WO2016165648A1

WO2016165648A1 - Electromagnetic clutch

Info

Publication number: WO2016165648A1
Application number: PCT/CN2016/079399
Authority: WO
Inventors: 付占江; 张厚政; 李树素; 董友军
Original assignee: 盖茨胜地汽车水泵产品(烟台)有限责任公司
Priority date: 2015-04-17
Filing date: 2016-04-15
Publication date: 2016-10-20
Also published as: CN105570341A; CN105605121B; CN205503810U; CN105570341B; CN105605121A; CN104747621A

Abstract

An electromagnetic clutch comprises a driving wheel (2) for receiving external forces, electromagnets (24, 32), an armature assembly capable of moving between a first position and a second position along the axis direction of a rotating shaft (7a) and driven wheel components (18, 20). The driven wheel components are constructed to be detached from the driving wheel (2) as the armature assembly reaches the first position, and to be engaged with the driving wheel (2) as the armature assembly reaches the second position. The armature assembly comprises a permanent magnet (19). When applying a first current to the electromagnets (24, 32), the armature assembly moves toward the first position; when applying an opposite second current to the electromagnets (24, 32), the armature assembly moves toward the second position. The electromagnetic clutch also comprises a flexible component (30) exerting a force on the armature assembly always along the direction that the armature assembly moves toward the second position. When the armature assembly reaches the first position, the permanent magnet (19) of the armature assembly and a magnetizable component can be attracted with each other, enabling keeping the armature assembly at the first position while decreasing or turning off the current to the electromagnets (24, 32). The electromagnetic clutch has relatively low power consumption and a relatively long service life.

Description

Electromagnetic clutch

Technical field

The present invention relates to an electromagnetic clutch, particularly an electromagnetic clutch for an engine cooling system or an air conditioning system of an automobile.

Background technique

An electromagnetic clutch is a device that performs disengagement under electromagnetic force (ie, achieves transmission and interruption of power), which controls engagement and disengagement of the clutch by turning on/off the electromagnetic coil in the clutch. Electromagnetic clutches are widely used in various fields such as mechanical, electronic/electrical, such as engine cooling systems for automobiles, air conditioning systems, and the like.

Taking the engine cooling system as an example, the system is one of the key systems to ensure the normal operation of the car. The engine cooling system includes a water pump that pumps the coolant to cause rapid flow of coolant in the engine cooling circuit to absorb heat generated by the engine while maintaining the engine temperature at normal or optimal operating temperatures. Normally, the engine is optimally operated when the water temperature (temperature of the coolant) is 90 degrees. Some of the existing car's water pump pulleys (drive wheels) are directly connected to the rotating shaft. Therefore, after the vehicle is started, the water pump is always running, and the coolant inside the driving engine is continuously circulated. This cycle causes the temperature of the engine to rise very slowly when the car starts. If it is necessary to bring the water temperature to about 90 degrees, the engine warm-up time takes about 20 minutes in the pure idle state.

Therefore, the prior art has proposed a design that disconnects the pulley from the water pump when the vehicle is started, which can reduce the engine warm-up time to about 5 minutes. The warm-up time is greatly shortened, which can make the engine reach the best working condition as soon as possible, reduce fuel consumption, and be more energy-saving and environmentally friendly.

Such an existing design is disclosed in Chinese Patent Application Publication No. CN102216639A. The energization/de-energization of the actuator member 160 by the energizing/de-energizing and returning springs of the actuator (electromagnetic coil), thereby driving the coil spring 104 to contract or expand in the radial direction, enables the pulley to be disconnected or engaged with the water pump. Disconnecting the pulley from the pump requires the actuator (electromagnetic coil) to remain energized for approximately 5 minutes.

However, a long-time energization current causes the actuator (electromagnetic coil) to generate heat, which in turn causes the actuator winding resistance to increase, and the current to drop, thereby causing the actuator electromagnetic force to drop, further causing the pull-out device to return to the winding. The spring loses its confinement and expands radially to the inner surface of the drive member, eventually causing the clutch to fail.

In addition, the actuator member 160 has no polarity, so that the attraction of the actuator member is achieved only by the electromagnetic force of the electromagnet, which requires a higher electromagnetic force for the electromagnet, that is, a large current requirement. Therefore, it will increase energy consumption and shorten the life of the electromagnet.

Moreover, when the spiral spring coil is expanded to the inner surface of the clutch, due to the problem of the internal stress control of the coil or the change in the friction coefficient caused by the condensation of the surface due to the temperature change, the frictional force may be insufficient to cause the clutch engagement transmission to fail.

Another prior art design is disclosed in U.S. Patent Application Publication No. US 2010/0263981 A1. The disclosed clutch is provided with: a permanent magnet 9; a respective magnetic guiding device 10, 11; an electromagnet 8; an armature 3 made of a soft magnetic material; and a rotor 2a. When the electromagnet passes the current in the first direction, the magnetic field of the electromagnet and the permanent magnet superimposes and cooperates to apply the force to the left side of the armature, the armature moves to the left side, the gap between the system and the rotor becomes smaller, and the permanent magnet/rotor pairs the armature The force is increased and the armature can be held in the left position, at which point the electromagnet can disconnect or reduce the current. When the electromagnet passes the current in the opposite direction, the electromagnet generates a magnetic field opposite to the permanent magnet to offset the force of the permanent magnet on the armature. At this time, the armature receives a small force and moves to the right side under the spring force to reset.

In this solution, the electromagnet needs to cancel the magnetic field of the permanent magnet when the armature is disconnected from the rotor, instead of directly exerting a force on the armature, so that a large current is required to be provided on the electromagnet to achieve the function, which is not conducive to energy conservation, and High currents have a greater impact on electrical systems.

In addition, in this solution, the torque of the pulley is directly transmitted by the attraction of the armature and the rotor, which has high requirements on the strength of the armature, and the armature is relatively easy to generate large wear.

Japanese Patent Application Publication No. 2007-205513 discloses another prior art design in which a clutch is provided with an electromagnet 23, a rotor 22, an armature 21 made of a soft magnetic material, a permanent magnet 28 fixed in the rotor, and an elastomer. 29. Similar to the aforementioned U.S. Patent Application Publication, when the electromagnet is turned on in the first direction, the electromagnet and the permanent magnet together exert a force on the armature, so that the armature is attracted to the left side, between the armature and the permanent magnet and the rotor. The gap becomes smaller, forever The force of the magnet on the armature becomes large, and the armature can be held to the left side only by the permanent magnet. At this point, the electromagnet can be powered down or reduced in current. When the electromagnet is turned on in the opposite direction, the electromagnet generates a magnetic field opposite to the permanent magnet to offset the force of the permanent magnet on the armature, and the armature moves to the right side under the action of the elastic body to reset. In this solution, when the electromagnet disconnects the armature from the rotor, it is necessary to cancel the magnetic field of the permanent magnet, instead of directly exerting a force on the armature. This method requires a large current on the electromagnet to realize the reset of the armature, which is not conducive to saving. Energy, and large currents have a greater impact on electrical systems.

