Torque transmission device

Abstract

A torque transmission device 10 comprises: a wheel that rotates by receiving torque from a worm gear; a rotary member 18 provided to be rotatable relative to the wheel; and a viscous fluid interposed between the wheel and the rotary member. The wheel has a first rotating part. The rotary member 18 has: a connection part that is connected to an external part and transmits torque; and a second rotating part that forms a space for holding the viscous fluid together with the first rotating part. The viscous fluid generates a resistive force in response to a rotational motion of the first rotating part or the second rotating part, transmits the torque from the wheel to the rotary member 18, and causes the rotary member to rotate together with the wheel. When torque is input from the connection part side, the wheel is stopped by the worm gear and does not rotate. The second rotating part rotates relative to the first rotating part due to the torque input from the connection part side.

Description

Torque Transmission Device

[0001] The present invention relates to a torque transmission device that transmits torque input from a torque transmission means to an outside.

[0002] Patent Document 1 discloses an electric locking device that locks a glove box opening / closing member in a closed position relative to the opening. The electric locking device includes a rod that engages and disengages with a locking portion provided in the opening, and an actuator that slides the rod to disengage from the locking portion. The actuator includes a case, a motor, a wheel that is rotated by driving the motor, a rotor that engages with the wheel with a gap, and a torsion spring that biases the rotor in a direction to engage with the locking portion. When a rotational force is applied from the rod to the rotor in a direction to release the locking portion, the rotor and wheel disengage, and the rotor rotates independently of the wheel against the torsion spring.

[0003] International Publication No. 2022-185890

[0004] In the technology described in Patent Document 1, when the wheel and rotor are disengaged, the torsion spring biases the rotor in only one direction, and does not generate resistance to rotation of the rotor in both directions. It would be desirable to be able to generate resistance to rotation of the rotor in both directions.

[0005] An object of the present invention is to provide a torque transmission device that can apply resistance force when a rotating member rotates, regardless of the direction of rotation.

[0006] To solve the above problems, one aspect of the present invention provides a torque transmission device that includes a wheel that receives torque from a torque transmission means and rotates forward or backward around an axis, a rotating member that is rotatable relative to the wheel, and a rotational resistance imparting means interposed between the wheel and the rotating member. The wheel has a first rotating portion. The rotating member has a connecting portion that connects to the outside and transmits torque, and a second rotating portion that forms a space that holds the first rotating portion and the rotational resistance imparting means. The rotational resistance imparting means generates resistance when subjected to rotational motion from the first rotating portion or the second rotating portion, and transmits torque from the wheel to the rotating member, causing the rotating member to rotate forward or backward together with the wheel. When torque is input from the connecting portion side, the wheel is stopped by the torque transmission means and does not rotate. The second rotating portion rotates forward or backward relative to the first rotating portion depending on the torque input from the connecting portion side.

[0007] According to the present invention, it is possible to provide a torque transmission device that can apply resistance force regardless of the direction of rotation when a rotating member rotates.

[0008] 1 is a perspective view of a torque transmission device of a first embodiment; 2 is an exploded view of a torque transmission device of a first embodiment; 3 is a perspective view of a torque transmission device with a second case and a terminal portion removed; 4 is a cross-sectional view of a torque transmission device of a first embodiment; 5 is an exploded view of a torque transmission device of a second embodiment; 6 is an exploded view of a sub-assembly of a second embodiment; 7 is a cross-sectional view of a torque transmission device of a second embodiment; 8 is a cross-sectional view of a sub-assembly of a second embodiment;

[0009] Fig. 1 is a perspective view of a torque transmission device 10 according to a first embodiment. Fig. 2 is an exploded view of the torque transmission device 10 according to the first embodiment. Fig. 3 is a perspective view of the torque transmission device 10 with a second case 14 and a terminal portion 20 removed.

[0010] The torque transmission device 10 is used, for example, to open and close the lid of a glove box or console box in an automobile. An opening / closing body, which is the lid, is attached to an opening formed in a fixed body of the glove box or console box so that it can be opened and closed. The torque transmission device 10 is driven in response to the operation of an operation button, rotating the opening / closing body in an opening direction and a closing direction, thereby automatically opening and closing the opening / closing body.

[0011] The torque transmission device 10 comprises a first case 12, a second case 14, a gear portion 16, a rotating member 18, a terminal portion 20, a motor 22, a worm gear 24, a first rotating portion 26, a wheel 28, a seal ring 30, a ring member 32, and a rotational resistance imparting means.

