Patent Description:
There are many application scenarios requiring switching mechanism in the power system of new energy vehicles, such as gear shifting, disconnect, locking differential, parking, etc. An electromagnetic clutch is a preferred choice to realize the function of switching mechanism. With the continuous development of the new energy vehicle industry, the performance requirements of the electromagnetic clutch are becoming higher. However, conventional electromagnetic clutches have many disadvantages such as complex overall structure, incompactness, larger occupied space, fewer applicable scenarios, limited layout space and installation position, which affect the spatial configuration of various components in the power system of the new energy vehicle to a certain extent.

<CIT> and <CIT> provide a locking structure of a differential. The locking structure comprises a bi-stable electromagnetic clutch sleeved on an output axle shaft on one side of the differential.

<CIT> provides an electronic control clutch comprises two parts of a full contact type self-excitation space wedge-shaped mechanism and a wedging control mechanism, wherein the full contact type self-excitation space wedge-shaped mechanism is used for transmitting the torque, the friction of the full contact type self-excitation space wedge-shaped mechanism is self-adaptive to the transmitted torque, and the wedging control mechanism responds to electric signals.

In view of the above background, the present disclosure provides a monostable electromagnetic clutch to overcome the above problems or at least partially solve the above problems.

In order to achieve the above object, the present disclosure adopts the following technical solutions.

A monostable electromagnetic clutch, comprising a movable assembly and an electromagnetic assembly, wherein the movable assembly is provided thereon with return springs, the movable assembly can pass through the electromagnetic assembly, the electromagnetic assembly generate electromagnetic force when it is energized, and under a driving action of the electromagnetic force, the movable assembly can reciprocate in the electromagnetic assembly.

According to the invention, the movable assembly comprises a movable push disc and a plurality of movable iron cores connected to the movable push disc, and the movable iron cores can pass through the electromagnetic assembly and reciprocate in the electromagnetic assembly.

Further, the electromagnetic assembly comprises a yoke assembly and an electromagnetic coil assembly, the electromagnetic coil assembly is disposed in the yoke assembly, and the movable iron cores pass through the yoke assembly and the electromagnetic coil assembly and are connected to the movable push disc. Under the action of electromagnetic force, the movable iron cores and the movable push disc connected thereto can reciprocate along the interior of the yoke assembly and the electromagnetic coil assembly.

The advantages and beneficial effects of the present invention are as follows.

The present invention adopts a modular design, and the movable assembly, electromagnetic assembly and return springs are integrated into an electromagnetic clutch basic unit is just consisted by two iron cores with coils on them, the movable assembly and yokes can be flexible changed based on the iron cores location. The structural design of the present invention is flexible and compact, and can be combined in a different way according to different applications and different structural spaces. A plurality of electromagnetic clutch basic units can be used separately, or combined freely, and after combination, they can be freely arranged in a variety of installation positions and spaces as required. Regarding the distribution space, they can be distributed evenly, symmetrically or asymmetrically according to actual needs, and the use of space can be fully optimized.

By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to a person of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments, and should not be considered as a limitation. Moreover, throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:.

In the drawings: <NUM>. movable assembly; <NUM>. electromagnetic assembly; <NUM>. yoke assembly; <NUM>. electromagnetic coil assembly; <NUM>. movable iron core; <NUM>. coil bobbin; <NUM>. second yoke; <NUM>. electromagnetic coil; <NUM>. first yoke; <NUM>. movable push disc; <NUM>. fixing pin; <NUM>. return springs; <NUM>. bearing; <NUM>. L-shaped movable push disc; <NUM>. differential case; <NUM>. end-toothed disc; <NUM>. planetary gear; <NUM>. half axle gear; <NUM>. end-toothed half axle gear; <NUM>. locating pin; <NUM>. position sensor.

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions will be described clearly and completely in conjunction with specific embodiments of the present disclosure and corresponding drawings. Obviously, the embodiments described herein are only part of the embodiments of the invention, rather than all of the embodiments. Based on these embodiments, all other embodiments obtained by a person of ordinary skill in the art without paying creative work shall fall within the protection scope of the appended claims.

The technical solutions of embodiments of the invention will be described in detail below in conjunction with the accompanying drawings. A monostable electromagnetic clutch according to the present disclosure comprises a movable assembly <NUM> and an electromagnetic assembly <NUM>. The movable assembly <NUM> is provided thereon with a return springs <NUM>. When it actually works, the movable assembly <NUM> can pass through the interior of the electromagnetic assembly <NUM>, the electromagnetic assembly <NUM> can generate an electromagnetic force when it is energized, and under the action of the electromagnetic force, the movable assembly <NUM> can reciprocate in the electromagnetic assembly <NUM>.

