Rotary power transmission device with bistable clutch

Abstract

To provide a rotary power transmission device with a bistable clutch.SOLUTION: A power transmission device includes a clutch, an actuator and a stop member. The clutch is received in a first housing, and has a first clutch member coupled to a second housing, and a second clutch member coupled to the first housing. The second clutch member is movable and selectively engageable with the first clutch member. The actuator has a coil and a plunger driven for movement by a magnetic field generated by the coil so that the plunger moves axially to move the second clutch member relative to the first clutch member. The stop member has a retracted position separated from the plunger and an advanced position within a path of movement of the plunger so as to limit movement of the plunger when the stop member is in the advanced position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross - reference to related applications This application claims the benefit of U.S. Provisional Application No. 63 / 347,318, filed May 31, 2022, the entire content of which is incorporated herein by reference.

[0002] The present disclosure generally relates to rotational power transmission having a clutch device where the clutch is driven by an electric actuator and can be maintained at both the engaged position and the disengaged position of the clutch when no electricity is applied to the electric actuator.

Background Art

[0003] An electromagnetic actuator can be used to move a clutch between an engaged position and a disengaged position by applying electricity to a wire coil that generates a magnetic field. To maintain one or both positions of the clutch, electricity is continuously supplied to the coil to continuously generate a magnetic field. This continuously supplied electricity increases the power consumption of the vehicle and reduces the efficiency of the device and the vehicle.

Summary of the Invention

[0004] In at least some implementations, a rotational power transmission device includes a first housing, a second housing, a clutch, an actuator, and a stop member. The first housing has an interior in which a plurality of gears are received for rotation, and the second housing is supported by the first housing. The clutch has a first clutch member received within the first housing and connected to the second housing, and a second clutch member connected to the first housing, the second clutch member being movable and selectively engageable with the first clutch member. The actuator has a coil and a plunger that is moved by a magnetic field generated by the coil, the plunger moving along an axis to move the second clutch member relative to the first clutch member. The stop member is P a retracted position spaced from the plunger and , within the plunger's movement pathThe stop member is movable between the forward position and the forward position, and restricts the movement of the plunger when the stop member is in the forward position.

[0005] In at least some implementations, the stopping member moves in response to a magnetic field generated by a coil. In at least some implementations, the stopping member moves toward the forward position when a current of a first polarity is supplied to the coil, and moves away from the forward position when a current of a second polarity is supplied to the coil.

[0006] In at least some implementations, the plunger has a first position in which it does not engage the second clutch member with the first clutch member, and a second position in which it engages the second clutch member with the first clutch member, and when the stop member is in the forward position, the stop member prevents the plunger from moving away from the second position. In at least some implementations, the stop member is maintained in the forward position in a state in which no magnetic field is generated by the coil. In at least some implementations, the retaining mechanism has a first position in which the retaining mechanism prevents the stop member from moving, and a second position in which the stop member can move. In at least some implementations, the retaining mechanism includes a ball that is yieldably biased by a spring into the movement path of the stop member.

[0007] In at least some implementations, the stopping member includes a permanent magnet inside the magnetic field generated by the coil, and the stopping member moves to an advanced position when a current of a first polarity is supplied to the coil, and moves to a retracted position when a current of a second polarity is supplied to the coil. In at least some implementations, the magnet but Attracted or anti Published By doing When a magnetic field is not generated by the coil, the stopping member is positioned in either the forward or backward position. A magnetic element is provided. When a magnetic field is generated by the coil, the stopping member moves against the force between the magnetic component and the magnet.

[0008] In at least some implementations, the stop member moves radially with respect to the axis. In at least some implementations, the plunger includes a radially extending stop surface, which is selectively radially superimposed on the stop member. In at least some implementations, the stop member includes a rounded portion, and the plunger includes a projection, which is received by the rounded portion when the stop member is in the advanced position, in order to hold the stop member yieldably in the advanced position.