[0012] The first case 12 and the second case 14 are coupled to each other and house internal actuator components. The first case 12 is located on the lower side, and the second case 14 is located on the upper side. The motor 22 is driven in response to an operation by the occupant. The worm gear 24 is directly connected to the motor shaft and has teeth 24a on its outer periphery. The worm gear 24 functions as a torque transmission means that transmits torque generated by driving the motor 22 to the wheels 28. The terminal portion 20 is electrically connected to the motor 22 and has negative and positive conductive portions on its inner side.

[0013] The first case 12 has a recess 34, ribs 36, claws 37, a motor housing 38, and a semi-cylindrical portion 40. As shown in Fig. 2, the recess 34 is formed as a cylindrical recess and rotatably supports the wheel 28. A plurality of ribs 36 are formed on the inner peripheral surface of the recess 34 at equal intervals in the circumferential direction and extend in the direction of the central axis of the wheel 28. The plurality of ribs 36 support the rotation of the wheel 28.

[0014] A plurality of claws 37 are formed to protrude from the outer surface of the first case 12. The motor housing portion 38 forms a space that houses half of the motor 22. The semi-cylindrical portion 40 is connected to the motor housing portion 38 and forms an opening.

[0015] The second case 14 has an insertion tube portion 42, an upper housing portion 44, a motor housing portion 46, a semi-cylindrical portion 48, and an elastic locking portion 49. The insertion tube portion 42 is formed in a cylindrical shape and opens upward, allowing a portion of the rotating member 18 to be inserted therein. The upper housing portion 44, when coupled with the first case 12, forms a space to house the rotating member 18, the first rotating portion 26, and the wheel 28.

[0016] The motor housing portion 46 mates with the motor housing portion 38 to form a space for housing the motor 22. The semi-cylindrical portion 48 mates with the semi-cylindrical portion 40 to form an opening for inserting the terminal portion 20. The elastic locking portion 49 locks onto the claw portion 37 of the first case 12 to join the first case 12 and the second case 14. The joined first case 12 and second case 14 are simply referred to as the case.

[0017] The gear unit 16 is connected to an external component to transmit torque. Here, the external component may be, for example, a gear on the opening / closing body side. The gear unit 16 rotates the gear on the opening / closing body side, thereby opening and closing the opening / closing body. The gear unit 16 has a rectangular connecting hole 16a. The rotating member 18 and the first rotating unit 26 are connected to form an oil damper. A detailed description will now be given with reference to new drawings.

[0018] 4 is a cross-sectional view of the torque transmission device 10 of the first embodiment. The rotating member 18 has a second rotating portion 50, an annular plate portion 51, a neck portion 52, a connecting portion 54, a first inner cylindrical portion 56, and a second inner cylindrical portion 58. The second rotating portion 50 is formed in a cylindrical shape. The annular plate portion 51 projects radially inward from the upper end of the second rotating portion 50.

[0019] The neck portion 52 is formed in a cylindrical shape with a smaller diameter than the second rotating portion 50, and protrudes upward from the inner peripheral edge of the annular plate portion 51. The connecting portion 54 protrudes from the upper end of the neck portion 52 and is formed in a prismatic shape. The connecting portion 54 protrudes from the insertion tube portion 42 of the second case 14. The connecting portion 54 is connected to the gear portion 16 to transmit torque to the outside.

[0020] The first inner cylindrical portion 56 is located inside the second rotating portion 50 and is formed cylindrically with a smaller diameter than the second rotating portion 50. The second inner cylindrical portion 58 is located inside the first inner cylindrical portion 56 and is formed cylindrically with a smaller diameter than the first inner cylindrical portion 56. The second inner cylindrical portion 58 extends from the second rotating portion 50 to the inside of the neck portion 52. The second rotating portion 50 is formed in multiple layers by the first inner cylindrical portion 56 and the second inner cylindrical portion 58. Through holes are formed in the first inner cylindrical portion 56 and the second inner cylindrical portion 58 and function as passages for the filled viscous fluid 33.

[0021] A ring member 32 is wound around the outer circumferential surface of the second rotating part 50. The ring member 32 may be an O-ring and is made of an elastic material.

[0022] The first rotating part 26 has a first cylindrical part 60, a columnar part 62, a second cylindrical part 64, an engagement recess 65, a circumferential groove part 66, and an annular protrusion part 67. The first cylindrical part 60 is formed in a cylindrical shape and opens upward. The second cylindrical part 64 is located inside the first cylindrical part 60 and is formed in a cylindrical shape with a smaller diameter than the first cylindrical part 60.

