JPH0130017B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic clutch/brake that activates the brake when the clutch is disengaged to prevent load drift.

Conventionally, this type of electromagnetic clutch/brake has been used that has an electromagnetic mechanism for the clutch and an electromagnetic mechanism for the brake, but it is unavoidable that it is large and the manufacturing cost is high. There were some problems, such as it was bulky.

Therefore, an electromagnetic clutch/brake was developed, such as that described in U.S. Pat. No. 3,893,191, in which both the clutch and brake are actuated by a single electromagnetic mechanism.

As shown in the vertical side view of FIG. 4, this electromagnetic clutch/brake includes a key 22 fitted in a keyway 23, and an input rotating member 8 that is mounted on an input shaft 21 with a set screw 24. , a clutch armature 10 supported by the input rotating member 8 via a spring 9 so as to be movable in the axial direction; a clutch armature 10 having a surface facing the clutch surface of the clutch armature 10 and coaxial with the input shaft 21; An output rotating member 3 that is fitted onto an output shaft 17 disposed in and mounted with a set screw 25;
A field core 1 is supported by a boss 3B via a bush 26 so as to be freely rotatable, and has a built-in electromagnetic coil 2, and is prevented from rotating by a pin 4 on the anti-clutch armature 10 side of the field core 1, so as to be movable in the axial direction. A supported brake armature 5 is interposed between the brake armature 5 and a pressure receiving cup 27 screwed to the bracket 1B of the field core 1, and a center hole is splined to the boss 3B of the output rotating member 3. The brake plate 3 is spline-fitted to the brake hub 28 which is press-fitted and prevented from coming off with a snap spring 29.
0, a compression spring 6 is provided which is interposed between the field core 1 and the brake armature 5 and presses the brake plate 30 toward the pressure receiving cup 27 via the brake armature 5.

In this electromagnetic clutch/brake, when a voltage is applied to the electromagnetic coil 2, the magnetic flux Φ generated thereby resists the spring force of the spring 9 and the compression spring 6 and outputs the clutch armature 10 and the brake armature 5, respectively. By magnetically attracting the rotating member 3 and the field core 1, the rotation of the input shaft 21 is transmitted to the output shaft 17, and when the voltage application to the electromagnetic coil 2 is stopped, the magnetic flux Φ disappears and the clutch armature 10 and the brake armature 5 are separated from the output rotating member 3 and the field core 1 by the spring force of the spring 9 and the compression spring 6, respectively, and rotation transmission from the input shaft 21 to the output shaft 17 is cut off. The armature 5 receives the spring force of the compression spring 6, and has friction members 31 on both sides.
31 is affixed to the pressure receiving cup 27 side to brake the inertial rotation of the output shaft 17, and furthermore, the spring force of the compression spring 6 is made relatively larger than that of the spring 9. Accordingly, when energizing, the clutch engages an instant before the brake releases, and when demagnetizing, the brake operates an instant before the clutch disengages.

However, in such an electromagnetic clutch/brake, the brake armature 5 is pressed against the pressure receiving cup 27 screwed to the field core 1 via the brake plate 30 that rotates together with the output rotating member 3. Therefore, in order to obtain a braking action, a brake plate 30 with friction members 31, 31 pasted on both sides and a pressure receiving plate 27 are required, and in addition, the brake plate 30 is integrated with the output rotating member 3. Since it must be configured to be rotatable and movable in the axial direction, the brake hub 28 that is spline-fitted to the brake plate 30 is also required, making the structure extremely complicated, and this makes it difficult to downsize the device. Not only is this difficult, but the inertial load on the brake side increases, and furthermore, the brake plate 30 supported by the brake hub 28
A friction member 31 is fixed to the brake plate 30 in order to be able to rotate continuously in the axial direction between the brake armature 5 and the pressure receiving cup 27 without being held between them when the clutch is engaged. , 31 is the brake armature 5
There was a problem in that it hit the pressure receiving cup 27 and produced an unpleasant sound.

