JPH07217670A - Electromagnetic clutch - Google Patents

Abstract

(57) [Abstract] [Purpose] An electromagnetic clutch is provided to firmly connect a drive-side rotor and a driven-side rotor to increase transmitted power and to reliably disconnect the two rotors. A magnetic adhering means 24 for contacting and separating the drive side rotor 21 and the driven side rotor 22 in the axial direction by an electromagnetic force is provided, and a taper inner surface 25a is provided on the one side rotor 21 and a taper outer surface brought into close contact therewith. 27a to the rotor 22 on the other side
In this case, the two rotors 21 and 22 are connected to each other by bringing the tapered inner surface 25a and the tapered outer surface 27a into contact with each other, and realize the solid connection by the wedge effect.

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 connects a drive-side rotor and a driven-side rotor, which are concentrically arranged, by an electromagnetic force.

[0002]

2. Description of the Related Art As a means for transmitting the power of a rotary drive source to a device driven by a rotary drive source such as a motor or for disconnecting the device from the rotary drive source, there is an electromagnetic clutch utilizing electromagnetic force. BACKGROUND ART Conventionally, electromagnetic clutches have been used in a wide range of fields such as industrial machines such as machine tools and printing machines, OA equipment such as copying machines and printers, vending machines, elevators and vehicles. As such an electromagnetic clutch, various types such as dry type, wet type, and void type have been devised. In addition, a system using a spring as shown in FIG. 4 is widely used because the power can be surely cut off and connected by a simple structure.

This electromagnetic clutch 1 has a drive-side rotor 4 fixed via a key 3 to a rotary shaft 2 connected to a rotary drive source (not shown), and the rotary shaft arranged concentrically with the drive-side rotor 4. 2, a driven-side rotor 6 rotatably attached via a bearing 5, and an electromagnet and a magnetic member such as an electromagnetic coil 7 arranged at a position sandwiching a flange portion 4a provided on the driving-side rotor 4 in the axial direction. 8 is provided. The electromagnetic coil 7 is relatively rotatably attached to the rotary shaft 2 via a bearing 10 and is fixed to an external structure 11 by a bolt 12. So-called coil stationary electromagnetic clutch 1
Is. The magnetic member 8 is formed in a ring plate shape and is fixed to the driven rotor 6 via a plate spring 13. In FIG. 4, reference numeral 14 is a cable for supplying electric power for exciting the electromagnetic coil 7, and 15 is a pulley fixed to the driven side rotor 6 for transmitting power to the outside by a belt (not shown) or the like.

According to the electromagnetic clutch 1 thus constructed, the leaf spring 13 is provided between the driving rotor 4 and the magnetic member 8 fixed to the driven rotor 6 when the electromagnetic coil 7 is not excited. Therefore, the drive side rotor 4 is rotated independently without transmitting power to the driven side rotor 6. When electric power is supplied to the electromagnetic coil 7 and the electromagnetic coil 7 is excited, the magnetic member 8 is attracted toward the electromagnetic coil 7 by the electromagnetic force while resisting the elastic force of the leaf spring 13. Therefore, the magnetic member 8 and the drive side rotor 4 are
The flange portion 4a is brought into contact with the flange portion 4a, and the frictional force transmits power.

[0005]

However, in the electromagnetic clutch 1 having the above structure, the flange portion 4 of the drive side rotor 4 is provided.
Since a and the magnetic member 8 are brought into contact with each other on a flat surface and the power is transmitted by the frictional force generated according to the pressure contact force by the electromagnetic force, the power that can be transmitted depends on the electromagnetic force,
It was difficult to increase it. In particular, in the electromagnetic clutch 1 provided in a device that requires downsizing and low power consumption, it is difficult to secure a wide cross-sectional area of the iron core because the outer diameter dimension thereof is limited. Due to dimensional and electric power restrictions, it is difficult to design the electromagnetic coil 7 having a large magnetomotive force, and there is an inconvenience that reliable transmission of power cannot be performed.

The present invention has been made in view of the above-mentioned circumstances, and firmly connects the drive side rotor and the driven side rotor to increase the transmission power and surely disconnects the two rotors. The purpose of the present invention is to provide an electromagnetic clutch that can be used.

[0007]

In order to achieve the above object, the present invention relates to a drive side rotor which is rotationally driven, a driven side rotor which is arranged concentrically with the drive side rotor, and these rotors are electromagnetically coupled. And a magnetically adhering means for contacting and separating in the axial direction by a force, wherein one side of the driving side rotor or the driven side rotor is provided with a tapered inner surface gradually increasing in diameter toward the other side rotor, and the other side rotor. In addition, there is proposed an electromagnetic clutch provided with a tapered outer surface which is brought into close contact with the tapered inner surface.