[0023] The cylindrical portion 62 is located inside the second cylindrical portion 64 and is formed with a smaller diameter than the second cylindrical portion 64. The cylindrical portion 62 protrudes upward beyond the first cylindrical portion 60 and the second cylindrical portion 64. The circumferential groove portion 66 is located on the lower end side of the outer peripheral surface of the first rotating portion 26 and is formed in a groove shape along the circumferential direction. A seal ring 30 is attached to the circumferential groove portion 66. The annular protrusion 67 is formed below the circumferential groove portion 66 and protrudes from the outer peripheral surface of the first rotating portion 26.

[0024] The engagement recess 65 is recessed into the lower surface of the first rotating part 26 and has a rectangular or cross shape when viewed from below. The engagement recess 65 engages with the wheel 28.

[0025] The connection between the rotating member 18 and the first rotating part 26 will now be described. Viscous fluid 33 is filled inside at least one of the rotating member 18 and the first rotating part 26, and the first rotating part 26 is inserted into the rotating member 18. The annular protrusion 67 is fitted into the rotating member 18, thereby connecting the rotating member 18 and the first rotating part 26.

[0026] At this time, a filling space for the viscous fluid 33 is formed between the rotating member 18 and the first rotating part 26. The second rotating part 50 and the first rotating part 26 form a filling space that holds the viscous fluid 33. The filling space is sealed by the seal ring 30. The filling space is formed by the second rotating part 50, the first inner cylindrical part 56, the second inner cylindrical part 58, and the first cylindrical part 60, the second cylindrical part 64, and the columnar part 62 that are inserted into the space formed thereby. The first inner cylindrical part 56, the second inner cylindrical part 58, the first cylindrical part 60, and the second cylindrical part 64 have through holes formed therein that allow the viscous fluid 33 to move between the layers.

[0027] Because the filled spaces are configured in multiple layers inside the second rotating portion 50 and the first rotating portion 26 of the rotating member 18, the contact area of ​​the viscous fluid 33 increases, allowing for increased shear force. When the first rotating portion 26 or the second rotating portion 50 rotates, the viscous fluid 33 exerts a shear force. When the first rotating portion 26 and the second rotating portion 50 rotate relatively around their axes, the viscous fluid 33 generates a resistance force that resists the relative rotation. The viscous fluid 33 functions as a rotational resistance imparting means that imparts resistance to the relative rotation of the rotating member 18 and the first rotating portion 26. The viscous fluid 33 is interposed between the wheel 28 and the rotating member 18, more specifically, between the first rotating portion 26 and the rotating member 18.

[0028] The rotating member 18 is provided so as to be rotatable relative to the first rotating part 26 and the wheel 28. The viscous fluid 33 generates a resistance force against this relative rotation. The viscous fluid 33 generates a resistance force between the first rotating part 26 and the second rotating part 50, making it possible to stop the opening / closing body at any rotational position.

[0029] The wheel 28 has a cylindrical portion 70, an inner peripheral portion 72, a gear portion 74, and an engaging protrusion 76. The cylindrical portion 70 has a smooth outer peripheral surface on the lower portion of the wheel 28. The gear portion 74 is formed on the outer periphery of the wheel 28. The gear portion 74 has teeth 74a formed circumferentially on the upper portion of the cylindrical portion 70.

[0030] The inner peripheral portion 72 is formed in a smooth cylindrical shape, and is formed so that the second rotating portion 50 of the rotating member 18 can be inserted therein. The engaging protrusions 76 protrude upward and are formed in a rectangular or cross shape when viewed from above. The engaging protrusions 76 of the wheel 28 engage with the engaging recesses 65 of the first rotating portion 26, causing the wheel 28 and the first rotating portion 26 to rotate integrally. The first rotating portion 26 is provided inside the wheel 28. Note that, although the embodiment shows an embodiment in which the first rotating portion 26 and the wheel 28 are formed separately, they may also be formed integrally.

[0031] The second case 14 has a hanging portion 45 and a circumferential protrusion 47 on the inside. The hanging portion 45 hangs down from the upper surface and forms an annular wall. The hanging portion 45 is disposed coaxially with the insertion tube portion 42. A step is formed at the lower end of the hanging portion 45 to hold the ring member 32.

