JPH08226459A - Electromagnetic clutch - Google Patents

Abstract

PURPOSE: To prevent the energy of magnetic flux from dispersion by providing convex attracting parts having nearly same shaped absorbing surfaces on the tip approximately parallel to the opposite surfaces respectively on the opposite surfaces of two of a rotor, armature and yoke having opposite surfaces opposed in the direction of an output shaft to generate the magnetic flux. CONSTITUTION: A large disk-like armature 3 is coupled with a large disk-like rotor 1 for transmitting a drive force from a drive source to output the drive force to an output shaft 8. Convex attracting parts 5a, 10b having nearly same shaped attracting surfaces 5a, 10b on an opposite surface 4a in the nearly parallel tip are provided respectively on the armature 3 and yoke 10 opposed to each other in the direction of the output shaft 8 to generate the magnetic flux by exiting an electromagnetic coil 9. Thus, the energy of the magnetic flux is not dispersed, so that the magnetic flux can be effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch that transmits a driving force by exciting an electromagnetic coil.

[0002]

2. Description of the Related Art An electromagnetic clutch intermittently transmits a driving force of a driving source to an output shaft by exciting or non-exciting an electromagnetic coil. As disclosed in JP-B-62-17943, the driving source is The rotor 1 that transmits the driving force from the rotor 1, the armature 3 that outputs the driving force to the output shaft 8 by coupling with the rotor 1, and the rotor 1 that is excited by the electromagnetic coil 9
And a yoke 10 for connecting the armature 3 (see FIG. 6).
And FIG. 7). In this device, by energizing the electromagnetic coil 9 to excite the yoke 10, a magnetic flux flows between the yoke 10 and the rotor 1, and as a result, the rotor 1 is attracted to the yoke 10 side,
By coupling with the armature 3, the driving force of the rotor 1 is transmitted to the output shaft 8 via the armature 3.

Further, as shown in FIGS. 8 and 9, the yoke is
10, the magnetic flux flows across the rotor 1 and the armature 3, and the armature 3 is attracted to the rotor 1,
In some cases, rotor 1 and armature 3 are combined.

[0004]

The electromagnetic clutch described above is easy to use because the driving force is transmitted to the output shaft only by energizing the electromagnetic coil. However, since the magnetic flux between the yoke and the rotor shown in FIG. 7 and the magnetic flux between the rotor and the armature shown in FIG. 9 have portions that are not perpendicular to the facing surface of the rotor, the energy of the magnetic flux is dispersed, and as a result, The coupling force between the rotor and the armature that effectively uses the magnetic flux may not be obtained. Therefore, in order to increase the transmission torque, the number of turns of the electromagnetic coil is increased or the voltage applied to the electromagnetic coil is increased to increase the attractive force.

The present invention has been made in view of the above points, and an object thereof is to provide an electromagnetic clutch that can effectively use magnetic flux.

[0006]

An electromagnetic clutch according to a first aspect of the present invention is a generally disk-shaped rotor that transmits a driving force from a drive source, and a rotor that is coupled to the rotor to output the driving force to an output shaft. In an electromagnetic clutch having a disk-shaped armature and a yoke through which magnetic flux flows so that the rotor and the armature are coupled by energizing an electromagnetic coil, facing surfaces of the rotor, armature and yoke that face each other in the output axis direction. The magnetic flux flows on the opposing surfaces of the two having the above-mentioned structure, and a convex suction portion having a suction surface of substantially the same shape at the tip substantially parallel to the facing surface is provided.

In the electromagnetic clutch according to the second aspect, at least one of the suction portions according to the first aspect is formed in a tapered shape so that the suction surface has a smaller area.

[0008]

According to the structure of the first aspect, since the magnetic flux flows between the suction surfaces of substantially the same shape, the magnetic flux becomes substantially perpendicular to the suction surface and the energy of the magnetic flux is not dispersed, so that the magnetic flux can be effectively used.

According to the structure of claim 2, in addition to the effect of claim 1, since the magnetic flux is substantially perpendicular to the suction surface and the energy of the magnetic flux is not dispersed, the magnetic flux can be used more effectively.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. Members having the same basic functions as those described in the conventional example are designated by the same reference numerals.
The electromagnetic clutch A intermittently transmits the driving force of the driving source to the output shaft by exciting and non-exciting the electromagnetic coil 9, and as shown in FIG. 2, the rotor 1, the armature 3, the output shaft 8, the electromagnetic The coil 9 and the yoke 10 are the main constituent members.

The rotor 1 transmits a driving force from a driving source (not shown) such as a motor, and is made of, for example, iron, and has a facing surface 1a, an outer surface 1b, an outer peripheral surface 1c and an inner peripheral surface 1d. It is formed into a generally flat plate shape by a manufacturing method such as cutting or sintering. Although not shown, there is a V-shaped belt groove on the outer peripheral surface 1c. One end of the belt is stretched over the belt groove and the other end is stretched over the drive source, so that the driving force of the drive source is increased. It is transmitted to the rotor 1 and the rotor 1 rotates. Further, a bearing 2 is inserted between the inner peripheral surface 1d and an output shaft 8 which will be described later, so that the rotation of the rotor 1 is not transmitted to the output shaft 8.

