Actuator apparatus

Abstract

To ensure high quietness.SOLUTION: An actuator apparatus 50 comprises a motor 51 serving as a drive source, a sun gear 75 that is rotationally driven by the motor 51 at a coaxial position with a motor shaft 73, and a ring gear 76 that is coaxially disposed on a radially outer side of the sun gear 75. The actuator apparatus 50 further comprises a support member 78 that non-rotatably supports the ring gear 76, a planetary gear 79 that meshes with the sun gear 75 and the ring gear 76, and a planetary carrier 80 that supports the planetary gear 79 rotatably on its own axis and orbitally. Furthermore, a first shaft end portion 80a of the planetary carrier 80, which is apart from the motor 51, is supported by a rotation shaft 75x of the sun gear 75. Also, a radially outer side position of a second shaft end portion 80b of the planetary carrier 80, which is close to the motor 51, is supported by a rotation support portion 100 provided for the support member 78 of the ring gear 76.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an actuator device. [Background technology]

[0002] Conventionally, there is an actuator device in which a reducer is arranged coaxially with a motor that serves as a drive source by using a planetary gear mechanism. For example, the actuator device disclosed in Patent Document 1 configures a reducer using two-stage planetary gear mechanisms arranged side by side on the same axis. This configuration ensures a high reduction ratio. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent Application Publication No. 3293417 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described conventional technology configuration poses a problem of vibration and noise generation. [Means for solving the problem]

[0005] The actuator device of the present invention comprises a motor serving as a drive source, a sun gear that is rotationally driven by the motor at a position coaxial with the motor shaft, a ring gear that is arranged coaxially radially outside the sun gear, a support member that supports the ring gear so that it cannot rotate, planetary gears that mesh with the sun gear and the ring gear, and a planetary carrier that supports the planetary gears so that they can rotate and revolve, and the planetary carrier has a first shaft end that is separated from the motor supported by the rotating shaft of the sun gear, and a second shaft end that is closer to the motor and has a radially outer position that is supported by a rotation support portion provided on the support member.

[0006] According to the above configuration, the first shaft end of the planetary carrier is journaled on the sun gear's rotation shaft, ensuring high coaxiality of the planetary carrier relative to the sun gear's rotation shaft. Furthermore, by supporting the radially outer position of the second shaft end with a rotation support portion provided on the support member, assembly is facilitated and the planetary carrier can be stably supported in a so-called double-supported state. Furthermore, because the support positions of the planetary carrier set on the first shaft end and the second shaft end are each spaced apart from the motor, motor vibration is less likely to be transmitted to the planetary carrier. This ensures high quietness. Additionally, the compact support structure in which the sun gear's rotation shaft journals the first shaft end of the planetary carrier allows for a more compact device. [Effects of the Invention]

[0007] According to the present invention, high quietness can be ensured. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a vehicle provided with a door device. [Figure 2] FIG. 2 is a side view of the door device. [Figure 3] FIG. 3 is a cross-sectional view of the door device. [Figure 4] FIG. 4 is a cross-sectional view of the actuator device. [Figure 5] FIG. 5 is an exploded perspective view of the actuator device. [Figure 6] FIG. 6 is a perspective view of the planetary gear, the planetary carrier, and the motor shaft. [Figure 7] FIG. 7 is a perspective view of the planetary gear and planetary carrier, as well as the motor shaft and sun gear. [Figure 8] FIG. 8 is a perspective view of a support member formed integrally with a ring gear. [Figure 9]FIG. 9 is a cross-sectional view of an actuator device according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment in which the actuator device is applied to a power back door device of a vehicle will be described below with reference to the drawings. <Backdoor> As shown in Fig. 1, the vehicle 1 of this embodiment has a door opening 3 that is provided at the rear end 2r of the vehicle body 2 and opens toward the rear of the vehicle (to the right in Fig. 1). Furthermore, in the vehicle 1 of this embodiment, the door opening 3 is provided with a back door 5 that has a rotation fulcrum X0 at the upper end of the door opening 3 and is configured as a so-called flip-up door that opens and closes in the vertical direction. The vehicle 1 of this embodiment also has a door device 10 that has an axis-shaped outer shape and is interposed between the back door 5 and the vehicle body 2 at the end position of the door opening 3 in the width direction.

[0010] <Door device> 2 and 3, the door device 10 of this embodiment includes a first cylindrical member 21 and a second cylindrical member 22 that are concentrically arranged. The door device 10 allows relative axial displacement of the first cylindrical member 21 and the second cylindrical member 22. This allows the door device 10 of this embodiment to expand and contract its axial length L.

[0011] Specifically, in the door device 10 of this embodiment, the first cylindrical member 21 includes a cover tube 31 and a guide tube 32 that is coaxially arranged within the cover tube 31. The second cylindrical member 22 includes an outer tube 33 and an inner tube 34 that is coaxially arranged within the outer tube 33. The first cylindrical member 21 and the second cylindrical member 22 are configured such that the outer tube 33 has a smaller diameter than the cover tube 31, and the inner tube 34 has a smaller diameter than the guide tube 32.