[0009] In at least some implementations, the stop member is connected to a pivot, and the stop member rotates around the pivot between an advanced position and a retracted position. In at least some implementations, the magnet is spaced away from the pivot and has a first pole closer to the stop member than a second pole, and the stop member rotates around the pivot as the coil generates a magnetic field.

[0010] In at least some implementations, the stopping member includes a ball that is yieldably biased to an advanced position by a spring to yieldably restrain the movement of the plunger, and the plunger moves relative to the stopping member as the coil generates a magnetic field. In at least some implementations, a holding mechanism is associated with a second clutch member to yieldably hold the position of the second clutch member.

[0011] In at least some implementations, the rotary power transmission device includes a first housing having an interior into which a plurality of gears are received for rotation; a second housing supported by the first housing; a clutch having a first clutch member received within the first housing and connected to the second housing, and a second clutch member connected to the first housing, wherein the second clutch member is movable and selectively engageable with the first clutch member; an actuator having a coil and a plunger driven to move by a magnetic field generated by the coil, wherein the plunger moves along an axis and moves the second clutch member relative to the first clutch member; and a stop member. The stop member is, P Retreating position away from Ranja and , within the plunger's movement path The stop member is movable between the forward position and the forward position, restricting the movement of the plunger when the stop member is in the forward position, and the stop member moves in response to the magnetic field generated by the coil.

[0012] In at least some implementations, the stopping member holds the plunger's position, allowing the clutch to be kept engaged and torque-transmitting without, for example, the need to maintain power to the actuator's coil. Thus, the clutch state can be maintained with less power consumption, improving the device's efficiency. The stopping member may include a magnet so that it moves in response to a magnetic field generated by the coil. Iron or magnetic components may be provided to attract or repel the stopping member, and such attractive or repulsive forces are overcome by the magnetic field generated by the coil, controlling the movement of the stopping member between its forward and retracted positions.

[0013] A detailed description of preferred embodiments and best modes are shown below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0014] [Figure 1] This is a cross-sectional view of a part of a differential having an electrically operated clutch and an electrically operated deactivating member, with the clutch shown in the released position. [Figure 2] This is a cross-sectional view of a portion of the differential, with the clutch shown in the engaged position and the stop member shown in the forward position. [Figure 3] This is a cross-sectional view of a portion of an electrically operated clutch, including a detent retaining member. [Figure 4] This is a cross-sectional view of a part of a differential having an electrically operated clutch and an electrically operated deactivating member, with the clutch shown in the released position. [Figure 5] This is a cross-sectional view of a portion of the differential, with the clutch shown in the engaged position and the stop member shown in the forward position. [Figure 6] This is a cross-sectional section of a portion of an electrically operated stop member having a pivot, shown in the forward position. [Modes for carrying out the invention]

[0015] Referring more closely to the drawings, Figures 1 and 2 show a portion of the differential 10, such as one that can be used in an e-axle (e.g., an e-motor-driven final drive unit or any drive assembly). The differential 10 includes an outer housing 12, two or more pinion gears 14 (only one is shown in Figures 1 and 2), and a pair of side gears 16, 18 configured to be connected to rotating shafts 20, 22, which can, for example, drive wheels. Thus, the side gears 16, 18 rotate with the shafts 20, 22 (as schematically shown in Figure 1) about a shaft axis 24, and the pinion gear 14 is rotatable about an axis 26 defined by a pinion gear shaft 28, which extends through the pinion gear.