[0032] The ring member 32 is provided on the outer periphery of the rotating member 18 and is located between the hanging portion 45 and the second rotating portion 50. The axial movement of the ring member 32 is restricted by the hanging portion 45 and the upper end of the wheel 28. The ring member 32 is elastic and comes into elastic contact with the second case 14 that houses the rotating member 18. The ring member 32 can generate a frictional force against the rotation of the rotating member 18. The ring member 32 can also suppress axial wobble of the rotating member 18.

[0033] As shown in FIG. 3 , the teeth 24a of the worm gear 24 mesh with the teeth 74a of the gear portion 74. The teeth 74a of the gear portion 74 and the teeth 24a of the worm gear 24 are configured to a shape that prevents the worm gear 24 from rotating due to torque from the connecting portion 54, i.e., a lead angle that prevents rotation. In other words, the worm gear 24 can transmit torque from the motor 22 side to the wheel 28, while blocking torque from the wheel 28 side, which is in the opposite direction to the motor 22 side. The worm gear 24 and the wheel 28 transmit only torque from the motor 22 side. In this way, by setting the angles of the teeth 24a, 74a of the worm gear 24 and the gear portion 74, it is possible to prevent back electromotive force from being generated in the motor 22 with a simple configuration. The angle between the tooth portion 24 a of the worm gear 24 and the tooth portion 74 a of the gear portion 74 , that is, the reference cylinder lead angle, is set so that the torque from the connecting portion 54 does not cause the worm gear 24 to rotate.

[0034] The operation of the torque transmission device 10 will now be described. The motor 22 is driven by a user's operation signal, and rotates the motor shaft forward or backward in response to the operation signal. The worm gear 24 is connected to the motor shaft and rotates forward or backward together with the motor shaft, i.e., in either direction. Forward rotation of the motor shaft acts in the direction of opening the opening / closing body, and reverse rotation acts in the direction of closing the opening / closing body.

[0035] The torque of the worm gear 24 is transmitted to the wheel 28, causing the wheel 28 to rotate forward or backward around its axis. The first rotating portion 26 rotates integrally with the wheel 28, pulling the viscous fluid 33 in the rotational direction. The second rotating portion 50 of the rotating member 18 is pulled by the viscous fluid 33 and rotates together with the first rotating portion 26. The rotating member 18 rotates together with the first rotating portion 26, transmitting torque to the opening / closing body, which opens and closes in response to the drive of the motor 22. In this way, the viscous fluid 33 transmits the torque from the wheel 28 to the rotating member 18, causing the rotating member 18 to rotate together with the wheel 28.

[0036] Next, we will explain the operation when the user opens or closes the opening / closing body. When the user opens or closes the opening / closing body, the torque of the opening or closing operation is transmitted to the connecting portion 54 of the rotating member 18, causing the rotating member 18 to rotate forward or backward. The second rotating portion 50 rotates and pulls the viscous fluid 33 in the rotational direction. The first rotating portion 26 is pulled by the viscous fluid 33 and attempts to rotate, and the wheel 28 attempts to rotate together with the first rotating portion 26.

[0037] Here, the teeth 74a of the gear portion 74 and the teeth 24a of the worm gear 24 are set to a lead angle that prevents the worm gear 24 from rotating due to torque from the connecting portion 54 side. Therefore, the worm gear 24 does not rotate due to torque from the connecting portion 54 side. In other words, the wheel 28 stops the torque input from the connecting portion 54 side at the worm gear 24 and does not rotate. As a result, torque is input from the connecting portion 54 side, causing the second rotating portion 50 to rotate forward or backward relative to the first rotating portion 26, and the first rotating portion 26 and the wheel 28 do not rotate. In other words, the first rotating portion 26 and the second rotating portion 50 rotate relative to each other, and the viscous fluid 33 generates resistance to this relative rotation, thereby fulfilling its damping function. In this way, the torque transmission device 10 can output torque from the motor 22 to the outside and damp torque input from the outside using the viscous fluid 33.

[0038] 3 and 4, the first rotating portion 26 and the second rotating portion 50 are disposed radially inside the gear portion 74. By accommodating the first rotating portion 26 and the second rotating portion 50 inside the gear portion 74, the axial length of the torque transmission device 10 can be reduced, and the torque transmission device 10 can be made more compact.

[0039] 5 is an exploded view of the torque transmission device of the second embodiment. The torque transmission device of the second embodiment includes a first case 112, a second case 114, a connecting portion 116, a motor 22, a worm gear 24, a wheel component 128, and a subassembly 80. The subassembly 80 includes a fixed body 82, a first rotating portion 84, a second rotating portion 86, a viscous fluid 33, and a seal ring.

