JPH045855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electromagnetic powder clutch used in automobiles and various industrial machines, which uses magnetic powder as a medium to transmit torque.

[Prior Art] This type of electromagnetic powder clutch forms a working space between a drive member, which is a rotating body on the driving side, and a driven member, which is a rotating body on the driven side, and injects magnetic powder into this working space. At the same time, the magnetic particles are concentrated in the operating space by electromagnetic force, and the torque of the drive member is transmitted to the driven member by the magnetic attraction between the magnetic particles and the friction between the magnetic particles and the operating surface. ing.

[Problem to be solved by the invention]

However, in conventional electromagnetic powder type clutches, when the clutch is not energized, the magnetic particles separate from the working air and adhere to the drive member or the side surfaces of the driven member, and when the clutch is energized again, the magnetic particles cannot effectively collect in the working air. First, there was a problem in which the torque could not be transmitted sufficiently. In particular, the start-up characteristics when the clutch is engaged are poor, and large power transmission may not be possible from the beginning unless excitation is repeated several times.

The present invention was made based on the above circumstances, and its purpose is to effectively collect the magnetic particles that have fallen off from the working space into the working space, and to create an electromagnetic system that can transmit torque with a large force from the beginning. It is an attempt to provide a powder type clutch.

[Means to solve the problem]

In other words, in the present invention, the radial spacing in the working space is made the same size everywhere along the axial direction,
An inclined or bent end cavity is formed at both axial ends of this operating cavity, the diameter of which increases as it approaches the center in the axial direction, and an inclined or bent end cavity is formed on the drive member side of these end cavities. It is characterized in that the boundary between the bent inner surface and the operating space is located closer to the center of the driven member than both ends in the axial direction.

[Effect]

According to such a configuration, the magnetic particles separated from the operating surface during demagnetization and dispersed at the end of the operating space, the side surface of the drive member, and the driven member are tilted or bent by the centrifugal force caused by rotation. Due to the guiding effect of the end air, the particles are concentrated into the operating air. Therefore, an amount of magnetic particles effective for power transmission can be collected in the operating space, and the amount of magnetic particles magnetized during excitation increases, making it possible to transmit a large torque from the beginning of excitation. In this case, since the end cavities have an inclined or bent shape, they can smoothly guide the movement of magnetic particles due to centrifugal force, and the above-mentioned operation can be achieved with the inclined or bent inner surface formed on the drive member side of these end cavities. Since the boundary with the air is located closer to the center than both ends of the driven member in the axial direction, there are fewer magnetic particles that tend to gather in the operating air due to centrifugal force, and the magnetic particles are effective for power transmission. It will surely gather in the working space and improve the efficiency of torque transmission.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 1 is a drive member which is a rotating body on the drive side, and this drive member 1
is a yoke 2a made of a magnetic material divided into left and right halves,
The excitation coil 3 is housed in 2b, and one yoke 2
A flange 4 and a front cover 5 are attached to the other yoke 2b, a driven holder 6 is attached to the other yoke 2b, a rear labyrinth 7 fixed to the driven holder 6, and a slip which is a current supply part also attached to the driven holder 6. It is constructed by integrally attaching rings 8...

When the electromagnetic powder clutch of the present invention is applied as a vehicle clutch, the flange 4 includes:
Engine crankshaft 10 via bolts 9...
The ring gear 11 attached to is connected.

The flow cover 5 and the rear labyrinth 7 are both made of non-magnetic material, and the driven member 2 of the front cover 5 and the rear labyrinth 7 is
An annular rubber magnet 12 is adhered to the tip portion facing 0 over the entire circumference. Brushes 13 are in sliding contact with the slip rings 8, and these brushes 13 are attached to a brush holder 14. The brush holder 14 is fixed to a clutch cover (not shown).

The driven member 20, which serves as a driven rotating body, is made of a magnetic material and has a hub 21 screwed in its center. An input shaft 22 of the transmission is engaged with the hub 21 via a spline 23, and the driven member 20 and input shaft 22 rotate together. hub 2
1 is fixed in the axial direction and rotatably supported by the driven holder 6 by a bearing 26 fixed by circlips 24 and 25.

Inner peripheral surface of drive member 1 and driven member 2
A working space 27 is formed between the outer circumferential surface of the magnet and the working space 27, and this working space 27 is filled with magnetic particles 28. When the magnetic particles 28 are excited by the excitation coil 3, the magnetic attraction force between the magnetic particles 28 and the frictional force between the magnetic particles 28 and the drive member 1 and the operating surface of the driven member cause the drive member 1 to move.
is transmitted to the driven member 20, causing both to rotate integrally.