In the above electromagnetic clutch, the magnetic attachment means is provided on one side of the driving side rotor or the driven side rotor so as to be relatively movable along the axial direction, and the magnetic member is pulled toward the other side rotor. A direction in which the magnetic member and the rotor on one side are provided with an engaging portion that abuts against each other and limits a relative movement range of the magnetic member, and the magnetic member is separated from the electromagnet. It is effective to adopt a structure in which a biasing means for biasing the

Further, the taper inner surface, the taper outer surface, or both may be made of a material having a constant friction coefficient.

[0010]

According to the electromagnetic clutch of the present invention, the driving-side rotor and the driven-side rotor concentrically arranged with the driving-side rotor are moved in the direction in which they approach each other by the operation of the magnetizing means. As a result, the inner taper surface provided on the rotor on one side and the outer taper surface provided on the rotor on the other side are brought into close contact with each other, and the frictional force between the two causes the rotational driving force of the drive side rotor to change. Will be transmitted to. In this case, since both rotors are connected by the contact between the inner surface of the taper and the outer surface of the taper, a large pressure contact force is generated due to the wedge effect, and a large friction force is secured. Further, since the inner surface of the taper and the outer surface of the taper are brought into contact with each other, it is possible to secure a sufficient frictional force or transmission force even if the outer diameter dimension is suppressed small.

Further, the magnetizing means is composed of a magnetic member provided on the rotor on one side so as to be relatively movable along the axial direction, and an electromagnet for attracting this to the rotor on the other side. Is activated, the electromagnet is excited, and the magnetic member is moved relative to the one rotor in the axial direction. In this case, since the magnetic member and the rotor on one side are provided with the engaging portions that abut each other,
The abutment of the engaging portion causes the rotor on one side to move toward the rotor on the other side together with the magnetic member. As a result, the taper inner surface and the taper outer surface provided on the rotor are brought into contact with each other to transmit power.

When the excited state of the electromagnet is released,
The magnetic attachment between the magnetic member and the electromagnet is released, and the magnetic member is moved in the direction away from the electromagnet by the biasing means. Also in this case, the magnetic member is first moved relative to the rotor on one side. Then, in the middle of its movement, it is brought into contact with the rotor on one side by the engaging portion. At this time, since an impact force is generated between the rotor and the magnetic member due to the contact, the impact force disconnects the taper inner surface from the taper outer surface.

Further, when the inner taper surface, the outer taper surface, or both are made of a material having a constant friction coefficient, the inner taper surface and the outer taper surface are slid when the transmission torque exceeds a certain value. , And can function as a torque limiter.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electromagnetic clutch according to the present invention will be described below with reference to FIGS. In addition,
In the electromagnetic clutch 20 of the present embodiment, the same parts as those of the conventional example shown in FIG. 4 are designated by the same reference numerals to simplify the description.

The electromagnetic clutch 20 of the present embodiment is common to the electromagnetic clutch 1 of the conventional example in that it is basically a coil stationary type electromagnetic clutch 20. However, the electromagnetic clutch 20 according to the present embodiment has the flange portion 21 of the drive side rotor 21.
The structure of a and the structure of the driven side rotor 22 and the magnetizing means 24 including the electromagnetic coil 7 and the magnetic member 23 are different from the conventional electromagnetic clutch 1.

The drive side rotor 21 of the electromagnetic clutch 20 of the present embodiment has a cylindrical shape having a tapered inner surface 25a on the outer peripheral portion of the flange portion 21a, the diameter of which gradually increases in the axial direction toward the driven side rotor 22. The unit 25 is provided. In FIG. 1, reference numeral 35 is a pin for transmitting a rotational force from the rotary shaft 2 to the drive side rotor 21, and 36 is a non-magnetic material for forming the magnetic circuit C formed by the electromagnetic coil 7 as shown in FIG. It is a part. Further, the driven rotor 22 is divided into two in the axial direction, and includes a fixed portion 26 on the left side and a moving portion 27 on the right side in the drawing. The fixed portion 26 is rotatably provided on the rotary shaft 2 via the bearing 5 together with the gear 28, and is restricted from moving in the axial direction. Moving unit 27
Is allowed to move in the axial direction, and the fixed portion 26
Relative rotation with respect to the fixed portion 26 is limited by a pin 29 arranged between and.