The armature 3 is connected to the rotor 1 by excitation of an electromagnetic coil which will be described later and outputs a driving force to the output shaft 8. The armature 3 is made of a soft magnetic material and has a large friction coefficient with the main body 4 and the suction portion 5. It has a coupling part 6 made of. Body 4
Is a substantially flat plate shape having a facing surface 4a, an outer surface 4b, an outer peripheral surface 4c and an inner peripheral surface 4d, and the inner peripheral surface 4d is a substantially ring-shaped spline 7
And is movable in the axial direction of the output shaft 8, but is formed so as to be integrated with the spline 7 with respect to rotation in the circumferential direction. Specifically, for example, spline 7
Is a pipe shape having a slit in the axial direction, and is provided on the inner peripheral surface 4d of the main body portion 4 with a projection fitted in the slit and movable in the axial direction.

The suction part 5 is substantially ring-shaped and has a main body part.
One has a suction surface 5a that is substantially parallel to the facing surface 4a of the body 4, and the other is connected to the facing surface 4a of the body portion 4, and a magnetic flux flows from the yoke 10 described later to the facing surface 4a. The coupling portion 6 also has a substantially ring-shaped facing surface 6a and is coupled to the facing surface 4a of the main body portion 4. The output shaft 8 outputs the driving force of the driving source to the outside and is integrated with the spline 7 by press fitting or the like.

The electromagnetic coil 9 is excited by being energized to generate a magnetic flux, and is formed in a substantially ring shape by a resin bobbin (not shown) and a coil wound around the bobbin. The magnetic flux generated by the excitation of the electromagnetic coil 9 flows through the yoke 10 described later.

The yoke 10 serves as a path for the magnetic flux generated in the electromagnetic coil 9, and is made of iron and formed in a substantially ring shape having a substantially C-shaped cross section. The suction surface 10b of the suction portion 10a, which is one end of the substantially C-shape, has substantially the same shape as the suction surface 5a of the suction portion 5 of the armature 3 and is arranged so as to be parallel to the suction surface 5a. . Further, the distance between the suction surface 10b and the suction surface 5a is formed to be slightly longer than the distance between the facing surface 6a of the coupling portion 6 and the facing surface 1a of the rotor 1.

In this electromagnetic clutch A, the electromagnetic coil
A magnetic flux is generated around the electromagnetic coil 9 by energizing 9, and the magnetic flux flows to the armature 3 via the yoke 10. Specifically, magnetic flux flows from the suction surface 10b of the suction portion 10a of the yoke 10 to the suction surface 5a of the suction portion 5 of the armature 3,
Will return to York 10. As a result, armature 3
Is sucked toward the suction portion 10a of the yoke 10, and the facing surface 6a of the connecting portion 6 of the armature 3 is connected to the facing surface 1a of the rotor 1. Therefore, the rotation of rotor 1 is
Is transmitted to the output shaft 8 via the
Output from 8 to outside. Also, when the energization of the electromagnetic coil 9 is stopped, the generation of magnetic flux stops, so the facing surface 6a of the coupling part 6 of the armature 3 and the facing surface 1a of the rotor 1 are separated, and the driving force of the drive source is output to the outside. Not done.

By the way, the suction surface of the suction portion 10a of the yoke 10
As shown in FIG. 2, the magnetic flux flowing from the 10b to the suction surface 5a of the suction portion 5 of the armature 3 is substantially perpendicular to the suction surface 10b and the suction surface 5a, so that the energy of the magnetic flux can be effectively used. Acts as a binding force for 1.

FIG. 3 shows a modification of the first embodiment, which is a yoke.
The shapes of the suction part 10a of 10 and the suction part 5 of the armature 3 are different. The suction portion 10a and the suction portion 5 are formed in a tapered shape so that their cross-sectional areas become smaller as they approach the suction surface 10b and the suction surface 5a at their tips. By doing so, it becomes substantially perpendicular to the suction surface 10b and the suction surface 5a, so that the energy of the magnetic flux more effectively acts as the coupling force between the armature 3 and the rotor 1.

Next, a second embodiment of the present invention will be described. The electromagnetic clutch A is one in which magnetic flux flows across the yoke 10, the rotor 1 and the armature 3.

The rotor 1 has a facing surface 1a, an outer surface 1b, and an outer peripheral surface 1c.
And has a substantially flat plate shape having an inner peripheral surface 1d, and has a suction portion 11 on the facing surface 1a. The suction portion 11 is substantially ring-shaped and has a suction surface 11a on one side which is substantially parallel to the facing surface 1a.
The other is coupled to the facing surface 1a, and the magnetic flux flows in this portion.