As shown in FIG. 2, end cavities 29a and 29b are formed at both end portions of the operating cavity 27 along the axial direction. These ends are empty 〓 29a, 29b
On the side of the drive member 1 facing the front cover 5 and the driven holder 6, there are inclined surfaces 30a and 30b whose inner diameters increase toward the center along the axial direction of the operating space 27. It is formed. At the corners of the driven member 20 facing the inclined surfaces 30a, 30b, there are inclined surfaces 31a, 31b parallel to the inclined surfaces 30a, 30b.
is formed. The terminal end 30aa of the one inclined surface 30a toward the center of the operating space 27 and the terminal end 31aa of the inclined surface 31a are opposed to each other at the same position along the axial direction, and the terminal end 30bb of the other inclined surface 30b and the terminal end 31bb of the inclined surface 31b are also opposed to each other at the same position along the axial direction. Therefore, the distance between the inclined surfaces 30a and 31a and the distance between 30b and 31b are constant along the axial direction, and these distances are largely bent with respect to the operating space 27. Continuously and smoothly. Therefore, the width of the working space 27 is constant throughout the axial direction.

In this case, the terminal ends 30aa and 3 toward the center of the operating space 27 on the inclined surfaces 30a and 30b formed on the inner surface on the drive member 1 side.
0bb, that is, the boundary between the inclined surfaces 30a, 30b and the working space 27, is naturally located closer to the center than both ends of the driven member 20 in the axial direction.

The operation of the embodiment with such a configuration will be explained.

In FIG. 1, power from the engine is transmitted from the ring gear 11 to the drive member 1 through the crankshaft 10, and therefore the drive member 1
rotates as the engine rotates.

When the electromagnetic coil 3 is energized to generate magnetic flux in the operating space 27 where the magnetic particles 28 are present, the magnetic particles 28
is magnetized, and the power of the engine is transmitted from the drive member 1 to the driven member 20 by the magnetic coupling force between the magnetic particles and the frictional force between the magnetic particles 28 and the operating surface. Therefore, the power of the engine is transmitted from the hub 21 via the spline 23 to the input shaft 22 of the transmission. Power is supplied from the brush 13 to the coil 3 that generates a magnetic flux in the working space 27 via the slip ring 8, and as a result of current flowing through the coil 3, the yokes 2a, 2b, the working space 27, and the driven member 20 are A magnetic circuit is formed through which a magnetic flux is generated. Therefore, whether or not rotational torque can be transmitted is determined by the presence or absence of excitation current to the coil 3.

When the coil 3 is energized, the magnetic particles 28 are most strongly magnetized in the operating space 27, but when the energization is cut off, the magnetization becomes open, and the magnetic particles 28 are attracted to the inner surface of the drive member 1 by centrifugal force. It is pushed and the connection is completely severed.

In this case, the magnetic particles 28 are discretely distributed not only in the working space 27 but also in the spaces 29a and 29b at both ends of the working space 27. Furthermore, when the engine is stopped, the particles are dispersed and adhere to the side surfaces of the front cover 5 and driven holder 6, the end surface of the driven member 20, and the like. The magnetic particles 28 dispersed in this manner may not smoothly move and condense within the working space 27 due to re-excitation, and therefore may not contribute to power transmission.

However, in the present invention, the end space 29
The magnetic particles 28 dispersed in a, 29b and outside can be forcibly fed into the working space 27 by centrifugal force. That is, when the engine is rotated, the drive member 1 rotates together with the engine even in a non-excited state, whereas the driven member 20 is stopped. In this case, the end is empty
The magnetic particles 28 in 29a and 29b are part of the drive member 1
The inclined surface 3 on the inner surface of the drive member 1 side is rotated by the centrifugal force.
It is pressed against 0a and 30b. Slanted surface 30a,
Since the diameter of magnetic powder 30b is increased toward the working space 27, these inclined surfaces 30a and 30b guide the magnetic particles 29 toward the working space 27. Therefore, the magnetic particles 29 in the end spaces 29a and 29b are effectively concentrated in the operating space 27 by the centrifugal force and the guiding action of the inclined surfaces 30a and 30b, and quickly contribute to power connection when excitation is re-energized. However, large torque transmission can be performed from the beginning, and the start-up characteristics are also improved.

In this case, the terminal ends 30aa and 31aa of the inclined surfaces, that is, the inclined surfaces 30a and 30b and the operating space 27
Since the boundary portion of the driven member 20 is located inside (on the center side) of the axial width of the driven member 20, the operating space 〓2
The magnetic particles 28 that try to move into the space 7 do not spill out and are effectively collected in the working space 27.

In addition, in the case of this embodiment, the inclined surfaces 30a and 31
Since a, 30b and 31b are parallel to each other, the distance between them is constant in the axial direction, and movement of the magnetic particles 28 toward the working space 27 is not inhibited.

Furthermore, since the terminal ends 30aa and 31aa and 30bb and 31bb of the inclined surface are opposed to each other at the same position along the axial direction, the end portions 29a and 29b are
The passage resistance of the magnetic particles 28 trying to move toward the working space 27 is reduced, so that the magnetic particles 28 can be guided and moved smoothly.