The Chinese utility model patent announcement CN202040232U discloses another existing design. In the disclosed clutch, a permanent magnet 21 is provided in the suction cup 2. The suction cup and the pulley are normally engaged. When the electromagnetic coil 11 is energized, a magnetic field repels the permanent magnet, and the pulley is separated from the suction cup, that is, the pulley is disconnected from the water pump. In this solution, the electromagnetic force of the electromagnetic coil is required to be high, that is, the current requirement is large, the energy consumption is increased, and the service life of the electromagnet is shortened. In addition, the electromagnetic coil needs to maintain a long power-on time, which is easy to generate heat, and also increases energy consumption. In this solution, the torque of the pulley is directly transmitted through the suction of the suction cup and the pulley, and the strength of the suction cup is high, and the suction cup is relatively easy to generate large wear.

The Chinese Utility Model Publication No. CN203769916U discloses a further prior art in which a first magnet 501 is fixed to the first rotating body 2, the first magnets are arranged circumferentially and have opposite polarities in the radial direction. When the electromagnet core 6 is deenergized, the suction pad 7 is attracted by the permanent magnet to engage with the first rotating body 2, and transmits the rotation of the first rotating body to the second rotating body 3. When the electromagnet core is energized, the suction disk 7 is separated from the first rotating body, and the first rotating body 2 is separated from the second rotating body 3. In this solution, the suction disc is also soft magnetic, not a permanent magnet. When the electromagnet core is energized, it is necessary to offset the magnetic field of the permanent magnet, instead of directly exerting a force on the suction disc, requiring a large current and high energy consumption; When it is necessary to disconnect the suction cup from the pulley, the electromagnet core needs to be energized for a long time, which also causes heat generation and high energy consumption. In addition, the suction disc directly transmits torque through friction, which has high requirements for the strength of the suction disc.

Summary of the invention

The technical problem to be solved by the present invention is to provide an electromagnetic clutch having a small power consumption and having a long service life.

The present invention provides an electromagnetic clutch comprising:

a shaft having an axis;

a drive wheel for receiving external power;

An electromagnet capable of generating a magnetic field when energized to the electromagnet;

An armature assembly, the armature assembly being movable between a first position and a second position in a direction of an axis of the rotating shaft;

a driven wheel assembly mounted on the rotating shaft, the driven wheel assembly being configured to move with the driving wheel to move away from the driving wheel as the armature assembly moves to the first position; with the armature assembly Moving to the second position, the driven wheel assembly moves to engage the driving wheel;

It is characterized in that

The armature assembly includes a permanent magnet;

When the first current in the first direction is applied to the electromagnet, the first force between the magnetic field generated by the electromagnet and the permanent magnet of the armature assembly, the armature assembly faces the first position motion;

a second force between a magnetic field generated by the electromagnet and a permanent magnet of the armature assembly when a second current in a second direction opposite to the first direction is applied to the electromagnet, the armature assembly Moving to the second position;

The electromagnetic clutch further includes an elastic member that applies a force to the armature assembly in a direction that moves the armature assembly to the second position;

When the armature assembly is moved to the first position, the permanent magnet of the armature assembly can be attracted to a magnetizable member such that the armature assembly is reduced or disconnected from the current to the electromagnet Can be held in the first position.

Wherein: the first position is a position close to the electromagnet, and the second position is a position away from the electromagnet.

The invention has the following technical effects:

The electromagnetic force requirement for the electromagnet is small, that is, the current requirement is small, energy saving; and the life of the electromagnet is prolonged.

DRAWINGS

1 is an exploded perspective view of an electromagnetic clutch according to a first embodiment of the present invention;

Figure 2 is a cross-sectional view showing an electromagnetic clutch in an assembled state according to a first embodiment of the present invention;

Figure 3 is a cutaway perspective view of the electromagnetic clutch in an assembled state according to a first embodiment of the present invention;

Figure 4 is a perspective view of a driving wheel of an electromagnetic clutch according to a first embodiment of the present invention;

Figure 5 is a cross-sectional view of a driving wheel of an electromagnetic clutch in accordance with a first embodiment of the present invention;

6-7 are perspective views of a driven wheel of an electromagnetic clutch according to a first embodiment of the present invention;

Figure 8 is a cross-sectional view of a driven wheel of an electromagnetic clutch in accordance with a first embodiment of the present invention;

9-10 are perspective views of a wedge block of an electromagnetic clutch in accordance with a first embodiment of the present invention;

Figure 11 is a side view of a wedge block of an electromagnetic clutch in accordance with a first embodiment of the present invention;

Figure 12 is a side view of the armature holder of the electromagnetic clutch according to the first embodiment of the present invention;

Figure 13 is a perspective view of an armature holder of an electromagnetic clutch according to a first embodiment of the present invention;

Figure 14 is a partial perspective view of the armature holder of the electromagnetic clutch according to the first embodiment of the present invention;

Figure 15 is a perspective view of an electromagnetic clutch in accordance with a second embodiment of the present invention;

Figure 16 is a cross-sectional view of an electromagnetic clutch in accordance with a second embodiment of the present invention;

Figure 17 is a cutaway perspective view of an electromagnetic clutch in accordance with a second embodiment of the present invention;

Figure 18 is a cross-sectional view of the electromagnet;

19-20 are perspective views of an armature assembly of an electromagnetic clutch in accordance with a second embodiment of the present invention;

Figure 21 is a perspective view of a driven wheel of an electromagnetic clutch in accordance with a second embodiment of the present invention;

22-23 are diagrams illustrating movement and clutch engagement of an armature assembly in accordance with the present invention. Schematic diagram of the relationship between states.

detailed description

[First Embodiment]

An electromagnetic clutch according to a first embodiment of the present invention will now be described with reference to Figs. 1-3 illustrate an electromagnetic clutch in accordance with a first embodiment of the present invention.

The electromagnetic clutch 100 according to the present invention mainly includes a housing assembly, a rotating shaft assembly, an electromagnet, a driving wheel assembly, and a driven wheel assembly.

The housing assembly includes a housing 1, an impeller 27 mounted on one of the outer sides of the housing 1 (shown on the left side in FIG. 1), and an impeller bearing-seal assembly (also referred to as a water seal) therebetween. 14. The housing 1 includes a cylindrical wall 1a defining a hole and a rib 1b as shown in FIG. The outer casing assembly also includes a dust cover 3.

The rotating shaft assembly includes a rotating shaft 7a and a bearing 7 mounted on the rotating shaft 7a. The shaft assembly is mounted into the housing 1 from a side opposite the impeller 27 such that the bearing 7 is entirely received in the housing 1 but one end of the shaft 7a extends beyond the housing to seal with the impeller 27 and the impeller bearing The components 14 are joined as shown in FIG.

A snap-fit mounting ring 29 is mounted on the cylindrical wall 1a of the housing 1 to mount an electromagnet (specifically, an iron yoke) described later on the housing 1. The fitting fixing ring 29 has engaging portions respectively engaged with the respective reinforcing ribs 1b so as to be positioned in the circumferential direction with respect to the cylindrical wall 1a when the electromagnet is mounted on the casing.