[0016] The differential 10 also includes a clutch assembly 30, which is driven by an actuator 32, the actuator 32 having a solenoid 34 having an annular wire coil 36 and a drive member, the drive member may include an armature or plunger 38, the armature or plunger 38 may be received axially overlapping with the coil 36, at least partially radially inward of the coil 36. In at least some implementations, the plunger 38 is also annular, and the plunger 38 and coil 36 are arranged coaxially around an axis 24, supported by an outer housing 12 of the differential 10, and rotate together with the outer housing 12. One shaft 20 extends coaxially through a portion of the housing 12 that extends through the coil 36 and plunger 38. Power is supplied to the coil 36, generating a magnetic field, which displaces the plunger 38 from a first or retracted position (Figure 1) to a second or forward position (Figure 2) relative to the coil 36 and the outer housing 12. To facilitate the return of the plunger 38 from the second position to the first position when power is not supplied to the coil 36, a biasing member such as a spring 42 may be applied to the plunger 38 or to a component that engages with the plunger, as shown below. In at least some implementations, the clutch assembly 30 is engaged when the plunger 38 is in the second position, and the clutch assembly 30 is released when the plunger 38 is in the first position. In the illustrated example, the plunger 38 is in the second position when power is supplied to the coil 36, and moves to the first position when power is not supplied to the coil 36; however, the reverse may also be true if desired (for example, the clutch assembly 30 may be moved to the engaged position by the biasing member 42 and released by the supply of power to the coil 36).

[0017] In at least some implementations, the clutch assembly 30 is an engaging clutch such as a dog clutch and includes a first clutch member 44 that is not movable in the axial direction (defined by the central axis 24 of the plunger) and a second clutch member 46 that is movable in the axial direction relative to the first member 44.

[0018] In at least some embodiments, the clutch assembly 30 can be used, for example, within a so-called free-running differential 10. The free-running differential 10 selectively blocks and permits torque transmission through the free-running differential 10. In this device, the first rotating body is the outer differential housing 12, the second rotating body is the inner housing 48, and the first rotating body and the second rotating body rotate about a common rotation axis 24. The inner housing 48 includes clutch teeth or, as in the illustrated embodiment, the inner housing 48 is connected to a first clutch member 44 that includes clutch teeth 50. In the illustrated example, the first clutch member 44 is connected to the pinion gear shaft 26 and axial movement with respect to the second clutch member 46 is suppressed.

[0019] Referring to FIG. 2, the second clutch member 46 is coaxial with the shaft 24 of the plunger 38 and can be received closer to the outside of the pinion gear 14 (i.e., farther from the shaft 24 than the pinion gear 14). The second clutch member 46 can include a rear surface 52 closer to the plunger 38 than the front surface 54, and the front surface 54 has at least one engagement feature such as a gear or clutch teeth 56 (e.g., dog clutch teeth), and the at least one engagement feature is configured to engage a corresponding engagement feature (e.g., a gear or dog clutch teeth 50) formed on the first clutch member 44.

[0020] In at least some implementations, the second clutch member 46 may be connected to a retainer 58. The retainer 58 may radially position the second clutch member 46 and / or provide a radial outer surface, which may be detected, if necessary, by a suitable sensor that enables detection of the position of the second clutch member 46 (and thus determination of the state of the clutch 30). In the illustrated embodiment, the retainer 58 is annular and includes a central opening 60 that is received across a tubular portion 62 of the outer housing 12, around which the plunger 38 is received. In at least some implementations, an axially extending support may be defined by an annular flange 64 or a separating finger radially spaced from the opening 60 to connect the retainer 58 to the second clutch member 46 at a location radially spaced from the tubular portion 62 of the outer housing 12. The second clutch member 46 can be confined between the first surface 66 of the retainer 58 adjacent to the rear surface 52 of the second clutch member 46 and the radially bent end 68 of the support surface 64, the radially bent end 68 of the support surface 64 engaging with the radially extending surface of the second clutch member 46 so as to be defined within a groove 70 formed on the radial inner surface of the second clutch member 46. In this way, the retainer 58 and the second clutch member 46 move together in both directions of movement of the second clutch member 46. The spring 42 can be held by the first surface 66 of the retainer 58 and act on the first surface 66 so as to bias the second clutch member 46 to a retracted position in which the teeth 56 of the second clutch member do not mesh with the teeth 50 of the first clutch member. The spring 42 is received between a portion of the outer housing 12 and a portion of the retainer 58 and may be located radially inside or radially outside the second clutch member 46, or both (for example, two or more springs may be provided). Like the coil 36 and plunger 38, the second clutch member 46 is also held by the outer housing 12 and rotates together with the outer housing 12.