Based on the above-mentioned viewpoints, the present invention solves all of the above-mentioned problems, and provides an ultra-compact device that is ideal for use in paper feeding control of electronic copying machines, computer peripherals, and various other office equipment. This provides an electromagnetic clutch/brake that can be made compact, and includes an annular field core as a fixing member with a built-in electromagnetic coil and a roughly U-shaped cross section, and a field core that faces the open side of the field core and an output rotating member 3 having a flange in which double magnetic resistance parts concentrically arranged at different diameter positions on the outside and an annular groove covering the opening side of the field core are formed;
A brake armature is supported in the concave groove of the output rotation member to face the opening side of the field core and to be rotatable integrally with the output rotation member 3 and movable in the axial direction. a compression spring that is interposed between the flange and presses the brake armature against a friction plate fitted into the opening of the field core;
A clutch armature is arranged on the anti-brake armature side of the flange of the output rotating member so that it can be magnetically attracted to the flange, and the clutch armature is rotatable as a unit and movable in the axial direction via a spring. A magnetic circuit of magnetic flux generated by applying a voltage to the electromagnetic coil is provided with a supporting input rotating member, and a magnetic circuit of the magnetic flux generated by applying a voltage to the electromagnetic coil is connected to the brake by the double magnetic resistance part formed on the flange of the output rotating member. It is characterized in that it is formed over the armature for the clutch and the armature for the clutch.

Therefore, in such an electromagnetic clutch/brake, the clutch armature and the brake armature are magnetically attracted to the output rotating member by the magnetic flux generated by applying voltage to the electromagnetic coil, that is, the input rotating member and the output rotating member are coupled together and rotated, thereby transmitting torque from the input rotating member to the output rotating member. On the other hand, when the magnetic flux disappears due to the stop of the voltage application, the spring As a result, torque from the input rotating member is no longer transmitted to the output rotating member from which the clutch armature is separated, and the brake armature is pressed against the field core as a fixed member by the compression spring and cannot rotate. The brakes will be applied immediately.

Next, the electromagnetic clutch/brake of the present invention will be explained by way of embodiments with reference to the drawings.

FIG. 1 is a longitudinal sectional side view of an embodiment of the electromagnetic clutch/brake of the present invention, and FIG.
This is a front view corresponding to the arrow direction in the figure.
Each figure shows a cross-sectional view corresponding to the line view in FIG. The same symbols are given.

As shown in the drawings, one annular field core 1 as a fixing member is screwed to a machine frame (not shown) or the like through a mounting plate 20 fixed to the back side surface. It has a substantially U-shaped cross section, and an electromagnetic coil 2 wound around a coil bobbin is housed within the annular groove. A metal 7 as a bearing is fitted into the center hole 1A of the field core 1, and a boss 3B of the output rotating member 3 is fitted through the metal 7 so as to freely rotate, and is rotated in the axial direction by a snap spring. Fixed.

The output rotating member 3 includes the cylindrical boss 3B,
It consists of a flange 3A having a substantially L-shaped cross section, in which a central hole is fitted and fixed to one end of the boss 3B on the opening side of the field core 1, and covers the outer periphery of the opening side of the field core 1. It has a shape with an annular groove.

Double magnetic resistance portions 1 are arranged concentrically at different diameter positions on the inner and outer sides of the flange 3A of the output rotating member 3.
2 and 13 are formed, and the magnetic resistance part 12
is a member made of a non-magnetic material embedded in a concentric ring shape in the back side portion (field core side) of the plastic friction member 11 embedded in the position opposite to the field core side of the flange 3A; are arcuate long holes drilled inside the magnetic resistance section 12, and a plurality of holes are formed in an annular arrangement as shown in FIG.

Note that this magnetic resistance section 13 is different from the magnetic resistance section 12.
It goes without saying that the magnetic resistance part 12 may be formed of a ring-shaped part made of a non-magnetic material in the same manner as in the above, or conversely, the magnetic resistance part 12 may be formed of a plurality of long holes bored in an arc shape in an annular arrangement.

A brake armature 5 is provided in an annular space formed between the opening side of the field core 1 and the output rotating member 3 covering the opening side.
It is supported by a guide pin 4 fixed to the flange 3A so as to be rotatable together with the output rotation member 3 and movable in the axial direction.

