JP2008067555A - Rotor assembly and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor assembly where a driving force transmission component is assembled to a rotor which has a simple structure and can easily be manufactured, and in which multiple types of driving force transmission components can be readily installed, and to provide a method of manufacturing the assembly. <P>SOLUTION: The rotor 3 is made into a simple shape fitted to press forming, and a bending part 3e as a projection that becomes one fastening means to an opposite member by press forming is formed. A notched groove 2a that becomes as the other fastening means is arranged in the circular driving force transmission component that becomes the opposite member. At assembling, the rotor 3 is press-fitted and fixed to the circular driving force transmission component, while the projection 3e is positioned to the notched groove 2a, and the projection 3e is stopped of coming off so that it will not be removed from the notched groove 2a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotor assembly in which a rotor that is simply formed by press molding is fitted and fixed to a worm wheel by simple positioning and fixing means, and a method for manufacturing the same.

Conventionally, a rotor of an electromagnetic clutch is integrated with a driving force transmission component, for example, a pulley provided with a plurality of V grooves for engaging a multistage V-belt to receive the rotational force of a driving source (for example, an engine or the like). I have. Since the V-groove has a complicated shape, it is mainly formed by casting (for example, see Patent Document 1) or forging (for example, see Patent Document 2).
For example, in the casting example of Patent Document 1, the clutch rotor is formed of a magnetic material such as iron, has a circular U-shaped cross section that covers the drive coil from the front, and a multi-stage V-belt is hung on the outer peripheral surface. A pulley to be passed is formed.

  Further, for example, in the example of forging in Patent Document 2, the rotor is provided with a rotor inner wall, an outer wall, and an intermediate intermediate ring as separate bodies, and a nonmagnetic material is filled between the inner wall, The outer wall and the intermediate ring are integrated, and the magnetic shielding part is formed of a nonmagnetic material. The outer wall of the rotor is integrally provided with a pulley around which a belt is stretched.

  The non-bridge type rotor requires positioning such as centering when the inner wall, the intermediate ring, and the outer wall are joined via the non-magnetic material. For this reason, the assembly processability is poor and the number of parts is large, so that there is a problem that the manufacturing cost increases. In the case of this forging, a plurality of forged products are joined by welding.

  Further, a sheet metal pulley (see, for example, Patent Document 3) is also formed by drawing a sheet material into a cup shape. In this case, since the pulley is formed by drawing, the shape of the rotor as in the casting cannot be made U-shaped in cross section, and the level of the multi-stage V-shaped groove is roughly provided in the flat plate material. It becomes processing. For this reason, the sheet metal pulley must be fixed to the rotor by fixing means such as a large number of bolts.

Furthermore, the fixing between the rotor and the driving force transmission component is performed by forming a fixing groove on the outer surface of the rotor or by using another fixing component.
JP-A-2-304221 JP-A-8-114240 Japanese Utility Model Publication No. 6-87736

However, in either case, since manufacturing equipment and manufacturing time are required, it is not suitable for mass production using a line.
For example, in forging, it is difficult to process a rotor having a U-shaped cross section and a thin outer cylindrical portion, and the primary processed products formed in a divided manner must be connected by welding or the like so as to have a desired shape as a whole. As described above, the conventional rotor processing method has various problems.
For this reason, it is difficult to mass-produce the rotor of the electromagnetic clutch in the flow line, and the manufacturing cost becomes high. Another factor is that the conventional electromagnetic clutch has a large number of parts, which increases the cost. In addition to the V belt, there are other means for rotating the rotor. The number of parts that can be used in common with the entire clutch is small. Further, the rotor is not lightweight, easy to manufacture, and does not have a structure that can handle various types of driving force transmission mechanisms.

  In addition, when the rotor and the driving force transmission component are fixed to each other, a groove that is formed on the outer surface of the rotor as described above requires another machining after the rotor is press-molded. Therefore, there is a disadvantage that mass production cannot be performed on a flow work line, and manufacturing costs are increased.

  In view of the above problems, an object of the present invention is to provide a rotor assembly in which the driving force transmission component is assembled to a rotor that has a simple configuration, is easy to manufacture, and can easily mount various types of driving force transmission components. It is to provide a manufacturing method.