[0021] The plunger 38 can be formed from a plurality of materials, which include a material that magnetically reacts to the magnetic field generated by the coil 36 and at least one other material that may or may not react to the magnetic field. Thus, when a magnetic field is generated by the coil 36, the plunger 38 can be driven from one position to another (e.g., from a retracted position to a forward position). If a magnetic field of the magnitude generated by a solenoid 34 of the type used in applications such as those described herein can displace a component formed from or including such a material, the materials used herein react to the magnetic field.

[0022] In at least some implementations, as shown in FIGS. 1 and 2, the plunger 38 includes a main body having a central axis that can be coaxial with the axis 24. The plunger 38 can be defined by a first body 74 and a second body 76. The first body 74 and the second body 76 are connected together and move as one unit or component and do not separate during use. The first body 74 is formed from a magnetically reactive material and can be received adjacent to the coil 36, radially inside the coil 36, with a small gap between the first body 74 and the coil 36. The second body 76 can have at least a portion that is radially inside at least a portion of the first body 74. The second body 76 can be annular and, in at least some implementations, can radially overlap a portion of the first body 74. The second body 76 can be conveniently overmolded onto the first body to facilitate the formation of the second body and the connection of the first and second bodies together, although other forming methods such as, but not limited to, casting, stamping, or extrusion can be used.

[0023] In the illustrated configuration, the plunger 38 includes or is associated with a radially outward-extending end component 78, the radially outward-extending end component 78 having an axially-extending rim 80, the axially-extending rim 80 engaging with a second surface 79 of the retainer 58 at a position where the second clutch member 46 is radially superimposed. That is, the rim 80 is radially aligned with the second clutch member 46. In at least some configurations, the end component 78 may be formed from the same material as the second body 76, or it may be formed as a separate component fixed to the second body 76. Of course, other configurations may be used as needed. The second body 76 may be formed from a non-magnetically reactive material (e.g., plastic, aluminum, stainless steel, etc.) and may provide a magnetic flux shield of a kind that improves the magnetic field strength on or within the area of ​​the first body 74, ensuring a proper response of the plunger 38 when the coil 36 is energized. In this way, the magnetic field is more concentrated or stronger within the region of the first body 74, increasing the magnetic flux in or within the first body and improving the response of the plunger 38 to the generated magnetic field.

[0024] As shown in Figures 1 and 2, the second body 76 may have an inner surface 82 that is received adjacent to or around the surface 84 of the differential housing 12. The inner surface 82 may define a pilot diameter that receives the plunger 38 across the annular surface 84 of the differential housing 12 so as to guide the plunger 38 in the linear axial direction relative to the differential housing 12. In at least some configurations, the housing surface 84 may be defined by a sleeve 86 that is received across the tubular extension of the housing 12. The sleeve 86 may include an axially extending portion 88 having an outer surface that defines at least a portion of the surface 84, and a radially extending portion 90 that is adjacent to the rear surface 92 of the plunger 38 (i.e., the surface or side furthest from the second clutch member 46) and can restrict the movement of the plunger 38 in this direction. The radially extending portion 90 is also connected to the coil housing 96 in which the coil 36 is received, and the coil housing 96 can be radially positioned and held relative to the outer housing 12. Other or further holding features may be provided for assembling the coil 36 on or relative to the outer housing 12.

[0025] In Figure 1, the differential 10 is shown in the released position of the clutch 30. In the illustrated configuration, in the released position of the clutch 30, no power is supplied to the coil 36, the plunger 38 is in the first position (i.e., the retracted position), and the second clutch member 46 is not engaged with the first clutch member 44 (i.e., the teeth 56 of the second clutch member do not mesh with the teeth 50 of the first clutch member). In the disengaged position, the shafts / axles 20 and 22 are not effectively driven and can rotate relative to the second clutch member 46 and the outer housing 12.