[0012] That is, in the door device 10 of this embodiment, when the first cylindrical member 21 and the second cylindrical member 22 are assembled, the first end 22a of the second cylindrical member 22 is inserted into the first cylindrical member 21. Specifically, the first end 33a of the outer tube 33 of the second cylindrical member 22 is inserted into the cover tube 31 of the first cylindrical member 21, and the first end 34a of the inner tube 34 is inserted into the guide tube 32 of the first cylindrical member 21. Thus, in the door device 10 of this embodiment, the first cylindrical member 21 and the second cylindrical member 22 are concentrically arranged while allowing relative displacement in the axial direction.

[0013] 2 and 3 show a state in which the first cylindrical member 21 and the second cylindrical member 22 are displaced relative to each other in the direction in which the axial length L of the door device 10 extends, causing the second end 22b of the second cylindrical member 22 to protrude from the second end 21b of the first cylindrical member 21. Furthermore, in this door device 10, the first cylindrical member 21 and the second cylindrical member 22 are displaced relative to each other, causing the second cylindrical member 22 to be substantially entirely recessed within the cylindrical interior of the first cylindrical member 21. As a result, the axial length L of the door device 10 of this embodiment is shortened.

[0014] The door device 10 of this embodiment also includes a compression coil spring 40 interposed between the first cylindrical member 21 and the second cylindrical member 22. In the door device 10 of this embodiment, the compression coil spring 40 is arranged coaxially with the first cylindrical member 21 and the second cylindrical member 22 in the gap between the guide tube 32 and the outer tube 33. In this state, the first end 40a of the compression coil spring 40 of this embodiment abuts against a pressure-receiving surface 41 on the first cylindrical member 21 side, which is provided at the first end 31a of the cover tube 31. Furthermore, the second end 40b of the compression coil spring 40 abuts against a pressure-receiving surface 42 on the second cylindrical member 22 side, which is provided at the second end 33b of the outer tube 33. As a result, the door device 10 of this embodiment urges the first cylindrical member 21 and the second cylindrical member 22 in opposite directions based on the elastic force of the compression coil spring 40. In other words, the first cylindrical member 21 and the second cylindrical member 22 are configured to be biased in a direction in which their axial lengths L extend.

[0015] The door device 10 of this embodiment also includes a substantially cylindrical third tubular member 43 that is coaxially fixed to the first end 21a of the first tubular member 21 in an axially extending manner. The door device 10 of this embodiment also includes connecting members 45, 45 provided on the first end 43a of the third tubular member 43 and the second end 22b of the second tubular member 22, which are located at both axial ends of the door device 10. Specifically, in the door device 10 of this embodiment, each of these connecting members 45, 45 is configured as a "socket" of a ball joint. The vehicle 1 of this embodiment also includes spherical fitting members (not shown) that form the ball joint together with each of the connecting members 45, 45, for the back door 5 and the door opening 3. As a result, the door device 10 of this embodiment is configured so that each of these connecting members 45, 45 is interposed between the tailgate 5 and the vehicle body 2, forming a rotational connection point X1 with respect to the vehicle body 2 and a rotational connection point X2 with respect to the tailgate 5 (see Figure 1).

[0016] 1, the door device 10 of this embodiment extends and contracts based on the relative axial displacement of the first tubular member 21 and the second tubular member 22, while rotating about a rotation connection point X1 relative to the vehicle body 2 and rotating about a rotation connection point X2 relative to the tailgate 5. The door device 10 of this embodiment is thus configured to allow the tailgate 5 provided in a door opening 3 that opens to the rear of the vehicle 1 to be opened and closed.

[0017] In the vehicle 1 of this embodiment, the door device 10 is configured such that, when the back door 5 is in a fully closed state, the pivot connection point X2 with respect to the back door 5 is located lower than the pivot connection point X1 with respect to the vehicle body 2. Furthermore, when the back door 5 is in a fully open state, the door device 10 is configured such that the pivot connection point X2 with respect to the back door 5 is located higher than the pivot connection point X1 with respect to the vehicle body 2. As a result, the door device 10 of this embodiment is configured such that the elastic force of the compression coil spring 40, which biases the first cylindrical member 21 and the second cylindrical member 22 in a direction in which the axial length L extends, acts in a direction in which the elastic force of the compression coil spring 40 acts in a direction in which the weight of the back door 5 that has been opened or closed is supported.

[0018] <Actuator device, spindle screw and spindle nut> 3, the door apparatus 10 of this embodiment includes an actuator device 50 housed in the third cylindrical member 43. In the door apparatus 10 of this embodiment, the actuator device 50 includes a motor 51 serving as a drive source and a reducer 52 that reduces the rotation of the motor 51 and outputs the reduced rotation. The door apparatus 10 of this embodiment also includes a spindle screw 61 that is rotationally driven by the actuator device 50, and a spindle nut 62 that screws onto the spindle screw 61. The door apparatus 10 of this embodiment is configured such that the first cylindrical member 21 and the second cylindrical member 22 are displaced relative to each other in the axial direction based on the operation of a linear drive unit 65 formed by the spindle screw 61 and the spindle nut 62.