The electromagnet includes an iron yoke 24 and an electromagnetic coil 32 positioned within the iron yoke 24. The electromagnet is mounted in a driving wheel (pulley) 2 for receiving external power (for example, power from an automobile engine or other external power), the electromagnet side abuts against the mounting ring 29, and the other side is adjacent to the active described later The radial component 2b of the wheel 2 is shown in Figures 1 and 2. The iron yoke 24 may be formed of, for example, a soft magnetic material (i.e., the iron yoke is a magnetizable member), and the electromagnetic coil 32 generates a magnetic pole on the iron yoke 24 when energized.

A cable formed by a socket 28 for fixing the end of the electromagnetic coil to the iron yoke 24 and a plug 25 for connecting the automobile cable to the socket 28 electrically connects the cable of the automobile with the electromagnetic coil of the electromagnet so as to The electromagnet is powered or de-energized.

The driving wheel 2 is the main component of the active part of the electromagnetic clutch, preferably a pulley. In other embodiments, the drive wheel can also be other components to which the pulley can be fixedly coupled.

4 and 5 show the configuration of the driving wheel 2, wherein Fig. 4 is a perspective view showing the driving wheel, and Fig. 5 is a sectional view showing the driving wheel.

As shown in Figures 4 and 5, the drive wheel comprises a cylindrical wall 2a and a radial member 2b in the form of a ring extending radially inwardly from the cylindrical wall 2a at a certain axial position. In an exemplary embodiment, the radial member 2b is preferably disposed integrally with the cylindrical wall 2a at an axially intermediate position within the drive wheel 2. However, the present invention is not limited thereto, and the radial member 2b may be disposed at other axial positions in the driving wheel 2 depending on the actual situation.

When the radial component 2b of the driving wheel 2 is made of a soft magnetic material (ie, the radial component 2b is a magnetizable component), the radial component can be regarded as the first rotor; when the radial component of the driving wheel is non- In the case of a soft magnetic material, a first rotor made of a soft magnetic material fixed relative to the driving wheel may also be provided.

As shown in Figures 1-3, the electromagnet is mounted within the drive wheel 2 adjacent the radial member 2b of the drive wheel 2.

As shown in Figures 4-5, the radial member 2b is provided with a magnetic isolation groove which enables the magnetic field of the electromagnet to act on the armature assembly described later by the guidance of the radial members. For example, the electromagnets may be rendered with a radially distributed opposite polarity to correspond to the permanent magnets of the armature assembly radially distributing the poles; or the electromagnets may be presented in a single polarity in the axial direction to correspond to the axially distributed magnetic poles of the armature assembly Permanent magnet.

The armature 19 and the armature frame 31 constitute an armature assembly. The driven wheel 18 and the wedge block 20 constitute a driven wheel assembly. The armature assembly and the driven wheel assembly are mounted on the opposite side of the radial member 2b of the drive wheel 2 from the electromagnet. The bearing 33 and the retaining ring 34 are radially mounted between the cylindrical body of the driven wheel 18 described later and the radial member of the driving wheel 2.

The armature assembly includes a permanent magnet that distributes the magnetic poles in a radial or axial direction, for example, an N pole on the radially inner side and an S pole on the radially outer side, or vice versa; or an N pole on one side and an S pole on the other side. The preferred solution is a radial distribution, which minimizes the electromagnetic force required for the electromagnet, ie, minimizes current and minimizes energy consumption. In the present embodiment, by performing the annular armature 19 Magnetization causes the armature 19 to become a permanent magnet. In an alternative embodiment, the permanent magnet structure may be a plurality of circular or annular members disposed on the armature 19. The armature is mounted to the armature frame 31 by screws 23.

A driven wheel assembly composed of the driven wheel 18 and the wedge block 20 is axially mounted between the armature 19 and the armature frame 31. As shown in FIG. 6-8, the driven wheel 18 has an axially extending cylindrical body for fixing (which may be an interference fit or other mounting manner) on the rotating shaft 7 (see FIG. 2); A plurality of equally spaced (circumferentially) radial arms 18a extending radially away from one end of the drive wheel. The radial arms are provided with mounting holes for mounting the armature frame 31 and the wedge block 20 to the radial arms via the wedge shaft 22. In the example shown, three radial arms are provided. However, the present invention is not limited thereto, and a plurality of radial arms different in number from three may be provided as needed.

Alternatively, the driven wheel 18 may be disposed in a two-layer structure in the axial direction, and the left side (near the side of the driving wheel) is provided with a circular ring structure 181 made of soft magnetic material, which may serve as the second rotor 181 ( That is, the second rotor is a magnetizable member; its right side (away from the side of the driving wheel) is provided with a plurality of radial arms 18a as described above. The radial arms 18a may be integrally formed with the cylindrical body of the driven wheel 18, or the separate components may be fixedly coupled to the cylindrical body by welding or otherwise. Alternatively, the plurality of radial arms 18a may also be a single annular structure extending radially from the cylindrical body.

In the case where the second rotor 181 is provided, the wedge block 20 is housed between the two-layer structure of the driven wheel through the wedge shaft 22, that is, between the second rotor 181 and the plurality of radial arms 18a. Further, the armature 19 and the armature frame 31 in the armature assembly are respectively disposed on both axial sides of the second rotor 181, wherein the armature 19 is adjacent to the left side in FIG. 1, and the armature frame 31 is adjacent to the right side in FIG.

As shown in FIGS. 9-11, the wedge block 20 includes a swing arm 20a and a wedge face 20b, and the swing arm 20a is mounted on the radial arm 18a of the driven wheel 18 via the wedge shaft 22. The wedge block 20 is rotatable about the wedge block axis 22. In this embodiment, the mating relationship between the wedge shaft 22 and the radial arm 18a of the driven wheel 18 and the mating relationship between the wedge shaft 22 and the wedge block 20 can be: a interference fit and clearance fit, respectively; or b clearance fit and Gap fit; or c clearance fit and interference fit.

The radial arm 18a of the driven wheel 18 is press-fitted with the counterbore at the left end of the wedge shaft 22 to form a wedge The stop face of the block shaft to the left end of the radial arm 18a. The shaft diameter of the wedge shaft 22 cooperating with the armature frame 31 is larger than the shaft diameter of the wedge shaft 22 and the radial arm 18a of the driven wheel 18, thereby forming a stop surface to the right side of the driven wheel. Thereby, the wedge shaft is axially constrained on the driven wheel. The armature frame 31 is also mounted on the (radial arm of) the driven wheel 18 via the wedge shaft 22, guided by the wedge shaft 22 (the wedge shaft 22 is in clearance fit with the armature frame 31), and is axially reciprocally movable. When the armature assembly is moved to the first position (illustrated as the left side in this embodiment), the armature frame 31 abuts on the right side of the radial arm of the driven wheel, when the armature assembly moves to the second position (in the present embodiment) In the example of the right side, the armature 19 abuts on the left side of the driven wheel, that is, the end face of the driven wheel can limit the movement of the armature assembly in the axial direction.

