JPS63289332A - Clutch - Google Patents

Abstract

PURPOSE:To make a clutch lighter in weight with good responsiveness as well as to reduce watt consumption by installing a first disk having a magnet at a position other than both ends of a driven shaft, and having a second disk with such a magnet as being repulsive to the said one engaged with an input shaft with elongation of a piezoelectric element. CONSTITUTION:A rotary disk 13a provided with a permanent magnet 14 at the central part of a driven shaft 13 is formed there, while a fixed member 19 is attached to this disk via a rolling bearing 18, and a piezoelectric element 21a is clamped to a flange part 19a. A rotary disk 16 provided with a permanent magnet 17 being opposed and repulsive to the permanent magnet 14 and an input spur gear 15 are engaged through hubs 15a and 16a and set up on the driven shaft 13, and a disk pressing member 22a as an extension mechanism is clamped to the other end of the piezoelectric element 21a. Then, with elongation by voltage impression of the piezoelectric element 21a, if it exceeds repulsive force of these permanent magnets 14 and 17 to be added to a ball bearing 23a, both these rotary disks 16 and 13a are coupled together. Consequently, lightweightness can be attained with good responsiveness.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a clutch used for transmitting and interrupting power, and particularly to a clutch that is used for transmitting and interrupting power, and particularly has two characteristics such as weight reduction, responsiveness, and low noise. Regarding the sneaky clutch.

[Prior Art] FIG. 3 is a sectional view showing the structure of a conventional excitation-operated electromagnetic clutch. In the figure, 1 is a spur gear (input side) for coupling with an external drive source (not shown), and is rotatably provided on a driven shaft (output side) 2. Further, a spring member 3 is attached to the hub 1a of the spur gear 1 extending rightward in the drawing along its outer periphery, and an armature core 4 is installed at the end of the spring member 3. A rotor 5 has a hub 5a extending rightward in the drawing. The rotor 5 is fixed to the driven shaft 2 by a fixing fitting 6 at a predetermined distance G1 from the armature 4. Further, on the surface of the rotor 5 facing the armature 4, a ring-shaped groove having a U-shaped cross section is formed so that the shaft center is common to the axis of the driven shaft 2. Body 7 is fitted. The friction body 7 uses a member having a high coefficient of friction (eg, rubber, resin, etc.). Further, a bearing 10 is attached to the hub 5a of the rotor 5. 8 is a yoke, which is rotatably attached to the bearing 10. Furthermore, an electromagnetic coil 9 is provided within the yoke 8 . 11 is a fixing member attached to the right end of the yoke 8 in the drawing, and serves to fix the clutch body.

In the electromagnetic clutch configured as described above, when the electromagnetic coil 9 is excited, the armature 4 is attracted to the rotor 5, and the armature 4 and the friction body 7 are brought into contact with each other under a predetermined pressure.

As a result, the spur gear 1 and the rotor 5 are coupled, and the driving force at the input end is transmitted to the output side. Then, when the electromagnetic coil 9 is de-energized, the armature 4 returns to its original position by the force of the spring member 3. As a result, the spur gear 1 and the rotor 5 are separated from each other, and the driving force at the input end is no longer transmitted to the output side.

[Problems to be Solved by the Invention] By the way, since a clutch using two electromagnetic coils uses electromagnetic coils, there are the following problems.

■Since it requires an electromagnetic coil and a yoke to house it, it is difficult to reduce weight.

■Poor response due to hysteresis of the electromagnetic coil.

■In order to strengthen the connection between the input and output sides, the value of the current flowing through the electromagnetic coil increases. Therefore, power consumption is large.

■A collision noise occurs when the armature is suctioned.

■Since leakage magnetic flux is generated, it cannot be used in applications where the influence of this leakage is a problem.

This invention was made against this background, and its purpose is to provide a clutch that can solve the above-mentioned problems (1) to (2).

"Means for Solving the Problems" The present invention provides a driven shaft with an end, and a first rotating shaft formed in a portion other than both ends of the driven shaft to coincide with the axis of the driven shaft. a disk; a first magnet provided on one surface of the first rotating disk; a second rotary disk that is slidably provided in the axial direction of the drive shaft and inputs a driving force from an external drive source; and a repulsive force on one surface of the second rotary disk with respect to the first magnet. a second magnet disposed in a direction such that the second magnet is oriented in the opposite direction; a fixing member rotatably attached to the driven shaft at a predetermined distance from the other surface of the first rotating disk; and one end fixed to the fixing member. A piezoelectric element formed in a bar shape with the other end extending toward the other surface of the second rotating disk (one having an inverse piezoelectric effect that produces a strain proportional to the electric field, and the other having an inverse piezoelectric effect producing a strain proportional to the square of the electric field) A disk having one end attached to the other end of the piezoelectric element (having a filter electrostriction effect) and the other end being curved along the circumferential direction of the other surface of the second rotating disk. It is characterized by comprising a pressing member and a rolling bearing provided at the other end of the disc suppressing member.