Here, the guide pin 4 is implanted in the flange 3A in an equiangularly divided arrangement on the same circumference as the magnetic resistance part 13.

A friction member 15 made of plastic is fixed to the field core 1 side of the brake armature 5, and a friction member 14 made of a non-magnetic material is connected to this friction member 15 by frictional engagement.
It is fitted into and fixed to the open end of the field core 1 at a position opposite to the field core 1 .

A plurality of bottomed holes are provided in the flange 3A in an equiangularly divided arrangement on the same circumference as the magnetic resistance part 13 and the guide pin 4, and a bottomed hole is provided in the brake armature 5 opposite thereto. A compression spring 6 is inserted into each pair of bottomed holes to press the brake armature 5 in a direction away from the flange 3A.

A tubular shaft-like member 32 is disposed on the end surface of the boss 3B of the output rotating member 3 on the side of the flange 3A.
The input rotating member 8 is fitted into the center hole B so that it can freely rotate while being prevented from moving in the axial direction.
The spring 9 is connected to the armature 1 for the clutch.
The armature 1 for the clutch is fixed to the flange 8A of the input rotating member 8 with rivets 18 and screws 19, and is arranged at a predetermined distance from the side surface of the flange 3A.
0 is supported via the spring 9 so as to be able to rotate together with the input rotating member 8 and to be movable in the axial direction.

The diameter of the center hole of the clutch armature 10 is the same as or larger than the outer diameter of the magnetic resistance section 13.

The torque transmission spring 9 shown here that also serves as an armature return is a leaf spring having double outer and inner annular parts 9B and 9C connected by a rib 9A. This is just one example of the spring 9, and it goes without saying that any other type of spring can be used as the spring 9 as long as it has the same function as this leaf spring.

In addition, what is indicated by the reference numeral 16 is the input rotating member 8.
These transmission members 16, such as pulleys and gears, may be fitted and fixed to the boss 8B of the input rotating member 8, or may be fixed to the flange 8A.

Moreover, the one indicated by the reference numeral 17 is inserted into the center hole of the output rotation member 3 and the tubular shaft-like member 32, and is prevented from coming off by, for example, a screw (not shown), and is integral with the output rotation member 3. The electromagnetic clutch/brake shown in this embodiment is attached to a driven machine, such as a paper feed roller shaft of a copying machine, for example. It is a driven member for

Further, what is indicated by the symbol Φ is a magnetic flux generated when a voltage is applied to the electromagnetic coil 2, and this magnetic flux Φ flows from the field core 1 to the flange of the output rotating member 3 (assuming the flow is clockwise in the drawing). 3A
A magnetic flux circuit is formed that flows from the boss 3B of the output rotating member 3 to the field core 1 via the clutch armature 10, flange 3A, brake armature 5, and flange 3A, bypassing the magnetic resistance parts 12 and 13 formed on the flange 3A. Clutch armature 10 and brake armature 5
This is to simultaneously excite the two.

The electromagnetic clutch of this invention having the above-mentioned configuration
When there is no voltage applied to the electromagnetic coil 2, that is, when it is de-energized, both the clutch armature 10 and the brake armature 5 are separated from the output rotating member 3, so the brake continues to operate on the input rotating member. Even if 8 is being rotated, no torque is transmitted from the input rotating member 8 to the output rotating member 3.

Also, at this time, the brake armature 5 pressed by the compression spring 6 comes into pressure contact with the field core 1, which is a fixed member, and a braking force acts on the output rotating member 3, which is connected to the field core 1 by the guide pin 4. Therefore, there is no rotation of the output rotating member 3 due to the rotation of the input rotating member 8.

Next, when a voltage is applied to the electromagnetic coil 2, a magnetic flux Φ is generated, and the two armatures 5 and 10 are magnetically attracted to the output rotating member 3 at the same time.

The clutch armature 10 resists the elastic restoring force of the spring 9, bends it, and magnetically attracts the output rotating member 3, and at the same time starts rotating the output rotating member 3 together with the input rotating member 8. Since the brake armature 5 is separated from the field core 1 by bending the compression spring 6, the output rotating member 3
The braking force that prevents the engine from starting has disappeared.