[0019] More specifically, in the door device 10 of this embodiment, the spindle screw 61 is rotatably supported by a bearing 63 provided at the second end 43b of the third cylindrical member 43. The spindle screw 61 is inserted into the guide tube 32 via the first end 32a of the guide tube 32, and is thereby arranged coaxially with the guide tube 32. The guide tube 32 of this embodiment has its first end 32a fixed to a fixing member 64 of the bearing 63 for the third cylindrical member 43. The spindle nut 62 is coaxially fixed to the first end 34a of the inner tube 34 inserted into the guide tube 32 via the second end 32b of the guide tube 32.

[0020] That is, the spindle screw 61 of this embodiment is supported so as to be rotatable relative to the first cylindrical member 21 but not displaceable in the axial direction. Moreover, the spindle nut 62 that threads onto this spindle screw 61 is fixed so as to be non-rotatable relative to the second cylindrical member 22 and not displaceable in the axial direction. Furthermore, in the door device 10 of this embodiment, the rotational output of the actuator device 50 housed in the third cylindrical member 43 is transmitted to the spindle screw 61 via a joint portion 66 that is juxtaposed coaxially with the actuator device 50. Then, in the door device 10 of this embodiment, the rotation of the spindle screw 61 causes the engagement position of the spindle nut 62 with respect to the spindle screw 61 to move in the axial direction.

[0021] Furthermore, in the door device 10 of this embodiment, the first cylindrical member 21 supporting the spindle screw 61 and the second cylindrical member 22 supporting the spindle nut 62 are displaced relative to each other in the axial direction based on the movement of the screw engagement position. In other words, the linear drive unit 65 formed by the spindle screw 61 and the spindle nut 62 converts the rotation output of the actuator device 50 into an axial displacement output. As a result, the door device 10 of this embodiment has a configuration as a linear actuator device 70 whose axial length L expands and contracts based on the driving force of the actuator device 50 using the motor 51 as a drive source.

[0022] The spindle screw 61 of this embodiment has a configuration of a so-called "trapezoidal screw" having a thread with a substantially trapezoidal cross section. The door device 10 of this embodiment is configured so that the spindle screw 61 and the spindle nut 62 can smoothly rotate relative to each other even when an axial force is applied to them.

[0023] That is, in the door device 10 of this embodiment, even when the axial length L is extended or contracted based on an external input, the first cylindrical member 21 and the second cylindrical member 22 move relatively in the axial direction while the spindle screw 61 rotates. As a result, in the vehicle 1 of this embodiment, a power back door device 71 is formed that can open and close the back door 5 by the driving force of the actuator device 50 or by manual operation by the user.

[0024] <Planetary gear mechanism> As shown in Figures 4 and 5, the actuator device 50 of this embodiment uses a planetary gear mechanism 72 in its reducer 52. Specifically, the planetary gear mechanism 72 includes a sun gear 75 that is rotationally driven by the motor 51 and is located coaxially with the motor shaft 73. The planetary gear mechanism 72 also includes a ring gear 76 that is located coaxially radially outward of the sun gear 75. In the planetary gear mechanism 72 of this embodiment, the ring gear 76 is formed integrally with a support member 78 that has a substantially cylindrical outer shape with a bottom, and is thereby non-rotatably supported, and is located coaxially with the sun gear 75. The planetary gear mechanism 72 also includes a planetary gear 79 that meshes with the sun gear 75 and ring gear 76, and a planetary carrier 80 that supports the planetary gear 79 so that it can rotate and revolve about its axis. As a result, the actuator device 50 of this embodiment is configured such that the planetary carrier 80 serves as the rotation output section 81 of the actuator device 50 that uses the planetary gear mechanism 72 in the reducer 52 .

[0025] More specifically, in the actuator device 50 of this embodiment, the sun gear 75 includes a toothed portion 83 that forms the main body of the sun gear 75, and a shaft fitting portion 84 that is provided at a base end 83b of the toothed portion 83. Specifically, in the sun gear 75 of this embodiment, the shaft fitting portion 84 has a substantially cylindrical outer shape that extends coaxially with the toothed portion 83. Furthermore, in the sun gear 75 of this embodiment, the shaft fitting portion 84 is fitted to the tip end 73a of the motor shaft 73 so as not to rotate relative to it. As a result, the sun gear 75 of this embodiment is configured so that the toothed portion 83, together with the shaft fitting portion 84, rotates integrally with the motor shaft 73 coaxially.

[0026] Furthermore, the sun gear 75 of this embodiment has a tooth portion 83 configured as a small-tooth-count helical gear 85 having helical helical teeth 85x extending along the rotation axis 75x of the sun gear 75. More specifically, in the sun gear 75 of this embodiment, the number of teeth of the tooth portion 83 is set to "2." Thus, the actuator device 50 of this embodiment is configured to reduce the meshing frequency of the planetary gear mechanism 72.