[Operation] According to the above configuration, the magnets attached to the first rotating disk and the second rotating disk repel each other, so that the first rotating disk and the second rotating disk are separated from each other at a predetermined distance. is seperated. When a voltage is applied to the piezoelectric element in this state, the piezoelectric element expands, and the disk suppressing member presses the second rotating disk via the rolling bearing. In this case, since the disk suppressing member is used as a "lever," the second rotating disk is pressed by a distance several times the distance that the piezoelectric element extends. As a result, the first rotating disk and the second rotating disk are coupled. Therefore, the driving force from the external drive source that is being transmitted to the second rotating disk is transmitted to the driven shaft via the first rotating disk. Then, when the voltage application to the piezoelectric element is stopped,
The piezoelectric element returns to its original length, the disk suppressing member separates from the second rotating disk, and the repulsive force of the magnets attached to each of the first rotating disk and the second rotating disk causes the first rotating disk to move away from the first rotating disk. and the second rotating disk are separated. As a result, the driving force is no longer transmitted to the first rotating disk.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the structure of an embodiment of the present invention, and FIG. 2 is a sectional view taken along line A--A in FIG. 1.

In FIG. 1, reference numeral 13 denotes a thick, hollow driven shaft, and the center of the driven shaft 13 has a circular cross section, and its center point is aligned with the axis of the driven shaft 13. A matching rotating disk 13a is formed. A ring-shaped groove with a U-shaped cross section is formed on the right side of the rotating disk 13a, and the axis is shared with the axis of the driven shaft 13, and a permanent magnet I4 is installed in this groove. installed. Reference numeral 15 denotes a spur gear, which is rotatably attached to the right end portion of the driven shaft 13 in the drawing. This spur gear 1
5 is for inputting driving force from a driving source (not shown). Furthermore, a tooth profile with a square cross section is formed at the tip of the hub 15a of the spur gear 15 that extends leftward in the drawing.

16 is a rotating disk, and the above-mentioned rotating disk +3
It is rotatably attached to the driven shaft 13 between the gear a and the spur gear 15 so as to be rotatable and slidable in the left-right direction in the drawing. The rotating disk 16 also includes a hub 1 extending rightward in the drawing.
6a is formed, and a tooth shape with a square cross section is formed at the tip portion of this hub 16a. The tooth profile of the hub +6a and the tooth profile formed on the hub 15a of the spur gear 15 mesh with each other. Further, a ring-shaped groove having a U-shaped cross section is formed on the left side of the rotating disk 16 in the drawing, and the axis is common to the axis of the driven shaft 13, and a permanent magnet 17 is placed in this groove. is installed. This permanent magnet I7 is attached to the rotating disk 16 so that the surfaces facing each other have the same magnetic pole as the permanent magnet 14 attached to the rotating disk 13a described above. and,
Due to the repulsive force between the permanent magnets 14 and 17, a corresponding gap G2 (for example, 50 μ) is obtained between the rotating disk 13a and the rotating disk 16. A rolling bearing 18 is attached to the driven shaft 13 and extends from the left end portion of the driven shaft 13 to the rotating disk 13a. Reference numeral 19 denotes a fixed member, which is formed into a cylindrical shape and is attached to the rolling bearing [8]. This fixing member 19
A collar portion 19a that opens outward is formed at the left end in the drawing, and the circumference of the collar portion 19a is equally divided by 3 on the right side of the drawing.
One end of each of the piezoelectric elements 2+a to 21c is glued to a location (see FIG. 2) using a bonding agent 20. Piezoelectric element 2+
Each of a to 21c is formed into a bar shape with a square cross section. Furthermore, disk pressing members 22a to 22c are attached to the other ends of the piezoelectric elements 21a to 21c, respectively. As shown in FIG. 2, this disk pressing member 22a is formed into a plate shape that is curved along a concentric circle, with its tip 22a1 extending in the direction toward the axis of the driven shaft 13. It's bent. In this case, the disk pressing member 22a is
As shown in FIG. 2, the position indicated by the symbol S2 serves as a fulcrum, and this fulcrum S and the disk suppressing member 22a
The distance Q1 between the end portion 22a1 and the point S3 is five times the distance Q between the fulcrum S2 and the axial center point S1 of the piezoelectric element 2+a. In this way, by using the disk pressing member 22a as a "lever," the end 22a1 of the disk pressing member 22a moves by a distance five times the extension distance of the piezoelectric element 21a. For example, if the extension distance of the piezoelectric element 21a is 15μ, the end portion 22a1 will move toward the disk suppressing member 22a by a distance of 75μ (15μ×15). Such a mechanism is called an enlargement mechanism. Further, the other disk suppressing members 22b and 22c are formed in the same manner as the disk suppressing member 22a described above, and serve as an expanding mechanism. Subsequently, a hemispherical groove opening toward the left in the drawing is formed in the end portion 22a1 of the disk pressing member 22a, as shown by hidden lines in FIG. A ball bearing 23a is rotatably mounted in this groove. The hole hair ring 23a has a rotary disk 16.
and a permanent magnet 14.1 provided on the fixed disk 13a.
7 has been added to the repulsive force.