The movable assembly <NUM> further comprises a movable push disc <NUM> and a plurality of movable iron cores <NUM> connected to the movable push disc <NUM>. The movable iron cores <NUM> can pass through the electromagnetic assembly <NUM> and reciprocate in the electromagnetic assembly <NUM>.

The electromagnetic assembly <NUM> further comprises a yoke assembly <NUM> and an electromagnetic coil assembly <NUM>. The electromagnetic coil assembly <NUM> is disposed in the yoke assembly <NUM>, and the movable iron cores <NUM> pass through the yoke assembly <NUM> and the electromagnetic coil assembly <NUM> at the same time and are connected to the movable push disc <NUM>. The working flow of this embodiment is as follows. When the electromagnetic coil assembly <NUM> is not energized, referring to <FIG>, the return springs <NUM> pushes the movable push disc <NUM> to a position close to the first yoke <NUM>, and at this moment the electromagnetic clutch keeps a disengaged state. When the electromagnetic coil assembly <NUM> is energized, referring to <FIG>, the movable iron core <NUM> and the yoke assembly <NUM> form a magnetic circuit. The electromagnetic force generated at this moment pushes the movable iron core <NUM> to a position close to the first yoke <NUM>, and at this moment the return springs <NUM> is compressed. The electromagnetic force is greater than the spring force to keep the electromagnetic clutch in an engaged state. Under the action of electromagnetic force and spring force, the movable iron core <NUM> and the movable push disc <NUM> connected thereto can reciprocate along the interior of the yoke assembly <NUM> and the electromagnetic coil assembly <NUM>. Preferably, in order to further improve the stability of connection, in an embodiment of the present disclosure, the movable iron core <NUM> is connected to the movable push disc <NUM> via a fixing pin <NUM>.

In an embodiment of the present invention, the return springs <NUM> may be provided on the movable push disc <NUM> or provided on the movable iron core <NUM>, as long as when the electromagnetic coil assembly <NUM> is not energized, the return springs <NUM> can push the movable push disc <NUM> together with the movable iron core <NUM> to a corresponding position to keep the electromagnetic clutch in a disengaged state.

Preferably, in an embodiment of the present invention, the yoke assembly <NUM> comprises a first yoke <NUM> and a second yoke <NUM> made of ferromagnetic material, the electromagnetic coil assembly <NUM> comprises an electromagnetic coil <NUM> and a coil bobbin <NUM>, the coil bobbin <NUM> is used to fix the electromagnetic coil <NUM>, and the electromagnetic coil <NUM> and the coil bobbin <NUM> are both provided between the first yoke <NUM> and the second yoke <NUM>. In this embodiment, the first yoke <NUM>, the second yoke <NUM>, and the electromagnetic coil <NUM> cooperate with the movable iron cores <NUM> to generate an electromagnetic force to keep the electromagnetic clutch in an engaged state.

Preferably, in an embodiment of the present invention, the first yoke <NUM> is provided thereon with a counterbore having a shape matching the shape of the end face of the movable iron core <NUM>. When the electromagnetic clutch is engaged, the movable iron core <NUM> can be embedded in the counterbore. The depth of the counterbore is also related to the travel distance of the movable push disc <NUM> or the movable iron core <NUM>.

In an embodiment of the present invention, the return springs <NUM> is provided as a position-returning spring assembly, which may be a linear spring, a non-linear spring, a spring assembly composed of linear and non-linear springs, or other types of springs.

Further, a preferred solution of the present invention is that a monostable electromagnetic clutch basic unit comprises two electromagnetic coil assemblies <NUM>, two movable iron cores <NUM>, two fixing pins <NUM>, one movable push disc <NUM>, one first yoke <NUM>, one second yoke <NUM> and a plurality of return springs <NUM>. In this embodiment, the electromagnetic clutch basic unit has fewer parts, is simple in structure and does not occupy much space. The electromagnetic clutch basic units can be applied separately, or a plurality of electromagnetic clutch basic units can be combined freely. Their application scenarios include but are not limited to the following scenarios.

Referring to <FIG>, in this embodiment, a plurality of electromagnetic clutch basic units is uniformly arranged circumferentially to form an annular electromagnetic clutch structure. In this example, four electromagnetic clutch basic units are uniformly distributed along the circumferential direction. The first yoke <NUM>, the second yoke <NUM> and the movable push disc <NUM> are all integrated into a whole disc.

This example can be applied to the situation where the circumferential space is larger and the axial space is smaller.