As shown in Figures 12-14, the armature frame 31 has an annular body 31a and a plurality of U-shaped forks 31b disposed on the outer circumference of the annular body. The shifting fork includes a first lever 31b1 and a second lever 31b2. The first lever and the second lever may have a cylindrical surface with respect to the axis of the rotating shaft, or may be planar; the first and second levers are The mating faces 311, 312 of the wedge block are helical or inclined planes with respect to the axis of the shaft, the oblique planes intersecting the axis of the shaft and are not perpendicular. In a preferred embodiment, the mating surface is a helicoid.

When the armature assembly is driven to move in the axial direction, the mating surface pushes the wedge block 20 mounted on the wedge shaft 22, and the urging force has a force component tangential to the circumferential direction, causing the wedge block to rotate about the wedge axis. That is, the axial movement of the armature assembly is converted into a rotational motion in the circumferential direction of the wedge block such that the wedge faces of the wedge block 20 frictionally engage or separate from the inner cylindrical surface of the drive wheel 2.

Optionally, the wedge block 20 is provided with a metal hoop 20c having a cylindrical shape or an arc shape. The metal hoop 20c is integrally or assembled on the wedge block 20 for mating with the mating surfaces 311 and 312 of the armature frame 31. Reduce friction and make the fit smoother.

2-3 show the assembled state of the electromagnetic clutch, and the dust cover (cap member) 3 is fitted with the driving wheel to form an enclosure on one side of the electromagnetic clutch. The mutual assembly between the components can be performed by known means and will not be described in detail herein.

The operation of the electromagnetic clutch according to the present invention will be described below with reference to FIG. 1.

First, the axial movement of the armature assembly when the electromagnet is turned on/off.

When the current is passed to the electromagnet in the first direction, the polarity of the electromagnet and the permanent magnet of the armature assembly The opposite polarity / attraction, acting on the armature assembly. Therefore, under the action of the electromagnetic force, the armature 19 and the mounted armature frame 31 move toward the first position, preferably the separated position of the clutch, against the force of the elastic member.

When the armature assembly is moved to the first position, the permanent magnets in the armature assembly are attracted to the first rotor made of soft magnetic material. The pull-in is a magnetic attraction with a gap. In other embodiments, the pull-in may also be a magnetic pull with mechanical contact corresponding to other clutch configurations. The armature assembly attracts the armature of the first rotor due to its own permanent magnet. Therefore, even if the current of the electromagnet is turned off, the armature can be acted only by the magnetic attraction force of the permanent magnet of the armature assembly and the soft magnetic material of the first rotor. The assembly remains in the first position or the armature assembly can be held in the first position by reducing the current to the electromagnet.

When the electric current is passed to the second direction opposite to the first direction, the polarity of the magnetic field formed by the electromagnet is the same as that of the permanent magnet of the armature assembly, and the electromagnet repels/pulls the armature assembly to the second position. (The joint position, which is illustrated as the right side in this embodiment) moves. The armature assembly is moved to the second position by the interaction of the electromagnetic force and the elastic member. At this time, the gap between the armature assembly and the first rotor is increased, the magnetic attraction force between the armature assembly and the first rotor is negligible, and the armature assembly can be held in the second position only by the elastic member. At this point, the power to the electromagnet can be stopped to reduce energy consumption.

When the second rotor is disposed on the driven wheel, the second rotor may be made of a soft magnetic material. When the armature assembly is moved to the second position, the permanent magnet of the armature assembly is attracted to the second rotor, and the suction may be a magnetic attraction with mechanical contact or a magnetic attraction with a gap. The interaction of the armature assembly with the second rotor and the force of the resilient member on the armature assembly further ensure that the armature assembly is held in the second position.

By integrating a control component, such as a counter commutator, on the receptacle 28, the magnetic poles of the electromagnet can also be controlled by direct control of the direction of current flow in the solenoid 32 by the on-board relay.

As described above, in the creation of the present invention, the electromagnet directly applies a repulsive or attracting magnetic force to the armature assembly containing the permanent magnet by the same or opposite magnetic pole polarity as the permanent magnet, and does not need to overcome the permanent as in the prior patent. The force of the magnet on the armature assembly either offsets the magnetic field of the permanent magnet. Therefore, in the creation of the present invention, the force of the electromagnet can be greatly reduced. The magnitude of the current in the electromagnet of the present invention can be reduced to about half of the current in the prior art with respect to the electromagnetic clutch disclosed in the aforementioned Japanese Patent Publication and the U.S. Patent. At the same time, after the armature assembly is moved to the first position or the second position, the armature assembly can be kept in the corresponding position without the action of the electromagnet (or only a small force), that is, the power supply to the electromagnet can be stopped ( Or only a small current is required, which can greatly reduce the energy consumption, that is, the action time of the large current pulse is very short and can be calculated in seconds. Compared with the several minutes of action time of the electromagnet in the prior art, the action time of the electromagnet is shortened by two orders of magnitude in the present invention, which greatly reduces the possibility of electromagnet heating.

Next, the movement of the driven wheel assembly with the axial movement of the armature assembly when the electromagnet is turned on/off will be described.

When the current in the second direction opposite to the first direction is made to move the electromagnet to move the armature assembly to the second position, the armature assembly (the armature 19 and the armature frame 31) is driven between the armature 19 of the armature assembly and the armature frame 31. The driven wheel assembly moves. When the armature frame 31 is moved to the second position in the axial direction, the mating surface 311 of the second lever 31b2 of the U-shaped fork of the armature frame 31 applies a force which is tangent to the circumferential direction of the ferrule 20c of the wedge block 20, The wedge block 20 is caused to rotate about the wedge shaft 22, the axis of the wedge shaft being parallel to the axis of the shaft. At this time, the wedge surface of the wedge block 20 is rotated in the direction in which the wedge surface of the wedge block 20 is engaged with the inner surface friction surface of the cylindrical wall 2a of the driving wheel 2 with the wedge shaft 22 as the rotation axis. When the wedge surface of the wedge block 20 is in frictional contact with the inner surface of the cylindrical wall 2a of the driving wheel 2, the wedge block 20 is subjected to the cylinder from the driving wheel 2 in the same direction as the pushing force of the mating surface 311 of the armature frame 31. The frictional force of the inner surface of the shaped wall 2a causes the wedge block 20 to be wedge-engaged with the inner surface of the cylindrical wall 2a of the clutch driving wheel 2, and the friction between the two is pushed by the wedge shaft 22 The driven wheel 18 thereby transmits rotational power to the rotating shaft. The wedge-in combination refers to the line connecting the wedge surface of the wedge block with the inner surface of the cylindrical wall of the driving wheel and the rotation axis of the wedge block, and the angle between the rotation axis of the wedge block and the axis of the rotating shaft. And the wedge-in combination is not a self-locking bond.

The second lever 31b2 (the lever that engages the wedge block with the driving wheel) is designed as an elastic member, so that the mating surface 311 is better fitted with the wedge block 20. The elastic deformation of the second lever 31b2 can cause a plurality of (three in the illustrated example) wedge blocks to substantially coincide with the pressure of the pulley. It is assumed that the engagement of the wedge block with the pulley is preceded by manufacturing tolerances/installation tolerances, and the three wedge blocks can be substantially synchronously coupled to the inner surface of the pulley by elastic deformation of the second lever.