[0026] To change the clutch 30 from the released position to the engaged position shown in Figure 2, power is supplied to the coil 36, and the plunger 38 is moved to the second position (i.e., the forward position). fart A driving magnetic field is generated, which drives the second clutch member 46 and engages it with the first clutch member (i.e., the teeth 58 engage and mesh with the teeth 50). In this position, the inner housing 48 is connected to the outer housing 12 and rotates together with the outer housing 12, and torque is transmitted to the axles 20 and 22.

[0027] In at least some implementations, there is a desire to maintain the engagement position of the clutch 30 without having to maintain power to the coil 36. In at least some implementations, this is achieved with a magnetically responsive stopping member 100. In the examples shown in Figures 1 and 2, the stopping member 100 is one or more plates or posts, further described as posts, and the posts have permanent magnets 102 connected to the posts, the permanent magnets 102 having a north pole and a south pole, and are assembled in the magnetic field generated by the coil 36. In the retracted position shown in Figure 1, the stopping member 100 does not obstruct the movement of the plunger 38. In the advanced position of the stopping member 100 shown in Figure 2, the free end 104 or the other part of the stopping member 100 is radially overlapped with the plunger 38 and positioned within the movement path of the plunger 38. Thus, when the stopping member 100 moves forward, it engages the plunger 38 and prevents the plunger 38 from moving back to the retracted position. In this manner, the plunger 38 is maintained in the forward position, advancing the second clutch member 46 and engaging it with the first clutch member 44, and this position can be maintained after the power supply to the coil is terminated.

[0028] When current is supplied to the coil 36 from the first pole, the plunger 38 moves to its forward position, advancing the stop member 100. When the coil is no longer energized, the stop member 100 remains in its forward position, holding the plunger 38 in the forward position and keeping the clutch 30 engaged.

[0029] The stop member 100 moves to the retracted position to allow the plunger 38 to return to the retracted position and the clutch 30 to the released position. To accomplish this, a second, opposite-polarity current is supplied to the coil 36. This generates an opposite magnetic field, which exerts a force on the permanent magnet 102 of the stop member 100 in the opposite direction to the magnetic field generated by the first-polarity current. This force moves the stop member 100 to the retracted position. With respect to the metallic / magnetically responsive plunger 38, the second, opposite-polarity and associated magnetic field also have the property of moving the plunger to the forward position. When the stop member 100 retracts, the current to the coil 36 can be terminated, thereby terminating the magnetic field acting on the plunger 38. When this termination occurs, the spring 42 acts on the plunger 38, driving the plunger 38 and the second clutch member 46 to the retracted position, thereby releasing the clutch 30.

[0030] To enable supplying electricity from different poles to the coil 36, a suitable circuit 106 may be provided between the power supply 108 and the coil 36. This circuit 106 may include an H-bridge 110 or other switching configuration or other circuit configuration suitable for supplying power to the coil 36 as described.

[0031] Magnetically responsive and electrically / magnetically driven stop members can be implemented in various ways. In the example shown in Figures 1 and 2, the stop member 100 is axially mounted on the front portion 112 of the coil 36, between the coil 36 and the second clutch member 46. In this implementation, the stop member 100 moves radially relative to the plunger 38 and selectively engages with the radially extending stop surface 114 of the plunger 38. This stop surface 114 is shown defined between the front 116 and rear 92 of the plunger, within a groove formed in the radially outer surface of the plunger 38.