On the other hand, since the working space 27 has a constant space size along the axial direction, the space can be kept small at any location in the axial direction, and thus the torque transmission rate can be increased. , it is possible to reduce the amount of current to the electromagnetic coil consumed for torque transmission.

It should be noted that the present invention can be practiced even with other embodiments as shown in FIG. That is, in the case of FIG. 3, the operating surfaces of the operating space 27 are sloped surfaces 40a, 40b and 41a, 41b whose diameter increases as they approach the center.

In addition, the end spaces 29a and 29b are each sloped surface 40.
The curved surfaces 42a, 42b, 43a, 43b are smoothly continuous with the curved surfaces 42a, 40b, 41a, 41b.

The terminal ends 42aa and 42bb of the inner curved surfaces 42a and 42b of the drive member 1 facing the end spaces 29a and 29b, that is, the boundary between the operating space 27, are located inside the axial width of the driven member 20 (the central part Therefore, centrifugal force causes movement along the curved surfaces 42a and 42b.
The magnetic particles 28 trying to move into the space 7 effectively gather in the working space 27.

In addition, as can be understood from each embodiment, the present invention is characterized by the shape of the operating space 27 and the end spaces 29a, 29.
The combination of shapes b can be arbitrarily selected, and the working space 27 may be formed into a curved surface whose diameter increases as it approaches the center.

In each embodiment, as shown in FIGS. 2 and 3, a groove 35 is formed along the circumferential direction in the center of the operating surface of the driven member 20.
5 is for detouring the magnetic flux of the exciting coil 3 to the driven member 20 side, and does not contribute to torque transmission.

Further, the recesses 36 formed on the operating surface of the driven member 20 in FIG. 2 are for making the distribution of magnetic particles uniform, and do not affect torque transmission.

Furthermore, the present invention uses the centrifugal force accompanying the rotation of the drive member 1 and the guiding action of the inclined or curved surface to move the magnetic particles in the end spaces 29a and 29b into the operating space.
27, the boundary between at least the inclined surfaces or curved surfaces 30a, 30b, 42a, 42b formed on the inner circumferential surface of the drive member 1 and the operating space 27 is at both axial ends of the driven member 20. It suffices if it is located closer to the center than the position. Therefore, the inclined surfaces or curved surfaces 31a, 31b, 43a,
43b and the operating space 27 are not necessarily the inner surfaces 30a, 30b, 4 of the drive member 1.
It is not necessary to match the boundary between 2a, 42b and the operating space 27.

〔Effect of the invention〕

As detailed above, according to the present invention, the magnetic particles separated from the operating surface during demagnetization and dispersed near the end of the operating space or the outside thereof form an inclined or bent shape due to the centrifugal force caused by rotation. Due to the guiding effect of the end spaces, the working spaces are concentrated in the center, which is effective for power transmission. Therefore, the amount of magnetic particles that are effectively magnetized during excitation increases, making it possible to transmit a large torque from the beginning of excitation, and improving the rise characteristics. In this case, since the end cavities have an inclined or bent shape, they can smoothly guide the movement of the magnetic particles due to centrifugal force, and the above-mentioned operation can be achieved with the inclined or bent inner surface formed on the drive member side of these end cavities. Since the boundary with the air is located closer to the center than both ends of the driven member in the axial direction, there is less spillage of magnetic particles that tend to collect in the operating air due to centrifugal force, and the magnetic particles are effective for power transmission. The air will surely gather in the air, increasing the efficiency of torque transmission. For this reason, there are advantages such as being able to reduce the amount of current applied to the electromagnetic coil required for torque transmission.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a longitudinal sectional view, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 is another embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of main parts. 1... Drive member, 3... Excitation coil, 20...
Driven member, 27...Operation space, 28...Magnetic powder,
29a, 29b... end empty, 30a, 30b, 4
0a, 40b... Drive member side inclined surface, 31
a, 31b, 41a, 41b...Driven member side inclined surface, 30aa, 30bb...Boundary part, 42a, 4
2b...Curved surface, 42aa, 42bb...Boundary part.

Claims (1)

[Claims] 1. A drive member, which is a driving side rotating body, and a driven member, which is a driven side rotating body, are concentrically opposed to each other with an interval in the radial direction, and the interval is a predetermined width in the axial direction. The working space is continuous in the circumferential direction and is filled with magnetic particles, and the magnetic particles are concentrated in the working space by electromagnetic force to transmit power between the drive member and the driven member. In an electromagnetic powder type clutch that performs Forms a sloped or bent end cavity where the
The electromagnetic device is characterized in that the boundary between the inclined or bent inner surface formed on the drive member side of the end cavities and the operating cavity is located closer to the center than both axial ends of the drive member. Powder clutch.