When the armature frame 31 is driven to move in the first position direction with the armature assembly, the mating surface 312 of the first lever 31b1 of the armature frame 31 pushes the wedge block 20 to the wedge surface of the wedge block 20 with the wedge shaft 22 as the rotation axis. Rotating in a direction separating from the inner surface of the cylindrical wall 2a of the driving wheel 2, thereby separating the wedge surface from the inner surface of the cylindrical wall 2a of the driving wheel 2, thereby realizing the separation function of the rotational power of the driving wheel and the driven wheel, The drive wheel is idling relative to the driven wheel.

In other embodiments, the armature frame can also be disposed on the left side of the driven wheel together with the armature, and the tilting/rotating direction of the mating surface of the shifting fork can be correspondingly provided, and the armature assembly can also be realized in the axial direction. When the one position and the second position are moved, the wedge block is engaged or disengaged from the inner surface of the cylindrical wall of the driving wheel.

The elastic member 30 as the second position holder of the armature assembly exerts a force on the armature assembly in a direction away from the first rotor in the axial direction, so that the elastic member 30 always acts in the direction of driving the armature assembly back to the second position. In the second position, the engagement of the armature assembly (specifically, the armature 19) with the electromagnetic assembly is broken. The elastic member may be a coil spring, a sheet spring, or a wave spring. The quantity can also be set to one as needed, or it can be multiple overlays or decentralized settings. The action can be either a stretched armature assembly or a biased armature assembly. In this embodiment, the elastic member is a coil spring or a plurality of axially superposed wave springs, one end of which is biased at the end of the rotating shaft or the end surface of the second rotor described later, and the other end is biased to the armature frame of the armature assembly. on. In other embodiments, the elastic member may also be a plurality of discretely disposed coil springs having one end abutting the driven wheel and the other end abutting the armature assembly. It is of course also possible to use a leaf spring widely used in the art, and the details are not described again.

For the driven wheel assembly, other configurations of the prior art may be employed instead of the above-described fork-wedge block structure of the present invention. For example, the winding coil described in the Chinese Patent Application Publication No. CN200980145448.X and the ball type structure as described in Japanese Patent Laid-Open Publication No. 2007-205513.

When the electromagnet fails, the pump may stop working and the engine temperature rises. The armature assembly including the permanent magnet rises to the Curie point under the influence of the heat conducted by the water pump, that is, when the ambient temperature of the armature assembly reaches the design demagnetization temperature, the magnetism of the permanent magnet decreases or disappears, thereby causing the a mutual attraction force between the permanent magnet of the armature assembly and the soft magnetic material of the first rotor or a magnetic field generated by the electromagnet to which the reduced first current is applied and a permanent magnet of the armature assembly The attraction force is reduced or disappeared, and the force applied by the elastic member to the armature assembly moves the armature assembly to the second position; when the armature assembly of the permanent magnet returns to the design temperature, the magnetic property can be restored. , or the magnetic sequence is restored, and the permanent magnet is magnetized by the electromagnet, that is, the permanent magnet is a non-permanently demagnetized material, and the electromagnetic clutch can still work normally after the magnetic or magnetic force of the permanent magnet of the armature assembly is restored to the design value. .

In view of such a situation, preferably, as in the exemplary embodiment of the present invention, the armature assembly and the driven wheel assembly are configured such that when the armature assembly is in the second position (the engagement of the armature assembly is broken), the driven wheel assembly The wedge block is wedged with the inner surface of the drive wheel. Therefore, when the sum of the attraction force of the armature assembly and the first rotor or the sum of the suction force of the armature assembly and the first rotor and the force of the electromagnet to the armature assembly is smaller than the force of the elastic member to the armature assembly, the armature assembly is moved to the second position. Moving, the wedge block 20 is rotated in a direction in which its wedge surface engages with the inner surface of the cylindrical wall 2a of the driving wheel 2, so that the wedge block is wedge-engaged with the inner surface of the cylindrical wall 2a of the driving wheel And the friction between the two pushes the driven wheel 18 through the wedge shaft 22 to transmit the rotational power to the rotating shaft to normally drive the water pump to work, thereby realizing the safety failure of the electromagnetic clutch.

In the present invention, the elastic member 30 having a small elastic force can be used, so that the armature assembly can be attracted to the left by a small current to the electromagnet, and the electromagnet is less likely to generate heat.

Further, in the present invention, since the wedge block is rotated in the direction in which the wedge face is in contact with the inner surface of the cylindrical wall 2a of the clutch driving wheel with the wedge shaft as the rotational axis, the wedge face of the wedge block ( After the friction surface is in contact with the inner surface of the cylindrical wall 2a of the clutch driving wheel, the wedge block is subjected to the cylindrical wall 2a from the driving wheel in the same direction as the engaging surface (preferably the helicoid) of the armature frame. The frictional force of the inner surface maintains the wedge block in wedge engagement with the inner surface of the clutch drive wheel; and the greater the torque transmitted by the clutch, the wedge The tighter the wedge between the block and the drive wheel, the greater the torque transmitted. As long as the transmitted torque is not greater than the structural damage of the two, the clutch will not be ineffective. With such structural features, even if water or oil between the wedge block and the driving wheel causes a serious decrease in the friction coefficient, the clutch can transmit the torque required for the design due to the wedge-in combination. .

The armature containing the permanent magnet subjected to the electromagnetic force of the electromagnet is placed in the joint position or the disengaged position by the electromagnetic force under the action of the electromagnetic force, and after the electromagnetic force disappears, both the permanent magnet and the peripheral ferromagnetic element are The soft magnetic material is sucked to maintain the position, so that the position maintaining function can be realized, and the working time of the electromagnet can be greatly shortened. As long as the armature can be pushed or pulled to the engaged position or the separated position, the power supply can be cut off, so that the energizing time of the electromagnetic coil of the clutch is extremely short, and there is no disadvantage that the function of the electromagnet is lowered due to heat generation.

[Second embodiment]

A second embodiment of the present invention will now be described with reference to Figs. 15-21. The structures, configurations, and features that can be used in the second embodiment in the first embodiment will not be repeatedly described.

The electromagnetic clutch 100' according to the second embodiment of the present invention also mainly includes a housing assembly, a rotating shaft assembly, an electromagnet, a driving wheel assembly, and a driven wheel assembly.

Referring to Figures 15-17, an electromagnetic clutch according to a second embodiment is combined with a water pump, the housing assembly of which comprises a water pump body 1c and a housing 1' and a dust cover 3' formed by a scroll 1d. The impeller 27' and the impeller bearing-seal assembly (water seal) 14' are installed between the water pump body 1c and the volute 1d.