[0027] That is, as the sun gear 75 rotates due to motor drive, noise is generated at the meshing portions of the planetary gear mechanism 72. Furthermore, it is preferable that the operating noise of the actuator device 50 be low in frequency. In light of this, the actuator device 50 of this embodiment employs a small-tooth helical gear 85 for the sun gear 75 that rotates due to motor drive. This configuration keeps the frequency of the noise generated at the meshing portions of the planetary gear mechanism 72, that is, the so-called "mesh frequency," low.

[0028] 4 to 7, in the actuator device 50 of this embodiment, the planetary carrier 80 has a generally cylindrical outer shape with a bottom. Specifically, in the actuator device 50 of this embodiment, the planetary carrier 80 is arranged coaxially with the motor shaft 73, and one axial end side (the upper end in FIG. 4) of the planetary carrier 80 arranged away from the motor 51 is referred to as the first axial end 80a. The other axial end side (the lower end in FIG. 4) of the planetary carrier 80 arranged closer to the motor 51 is referred to as the second axial end 80b of the planetary carrier 80. Furthermore, the planetary carrier 80 has a peripheral wall portion 87 and a axial end wall portion 88 that form the generally cylindrical shape with a bottom. In the planetary carrier 80 of this embodiment, the axial end wall portion 88, which is the bottom portion of the generally cylindrical shape with a bottom, is referred to as the first axial end 80a, so that the second axial end 80b side is open in the axial direction.

[0029] Moreover, the planetary carrier 80 of this embodiment has a plurality of holes 89 formed in its peripheral wall portion 87. The actuator device 50 of this embodiment is configured such that the tooth portions 86 of the planetary gears 79 supported by the planetary carrier 80 face radially outward through each of these holes 89.

[0030] Specifically, the actuator device 50 of this embodiment includes a pair of planetary gears 79, 79 arranged at two positions spaced apart at approximately equal intervals in the circumferential direction. Two holes 89, 89 corresponding to the planetary gears 79, 79 are provided in the peripheral wall portion 87 of the planetary carrier 80.

[0031] In the planetary carrier 80 of this embodiment, the base ends 79xb of the rotation shafts 79x of the planetary gears 79 are held by a holding member 90 having a substantially annular outer shape. In the actuator device 50 of this embodiment, the holding member 90 and the rotation shafts 79x of the planetary gears 79 are integrally formed. That is, the planetary carrier 80 of this embodiment holds the rotation shafts 79x of the planetary gears 79 at two positions spaced apart at substantially equal intervals in the circumferential direction. Furthermore, in the planetary carrier 80 of this embodiment, the rotation shafts 79x of the planetary gears 79 held by the holding member 90 are inserted into the cylindrical shape of the planetary carrier 80 from the second shaft end 80b side, which opens in the axial direction. In the planetary carrier 80 of this embodiment, the rotation shafts 79x, 79x of the planetary gears 79, 79 are disposed radially inside the substantially cylindrical peripheral wall portion 87, and the substantially annular holding member 90 is fixed to the second shaft end portion 80b. More specifically, the holding member 90 is fixed to the base end 87b of the peripheral wall portion 87.

[0032] The planetary carrier 80 of this embodiment also has a pair of support holes 91, 91 provided in a substantially disk-shaped shaft end wall portion 88 that constitutes the first shaft end 80a. Furthermore, in the planetary carrier 80 of this embodiment, the rotating shafts 79x, 79x of the planetary gears 79, 79 are inserted into the support holes 91, 91, respectively. More specifically, the tip ends 79xa, 79xa sides of the rotating shafts 79x, 79x are inserted into the support holes 91. Thus, the planetary carrier 80 of this embodiment is configured to stably support the rotating shafts 79x, 79x of the planetary gears 79, 79 by the first shaft end 80a and the second shaft end 80b that are spaced apart in the axial direction.

[0033] Furthermore, in the actuator device 50 of this embodiment, the sun gear 75, which rotates coaxially with the motor shaft 73, is also inserted into the cylindrical shape of the planetary carrier 80 from the second shaft end portion 80b side of the planetary carrier 80, which opens in the axial direction. As a result, the actuator device 50 of this embodiment is configured so that the sun gear 75 meshes with each of the planetary gears 79, 79 supported by the planetary carrier 80, radially inside the cylindrical peripheral wall portion 87.

[0034] Moreover, the planetary carrier 80 of this embodiment has a support hole 92 provided in the shaft end wall portion 88 constituting the first shaft end portion 80a at a position that is the center of the approximately disk-shaped portion. Furthermore, in the planetary carrier 80 of this embodiment, the rotating shaft 75x of the sun gear 75 is inserted into this support hole 92. As a result, the actuator device 50 of this embodiment is configured so that the first shaft end portion 80a of the planetary carrier 80 is journaled by the rotating shaft 75x of the sun gear 75, more specifically, by the tip 75xa of the rotating shaft 75x that protrudes from the tip 83a of the tooth portion 83.