[0032] In the examples shown in Figures 4 and 5, the same or similar components are designated using the same reference numerals as those used for the embodiments in Figures 1 and 2, and this further description of the embodiments will focus on the differences from the embodiments in Figures 1 and 2. In this configuration, the stop member 120 is assembled to the rear portion 122 of the coil housing 96, and the coil 36 is located between the stop member 120 and the second clutch member 46. In this configuration, the stop member 120 moves radially inward relative to the plunger 38 and selectively engages with the radially extending stop surface of the plunger 38. This stop surface is shown as being defined by the rear surface 92 of the plunger 38. In this configuration, a magnet may be provided on the shaft 124 or head 126 of the stop member 120. The stop member shaft 124 may optionally slide within a bore 129 or passage in the coil housing 96 or adjacent structure and may include a magnet 128 (e.g., a permanent magnet with north and south poles). An iron plug 131 or other iron structure (e.g., a magnetic component) may be provided at or near one end of the path of movement of the stop member 120, attracting the magnet 128 to the iron plug 131 and holding the stop member 120 in the retracted position until a suitable magnetic field from the armature acts on the stop member 120. The plug 131 can be conveniently passed through, rotated, and brought to a position that brings a desired stop for the retracted position of the stop member. In at least some implementations, the shaft 124 may extend beyond the head 126 (or the stop member 120 may include a projection extending from the head) and may provide an engaging surface that restricts the movement of the plunger 38 away from the retracted position (i.e., the shaft 124 may define the retracted position of the plunger). This is shown in Figure 4, where the plunger is retracted, the clutch is released, and the rear surface 92 of the plunger 38 is in contact with the shaft 124 at a location radially inward of the head 126.

[0033] In Figure 5, the clutch 30 is shown in the engaged state, the plunger 38 in the forward state, and the stop member 120 in the forward state. In this position, the head 126 radially overlaps the rear surface 92 of the plunger 38 and contacts the rear surface 92 of the plunger 38, maintaining the plunger in the forward position. The plunger 38 and the stop member 120 can be driven between their respective retracted and forward positions, as described with reference to the stop member 100.

[0034] In the example shown in Figure 6, the stopping member 130 is mounted on the coil 36 so as to be pivotable around a pin 132 connected to the coil housing 96 or an adjacent structure, and rotates or pivots the stopping member 130 between a forward position and a retracted position relative to the plunger 36. The direction of rotation or pivoting can be controlled according to the pole of the current supplied to the coil 36, and the movement or holding of the stopping member 130 can be made possible by a permanent magnet 134 on the coil housing 96, with one pole being at the end 136 of the stopping member 130. by near Distribution Placed, this End portion 136 is In the forward position Plunger 38 and Engaging end 138 In contrast, Pin 132 sandwiching On the opposite side Location ru.

[0035] In at least some implementations, the force of the spring 42 acting on the plunger 38 can hold the plunger 38 against the stop members 100, 120, and hold the stop members 100, 120 in the forward position, or assist in holding them in the forward position. Furthermore, in at least some implementations, iron material or magnets can be provided near the magnets on the stop members 100, 120 when the stop members are in the forward position, to assist in holding the stop members in the forward position (i.e., permanent magnets associated with the stop members can provide a force that has the property of holding the stop members in place).

[0036] If necessary, the stop member 120 and plunger 38 shown in Figures 4 and 5 may include a detent or other configuration to hold the stop member 120 in the forward position or to improve the holding of the stop member 120. In this configuration, this is achieved from the rounded portion 140 (axially variable surface) of the head 126 of the stop member 120 and the rear surface 92 of the plunger 38. Prominent This is indicated as an axial projection 142, which rests on a rounded portion 140 as the stopping member 120 moves forward, as shown in Figure 5. The radial movement of the stopping member 120 configured in this way increases the engagement between the stopping member 120 and the plunger 38, while the plunger is acted upon by the spring 42 and held against the stopping member 120 under spring force.

[0037] Other configurations can be used to improve the retention of the stop member in the forward position. For example, in the configuration shown in Figures 1 and 2 (indicated in Figure 2), the ball detent mechanism 144 is mounted on the coil housing 96. This ball detent mechanism 144 includes a ball 146, which is biased by a spring 148 and, as shown in Figure 2, overlaps the end 150 (or other part) of the stop member 100 when the stop member 100 moves forward, causing the stop member to retract. Yo Acting on the stopping member 、 twist strength Without sufficient force, the radial retraction of the stopping member is blocked. The magnetic field force used to retract the stopping member 100 is sufficient to overcome the spring biasing force on the ball 146 and allow the stopping member 100 to retract.