In this way, the clutch armature 10 and the brake armature 5 are attached to the output rotating member 3 at the same time.
The electromagnetic clutch/brake of this invention, which magnetically attracts and outputs, releases the braking at the moment of activation, and at the same time stops torque transmission, it enters the braking state and the output rotating member stops instantly. However, there is no harmful resistance when connecting or disconnecting these powers.

Further, an output rotating member and an input rotating member are arranged on one side of one field core 1, and the clutch armature 10 and the brake armature 5 can be simultaneously magnetically attracted to the flange 3A of one output rotating member 3 or returned and separated by a spring. Furthermore, since the magnetic resistance parts 12 and 13 are arranged so that the magnetic flux Φ forms a magnetic circuit extending between the flange 3A of the output rotating member 3 and both armatures 5 and 10, the structure becomes extremely simple and easy to manufacture. In addition to being easy to adjust, there are no parts that are difficult to adjust.

As is clear from the above description, the electromagnetic clutch/brake of the present invention has an output rotating member and an input rotating member arranged on one side of one field core, and one
In order to magnetically attract or demagnetize the clutch armature and the brake armature at the same time, a magnetic resistance section in which a magnetic circuit is formed between the output rotating member and both armatures is installed on the output rotating member. By placing the brake armature in direct pressure contact with the friction plate fitted into the opening of the field core,
As in the past, a brake armature pressed by a compression spring is braked by a field core as a fixed member via a brake plate and a pressure receiving cup, and the brake plate is also connected to an output rotating member by a brake hub. The brake plate is configured to have a complex structure that supports the brake plate so that it can rotate integrally and move in the axial direction, and furthermore, the brake plate is rotated with only a small gap between the brake armature and the pressure receiving cup when energized. A smaller shape, simpler structure, reduced inertial load and noise, which cannot be expected from electromagnetic clutches and brakes with a built-in structure.
This has an excellent advantage of being able to significantly reduce manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the electromagnetic clutch/brake of the present invention, FIG. 2 is a front view corresponding to the arrow direction in FIG. 1, and FIG. 3 is a sectional view corresponding to FIG. FIG. 4 is a longitudinal side view showing a conventional electromagnetic clutch/brake. In the drawings, 1...field core, 2...electromagnetic coil, 3
...Output rotating member, 3A...Flange, 3B...
Boss, 4... Pin, 10... Clutch armature, 6... Compression spring, 8... Input rotating member, 8
A...Flange, 8B...Boss, 9...Spring, 5
... Brake armature, 12, 13 ... Magnetic resistance section, 21 ... Input shaft, 27 ... Pressure receiving cup, 28 ... Brake hub, 30 ... Brake plate, Φ ... Magnetic flux.

Claims (1)

[Claims] 1 An annular field core 1 as a fixing member having a substantially U-shaped cross section and incorporating an electromagnetic coil 2
It has a flange 3A facing the opening side of the field core 1 and having double magnetic resistance parts 12 and 13 arranged concentrically at different diameter positions on the inner and outer sides, and facing the opening side of the field core 1. an output rotating member 3 in which a covering annular groove is formed; the output rotating member 3 has an output rotating member 3 in the groove facing the open side of the field core 1, and is rotatable integrally with the output rotating member 3; A brake armature 5 supported so as to be movable in the axial direction; and a friction plate interposed between the brake armature 5 and the flange 3A, and the brake armature 5 fitted into the opening of the field core 1. 14, a clutch armature 10 arranged on the anti-brake armature 5 side of the flange 3A of the output rotating member 3 so as to be magnetically attracted to the flange 3A, and this clutch armature 10. An input rotating member 8 is supported so as to be integrally rotatable and movable in the axial direction via a spring 9, and a magnetic circuit of magnetic flux Φ generated by applying a voltage to the electromagnetic coil 2 is connected to the output rotating member 3.
An electromagnetic clutch/brake, characterized in that it is formed across the brake armature 5 and the clutch armature 10 by the double magnetic resistance portions 12 and 13 formed on the flange 3A.