[0040] The first case 112 has a recess 34, ribs 36, claws 37, and a motor accommodating portion 38. A plurality of ribs 36 are formed on the inner peripheral surface of the recess 34 at intervals in the circumferential direction. Axial-extending slits are formed between the plurality of ribs 36 for fixing the fixed body 82. The second case 114 has an insertion tube portion 42, an upper accommodating portion 44, a motor accommodating portion 46, and an elastic locking portion 49.

[0041] The connecting portion 116 has an upper toothed portion 116a, a cylindrical portion 116b, a flange portion 116c, and a second toothed portion. The connecting portion 116 is connected to an external component to transmit torque. The upper toothed portion 116a is located at the top of the connecting portion 116, and the cylindrical portion 116b is located below the upper toothed portion 116a. The flange portion 116c is located at the bottom end of the connecting portion 116 and protrudes radially outward.

[0042] The wheel constituent member 128 is coupled to the first rotating portion 84 to form a wheel. The wheel constituent member 128 has a gear portion 74, a locking portion 88, and a protruding edge portion 89. The motor 22 rotates the worm gear 24 forward or reverse. The gear portion 74 meshes with the worm gear 24 and receives torque from the motor 22 via the worm gear 24.

[0043] The protruding edge portion 89 protrudes radially inward, forms the upper surface of the wheel constituent member 128, and is placed on the subassembly 80. A pair of locking portions 88 are formed by recessing the protruding edge portion 89. The number of locking portions 88 may be one, three, or more. The locking portions 88 are locked to the first rotating portion 84 to connect to the first rotating portion 84.

[0044] 6 is an exploded view of a subassembly 80 of the second embodiment. The fixed body 82 is formed in a cylindrical shape with a bottom and forms a space to accommodate the first rotating part 84 and the second rotating part 86. The fixed body 82 has an outer cylinder part 90, an inner cylinder part 92, a protrusion part 94, and a step part 96. The outer cylinder part 90 is formed in a cylindrical shape and forms the outer shape of the fixed body 82. The inner cylinder part 92 is formed in a cylindrical shape inside the outer cylinder part 90 and coaxially with the outer cylinder part 90. A slit 92a is formed in the inner cylinder part 92. The slit 92a functions as a flow path for moving the viscous fluid 33.

[0045] The step portion 96 forms a step that protrudes radially inward at the bottom of the outer tubular portion 90. The protrusion portion 94 is formed to protrude from the outer surface of the outer tubular portion 90 and extends in the axial direction. The protrusion portion 94 fits between adjacent ribs 36 formed on the first case 112, fixing the fixed body 82 to the first case 112. The fixed body 82 is fixed to the first case 112 and does not rotate.

[0046] The first rotating part 84 has an engaging part 120, an outer circumferential part 122, an inner circumferential part 124, and a central hole 126. A first seal ring 98 is provided on the outer circumferential surface of the first rotating part 84. The engaging part 120 is formed to protrude from the upper surface of the first rotating part 84. The engaging part 120 engages with the engaging part 88 of a wheel constituent member 128. This connects the wheel constituent member 128 and the first rotating part 84 and causes them to rotate integrally.

[0047] The outer circumferential portion 122 is formed in a cylindrical shape. The inner circumferential portion 124 is formed in a cylindrical shape inside the outer circumferential portion 122. Slits and through-holes that serve as flow paths for the viscous fluid 33 are formed in the outer circumferential portion 122 and the inner circumferential portion 124. The central hole 126 is formed to pass through the outer circumferential portion 122 and the inner circumferential portion 124, and the second rotating portion 86 can be inserted therein.

[0048] The second rotating portion 86 has a first toothed portion 130, a shaft portion 132, and an outer ring portion 134. The first toothed portion 130 is located at the top of the second rotating portion 86. The shaft portion 132 extends coaxially from the first toothed portion 130. The shaft portion 132 has an annular insertion hole into which the inner cylinder portion 92 can be inserted. The outer ring portion 134 is formed in an annular shape surrounding the shaft portion 132. The outer ring portion 134 is connected to the shaft portion 132 at the bottom side. A through hole that serves as a flow path for the viscous fluid 33 is formed in the shaft portion 132 and the outer ring portion 134.

[0049] The second seal ring 99 is provided on the outer periphery of the shaft portion 132. The second seal ring 99 is located on the upper end side of the shaft portion 132, close to the first tooth portion 130.

