.
A method of manufacturing a stator unit according to claim 10 or 11. The brazing material supplied to the grooves is in the form of powder, granules, or paste.
A method for manufacturing a stator unit according to any one of claims 10 to 12.

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