The armature 3 has a main body portion 4, a suction portion 5 and a connecting portion 6 as in the first embodiment. The suction surface 5a of the suction unit 5 faces the suction surface 11a, and
It is formed in almost the same shape as a. The coupling portion 6 also has a substantially ring-shaped facing surface 6a and is coupled to the facing surface 4a of the main body portion 4. The distance between the facing surface 6a and the facing surface 1a of the rotor 1 is formed to be slightly shorter than the distance between the suction surface 11a of the suction portion 11 and the suction surface 5a of the suction portion 5. Further, the yoke 10 is formed in a substantially ring shape having a substantially J-shaped cross section.

In this electromagnetic clutch A, the electromagnetic coil
A magnetic flux is generated around the electromagnetic coil 9 by energizing 9, and the rotor 1 and the armature 3 pass through the yoke 10.
Magnetic flux flows through. Specifically, the magnetic flux flowing from the yoke 10 to the rotor 1 flows from the suction surface 11a of the suction portion 11 of the rotor 1 to the suction surface 5a of the suction portion 5 of the armature 3 and then returns to the yoke 10. As a result, the armature 3 is sucked toward the suction portion 11 of the rotor 1, and the facing surface 6a of the connecting portion 6 of the armature 3 is connected to the facing surface 1a of the rotor 1.
Therefore, the rotation of the rotor 1 is transmitted to the output shaft 8 via the armature 3, and the driving force of the drive source is output from the output shaft 8 to the outside. Further, when the energization of the electromagnetic coil 9 is stopped, the generation of magnetic flux is stopped, so that the facing surface 6a of the coupling portion 6 of the armature 3 and the facing surface 1a of the rotor 1 are separated, and the driving force of the driving source is output to the outside. Not done.

This is also the suction surface of the suction portion 11 of the rotor 1.
As shown in FIG. 5, the magnetic flux flowing from 11a to the suction surface 5a of the suction portion 5 of the armature 3 is substantially perpendicular to the suction surface 11a and the suction surface 5a, so that the energy of the magnetic flux is effective. Acts as a binding force for 1.

The armature and the yoke in the first embodiment and the rotor and the armature in the second embodiment are provided with the suction portions. However, in the case where the rotor and the yoke are attracted by the structure of the electromagnetic clutch, A suction portion may be provided on the yoke. Further, the installation position of the suction part is not limited to this embodiment, and if the two of the rotor, armature, and yoke are close to each other and the magnetic flux flows, the suction surface having substantially the same shape is used as the tip. It is possible to provide a convex suction part included in. Further, the flow direction of the magnetic flux is not limited to this embodiment, and may flow in the opposite direction. Further, forming the suction portion in a tapered shape is not always necessary in the case where suction force is not required so much.

[0025]

In the electromagnetic clutch according to the first aspect of the present invention, since the magnetic flux flows between the suction surfaces having substantially the same shape, the magnetic flux becomes substantially perpendicular to the suction surface and the energy of the magnetic flux is not dispersed, so that the magnetic flux can be effectively used. Therefore, the coupling force between the rotor and the armature can be increased without increasing the number of turns of the electromagnetic coil or the applied voltage.

Further, in the electromagnetic clutch according to the second aspect, the magnetic flux is substantially perpendicular to the attracting surface and does not disperse the energy of the magnetic flux. Therefore, the magnetic flux can be used more effectively, and therefore the effect of the first aspect is promoted.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an electromagnetic clutch showing a first embodiment of the present invention.

FIG. 2 is a flow chart of magnetic flux of the electromagnetic clutch.

FIG. 3 is a cross-sectional view showing a modified example of the facing portion.

FIG. 4 is a schematic sectional view of an electromagnetic clutch showing a second embodiment of the present invention.

FIG. 5 is a flow chart of magnetic flux of the electromagnetic clutch.

FIG. 6 is a sectional view of an electromagnetic clutch showing a conventional example of the present invention.

FIG. 7 is a flow chart of magnetic flux of the electromagnetic clutch.

FIG. 8 is a sectional view of an electromagnetic clutch showing another conventional example of the present invention.

FIG. 9 is a flow chart of magnetic flux of the electromagnetic clutch.

[Explanation of symbols]

 A Electromagnetic clutch 1 Rotor 2 Bearing 3 Armature 4 Body part 5 Suction part 5a Suction surface 6 Coupling part 7 Spline 8 Output shaft 9 Electromagnetic coil 10 Yoke 10a Suction part 10b Suction surface

Claims (2)

[Claims] 1. A substantially disk-shaped rotor for transmitting a driving force from a driving source, a substantially disk-shaped armature for outputting the driving force to an output shaft by coupling with the rotor, and energizing an electromagnetic coil. An electromagnetic clutch having a yoke through which magnetic flux flows so that the rotor and the armature are coupled by a magnetic flux flowing between two opposing surfaces of the rotor, armature, and yoke that have opposing surfaces facing each other in the output axis direction. The electromagnetic clutch is characterized in that each of the convex clutches has a suction surface having substantially the same shape at a tip substantially parallel to the facing surface. 2. The electromagnetic clutch according to claim 1, wherein at least one of the suction portions is formed in a tapered shape such that the suction surface has a smaller area.