In order to achieve the above object, the present invention employs the following means.
In the present invention, the rotor has a simple shape suitable for press molding, and at the same time, a bent portion serving as one of the locking means for the mating member is formed simultaneously by press molding, so that the annular driving force transmission component serving as the mating member is formed. A notch groove is provided as the other of the locking means, and during assembly, the rotor is press-fitted and fixed to the annular driving force transmission part while positioning the bent portion in the notched groove, and the bent portion is detached from the notched groove. And a rotor assembly manufactured by the method. Specifically:
(1) The rotor assembly is
An outer cylindrical portion having an annular plate portion, an inner cylindrical portion having an end portion provided at right angles to an inner end of the annular plate portion, and an outer cylindrical portion having an end portion provided at right angles to an outer end of the annular plate portion; A rotor provided with one or more arbitrary number of convex portions facing outward in the cylindrical portion;
It consists of an annular driving force transmission component with one or more notch grooves on the inner surface,
The convex portion of the rotor is positioned and fixed in the notch groove of the driving force transmission component, and the outer cylindrical portion of the rotor is press-fitted and fixed to the annular driving force transmission component.
(2) The rotor assembly described in (1) above is
The convex portions are provided in the rotor at predetermined intervals in the circumferential direction around the axis, and the notch grooves are provided on the inner surface of the driving force transmission component at the predetermined intervals in the circumferential direction. It is characterized by that.
(3) The rotor assembly according to the above (1) or (2) is
The convex portion is a bent portion formed by forming two pairs of cuts at a predetermined interval in a portion corresponding to the outer cylindrical portion of the rotor and bending the cut and raised pieces defined by the cut. It is characterized by.
(4) The rotor assembly according to any one of (1) to (3),
The ratio of the circumferential width of the convex portion to the thickness in the axial direction is in a range from 1.2: 1 to 2: 1.
(5) The rotor assembly according to any one of (1) to (4) above,
The driving force transmission component is a worm wheel made of synthetic resin.
(6) The rotor assembly according to any one of (1) to (5),
The rotor is formed by press-molding a metal plate.
(7) The method for manufacturing the rotor assembly is as follows:
An outer cylindrical portion having an annular plate portion, an inner cylindrical portion having an end portion provided at right angles to an inner end of the annular plate portion, and an outer cylindrical portion having an end portion provided at right angles to an outer end of the annular plate portion; An annular transmission part is inserted from the opposite side of the opening end into the rotor having one or more convex parts directed outwardly on the cylindrical part, and the convex part of the rotor is cut off from the annular transmission part. A first procedure for press-fitting the annular transmission part into the outer surface of the rotor in accordance with a notch groove;
And a second procedure for fitting a stopper into the notch groove so as to prevent the protrusion from coming out when the convex part is in the depth of the notch groove.

The rotor of the present invention has a simple and simple structure, and the bent portion can be easily formed by press-molding a metal plate. Therefore, manufacturing becomes easy and large-scale, continuous, and automated production can be performed by a machine.
The rotor can be press-fitted and fixed to the driving force transmission component while positioning the bent portion of the rotor in the notch groove of the driving force transmission component. Therefore, the rotor and the driving force transmission component can be firmly fixed.

Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a rotor assembly provided with a worm wheel in the rotor of the present invention. However, the worm screw is not included in the rotor assembly, as indicated by the dotted line.
FIG. 1 shows an example of a worm wheel among various driving force transmission components.
FIG. 2 is an explanatory diagram of the rotor of the present invention. 2A is a cross-sectional view taken along the line AA in FIG. 2B, FIG. 2B is a plan view of the rotor, and FIG. 2C is a view as viewed from B in FIG.