[0038] Next, as shown in Figure 3, a ball detent or other holding mechanism may be implemented to temporarily hold the position of one or both of the plunger 38 and the second clutch member 46. In Figure 3, the first detent mechanism 152 includes a ball 154, which is biased toward the plunger 38 by a spring 156, and holds the plunger 38 in a yieldable position (e.g., the forward position in at least some implementations). The second detent mechanism 158 includes a ball 160, which is biased toward the second clutch member 46 by a spring 162, and holds the second clutch member 46 in a yieldable position (e.g., the forward position in at least some implementations). In this context, yieldable means that the component is held in one position unless there is a force stronger than the detent mechanism acting on the component to move the component relative to the detent mechanism.

[0039] In the case of an electrically driven actuator, the clutch 30 can be selectively engaged and disengaged to provide a desired torque transmission configuration. The electrically driven stop members 100, 120, and 130 enable the clutch 30 to be maintained engaged without the need to maintain a current supply to the coil 36. Thus, the plunger 38 can be maintained in both the retracted and forward positions without requiring electricity to the coil 36, and electricity can be supplied to the coil 36 to change the state of the clutch 30 as described above. Alternatively, in a configuration in which the plunger 38 is spring-biased in the forward position and moved to the retracted position by a solenoid 34, the stop members may be configured to maintain the retracted position of the plunger 38 and the disengaged state of the clutch 30 without supplying current to the coil 36.

[0040] The embodiments of the present invention disclosed herein constitute preferred embodiments of the invention, and numerous other embodiments and forms are possible. This specification is not intended to describe all possible equivalents or derivatives of the invention. The terms used herein are descriptive, not restrictive, and it should be understood that various modifications can be made without departing from the spirit or scope of the invention. Electrically operated clutches and electromagnetically operated stop members can be used in a wide range of applications, for example, by referring to differential disengagement which can be used in applications such as e-axles. For example, but not limited to, clutches and stop members can be used to maintain a desired position of the clutch in secondary drive applications such as internal combustion engine drivetrains and hybrid electric drivetrains. This system can be used with a front or rear axle on an internal combustion engine or hybrid electric vehicle having a primary drive axle, in which case the secondary drive axle is not always necessary and can be disengaged. This disengagement system may be within the range of the differential described or different disengagement assemblies known in the art. This disconnection system may be found in larger applications such as two-drive axles and off-road applications, or within a locking differential. Furthermore, the system can be used for any final drive unit, such as an axle assembly containing a hypoid gear, whether forward or rearward, as in the case of a transfer case or power transmission unit and transmission system.

[0041] All terms used in the claims are intended to be given their broadest and most reasonable form and the ordinary meaning of the term as understood by those skilled in the art, unless otherwise explicitly indicated herein. In particular, the use of singular articles such as “a, the, said” should be read as listing one or more of the elements shown, unless the claims explicitly list the opposite limitation.

Claims

1. A rotational power transmission device, wherein the rotational power transmission device is A first housing having an interior into which multiple gears are received for rotation, A second housing supported by the first housing, A clutch comprising a first clutch member received within the first housing and connected to the second housing, and a second clutch member connected to the first housing, wherein the second clutch member is movable and selectively engageable with the first clutch member, An actuator having a coil and a plunger driven to move by a magnetic field generated by the coil, wherein the plunger moves along an axis and moves the second clutch member relative to the first clutch member, A stop member that is movable between a retracted position away from the plunger and a forward position within the movement path of the plunger, wherein the stop member restricts the movement of the plunger when the stop member is in the forward position. A rotary power transmission device comprising the above features.

2. The device according to claim 1, wherein the stopping member moves in response to the magnetic field generated by the coil.