[0050] 7 is a cross-sectional view of the torque transmission device 100 of the second embodiment. The gear portion 74 meshes with the worm gear 24, which is the torque transmission means. The teeth of the gear portion 74 and the teeth of the worm gear 24 are configured so that the worm gear 24 does not rotate due to torque input from the connecting portion 116 side.

[0051] The connecting portion 116 is inserted into the insertion tube portion 42 of the first case 112. The flange portion 116c is hooked onto the back edge of the insertion tube portion 42 to prevent the connecting portion 116 from coming off the first case 112.

[0052] The connecting portion 116 has second teeth 116d on the inner periphery of the cylindrical portion 116b. The second teeth 116d mesh with the first teeth 130 of the second rotating portion 86. The rotation axes of the first teeth 130 and the second teeth 116d are offset from each other.

[0053] The connecting portion 116 and the second rotating portion 86 rotate in conjunction with each other. When the second rotating portion 86 rotates, the connecting portion 116 rotates, and when the connecting portion 116 rotates, the second rotating portion 86 rotates. In this way, the connecting portion 116 and the second rotating portion 86 constitute a rotating member and are provided so as to be rotatable relative to the wheel.

[0054] The first toothed portion 130 is formed with a smaller diameter than the second toothed portion 116d. Because the second toothed portion 116d is disposed on the outer side, it is possible to increase the output to the outside. Meanwhile, because the rotation amount of the first toothed portion 130 increases in response to an input from the outside, the rotational resistance increases, improving the damper effect. Even if the viscosity of the viscous fluid 33 is reduced to facilitate manufacturing, the damper performance does not deteriorate. By inserting the first toothed portion 130 into the second toothed portion 116d, the torque transmission device 10 is made smaller in the radial direction than when second toothed portions are provided on the outer peripheral surface of the cylindrical portion 116b and the first toothed portion 130 is arranged in parallel with the second toothed portions.

[0055] The connecting portion 116 and the second rotating portion 86 may be integrally formed. For example, instead of the connecting portion 116, the first tooth portion 130 may be formed by extending upward, and the first tooth portion 130 may function as the connecting portion.

[0056] The gear portion 74 of the wheel component 128 surrounds the outer cylindrical portion 90 of the fixed body 82. When the gear portion 74 is rotated by the worm gear 24, the second rotating portion 86 rotates by the same amount.

[0057] The fixed body 82 is provided so as to be unable to rotate relative to the first case 112. The first rotating part 84 and the second rotating part 86 are inserted inside the fixed body 82. The outer cylinder part 90 of the fixed body 82 faces the outer circumferential part 122 of the first rotating part 84. The outer ring part 134 of the second rotating part 86 fits between the outer circumferential part 122 and the inner circumferential part 124 of the first rotating part 84.

[0058] The shaft 132 of the second rotating part 86 has an insertion hole 132a cut out from the lower end upward. The inner cylinder part 92 of the fixed body 82 is inserted into the insertion hole 132a. The fixed body 82, the first rotating part 84, and the second rotating part 86 form a space that holds the viscous fluid 33.

[0059] The viscous fluid 33 is interposed between the wheel and the rotating member. The viscous fluid 33 fills the internal space formed by the fixed body 82, the first rotating part 84, and the second rotating part 86. The space holding the viscous fluid 33 is closed by a first seal ring 98 and a second seal ring 99. The first seal ring 98 abuts against the outer surface of the outer cylinder part 90 of the fixed body 82 and the outer periphery 122 of the first rotating part 84. The second seal ring 99 abuts against the inner periphery 124 of the first rotating part 84 and the shaft part 132 of the second rotating part 86.

[0060] The viscous fluid 33 is interposed between the first rotating part 84 and the fixed body 82, and between the second rotating part 86 and the fixed body 82. In other words, when the first rotating part 84 rotates relative to the fixed body 82, a resistance force is generated by the shear force of the viscous fluid 33. Furthermore, when the second rotating part 86 rotates relative to the fixed body 82, a resistance force is generated by the shear force of the viscous fluid 33. This allows the first rotating part 84 and the second rotating part 86 to rotate independently, and since a resistance force is generated when each part rotates, the damping force of the damper can be increased.

[0061] The size of the holding space for the viscous fluid 33 formed by the second rotating part 86, the fixed body 82, and the first rotating part 84 is larger than the size of the holding space for the viscous fluid 33 formed by the first rotating part 84, the fixed body 82, and the second rotating part 86. In other words, the area of ​​contact between the second rotating part 86 and the viscous fluid 33 is larger than the area of ​​contact between the first rotating part 84 and the viscous fluid 33. As a result, the second rotating part 86 receives a larger resistance force than the first rotating part 84, thereby improving the damping effect.