Referring to <FIG> and <FIG>, in this embodiment, two electromagnetic clutch basic units are combined to form an arc-shaped subassembly, and then the two arc-shaped subassemblies are symmetrically distributed. The first yoke <NUM> and the second yoke <NUM> are integrated into two arc-shaped discs. The movable push disc is integrated into an L-shaped disc.

This example can be applied to the situation where the space in the circumferential direction is limited.

Referring to <FIG>, in this embodiment, the electromagnetic clutch basic units are independently distributed in four corners. The first yoke <NUM> and the second yoke <NUM> are designed according to the space and the magnetic circuit, and give way to other parts or assemblies as far as possible without affecting the magnetic circuit so as to fully optimize the use of space, and the movable push disc is integrated into a whole round L-shaped disc.

Referring to <FIG>, in this embodiment, the example <NUM> is specifically applied to the differential lock function. In this embodiment, the electromagnetic clutch in example <NUM> is sleeved at a side of a differential. The movable push disc <NUM> is connected to the L-shaped movable push disc <NUM> via a bearing <NUM>, so that the movable assembly of the electromagnetic clutch body can only move linearly in the axial direction. At the same time, in order to limit the rotation and movement in other degrees of freedom of the movable assembly of the electromagnetic clutch body, in this embodiment, the movable push disc <NUM> is also provided thereon with a locating pin <NUM>, which is fixed and restricts the movable assembly to move only axially. The L-shaped movable push disc <NUM> and an end-toothed disc <NUM> are connected by bolts, pins or protrusions on the L-shaped movable push disc <NUM>/ the end-toothed disc <NUM>. The connecting part passes through the differential case <NUM>. The outer edge of the end-toothed disc is provided with a key, the differential case is correspondingly provided with a key slot, and during the rotation of the differential, the end face teeth are driven by the key connection to transmit rotation speed and torque.

As shown in <FIG>, an end-toothed half axle gear <NUM> is provided with end face teeth which can mesh with end face teeth on the end-toothed disc <NUM>. A spring assembly is provided between the differential case <NUM> and the L-shaped movable push disc <NUM>. When the electromagnetic clutch is in a disengaged state, the spring assembly between the differential case <NUM> and the L-shaped movable push disc <NUM> keeps the end face teeth on the end-toothed disc <NUM> and the end face teeth on the end-toothed half axle gear <NUM> in a disengaged state. At this moment, the differential can operate in a different-speeds mode and in a normal mode. When an excitation current is supplied to the electromagnetic coil <NUM>, the electromagnetic clutch engages, and the movable iron core <NUM> moves toward the first yoke <NUM>. At the same time, the fixing pin <NUM> is driven to move in the same direction, and the fixing pin <NUM> drives the movable push disc <NUM> to move in the same direction. The movable push disc <NUM> pushes the L-shaped movable push disc <NUM> via a bearing <NUM>. The L-shaped movable push disc <NUM> pushes the end-toothed disc <NUM> to move toward the end-toothed half axle gear <NUM> via the connecting part until the end-toothed disc <NUM> is engaged with the end face teeth of the end-toothed half axle gear. The movable assembly stops upon moving to a position-limiting device on the differential case <NUM> and the L-shaped movable push disc <NUM>. The differential lock is now in an engaged/locked state. There is no relative movement between the end-toothed half axle gear <NUM> and the differential case <NUM> after the differential is locked. At this moment, the end-toothed half axle gear <NUM> in the differential transmits the rotation speed and torque to another half axle gear <NUM> via a planetary gear <NUM>. At this moment, the torques at two sides of the differential are completely the same, and the differential lock function is realized.

Claim 1:
A monostable electromagnetic clutch, comprising: a movable assembly (<NUM>) and an electromagnetic assembly (<NUM>), wherein the movable assembly (<NUM>) is provided thereon with return springs (<NUM>), the movable assembly (<NUM>) can pass through the electromagnetic assembly (<NUM>), and under a driving action of an electromagnetic force of the electromagnetic assembly (<NUM>) and a spring force of the return springs (<NUM>), the movable assembly (<NUM>) can reciprocate in the electromagnetic assembly (<NUM>);
the movable assembly (<NUM>) comprises a movable push disc (<NUM>) and a plurality of movable iron cores (<NUM>) connected to the movable push disc (<NUM>), and the movable iron cores (<NUM>) can pass through the electromagnetic assembly (<NUM>);
characterized in that: the electromagnetic assembly (<NUM>) comprises a yoke assembly (<NUM>) and an electromagnetic coil assembly (<NUM>), the electromagnetic coil assembly (<NUM>) is disposed in the yoke assembly (<NUM>), and the movable iron cores (<NUM>) pass through the yoke assembly (<NUM>) and the electromagnetic coil assembly (<NUM>) and are connected to the movable push disc (<NUM>).