The shaft assembly also includes a rotating shaft 7a' and a bearing 7' mounted on the rotating shaft 7a'. The shaft assembly is mounted into the water pump body 1c from the side opposite to the impeller 27' such that the bearing 7' is entirely housed in the water pump body 1c and one end of the shaft 7a' extends into the impeller 27' and the impeller bearing-seal assembly. 14' phase bonding, as shown in Figure 15-17.

As shown in Fig. 18, the electromagnet 101 includes an iron yoke 24' and an electromagnetic coil 32' positioned in the iron yoke 24'. The electromagnet 101 is mounted on the water pump body 1c and mounted on a driving wheel for receiving external power (for example, power from an automobile engine or other external power) Wheel) 2' inside. The iron yoke 24 may be formed, for example, of a soft magnetic material (i.e., the iron yoke 24 is a magnetizable member), and the electromagnetic coil 32' energizes to generate a magnetic pole on the iron yoke 24' as shown.

The cable of the car and the solenoid of the electromagnet are electrically connected by a connector 28' for fixing the end of the electromagnetic coil to the iron yoke 24' and a connector 25' for connecting the car cable to the socket 28'. Connect to power or de-energize the electromagnet. A socket base cover 26' and a controller 27' may also be disposed between the socket 28' and the plug 25', as shown in FIG.

Similar to the first embodiment, the driving wheel 2' is the main component of the active portion of the electromagnetic clutch, preferably a pulley. In other embodiments, the drive wheel can also be other components to which the pulley can be fixedly coupled.

Unlike the first embodiment, the driving wheel 2' according to the second embodiment does not include a radially inwardly extending radial member in the form of a ring which can function as a first rotor, including only a cylindrical shape. unit.

As shown in FIGS. 16 and 17, the bearing 33' (for example, a double row ball angular contact bearing) and the electromagnet 101 are axially connected in series between the stepped cylindrical portion of the water pump body 1c and the driving wheel 2', respectively, and the water pump. The body is fixedly fitted with a gap between the cylindrical inner wall of the driving wheel 2'.

As shown in Fig. 15-17, a positioning ring 35' and a retaining ring 34' are disposed between the electromagnet 101 and the bearing 33'. The positioning ring 35' limits the spacing between the inner ring of the bearing 33' and the electromagnet 101 to avoid scratching during rotation. The retaining ring 34' limits the axial rotation of the outer ring of the bearing 33' relative to the drive wheel 2'.

The armature assembly 102 is located on the other side of the electromagnet 101 (on the right side of the drawing). As shown in Figures 19-20, in the second embodiment as shown, the armature assembly 102 is disposed by integral injection molding.

Similar to the first embodiment, the armature assembly 102 includes permanent magnets 102b2 that distribute magnetic poles in a radial or axial direction, such as a radially inner side of the N pole, a radially outer side of the S pole, and vice versa; or an axial side of the N The pole is the S pole on the other side. The preferred solution is a radial distribution, which minimizes the electromagnetic force required for the electromagnet, ie, minimizes current and minimizes energy consumption.

As shown in FIGS. 19-20, in the second embodiment, the armature assembly includes a plurality of grooves 102b1 and a plurality of permanent magnets 102b2 spaced apart in the circumferential direction. Alternatively, the permanent magnets may be otherwise disposed in the armature assembly. For example, a permanent magnet is a single annular permanent magnet. Embedded in the armature assembly.

The armature assembly 102 also includes, on its opposite side from the electromagnet, a first lever 31b1' and a second lever 31b2' which constitute a shifting fork for dialing a wedge block as described later. In the second embodiment, the first lever and the second lever have a design similar to that of the first embodiment, and the description thereof will not be repeated here.

As shown in Fig. 19, the inner circumferential side of the armature assembly 102 is provided with a spline groove 102a1 or a spline, which cooperates with a spline or a spline groove which will be described later on the outer side of the cylindrical portion of the driven wheel, and is opposed to The driven wheel can move axially.

Of course, similar to the first embodiment, the armature assembly can also be formed from separate components or portions, or can have other configurations as long as the armature assembly includes permanent magnets and its motion can drive the driven wheel assembly to move.

As shown in FIGS. 15 and 21, the driven wheel 18' and the wedge block 20' constitute the driven wheel assembly 103. The driven wheel 18' may have a structure substantially similar to that of the driven wheel 18 of the first embodiment, that is, having: an axially extending cylindrical body for attachment to the rotating shaft; and a radial direction at an end remote from the driving wheel Extending a plurality of equally spaced (longitudinal) radial arms 18a'. Alternatively, the driven wheel 18 may also be provided in a two-layer structure in the axial direction, and the left side thereof is provided with a circular ring structure made of soft magnetic material, which may serve as the second rotor 181'; The plurality of radial arms 18a'.

The outer side of the cylindrical portion (shaft portion) of the driven wheel 18' according to the second embodiment is further provided with a spline 18a1 (or a spline groove) that engages with the aforementioned spline groove 102a1 and can also be disposed on the left side of the second rotor 181'. A protrusion (stop boss) 181a that can be received within the slot 102b1 of the armature assembly for limiting and maintaining a gap between the driven wheel assembly 103 and the armature assembly 102.

The wedge block 20' has the same or similar configuration as the first embodiment, is mounted to the radial arm 18a' of the driven wheel 18' by a pin 22', and is rotatable about the pin.

The driven wheel assembly 103 is integrally mounted axially on the opposite side of the armature assembly 102 from the electromagnet, and the cylindrical portion of the driven wheel 18' extends through the central bore of the armature assembly 102 such that the spokes of the driven wheel 18' The (or splined groove) 18a1 mates with the splined groove (or spline) 102a1 of the armature assembly and causes the first/second lever to mate with the wedge block 20'.

As shown in FIGS. 16 and 17, the inner circumference of the cylindrical portion of the driven wheel 18' is fixedly engaged with the water pump shaft, the spring cover 35 is mounted on the armature assembly 102, and one end of the spring 30' (elastic member) abuts against the spring cover 35. The other end abuts the water pump shaft 7a', forcing the armature assembly to move away from the electromagnet.

The operation of the electromagnetic clutch according to the second embodiment will be described below with reference to Fig. 15 .

When the electric current is passed to the electromagnet in the first direction, the polarity of the electromagnet is opposite to/the opposite of the polarity of the permanent magnet of the armature assembly, acting on the armature assembly. Therefore, under the action of the electromagnetic force, the armature assembly moves against the force of the elastic member toward the first position, preferably the disengaged position of the clutch.

When the armature assembly is moved to the first position (shown to the left), the permanent magnets in the armature assembly are attracted to the iron yoke (magnetizable component) of the electromagnet. Since the armature assembly attracts its own permanent magnet and the iron yoke (magnetizable member) of the electromagnet, similarly to the first embodiment, even if the current of the electromagnet is turned off, only the permanent magnet of the armature assembly and the iron yoke of the electromagnet are passed ( The magnetic attraction force of the magnetizable component can also maintain the armature assembly in the first position, or the armature assembly can be held in the first position by reducing the current to the electromagnet.