[0035] In the actuator device 50 of this embodiment, an annular portion 93 extending along the circumferential edge of the shaft end wall portion 88 is provided on an end surface 88s of the shaft end wall portion 88 that constitutes the first shaft end portion 80a of the planetary carrier 80. Furthermore, a plurality of engaging protrusions 94 are provided radially inward of the annular portion 93, similarly protruding axially from the end surface 88s of the shaft end wall portion 88 and spaced apart at approximately equal intervals in the circumferential direction. Specifically, the planetary carrier 80 of this embodiment has three engaging protrusions 94 spaced apart at approximately equal intervals in the circumferential direction. The actuator device 50 of this embodiment is configured so that the first shaft end portion 80a of the planetary carrier 80, which constitutes the rotation output portion 81, is connected to the joint portion 66 that is coaxially arranged with the actuator device 50, using the engaging protrusions 94.

[0036] 4, 5, and 8, in the actuator device 50 of this embodiment, the ring gear 76 is provided integrally with a support member 78 having a substantially cylindrical outer shape with a bottom, with the teeth portion 95 protruding from an inner circumferential surface 78s of the support member 78. Furthermore, in the actuator device 50 of this embodiment, the planetary carrier 80 and the sun gear 75 configured as described above are also arranged within the cylindrical shape of the support member 78, along with the ring gear 76. As a result, the actuator device 50 of this embodiment is configured such that the sun gear 75 and the planetary carrier 80 are coaxially arranged radially inward of the ring gear 76, with the ring gear 76 supported non-rotatably.

[0037] More specifically, in the actuator device 50 of this embodiment, the support member 78 of the ring gear 76 has a bottom portion 96 that is located axially closer to the motor 51 than the ring gear 76 that is integral with the support member 78. The support member 78 of this embodiment also has an insertion hole 97 that axially penetrates the bottom portion 96 at the center of a bottom surface 96s that has a substantially circular planar shape facing the interior of the cylinder. Furthermore, in the actuator device 50 of this embodiment, the motor shaft 73 and the shaft fitting portion 84 of the sun gear 75 are inserted into the insertion hole 97 provided in the bottom portion 96 of the support member 78. Thus, in the actuator device 50 of this embodiment, the sun gear 75 and the planetary carrier 80 are coaxially arranged radially inside the ring gear 76 without interfering with the bottom portion 96 of the support member 78.

[0038] Furthermore, in the actuator device 50 of this embodiment, a circular recess 98 is provided in a bottom surface 96s of the bottom portion 96 facing the inside of the cylindrical shape of the support member 78, at a central position that is coaxial with the insertion hole 97. The actuator device 50 of this embodiment is configured so that the circular recess 98 provided in the bottom surface 96s of the bottom portion 96 serves as a rotation support portion 100, and rotatably supports the second shaft end portion 80b of the planetary carrier 80.

[0039] 4, 7, and 8, in the actuator device 50 of this embodiment, the second axial end portion 80b of the planetary carrier 80 axially abuts against a bottom surface 98sb of a circular recess 98 provided in a bottom surface 96s facing the inside of the cylindrical shape of the support member 78. As a result, the actuator device 50 of this embodiment is configured to support the axial load of the planetary carrier 80 with the second axial end portion 80b of the planetary carrier 80, more specifically, the axial end surface 80bs, in sliding contact with the bottom surface 98sb of the circular recess 98.

[0040] Furthermore, in the actuator device 50 of this embodiment, the diameter D1 of the circular recess 98 is approximately equal to the diameter D0 of the circumferential wall portion 87 that constitutes the second shaft end portion 80b of the planetary carrier 80 (D1 ≈ D0). Specifically, the diameter D1 of the circular recess 98 is set slightly larger than the diameter D0 of the circumferential wall portion 87. As a result, the planetary carrier 80 of this embodiment is configured to rotate coaxially with the sun gear 75 arranged within the cylindrical shape, with the outer peripheral surface 87s of the cylindrical circumferential wall portion 87 in sliding contact with the inner peripheral surface 98ss of the circular recess 98 at the second shaft end portion 80b.

[0041] That is, in the planetary carrier 80 of this embodiment, the outer peripheral surface 87s of the peripheral wall portion 87 is disposed at a radially outer position of the second shaft end portion 80b. Furthermore, in the actuator device 50 of this embodiment, the inner peripheral surface 98ss of the circular recess 98 is a peripheral surface that extends in the circumferential direction and faces the outer peripheral surface 87s of the peripheral wall portion 87 disposed at a radially outer position of the second shaft end portion 80b. Thus, in the actuator device 50 of this embodiment, the inner peripheral surface 98ss of the circular recess 98 functions as a sliding bearing, thereby supporting the radial load of the second shaft end portion 80b and stably supporting the planetary carrier 80 for free rotation.