On the outer peripheral portion of the moving portion 27, there is provided a tapered outer surface 27a which is inserted into the tubular portion 25 of the drive side rotor 21 and is brought into close contact with the tapered inner surface 25a thereof. The moving portion 27 is formed in a ring shape, and the magnetic member 23 is inserted and arranged inside the moving portion 27 so as to be movable along the axial direction. Further, a groove portion 27b along the axial direction is formed in the inner diameter portion of the moving portion 27, and the pin 30 provided on the magnetic member 23 prevents relative rotation between the moving portion 27 and the magnetic member 23. There is.

The magnetic member 23 corresponds to the driven rotor 2
It is formed in a tubular shape to be inserted into the second moving portion 27, and is supported by a metal bearing 31 provided on the rotary shaft 2 so as to be movable in the axial direction. At one end of the magnetic member 23, that is, at the end of the drive-side rotor 21 on the side desired by the flange portion 21a, a flange-shaped magnetized portion 23a facing the electromagnetic coil 7 with the flange portion 21a interposed is provided. Has been. The magnetized portion 23a has an outer diameter larger than the inner diameter of the moving portion 27, and when the magnetic member 23 is moved away from the electromagnetic coil 7, the magnetized portion 23a moves. End face 2 of part 27
Engaging portion 32 that abuts 7c and locks the relative movement of both
Is formed.

At the other end of the magnetic member 23, the nut 3
3 is screwed together. The outer diameter of the nut 33 is also larger than the inner diameter of the moving portion 27. When the magnetic member 23 is moved in the direction of the electromagnetic coil 7, the nut 33 comes into contact with the end surface 27d of the moving portion 27. An engaging portion 32 that simultaneously moves the magnetic member 23 and the moving portion 27 is formed. Further, a gap G is formed between the nut 33 and the moving portion 27, and the moving portion 27 and the magnetic member 23 can relatively move in the axial direction within the range of the dimension of the gap G. It is like this.

Further, an inner flange-shaped protrusion 23b is formed on the inner diameter portion of the magnetic member 23, and a coil is provided between the end face of the protrusion 23b and the end face of the flange portion 21a of the drive side rotor 21. A biasing means such as a spring 34 is provided. As a result, the magnetic member 23 is moved to the drive side rotor 21.
On the other hand, it is always urged in the direction of separation.

The operation of the electromagnetic clutch 20 thus constructed will be described below. According to the electromagnetic clutch 20 of this embodiment, when the electromagnetic coil 7 is supplied with electric power and excited, the electromagnetic force moves the magnetic member 23 in a direction in which the magnetic member 23 approaches the drive side rotor 21. Magnetic member 2
3 is driven by the coil spring 34 to drive side rotor 21.
Since it is urged in the direction away from, it is moved against the urging force.

Since the magnetic member 23 is inserted into the inner diameter portion of the moving portion 27 of the driven side rotor 22 so as to be relatively movable,
The nut 32 comes into contact with the end face 27d of the moving portion 27 when the moving portion 27 and the nut 33 are moved by the dimension of the gap G, and thereafter, the moving portion 27 also moves in the axial direction as the magnetic member 23 moves. Can be moved. When the moving portion 27 is moved to the drive side rotor 21 side, as shown in FIG. 2, the moving portion 27 is moved to the tapered inner surface 25a of the tubular portion 25 provided on the outer periphery of the flange portion 21a of the drive side rotor 21. The taper outer surface 27a provided on the outer circumference of the portion 27 is brought into pressure contact with each other, and the drive side rotor 21 and the moving portion 27 are connected by the frictional force generated between them.

As a result, the power of the drive side rotor 21 is also transmitted through the pin 29 to the fixed portion 26 whose relative movement along the circumferential direction is restrained by the moving portion 27 by the pin 29, and the transmitted power is transmitted. It can be taken out through the gear 28. In this case, the driving-side rotor 21 and the driven-side rotor 22 have the tapered inner surface 25a and the tapered outer surface 2 respectively.
Since they are connected by bringing them into contact with each other, the wedge effect between them makes a firm connection.

Further, the taper inner surface 25a and the taper outer surface 27
By connecting with a, the contact portion is arranged at an angle with respect to the axis, so even if the outer diameter of the electromagnetic clutch 20 is reduced, a sufficient frictional force is secured to ensure reliable connection. It becomes possible to carry out.