When the electric current is passed to the second direction opposite to the first direction, the polarity of the magnetic field formed by the electromagnet is the same as that of the permanent magnet of the armature assembly, and the electromagnet repels/pulls the armature assembly to the right. . Under the joint action of the electromagnetic force and the elastic member, the armature assembly is moved to the second position (engagement position, shown as the right side). At this time, the gap between the armature assembly and the iron yoke (magnetizable part) of the electromagnet is increased, the magnetic attraction force between the armature assembly and the iron yoke of the electromagnet is negligible, and the armature assembly can be only under the action of the elastic member. Stay in the second position. At this point, the power to the electromagnet can be stopped to reduce energy consumption.

Similar to the first embodiment, when the second rotor is disposed on the driven wheel, the second rotor may be made of a soft magnetic material (magnetizable member). When the armature assembly is moved to the second position, it is engaged with the second rotor. The interaction of the armature assembly with the second rotor and the force of the resilient member on the armature assembly further ensure that the armature assembly is held in the second position.

As described above, the second embodiment can obtain the same effect as the first embodiment, that is, the electromagnet directly faces the armature containing the permanent magnet by the same or opposite magnetic pole polarity as the permanent magnet. The component exerts a repulsive or attracting magnetic force that does not require overcoming the force of the permanent magnet on the armature assembly or offsetting the magnetic field of the permanent magnet as in the prior patents. Therefore, the force of the electromagnet can be greatly reduced, and the magnitude of the current in the electromagnet of the present invention can be reduced to about half of the current in the prior art with respect to the electromagnetic clutch disclosed in the aforementioned Japanese Patent Publication and the U.S. Patent. At the same time, after the armature assembly is moved to the left or right side, the armature assembly can be held in the corresponding position without the need of electromagnet force (or only a small force), that is, the power supply to the electromagnet can be stopped (or only A small current is required, which can greatly reduce the energy consumption, that is, the action time of the large current pulse is short and can be calculated in seconds. Compared with the several minutes of action time of the electromagnet in the prior art, the action time of the electromagnet is shortened by two orders of magnitude in the present invention, which greatly reduces the possibility of electromagnet heating.

When the electromagnet is turned on/off, the movement of the driven wheel assembly is similar to that of the first embodiment with the axial movement of the armature assembly.

When the current in the second direction opposite to the first direction is made to move the armature assembly to the second position (engagement position, shown as the right side), the engagement of the second lever 31b2' of the armature assembly faces the wedge block The ferrule of 20' exerts a force tangential to the circumferential direction such that the wedge block 20' rotates about the pin 22', the axis of the pin being parallel to the axis of the shaft. At this time, the wedge 22' is used as the rotation axis to rotate the wedge surface of the wedge block 20' in the direction in which the inner surface friction surface of the cylindrical wall of the driving wheel 2' is engaged. When the wedge surface of the wedge block 20' is in frictional contact with the inner surface of the cylindrical wall of the driving wheel 2', the wedge block 20' is subjected to the same direction from the driving force of the mating surface of the second lever 31b2'. The frictional force of the inner surface of the 2' cylindrical wall keeps the wedge block 20' wedge-engaged with the inner surface of the cylindrical wall of the clutch driving wheel 2' and passes the friction between the two The pin 22' pushes the driven wheel 18' to transmit rotational power to the rotating shaft.

As in the first embodiment, the second lever 31b2' (the lever that engages the wedge with the driving wheel) is designed as an elastic member, so that the mating surface is better fitted with the wedge block 20'. The elastic deformation of the second lever 31b2' can cause a plurality of (three in the illustrated example) wedge blocks to substantially coincide with the pressure of the pulley. It is assumed that the engagement of the wedge block with the pulley is preceded by manufacturing tolerances/installation tolerances, and the three wedge blocks can be substantially synchronously coupled to the inner surface of the pulley by elastic deformation of the second lever.

When the armature assembly is driven to move in the first position direction, the mating surface of the first lever 31b1' of the armature assembly pushes the wedge block 20' to the wedge 22' as the axis of rotation to the wedge surface of the wedge block 20' and the driving wheel 2 The inner surface of the cylindrical wall rotates in a direction separating, so that the wedge surface is separated from the inner surface of the cylindrical wall of the driving wheel 2', and the separation function of the driving power of the driving wheel and the driven wheel is realized, so that the driving wheel is relatively The idling wheel is idling.

The electromagnetic clutch according to the second embodiment can obtain the same technical effect as the electromagnetic clutch according to the first embodiment. In addition, in the second embodiment, when the armature assembly is moved to the first position and the current of the electromagnet is reduced or broken, the permanent magnet of the armature assembly directly engages with the iron yoke of the electromagnet, and the driving wheel The (belt) does not have radial components, thus simplifying the structure of the drive wheel and further reducing the cost of the electromagnetic clutch. In addition, the iron yoke of the electromagnet is axially connected in parallel with the bearing 33' (double row angular contact bearing), reducing the diameter of the electromagnetic clutch. Moreover, since the armature assembly and the driven wheel are splined/splined, the jamming effect of the step pin (wedge shaft) as a guide in the first embodiment is eliminated.

Many other variant embodiments are also conceivable by those skilled in the art from the above description of the first embodiment and the second embodiment. Some variant embodiments are described below by way of example (non-exclusive).

[Modification 1]

In the structure of the electromagnetic clutch of the first embodiment, the driving wheel 2 is provided with a radial member formed of a soft magnetic material (magnetizable member) as a first rotor for passing through when the current of the electromagnet is reduced or broken Engaging the permanent magnet of the armature assembly maintains the armature assembly in the first position. In fact, similar to the second embodiment, in the first embodiment, the driving wheel 2 may not be provided with a radial member as the first rotor, but also utilizes an iron yoke (magnetizable member) of the electromagnet and the armature assembly. The permanent magnet phase pulls the armature assembly in the first position while reducing or breaking the current of the electromagnet.

[Modification 2]

In the first embodiment and the second embodiment, when the armature assembly is moved close to the electromagnet In the first position (left side), the driven wheel assembly moves into separation from the driving wheel, and when the armature assembly moves to a second position (right side) away from the electromagnet, the driven wheel assembly (specifically, the wedge) moves into Drive wheel engagement (Case 1).

In this case, the magnetizable component, including the radial component of the drive wheel (first rotor) or the iron yoke of the electromagnet, is used for permanent passage with the armature assembly when reducing or breaking the first current of the electromagnet The magnet phase pulls the armature assembly in the first position (the driven wheel assembly is separated from the drive wheel); the resilient member applies a force to the armature assembly in a direction that causes the armature assembly to face the second position (the driven wheel assembly engages the drive wheel) Additionally, optionally, the second rotor disposed in the driven wheel assembly is configured to hold the armature assembly in the second position by engaging with the permanent magnet of the armature assembly while reducing or breaking the second current of the electromagnet (See Fig. 22, in which the direction of the arrow indicates the direction of movement of the armature assembly and the text on the arrow indicates the position or state relationship between the components/components at both ends of the arrow).