[0042] More specifically, as shown in Fig. 4, in the actuator device 50 of this embodiment, the axial section between the tooth portion 83 of the sun gear 75 and the shaft end 51a of the motor 51 is set to be a full circumferential clearance section δ. Specifically, in the actuator device 50 of this embodiment, this full circumferential clearance section δ is set to an axial positional range (lower positional range in Fig. 4) closer to the motor 51 than a base end 83b of the tooth portion 83, including the shaft fitting portion 84, of the sun gear 75 fitted to the motor shaft 73. Furthermore, this full circumferential clearance section δ is set to an axial positional range (upper positional range in Fig. 4) closer to the sun gear 75 than a position where the motor shaft 73 protrudes from the shaft end 51a of the motor 51. In the actuator device 50 of this embodiment, a gap ε is provided radially outward of the sun gear 75 and the motor shaft 73 throughout the full periphery of the sun gear 75 and the motor shaft 73 in this full circumferential clearance section δ. In other words, no members that come into contact with the sun gear 75 and the motor shaft 73 are disposed within the entire circumferential clearance section δ.

[0043] <Operation of this embodiment> Next, the effects of this embodiment will be described. That is, in the actuator device 50 of this embodiment, the first shaft end portion 80a of the planetary carrier 80, which is spaced apart from the motor 51, is supported by the rotation shaft 75x of the sun gear 75. This ensures high coaxiality of the planetary carrier 80 with respect to the rotation shaft 75x of the sun gear 75.

[0044] Furthermore, at the second shaft end 80b closer to the motor 51, the outer peripheral surface 87s of the peripheral wall portion 87 located at the radially outer side thereof is supported by a rotation support portion 100 provided on the support member 78 of the ring gear 76. As a result, the planetary carrier 80 is stably supported in a so-called double-supported state at the first shaft end 80a and the second shaft end 80b spaced apart in the axial direction.

[0045] Furthermore, the support positions of the planetary carrier 80 set at the first shaft end 80a and the second shaft end 80b are each spaced apart from the motor 51. Therefore, vibrations of the motor 51 are less likely to be transmitted to the planetary carrier 80.

[0046] <Effects of this embodiment> Next, the effects of this embodiment will be described. (1) The actuator device 50 includes a motor 51 serving as a drive source, a sun gear 75 that is rotationally driven by the motor 51 and is positioned coaxially with a motor shaft 73, and a ring gear 76 that is coaxially positioned radially outward of the sun gear 75. The actuator device 50 also includes a support member 78 that non-rotatably supports the ring gear 76, planetary gears 79 that mesh with the sun gear 75 and the ring gear 76, and a planetary carrier 80 that supports the planetary gears 79 rotatably and revolvably. A first shaft end 80a of the planetary carrier 80 that is spaced apart from the motor 51 is supported by a rotation shaft 75x of the sun gear 75. A radially outer position of a second shaft end 80b of the planetary carrier 80 that is closer to the motor 51 is supported by a rotation support portion 100 provided on the support member 78 of the ring gear 76.

[0047] According to the above configuration, the first shaft end 80a of the planetary carrier 80 is journaled on the rotation shaft 75x of the sun gear 75, thereby ensuring high coaxiality of the planetary carrier 80 with respect to the rotation shaft 75x of the sun gear 75. Furthermore, by supporting the radially outer position of the second shaft end 80b with the rotation support portion 100 provided on the support member 78, assembly is facilitated and the planetary carrier 80 can be stably supported in a so-called double-supported state. Furthermore, because the support positions of the planetary carrier 80 set on the first shaft end 80a and the second shaft end 80b are each spaced apart from the motor 51, vibrations of the motor 51 are less likely to be transmitted to the planetary carrier 80. This ensures high quietness. Additionally, by utilizing the compact support structure in which the first shaft end 80a of the planetary carrier 80 is journaled on the rotation shaft 75x of the sun gear 75, the device can be made more compact.

[0048] (2) In the actuator device 50, the axial section between the tooth portion 83 of the sun gear 75 and the shaft end portion 51a of the motor 51 is set to be a full circumferential clearance section δ. In this full circumferential clearance section δ, a gap ε is provided radially outward of the sun gear 75 and the motor shaft 73 around the entire circumference of the sun gear 75 and the motor shaft 73.

[0049] According to the above configuration, it is possible to suppress the occurrence of so-called "twisting" around the rotation axis 75x of the sun gear 75, which rotates coaxially with the motor shaft 73. This also makes it possible to improve quietness.

[0050] (3) The actuator device 50 has a sun gear 75 configured as a helical gear 85 with a small number of teeth. According to the above configuration, the frequency of the noise generated at the meshing portion of the planetary gear mechanism 72 as the sun gear 75 rotates due to motor drive, that is, the so-called "mesh frequency," can be kept low, thereby ensuring high quietness.

[0051] Furthermore, by using a small-tooth-count helical gear 85 for the sun gear 75, a high reduction ratio can be ensured with the single-stage planetary gear mechanism 72. Furthermore, the diameter of the sun gear 75 can be reduced, thereby enabling the device to be made more compact.