Next, in the above configuration, when a voltage is applied to the piezoelectric elements 21a to 21c, each piezoelectric element expands in the direction of arrow I3 in the figure. As a result, each disk suppressing member 223 to 22c
The rotary disk 16 is suppressed via each ball bear link 23a to 23c. This pressing force is applied to the permanent magnets 14 and 17.
When the repulsive force is exceeded, the rotating disk 16 joins with the rotating disk 13a.

As a result, the driving force applied to the spur gear 15 from the external driving source is transmitted to the driven shaft 13 via the rotating disk 16.

Then, when the voltage supply to the piezoelectric elements 2+a to 21c is stopped, the piezoelectric elements 21a to 21c return to their original lengths, each disc suppressing member 22a to 22c is separated from the rotating disc 16, and the permanent magnets 14 and 17 Due to the repulsive force of
Rotating disk 16 separates from rotating disk 13a. As a result, the driving force is no longer transmitted to the driven shaft 13.

As described above, in order to transmit the driving force applied to the spur gear 15, which is the input end, to the driven shaft 13, which is the output end, a piezoelectric element is used in place of the conventional electromagnetic coil. Since the rotating disk 13a and the rotating disk 16 are connected together by the stretching force, the advantages of piezoelectric elements such as high response speed, light weight, and low power consumption can be obtained.
Furthermore, since the rotating disk 16 is suppressed at points by the ball bearing link, the collision sound of the ball bearing hitting the rotating disk 16 is very small. Furthermore, since the piezoelectric element has no leakage magnetic flux, it can be used in applications where leakage magnetic flux is a problem. In addition, since a disk pressing member having an expansion function using a "lever" is provided in order to expand the extension distance of the piezoelectric element, the gap between the rotating disk +3a and the rotating disk 16 can be widened. This means that if the rotating disk 16 is coupled to the rotating disk +3a directly by utilizing the extension distance of the piezoelectric element,
The processing accuracy of each rotating disk 13a, 16 must be equal to or less than the extension distance of the piezoelectric element, but by using a disk pressing member with an expansion function, the distance corresponding to the extension distance of the piezoelectric element is increased. 13a
, +6' - the accuracy can be reduced by 14'.

[Effects of the Invention] As explained above, according to the present invention, a piezoelectric element r- is used, and the tension force generated by applying a voltage to the piezoelectric element is used to connect the output side, which is the driven shaft, to the driving member. Since it is coupled to the input side of Benefits include minimal impact noise during suction. Furthermore, it can be used in applications where the influence of leakage magnetic flux is a problem.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line 8-Δ in FIG. 1, and FIG. 3 is a sectional view showing the structure of a conventional electromagnetic clutch. 13... Driven shaft, +3a... Rotating disk (first rotating disk), 14. Permanent magnet (first magnet)
, +6・Rotating disk (second rotating disk), 17
...Permanent magnet (second magnet), 19... - Fixed member, 2 + a-21c - Piezoelectric element, 22a-2
2c...Disk suppression member, 23a-23c...Ball hair ring (rolling bearing).

Claims (1)

[Claims] A driven shaft with an end, a first rotating disk formed on a portion other than both ends of the driven shaft to coincide with the axis of the driven shaft, and a first rotating disk formed on one surface of the first rotating disk. a first magnet provided therein; and an external drive source provided opposite to each other at a predetermined distance from one surface of the first rotating disk and provided rotatably on the driven shaft and slidable in the axial direction of the driven shaft. a second rotating disk inputting driving force from the
a second magnet provided on one surface of the second rotating disk in a direction that produces a repulsive force with respect to the first magnet;
a fixing member rotatably attached to the driven shaft at a predetermined distance from the other surface of the first rotating disk; one end fixed to the fixing member and the other end attached to the other surface of the second rotating disk; a piezoelectric element formed in a bar shape extending toward a surface; and a disk pressing member having one end attached to the other end of the piezoelectric element and the other end curved along the circumferential direction of the other surface of the second rotating disk. and a rolling bearing provided at the other end of the disc pressing member.