The rotor assembly 1 of the present invention is assembled by press-fitting the worm wheel 2 and the rotor 3 while positioning.
As shown in FIG. 2, the rotor 3 is formed into a U-shaped cross section (a cross section cut radially from the axis center is U-shaped) by press forming means. In order to form a U-shaped cross section, an annular plate portion 3a, an inner cylindrical portion 3b provided with an end portion perpendicular to the inner end of the annular plate portion 3a, and an end portion perpendicular to the outer end of the annular plate portion 3a are provided. It consists of a continuous outer cylindrical portion 3c.
A stator core (not shown) having an electromagnetic coil (not shown) is accommodated in the U-shaped section of the rotor 3.
The rotor 3 is made of a magnetic material. Preferably, low carbon steel such as cold rolled steel of JIS standard is used.
In the annular plate portion 3a, an arcuate slit 3d serving as a magnetic shielding portion is formed by punching.
In the outer cylindrical portion 3c, a plurality of spaced-apart cut pieces are formed as bent portions 3e by cutting a predetermined length in the axial direction (in the direction of the central axis of the rotor) from the open end. A notch 3f is formed, and a strip-shaped piece between the notches 3f is bent outward by about 90 ° to form a bent portion 3e, and a convex portion directed outward is formed in the outer cylindrical portion. Bending portions 3e are provided in the rotor 3 at predetermined intervals in the circumferential direction around the axis (axis line of the rotor 3). The length of the bent portion 3e is determined by the relationship with the notch groove 2a of the worm wheel 2, and is cut when it is long. The number of the bent portions 3e is an arbitrary integer of 1 or more. The number is preferably 6. The ratio of the width W1 in the circumferential direction of the bent portion 3e to the thickness W2 is set in a range from 1.2: 1 to 2: 1. This ratio is preferable in terms of the strength of the rotor 3 with slits and the strength to prevent the driving force transmission component from coming off.
The inner periphery of the inner cylindrical portion 3b is formed so that a bearing (not shown) can be mounted by cutting. The outer cylindrical portion 3c has an outer peripheral side surface formed on a flat surface having no irregularities. For example, instead of a pulley having a conventional multi-stage V-groove, a worm wheel 2 having a flat inner surface and worm teeth 2b on the outer peripheral surface is fitted on the outer peripheral surface. In the outer cylindrical portion 3c of the rotor 3, a plurality of strip-like cut and raised pieces are formed as bent portions 3e at predetermined intervals from the lower end opening side upward. Relative displacement of the rotor 3 and the worm wheel 2 in the axial direction and the rotational direction can be prevented by fitting and fixing the bent portion 3e and the cutout groove 2a.
Since the rotor 3 is formed of a magnetic steel sheet by drawing such as press forming, manufacturing and structure are facilitated.
The rotor 3 is formed by press forming a single steel plate. For this reason, the output torque and magnetic characteristics of the rotor can be adjusted by the thickness of the steel sheet, and stable magnetic characteristics can be ensured.
On the other hand, a notch groove 2 a for insertion positioning corresponding to the bent portion 3 e of the rotor 3 is provided on the inner side surface of the worm wheel 2. The notch grooves 2a are provided on the inner surface of the driving force transmitting component so as to face the axial direction at predetermined intervals in the circumferential direction. The radial depth of the notch groove 2a is determined according to the length of the bent portion 3e. The bent portion 3e may be cut appropriately and shortened. The number of cutout grooves 2a is determined according to the bent portion 3e, and is an arbitrary integer of 1 or more.
When the worm wheel 2 is press-fitted into the outer surface of the rotor 3, the bent portion 3 e is positioned in the notch groove 2 a for insertion positioning, and the rotor 3 is press-fitted into the worm wheel 2. In this state, the wedge-shaped stopper 2c is fitted into the notch groove 2a to prevent it from coming off.
The worm wheel 2 is made of wear-resistant synthetic resin, aluminum alloy or the like. The worm wheel 2 is an example of a driving force transmission component. The driving force transmission component may be an annular body having a notch groove 2a, and may be an annular body provided with an arbitrary structure such as a multistage V-groove on the outer surface.