3. The device according to claim 2, wherein the stopping member moves toward the forward position when a current of a first polarity is supplied to the coil, and the stopping member moves away from the forward position when a current of a second polarity is supplied to the coil.

4. The device according to claim 1, wherein the plunger has a first position in which it does not engage the second clutch member with the first clutch member, and the plunger has a second position in which it engages the second clutch member with the first clutch member, and when the stop member is in the forward position, the stop member prevents the plunger from moving away from the second position.

5. The device according to claim 4, wherein the stopping member is maintained in the forward position in a state in which no magnetic field is generated by the coil.

6. The device according to claim 5, further comprising a holding mechanism, the holding mechanism having a first position that prevents the stopping member from moving and a second position that allows the stopping member to move.

7. The device according to claim 6, wherein the holding mechanism includes a ball that is yieldably biased by a spring to the movement path of the stopping member.

8. The device according to claim 3, wherein the stopping member includes a permanent magnet inside the magnetic field generated by the coil, the stopping member moves to the forward position when a current of a first polarity is supplied to the coil, and the stopping member moves to the retracted position when a current of a second polarity is supplied to the coil.

9. The device according to claim 8, further comprising a magnetic component which, when a magnetic field is not generated by the coil, the stopping member is positioned in either the forward position or the backward position, by which the magnet is attracted or repelled, and when a magnetic field is generated by the coil, the stopping member moves against the force between the magnetic component and the magnet.

10. The device according to claim 1, wherein the stopping member moves radially with respect to the axis.

11. The device according to claim 1, wherein the stopping member is connected to a pivot body, and the stopping member rotates around the pivot body between the forward position and the retracted position.

12. The device according to claim 11, further comprising a magnet having a first pole spaced apart from the pivot body and closer to the stopping member than to a second pole, wherein the stopping member rotates around the pivot body when the coil generates a magnetic field.

13. The device according to claim 1, wherein the stopping member includes a ball that is biased by a spring to yield to the forward position in order to yield the movement of the plunger, and the plunger moves relative to the stopping member when the coil generates a magnetic field.

14. The device according to claim 13, further comprising a holding mechanism associated with the second clutch member for yielding the position of the second clutch member.

15. The device according to claim 10, wherein the plunger includes a radially extending stop surface, and the radially extending stop surface is selectively superimposed radially on the stop member.

16. The device according to claim 15, wherein the stopping member includes a rounded portion, and the plunger includes a projection which is received by the rounded portion when the stopping member is in the forward position in order to hold the stopping member yieldable in the forward position.

17. A rotational power transmission device, wherein the rotational power transmission device is A first housing having an interior into which multiple gears are received for rotation, A second housing supported by the first housing, A clutch comprising a first clutch member received within the first housing and connected to the second housing, and a second clutch member connected to the first housing, wherein the second clutch member is movable and selectively engageable with the first clutch member, An actuator having a coil and a plunger driven to move by a magnetic field generated by the coil, wherein the plunger moves along an axis and moves the second clutch member relative to the first clutch member, A stop member that is movable between a retracted position away from the plunger and a forward position within the movement path of the plunger, wherein the stop member restricts the movement of the plunger when the stop member is in the forward position. A rotational power transmission device comprising the stopping member, wherein the stopping member moves in response to the magnetic field generated by the coil.

18. The device according to claim 17, wherein the stopping member includes a permanent magnet inside the magnetic field generated by the coil, the stopping member moves to the forward position when a current of a first polarity is supplied to the coil, and the stopping member moves to the retracted position when a current of a second polarity is supplied to the coil.

19. The device according to claim 18, further comprising a magnetic component which, when a magnetic field is not generated by the coil, the stopping member is positioned in either the forward position or the backward position, by which the magnet is attracted or repelled, and when a magnetic field is generated by the coil, the stopping member moves against the force between the magnetic component and the magnet.

20. The device according to claim 17, wherein the stopping member moves radially with respect to the axis.

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