[0052] In addition, by taking advantage of the small diameter of sun gear 75, motor 51 can be assembled with sun gear 75 fixed to tip 73a of motor shaft 73. This improves the efficiency of the manufacturing process, including motor 51, which serves as the drive source.

[0053] (4) The planetary carrier 80 has an outer peripheral surface 87s of a peripheral wall portion 87 having a substantially cylindrical outer shape, which is disposed radially outward from the second shaft end portion 80b. The support member 78 of the ring gear 76 is provided with a circular recess 98 at the second shaft end portion 80b of the planetary carrier 80, the circular recess 98 having an inner peripheral surface 98ss that faces the outer peripheral surface 87s of the peripheral wall portion 87. In the actuator device 50, the inner peripheral surface 98ss of the circular recess 98 forms a peripheral surface that extends in the circumferential direction, thereby forming a rotation support portion 100.

[0054] According to the above configuration, the inner peripheral surface 98ss of the circular recess 98 provided in the support member 78 of the ring gear 76 functions as a sliding bearing. This makes it possible to stably support the planetary carrier 80 while favorably supporting the radial load of the second shaft end portion 80b with a simple configuration.

[0055] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0056] In the above embodiment, the support member 78 of the ring gear 76 is provided with a bottom portion 96 having a circular recess 98. Furthermore, the inner peripheral surface 98ss of the circular recess 98 forms a peripheral surface that extends in the circumferential direction and faces the radially outer position of the second shaft end portion 80b of the planetary carrier 80. This allows the circular recess 98 to function as a rotation support portion 100.

[0057] However, the present invention is not limited to this, and the configuration of the rotation support portion 100 provided on the support member 78 of the ring gear 76 may be changed as desired. For example, a bearing formed separately from the support member 78 of the ring gear 76 may be provided on the support member 78 of the ring gear 76. Then, this bearing may be configured as the rotation support portion 100.

[0058] Furthermore, such a bearing may be provided on the first shaft end portion 80a of the planetary carrier 80. The first shaft end portion 80a of the planetary carrier 80 may then be supported on the rotation shaft 75x of the sun gear 75 via this bearing.

[0059] In the above embodiment, the planetary carrier 80 has a generally cylindrical outer shape with a bottom. However, the shape of the planetary carrier 80 is not limited to this, and may be changed as desired. For example, the radially outer position of the second shaft end portion 80b supported by the rotation support portion 100 provided on the support member 78 of the ring gear 76 does not necessarily have to be the outer peripheral surface 87s of the peripheral wall portion 87.

[0060] The configuration of the support member 78 for the ring gear 76 may also be changed as desired. For example, in the above embodiment, the support member 78 having a substantially cylindrical outer shape with a bottom and the ring gear 76 are integrally formed, but the ring gear 76 and the support member 78 may be formed separately. Also, the support member 78 may not have a bottom 96. The ring gear 76 may be supported non-rotatably by a support member 78 having an outer shape other than a cylindrical shape.

[0061] In the above embodiment, the sun gear 75 is configured as a small-tooth-count helical gear 85. The number of teeth of this small-tooth-count helical gear 85 is two. However, the number of teeth of the small-tooth-count helical gear 85 used in the sun gear 75 may be changed to, for example, three or four. In other words, from the perspective of improving quietness, it is preferable that the number of teeth of this small-tooth-count helical gear 85 be four or less.

[0062] In the above embodiment, the sun gear 75 includes a shaft fitting portion 84 provided at the base end 83b of the tooth portion 83. The shaft fitting portion 84 is fitted to the tip end 73a of the motor shaft 73 so as to be non-rotatable relative to the tip end 73a, thereby rotating coaxially with the motor shaft 73.

[0063] However, the present invention is not limited to this, and as in an actuator device 50B shown in FIG. 9, a helical gear 85B with a small number of teeth that serves as a sun gear 75B may be formed integrally with a motor shaft 73B.

[0064] According to the above configuration, the shaft fitting portion 84 of the sun gear 75B is not necessary, and therefore the axial length of the motor shaft 73B protruding from the shaft end portion 51a of the motor 51 can be shortened. As a result, the motor 51 can be disposed closer to the planetary gear mechanism 72 that constitutes the speed reducer 52. This also contributes to the miniaturization of the device.

[0065] In the above embodiment, the actuator device 50 of the door device 10 opens and closes the flip-up type back door 5 based on the operation of the linear drive unit 65 formed by the spindle screw 61 and the spindle nut 62.

[0066] However, the present invention is not limited to this, and may be applied to a door device 10 that opens and closes a door of the vehicle 1 other than the flip-up type back door 5, such as a swing door. Furthermore, the present invention may be applied to a vehicle opening / closing body drive device that includes an opening / closing body other than a door, such as a trunk lid or a bonnet hood. Furthermore, the present invention may be applied to a linear actuator device 70 that is used for purposes other than the vehicle 1.