(Method for manufacturing rotor)
In order to form the bent portion 3e as the convex portion directed outward in the outer cylindrical portion of the rotor, for example, the following method may be used. First, two pairs of cuts 3f for forming cut and raised pieces on a magnetic steel plate (not shown) are formed at predetermined intervals. At the same time, the arc-shaped slit 3d serving as a magnetic shielding part is punched out. Next, the two-dimensional developed shape (the shape before the squeezing process) of the rotor 3 is punched from the plate material, and squeezed into a U-shaped cross section at the same time or in the next step. In this squeezing process or in the next step, the cut-and-raised piece defined by the cut 3f is bent outward (outward of the outer cylindrical portion) to form a bent portion 3e. When the bent portion 3e is long, it is cut to a predetermined length in the step of forming the previous cut 3f. The method of forming the bent portion 3e is not limited to this, and there are various manufacturing processes such as forming into a shape of a rotor having an annular plate portion, an inner cylindrical portion, and an outer cylindrical portion and then bending the cut. Can be considered.
(Manufacturing method of rotor assembly)
The rotor 3 made by the above-described rotor manufacturing method is arranged so that the opening end portion faces downward, and the annular worm wheel 2 prepared in advance is covered from above, and the convex portion 3e of the rotor 3 is placed on the worm wheel 2 The worm wheel 2 is press-fitted into the outer surface of the rotor 3 in accordance with the notch groove 2a. A wedge-shaped retainer 2c is fitted and fixed in the notch groove 2a in order to hold the projecting part 3e so that it does not come out when the projecting part 3e is in the depth of the notch groove 2a.
The present invention is not limited to the above-described embodiments, and the rotor manufacturing method and the rotor assembly manufacturing method are fixed by press-fitting and fixing the rotor to the annular driving force transmission component while positioning using the convex portion and the notch groove. It can apply widely to what takes the mode to do.

It is sectional drawing of the rotor assembly provided with the worm wheel in the rotor of this invention. It is explanatory drawing of the rotor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic clutch 2 Worm wheel 2a Notch groove 2b Worm tooth 2c Stopping 3 Rotor 3a Annular plate part 3b Inner cylindrical part 3c Outer cylindrical part
3d Arc-shaped slit 3e Convex part 3f Cut 3g Slit

Claims (7)

An outer cylindrical portion having an annular plate portion, an inner cylindrical portion having an end portion provided at right angles to an inner end of the annular plate portion, and an outer cylindrical portion having an end portion provided at right angles to an outer end of the annular plate portion; A rotor provided with one or more arbitrary number of convex portions facing outward in the cylindrical portion;
It consists of an annular driving force transmission component with one or more notch grooves on the inner surface,
A rotor assembly characterized in that a convex portion of the rotor is positioned and fixed in a notch groove of the driving force transmission component, and an outer cylindrical portion of the rotor is press-fitted and fixed to the annular driving force transmission component. The convex portions are provided in the rotor at predetermined intervals in the circumferential direction around the axis, and the notch grooves are provided on the inner surface of the driving force transmission component at the predetermined intervals in the circumferential direction. The rotor assembly according to claim 1. The convex portion is a bent portion formed by forming two pairs of cuts at a predetermined interval in a portion corresponding to the outer cylindrical portion of the rotor and bending the cut and raised pieces defined by the cut. The rotor assembly according to claim 1 or 2. 4. The ratio of the circumferential width to the axial thickness of the convex portion is in a range from 1.2: 1 to 2: 1. 5. The described rotor assembly. The rotor assembly according to any one of claims 1 to 4, wherein the driving force transmission component is a worm wheel made of synthetic resin. The rotor assembly according to claim 1, wherein the rotor is formed by press-molding a metal plate. An outer cylindrical portion having an annular plate portion, an inner cylindrical portion having an end portion provided at right angles to an inner end of the annular plate portion, and an outer cylindrical portion having an end portion provided at right angles to an outer end of the annular plate portion; An annular transmission part is inserted from the opposite side of the opening end into the rotor having one or more convex parts directed outwardly on the cylindrical part, and the convex part of the rotor is cut off from the annular transmission part. A first procedure for press-fitting the annular transmission part into the outer surface of the rotor in accordance with a notch groove;
A rotor assembly comprising: a second procedure for fitting a stopper in the notch groove so as to hold the protrusion so that the protrusion does not come out when the convex part is in the depth of the notch groove. Solid manufacturing method.

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