[0062] The fixed body 82 accommodates the first rotating part 84 and the second rotating part 86. The first rotating part 84 and the second rotating part 86 are inserted inside the outer cylindrical part 90 to form a holding space for the viscous fluid 33. This allows the components that make up the damper, shown as a subassembly 80 in FIG. 5, to be made compact. Furthermore, because it is only necessary to insert the first rotating part 84 and the second rotating part 86 into the fixed body 82, the components that make up the damper can be easily manufactured.

[0063] 8 is a cross-sectional view of the subassembly 80 of the second embodiment. The operation of the subassembly 80 will now be described. The subassembly 80 operates in three modes.

[0064] (First Mode) The first mode is a normal operation when torque is input from the motor 22, in which the first rotating part 84 and the second rotating part 86 rotate. The first rotating part 84 included in the wheel receives torque from the worm gear 24 and rotates forward or backward around its axis, pulling the viscous fluid 33 in the rotational direction. The second rotating part 86 is pulled by the viscous fluid 33 and rotates together with the first rotating part 84. The rotation of the second rotating part 86 outputs torque to the outside. When subjected to the rotational motion of the first rotating part 84 or the second rotating part 86, the viscous fluid 33 generates resistance, which transmits the torque from the first rotating part 84 to the second rotating part 86, causing the rotating member to rotate forward or backward together with the wheel.

[0065] (Second Mode) The second mode is an operation in which torque is input from the outside, and only the second rotating part 86 rotates. When the connecting part 116 rotates due to torque from the outside, the second rotating part 86 rotates forward or backward, pulling the viscous fluid 33 in the rotational direction. The first rotating part 84 is pulled by the viscous fluid 33 and attempts to rotate, and the wheel constituent member 128 attempts to rotate together with the first rotating part 86.

[0066] Here, the teeth of the gear portion 74 and the teeth of the worm gear 24 are set to a lead angle that prevents the worm gear 24 from rotating due to torque from the connecting portion 116 side. Therefore, the wheel constituent member 128 stops the torque input from the connecting portion 116 side at the worm gear 24, and does not rotate, and the first rotating portion 84 also does not rotate. Because the second rotating portion 86 rotates but the first rotating portion 84 does not rotate, the viscous fluid 33 generates a resistance force, and the damping function of the damper is exerted.

[0067] (Third Mode) The third mode is an operation in which torque is input from the motor 22, and only the first rotating part 84 rotates. For example, the third mode is executed when the user drives the motor 22 while the opening / closing body is stopped.

[0068] The first rotating part 84 included in the wheel receives torque from the worm gear 24 and rotates forward or backward around its axis, pulling the viscous fluid 33 in the rotational direction. The second rotating part 86 is pulled by the viscous fluid 33, but cannot rotate because the opening / closing body is restrained. Therefore, the motor 22 rotates up to the first rotating part 84. Even when the opening / closing body is not rotating, the motor 22 can output torque to the first rotating part 84, so the load on the motor 22 can be reduced. Furthermore, the torque input to the first rotating part 84 can be converted into resistance force by the viscous fluid 33.

[0069] In the second embodiment, the functions of the fixed body 82 and the first rotating part 84 may be reversed. For example, the first rotating part 84 may be fixed to the second case 114 so as not to rotate and function as a fixed body, and the fixed body 82 may be engaged with the wheel constituent member 128 and rotate integrally therewith. The internal structure of the subassembly 80 may be modified to a different structure as long as it is a structure that can generate shear forces when only the first rotating part 84 rotates, when only the second rotating part 86 rotates, and when both the first rotating part 84 and the second rotating part 86 rotate.

[0070] The present invention is not limited to the above-described embodiments, and various modifications such as design changes may be made to the embodiments based on the knowledge of those skilled in the art, and such modified embodiments may also be included within the scope of the present invention.

[0071] For example, although the embodiment has been described in which the first rotating portion 26 and the second rotating portion 50 are formed in three layers, the present invention is not limited to this. Depending on the viscosity of the viscous fluid and the size of the torque transmission device 10, the first rotating portion 26 and the second rotating portion 50 may be formed in one layer or two layers.