On the other hand, the drive side rotor 21 and the driven side rotor 2
In the case of disconnecting the connection with 2, the power supply to the electromagnetic coil 7 is stopped as in the conventional case, and the magnetically attached state between the electromagnetic coil 7 and the magnetic member 23 is released. As a result, the magnetic member 23 is rapidly moved in the direction away from the drive side rotor 21 by the elastic force of the coil spring 34. When the excitation of the electromagnetic coil 7 is released, the magnetic member 23 and the moving portion 27 of the driven rotor 22 are moved.
Since a gap G is formed between the magnetic member 2 and
3 is moved at a high speed in a direction to reduce the gap, and the magnetically attached portion 23a is brought into contact with the end surface 27c of the moving portion 27 (a state shown by a chain line in FIG. 2).

Therefore, the electromagnetic clutch 20 of the present embodiment.
According to the above, the magnetic member 23 and the moving portion 27 collide with each other, so that an impact force is generated between them in a direction in which the drive side rotor 21 and the driven side rotor 22 are separated from each other. That is,
In the electromagnetic clutch 20 of this embodiment, both rotors 21 and 22 are
By making the tapered inner surface 25a and the tapered outer surface 27a contact with each other, they are firmly connected by the wedge effect, but they are easily separated by the impact force generated between them. As a result, the drive side rotor 2
It is possible to immediately cut off the transmission of power from 1 to the driven rotor 22.

The moving portion 27 of the driven side rotor 22 of this embodiment has no influence on the path of the magnetic flux obtained when the electromagnetic coil 7 is energized, that is, on the construction of the magnetic circuit C. Is not limited to a magnetic material, and any material can be applied. That is, the life of the electromagnetic clutch 20 can be easily improved by using a material having high wear resistance. Further, a material having a predetermined static friction coefficient or dynamic friction coefficient, for example, an appropriate engineering plastic can be applied. In this case, a function as a so-called torque limiter for setting the upper limit of the transmission torque is added. It becomes possible.

Next, another embodiment of the electromagnetic clutch according to the present invention will be described with reference to FIG. The electromagnetic clutch 40 of the present embodiment is different from the above-mentioned embodiment and the conventional example,
A coil rotation type electromagnetic clutch 40 is shown.

That is, the electromagnetic clutch 40 of this embodiment is different from the above-mentioned embodiment in that the electromagnetic coil 7 is integrally fixed to the drive side rotor 41. Electric power is supplied to the electromagnetic coil 7 via a brush 44.

According to the electromagnetic clutch 40, the magnetic member 42 is magnetically attached by energizing the electromagnetic coil 7 in the same manner as in the above embodiment, and the magnetic member 42 resists the elastic force of the coil spring 34. Moved axially. At this time,
The nut 45 provided on the magnetic member 42 causes the driven rotor 43
Of the drive side rotor 41, and the tapered outer surface 46a provided on the outer peripheral portion of the drive side rotor 41 is in contact with the moving portion 46 of the drive side rotor 41a.
Is pressed against. As a result, due to the wedge effect between the tapered outer surface 46a and the tapered inner surface 41a, both rotors 41
43 is firmly connected, the power of the drive-side rotor 41 is transmitted to the driven-side rotor 43, and is taken out through the rotary shaft 47.

Also, when the power supply to the electromagnetic coil 7 is cut off, the magnetic member 42 returns by the elastic force of the coil spring 34, collides with the end face of the moving portion 46, and impacts, as in the above embodiment. Generate force. The impact force ensures that the outer taper surface 46a and the inner taper surface 41a are separated.

The following techniques can be employed in the present invention. Drive side rotors 21 and 41 have tapered inner surfaces 25a and 41
a is provided to the driven side rotors 22 and 43 to form a tapered outer surface 27a.
46a is provided, but instead of this, the drive side rotors 21 and 41 are provided with tapered outer surfaces, and the driven side rotor 2
The taper inner surface may be provided on 2.43. Although the coil spring 34 is used as the urging means for separating the drive-side rotors 21 and 41 from the magnetic members 23 and 42, other arbitrary urging means such as a disc spring, a leaf spring, or Any other elastic body may be used. Although the electromagnetic coil 7 is arranged on the drive side rotors 21 and 41 and the magnetic members 23 and 42 are arranged on the driven side rotors 23 and 43, the positional relationship can be reversed instead. . Although any material such as iron can be adopted as the magnetic members 23 and 42, a pure iron-based magnetic material having a fast magnetic reaction is preferable in consideration of the response speed. The engaging portion 32 is a flange-shaped magnetic attachment portion 23a formed on the magnetic member 23, an end surface 27c of the moving portion 27 of the driven side rotor 22, and a nut 33 attached to the magnetic member 23.
And the end surface 27d of the moving portion 27 of the driven rotor 22 is not limited to this structure, the moving portion 27 having the tapered outer surfaces 27a and 46a.
Other structures may be used as long as 46 and the magnetic members 23 and 42 can be attached so as to be relatively movable in the axial direction within a certain range. Inner taper surfaces 25a and 41a and outer taper surface 27a
The inclination angle of 46a is not particularly limited, but the certainty of the connection due to the wedge effect can be achieved, and the engaging portion 3
The inclination angle can be set so as to be easily separated by the impact force in 2. Driven-side rotor 2 having tapered outer surfaces 27a and 46a
Although 2.43 is made of engineering plastic having a constant friction coefficient, it may be made of any other material instead of this. That is, the magnetic member 2
Since it is provided separately from 3.42, its material can be freely selected. Although only the tapered outer surfaces 27a and 46a are made of the above material, the tapered inner surfaces 25a and 41a may be made of the above material, or both of them may be made of the above material.