[0067] The configuration of the linear drive unit 65 may be changed as desired. It does not necessarily have to include the spindle screw 61 and the spindle nut 62. For example, it may be configured to use a rack and pinion mechanism, a hydraulic cylinder, or the like. Furthermore, it is not necessarily required that the axial length L be expandable. In other words, the linear drive unit 65 may be configured to convert the rotation output of the actuator device 50 into an axial displacement output. The linear drive unit 65 may also be applied to a vehicle opening / closing body drive device that does not include such a linear drive unit 65.

[0068] Furthermore, with regard to the power back door device 71 that opens and closes the flip-up back door 5 using the door device 10 equipped with the actuator device 50 and linear drive unit 65 similar to those of the above embodiment, the number and arrangement of the door devices 10 used may also be arbitrary. For example, a pair of left and right door devices 10, 10 provided at both ends of the width of the door opening 3 may be used to support both sides of the back door 5 in the vehicle width direction. Alternatively, a door device 10 equipped with the actuator device 50 and linear drive unit 65 may be provided at one end of the door opening 3 in the width direction, and a so-called stabilizer without a drive function may be provided at the other end of the width direction. As a result, the door device 10 provided on one side extends and contracts in conjunction with the extension and contraction of the door device 10 provided on the other side, thereby opening and closing the back door 5 with both sides of the vehicle width supported.

[0069] <Additional Notes> Next, the technical ideas that can be understood from the above-described embodiment and modified examples will be described. (i) The axial section between the tooth portion of the sun gear and the shaft end of the motor is defined as a full-circumferential clearance section, and in this full-circumferential clearance section, a gap is provided radially outside the sun gear and the motor shaft around the entire circumference of the sun gear and the motor shaft.

[0070] According to the above configuration, it is possible to suppress so-called "twisting" around the rotation axis of the sun gear that rotates coaxially with the motor shaft, thereby improving quietness.

[0071] (b) The sun gear is a helical gear with a small number of teeth. With the above configuration, the frequency of the noise generated at the meshing portion of the planetary gear mechanism as the sun gear rotates due to motor drive, that is, the so-called "mesh frequency," can be kept low. Note that the "small number of teeth helical gear" in this case refers to a helical gear with four or fewer teeth. This ensures high quietness.

[0072] Furthermore, by using a helical gear with a small number of teeth for the sun gear, a high reduction ratio can be achieved with a single-stage planetary gear mechanism.Furthermore, the diameter of the sun gear can be made smaller, which in turn allows for a more compact device.

[0073] In addition, by taking advantage of the small diameter of the sun gear, the motor can be assembled with the sun gear fixed to the end of the motor shaft, thereby improving the efficiency of manufacturing the motor, which serves as the drive source.

[0074] (c) The small-tooth helical gear is integrally formed with the motor shaft. With the above configuration, the axial length of the motor shaft can be shortened because there is no need to fix the small-tooth helical gear that constitutes the sun gear to the motor shaft. As a result, the motor can be located closer to the planetary gear mechanism that constitutes the reducer. This allows for a more compact device.

[0075] (iv) The rotation support portion is a peripheral surface extending in the circumferential direction and facing a radially outer position of the second shaft end portion. According to the above configuration, the peripheral surface of the support member for the ring gear functions as a plain bearing, which allows the planetary carrier to be rotatably supported stably while favorably bearing the radial load of the second shaft end with a simple configuration.

[0076] (e) A vehicle opening / closing body drive device including the actuator device. (f) A linear actuator device comprising the actuator device and a linear drive unit that converts the rotational output of the actuator device into an axial displacement output. [Explanation of symbols]

[0077] 50...actuator device, 51...motor, 73...motor shaft, 75...sun gear, 75x...rotating shaft, 76...ring gear, 78...support member, 79...planetary gear, 80...planetary carrier, 80a...first shaft end, 80b...second shaft end, 87...circumferential wall portion, 87s...outer peripheral surface (radially outer position), 100...rotation support portion.

Claims

1. a motor serving as a drive source; a sun gear that is coaxial with the motor shaft and is rotationally driven by the motor; a ring gear disposed coaxially radially outside the sun gear; a support member that supports the ring gear so that it cannot rotate; a planetary gear meshing with the sun gear and the ring gear; a planetary carrier that supports the planetary gear so that the planetary gear can rotate and revolve; Equipped with The planetary carrier is a first shaft end portion spaced apart from the motor is supported by a rotation shaft of the sun gear; An actuator device in which a radially outer position of a second shaft end portion close to the motor is supported by a rotation support portion provided on the support member.

2. an axial section between the teeth of the sun gear and a shaft end of the motor is defined as a full circumferential clearance section, In the full-circumferential clearance section, a gap is provided radially outward of the sun gear and the motor shaft over the entire circumference of the sun gear and the motor shaft. The actuator device according to claim 1 .

3. The sun gear is a helical gear with a small number of teeth. The actuator device according to claim 1 or 2.

4. The small-tooth helical gear is integral with the motor shaft. The actuator device according to claim 3 .

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