However, another technical solution is also conceivable. By changing the direction of the fork or the combination of the wedge block and the driving wheel, referring to FIG. 23, and in conjunction with FIG. 1, when the armature assembly is moved to the right side (away from the electromagnet) , that is, the first position in the solution), the driven wheel assembly moves to be separated from the driving wheel, and when the armature assembly moves to the left side (close to the position of the electromagnet, that is, the second position in the solution), the driven wheel assembly The motion is engaged with the drive wheel (Case 2).

In this case, the second rotor (magnetizable component) disposed in the driven wheel assembly is used to hold the armature assembly by attracting the permanent magnet of the armature assembly while reducing or breaking the first current of the electromagnet In the first position (the driven wheel set is separated from the drive wheel); the resilient member applies a force to the armature assembly in a direction that causes the armature assembly to face the second position (the driven wheel set engages the drive wheel).

A person skilled in the art can select the direction of the force of the elastic member according to the position of the elastic member (for example, selecting a tension spring or a compression spring), and ensure that the elastic member is along the armature assembly toward the second position (the driven wheel set and the driving wheel) The direction of the engagement applies a force to the armature assembly (see Figure 23, where the direction of the arrow indicates the direction of movement of the armature assembly and the text on the arrow indicates the position or state relationship between the components/components at the ends of the arrow).

In addition, those skilled in the art can appropriately select the driven wheel assembly and the driving wheel. The direction of movement of the armature assembly in the axial direction of engagement/disengagement and thus the mating faces of the wedges, the shifting forks (first and second levers).

Further, in the first embodiment and the second embodiment described above, in the axial direction, the electromagnet is located on the left side, and the armature assembly and the driven wheel assembly are located on the right side. However, those skilled in the art will appreciate that the position of the electromagnet and the armature assembly and the driven wheel assembly in the axial direction can be reversed.

Although the present invention has been described with reference to the exemplary embodiments, it should be understood that the invention is not limited to the illustrated embodiments. The scope of the following claims is to be accorded

Claims

An electromagnetic clutch includes:

a shaft having an axis;

a drive wheel for receiving external power;

An electromagnet capable of generating a magnetic field when energized to the electromagnet;

An armature assembly, the armature assembly being movable between a first position and a second position in a direction of an axis of the rotating shaft;

a driven wheel assembly mounted on the rotating shaft, the driven wheel assembly being configured to move with the driving wheel to move away from the driving wheel as the armature assembly moves to the first position; with the armature assembly Moving to the second position, the driven wheel assembly moves to engage the driving wheel;

It is characterized in that

The armature assembly includes a permanent magnet;

When the first current in the first direction is applied to the electromagnet, the first force between the magnetic field generated by the electromagnet and the permanent magnet of the armature assembly, the armature assembly faces the first position motion;

a second force between a magnetic field generated by the electromagnet and a permanent magnet of the armature assembly when a second current in a second direction opposite to the first direction is applied to the electromagnet, the armature assembly Moving to the second position;

The electromagnetic clutch further includes an elastic member that applies a force to the armature assembly in a direction that moves the armature assembly to the second position;

When the armature assembly is moved to the first position, the permanent magnet of the armature assembly can be attracted to a magnetizable member such that the armature assembly is reduced or disconnected from the current to the electromagnet Can be held in the first position.
The electromagnetic clutch of claim 1 wherein: said first position is a position adjacent said electromagnet and said second position is a position remote from said electromagnet.
The electromagnetic clutch according to claim 2, wherein said magnetizable member is a first rotor located between said electromagnet and the armature assembly in a direction of an axis of said rotating shaft and comprising a soft magnetic material.
The electromagnetic clutch of claim 3 wherein said drive wheel has an annular radial member extending in a radial direction, said radial member forming said first rotor.
The electromagnetic clutch according to claim 4, wherein the first rotor is provided with a magnetic isolation groove, and the magnetic isolation groove is capable of guiding a specific magnetic field of the electromagnet to act on the permanent magnet of the armature assembly through the first rotor.
The electromagnetic clutch according to claim 3, wherein the armature assembly comprises an armature having a permanent magnet and an armature holder for mounting the armature, the armature frame driving the driven wheel assembly to move in accordance with the axial movement of the armature assembly Engage or separate from the drive wheel.
The electromagnetic clutch according to claim 6, wherein said armature is provided separately from the armature frame, and is disposed on both sides of the driven wheel assembly in a direction along an axis of said rotating shaft, respectively.
The electromagnetic clutch according to claim 6, wherein said armature comprises an annular member and one or more permanent magnets disposed on the annular member in a circumferential direction or are annular permanent magnets.
The electromagnetic clutch of claim 8 wherein said annular member is made of a non-magnetizable material.
The electromagnetic clutch according to claim 2, wherein said electromagnet comprises an iron yoke and an electromagnetic coil positioned in the iron yoke, and said magnetizable member is an iron yoke of said electromagnet.
The electromagnetic clutch according to claim 10, wherein said armature assembly is an integrally formed ring member having a permanent magnet and a shifting fork for moving the driven wheel assembly.
The electromagnetic clutch according to claim 11, wherein: said driven wheel assembly includes a cylindrical portion having a spline and a spline groove engaged with said spline, said ring member being formed with said In another of the spline and the splined groove, the axial movement of the armature assembly is axially guided by the engagement of the spline with the splined groove.
The electromagnetic clutch of claim 10 wherein: said electromagnetic clutch further comprises a double row ball angular contact bearing, said bearing being axially juxtaposed with said electromagnet and located opposite said driven wheel assembly of said electromagnet One side.
An electromagnetic clutch according to any one of claims 2 to 13 wherein: When the armature assembly is moved to the first position, there is a predetermined gap between the armature assembly and the magnetizable member.
An electromagnetic clutch according to any one of claims 2 to 13, wherein said electromagnetic clutch further includes a second rotor, said second rotor being located in a direction of an axis of said rotating shaft of said armature assembly On the opposite side of the electromagnet, the second rotor comprises a soft magnetic material, the permanent magnet of the armature assembly and the soft magnetic material of the second rotor when the armature assembly is moved to the second position mutual attraction.
The electromagnetic clutch of claim 1 wherein: said first position is a position remote from said electromagnet and said second position is a position adjacent said electromagnet.
The electromagnetic clutch according to claim 16, wherein: said electromagnetic clutch includes a second rotor, said second rotor being located on a side of said armature assembly opposite to said electromagnet in a direction of an axis of said rotating shaft Above, the second rotor comprises a soft magnetic material and the magnetizable component is the second rotor.
The electromagnetic clutch of claim 17 wherein said electromagnetic clutch further comprises a first rotor on the opposite side of the armature assembly from the second rotor and comprising a soft magnetic material.
The electromagnetic clutch of claim 18 wherein said drive wheel has an annular radial member extending in a radial direction, said radial member forming said first rotor.
The electromagnetic clutch according to claim 19, wherein the first rotor is provided with a magnetic flux barrier that is capable of guiding a specific magnetic field of the electromagnet to act on the permanent magnet of the armature assembly through the first rotor.
The electromagnetic clutch according to claim 18, wherein said electromagnet comprises an iron yoke and an electromagnetic coil positioned in the iron yoke, and said first rotor is an iron yoke of said electromagnet.