[0033]

As described in detail above, the electromagnetic clutch according to the present invention is provided with the magnetic attachment means for axially moving the driving side rotor and the driven side rotor into contact with and separating from each other by the electromagnetic force. Since the inner taper is provided and the outer taper that is brought into close contact with this is provided on the rotor on the other side, the drive side rotor and the driven side rotor are brought into close contact with each other by the operation of the magnetizing means. By doing so, there is an effect that a strong connection can be realized by the wedge effect and a large power can be transmitted. Further, even when the outer diameter of the electromagnetic clutch is limited, a large frictional force can be secured at the connecting portion, so that a large power can be reliably transmitted.

In the electromagnetic clutch having the above structure,
The magnetic attachment means is composed of a magnetic member provided on the rotor on one side so as to be relatively movable along the axial direction, and an electromagnet that attracts the magnet member in the rotor direction on the other side. By providing an engaging portion that abuts against the magnet and limits the relative movement range of both, and by providing a biasing means that biases the magnetic member in a direction away from the electromagnet, when the excitation of the electromagnet is released, the magnetic member is released. Since the urging means can bring the rotor into contact with the rotor on one side to generate an impact force in the direction of disconnecting the connection between the tapered inner surface and the tapered outer surface, the firmly connected tapered inner surface and tapered outer surface The effect that the and can be easily and reliably separated can be obtained.

Further, if either or both of the tapered inner surface and the tapered outer surface, which are in close contact with each other, are made of a material having a constant coefficient of friction, the power to be transmitted has a predetermined magnitude. When it exceeds, there is an effect that it is possible to add a function as a so-called torque limiter that slides the inner surface of the taper and the outer surface of the taper. Particularly, the magnetic member and the rotor are separate members.
In the electromagnetic clutch, since the material of the taper inner surface and the taper outer surface is not limited to the magnetic material, it is possible to easily realize the torque limiter of the consumption torque by freely selecting the material.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an electromagnetic clutch according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a connecting portion between a driving side rotor and a driven side rotor of the electromagnetic clutch of FIG.

FIG. 3 is a longitudinal sectional view showing another embodiment of the electromagnetic clutch according to the present invention.

FIG. 4 is a vertical cross-sectional view showing a conventional example of a coil stationary electromagnetic clutch.

[Explanation of symbols]

 7 Electromagnetic coil (electromagnet) 20/40 Electromagnetic clutch 21/41 Drive side rotor 22/43 Driven side rotor 23/42 Magnetic member 24 Magnetizing means 25a / 41a Tapered inner surface 27a / 46a Tapered outer surface 32 Engagement portion 34 Coil spring ( Urging means)

Claims (3)

[Claims] 1. A drive-side rotor that is rotationally driven, a driven-side rotor that is arranged concentrically with the drive-side rotor, and a magnetizing means that causes these rotors to contact and separate in the axial direction by electromagnetic force, One side of the drive side rotor or the driven side rotor is provided with a taper inner surface that gradually increases in diameter toward the other side rotor, and the other side rotor is provided with a taper outer surface that is in close contact with the taper inner surface. An electromagnetic clutch that is characterized. 2. The magnetizing means comprises a magnetic member provided on one side of the driving side rotor or the driven side rotor so as to be relatively movable along the axial direction, and an electromagnet for pulling the magnetic member toward the other side rotor. An engaging portion is provided on the magnetic member and the one side rotor to abut against each other to limit a relative movement range of the both, and the magnetic member is urged in a direction of separating the magnetic member from the electromagnet. The electromagnetic clutch according to claim 1, further comprising urging means. 3. The electromagnetic clutch according to claim 1, wherein the tapered inner surface, the tapered outer surface, or both are made of a material having a constant friction coefficient.