[0072] In addition, although the embodiment shows an embodiment in which the rotational resistance imparting means is a viscous fluid such as oil, the present invention is not limited to this embodiment. For example, the rotational resistance imparting means may be an elastic member such as rubber or a torsion spring. In either case, the rotational resistance imparting means generates resistance to the relative rotation between the first rotating part 26 and the second rotating part 50.

[0073] In addition, in the embodiment, the torque transmission means connected to the wheel 28 is the worm gear 24, but this is not limiting. For example, depending on the arrangement of the motor 22, the torque transmission means may be a spur gear.

[0074] Furthermore, in the embodiment, the first rotating portion 26 is provided inside the wheel 28, but this is not limiting. For example, the first rotating portion 26 may be provided at a position that protrudes from the wheel 28, may be located outside the wheel 28, or may be located from the inside to the outside of the wheel 28. In any case, the first rotating portion 26 is supported by the wheel 28.

[0075] The present invention relates to a torque transmission device that transmits torque input from a torque transmission means to an outside.

[0076] 10 Torque transmission device, 12 First case, 14 Second case, 16 Gear portion, 18 Rotating member, 20 Terminal portion, 22 Motor, 24 Worm gear, 24a Tooth portion, 26 First rotating portion, 28 Wheel, 30 Seal ring, 32 Ring member, 33 Viscous fluid, 34 Recessed portion, 36 Rib, 37 Claw portion, 38 Motor accommodating portion, 40 Semi-cylindrical portion, 42 Insertion cylindrical portion, 44 Upper accommodating portion, 45 Hanging portion, 46 Motor accommodating portion, 47 Circumferential convex portion, 48 Semi-cylindrical portion, 49 Elastic locking portion, 50 Second rotating portion, 51 Annular plate portion, 52 Neck portion, 54 Connecting portion, 56 First inner cylindrical portion, 58 Second inner cylindrical portion, 60 First cylindrical portion, 62 cylindrical portion, 64 second cylindrical portion, 65 engaging recess, 66 circumferential groove portion, 67 annular protrusion portion, 70 cylindrical portion, 72 inner peripheral portion, 74 gear portion, 74a tooth portion, 76 engaging protrusion portion.

Claims

1. A torque transmission device comprising: a wheel that receives torque from a torque transmission means and rotates in either forward or reverse about its axis; a rotating member that is rotatable relative to the wheel; and rotational resistance imparting means interposed between the wheel and the rotating member, wherein the wheel has a first rotating part, and the rotating member has a connecting part that is connected to the outside and transmits torque, and a second rotating part that forms a space to hold the first rotating part and the rotational resistance imparting means, wherein the rotational resistance imparting means generates resistance when subjected to the rotational movement of the first rotating part or the second rotating part, and transmits the torque from the wheel to the rotating member, causing the rotating member to rotate in either forward or reverse together with the wheel, wherein the wheel is stopped by the torque transmission means and does not rotate when torque is input from the connecting part side, and the second rotating part rotates in either forward or reverse relative to the first rotating part depending on the torque input from the connecting part side.

2. The torque transmission device described in claim 1, characterized in that the wheel has a gear portion on its outer periphery that meshes with the torque transmission means, and the teeth of the gear portion and the teeth of the torque transmission means are set in a shape that prevents the torque transmission means from rotating due to torque input from the connecting portion side.

3. A torque transmission device according to claim 2, further comprising a motor for rotating said torque transmission means forward or backward, said torque transmission means being a worm gear.

4. A torque transmission device according to claim 2 or 3, characterized in that the first rotating portion and the second rotating portion are arranged overlapping each other on the radially inner side of the gear portion.

5. A torque transmission device according to any one of claims 1 to 3, further comprising a ring member formed in an elastic ring shape and attached to the outer periphery of the rotating member, the ring member elastically contacting a case that houses the rotating member.

6. A torque transmission device as described in any one of claims 1 to 3, characterized in that it comprises a fixed body that is non-rotatable, the first rotating part is rotatable relative to the fixed body, the second rotating part is rotatable relative to the fixed body, and the rotational resistance imparting means is interposed between the first rotating part and the fixed body, and between the second rotating part and the fixed body.

7. The torque transmission device according to claim 6, wherein the fixed body is formed in a cylindrical shape and accommodates the first rotating part and the second rotating part.

8. A torque transmission device as described in claim 6, characterized in that the second rotating portion has a first tooth portion, the connecting portion has a cylindrical portion and a second tooth portion formed on the inner circumference of the cylindrical portion and meshing with the first tooth portion, and the first tooth portion has a smaller diameter than the second tooth portion.

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