Worm wheel driving device and internally hollow swivel actuator using same

Abstract

The present invention relates to a worm wheel driving device and an internally hollow swivel actuator using same, wherein the worm wheel driving device has a slim structure by transmitting rotational forces from first and second motor driving units to a worm wheel through first and second worm gears, respectively, and by directly connecting a car seat to the top of the worm wheel. The worm wheel driving device according to the present invention comprises: an actuator housing having a hollow cylindrical part protruding upward from the center of the housing; and first and second motor driving units which are arranged on both sides of the bottom surface of the actuator housing, face the hollow cylindrical part, have first to fourth driving motors formed on opposite ends of first and second rotary shafts, respectively, and have first and second worm gears integrally formed on the centers of the first and second rotary shafts to generate the rotation outputs of the first to fourth driving motors, wherein the first and second worm gears respectively mesh with the opposite side surfaces of the worm wheel, which is rotatably supported on the outer circumference of the hollow cylindrical part, thereby enabling torque conversion via speed reduction.

Description

Worm wheel drive device and internal hollow swivel actuator using the same

[0001] The present invention relates to an internal hollow swivel actuator, and more particularly, to a worm wheel driving device capable of realizing a slim structure by transmitting the rotational power of first and second motor driving units to a large-diameter worm wheel through first and second worm gears, respectively, and directly connecting a car seat to the upper end of the worm wheel, and to an internal hollow swivel actuator using the same.

[0002] An electric actuator converts the rotational force generated from a rotational power source into torque, and uses the high-torque rotational force to rotate or linearly move a driven body.

[0003] Meanwhile, recently, a swivel actuator has been used to rotate the passive body (i.e., the car seat) left and right together with a turntable as an actuator for rotating the car seat left and right.

[0004] Considering that conventional car seat actuators use a DC motor laid down inside a low-height housing, a swivel actuator having a compact and slim structure is proposed by vertically installing an Al motor-type BLDC motor on the bottom of the housing and installing a reduction gear train on the top.

[0005] However, conventional swivel actuators have a complex housing structure and an overall slim structure cannot be realized because the drive motor is placed at the bottom of the housing, the reducer is placed in the middle, and the rotary table with the ring gear formed inside is placed at the top.

[0006] In addition, various types of reducers are applied for torque conversion, and among these, the cycloid type reducer has the advantages of a high reduction ratio and low backlash for its size, but has the problem of poor mass productivity due to its complex structure and inability to realize a miniaturized and slim structure.

[0007] Moreover, since a single drive motor arranged on one side of a reducer is used to provide rotational force to a reducer gear stage through a worm gear formed integrally on an output shaft, when the drive motor is assembled into a reducer gear module, the actuator's outer shape becomes larger on one side, and when force is applied, the output shaft of the drive motor is biased on one side, which may cause a problem in that it cannot support the force.

[0008] Accordingly, the present invention has been proposed to solve the problems of the above-mentioned prior art, and its purpose is to provide a worm wheel driving device capable of supporting a large load by stably driving a worm wheel by transmitting the rotational power of the first and second motor driving units to a large-diameter worm wheel through the first and second worm gears, and an internal hollow swivel actuator using the same.

[0009] Another object of the present invention is to provide a worm wheel drive device capable of simplifying the overall structure and realizing a slim structure by gear-engaging first and second worm gears of first and second motor drive units facing the worm wheel located at the center of the actuator housing and directly connecting a car seat to the upper part of the worm wheel, and an internal hollow swivel actuator using the same.

[0010] Another object of the present invention is to provide a worm wheel drive device capable of realizing an overall slim structure by arranging a motor drive unit and a worm wheel on the same plane inside a cylindrical housing, and an internal hollow swivel actuator using the same.

[0011] Another object of the present invention is to provide an internal hollow swivel actuator that provides a structure capable of preventing damage even when a large external force is applied to a rotation shaft by stably accommodating and supporting a motor housing of a motor drive unit in an actuator housing.

[0012] Another object of the present invention is to provide a worm wheel drive device that can freely increase the number of drive motors according to the required torque and does not require a complex reduction gear train by transmitting the rotational power of the motor drive unit to the worm wheel to which the car seat is directly connected, and an internal hollow swivel actuator using the worm wheel drive device.

[0013] Another object of the present invention is to provide an internal hollow swivel actuator that can eliminate tolerances occurring when gears are engaged and make backlash zero by suppressing left-right displacement in the housing using set screws at both ends of the first and second rotary shafts.

[0014] In order to achieve the above object, a worm wheel drive device for a swivel actuator according to one feature of the present invention comprises: an actuator housing having a hollow cylindrical portion protruding upward in the center; a first motor drive unit disposed on one side of the bottom surface of the actuator housing so as to face the hollow cylindrical portion, and having first and second drive motors formed at rear ends of first and second rotational axes which are disposed separately from each other on the same line, and having both ends of a first worm gear which generates rotational output of the first and second drive motors between the first and second rotational axes connected; And a second motor drive unit including a third and fourth drive motors formed at the rear ends of third and fourth rotation shafts which are arranged opposite to the hollow cylindrical portion on the other side of the bottom surface of the actuator housing and are arranged separately from each other on the same line, and a second worm gear having both ends connected to generate the rotational output of the third and fourth drive motors between the third and fourth rotation shafts; wherein the first and second worm gears are gear-coupled to opposite sides of a worm wheel which is rotatably supported on the outer periphery of the hollow cylindrical portion, respectively, so that torque conversion according to deceleration is performed.

[0015] The first motor drive unit includes first and second drive motors formed at rear ends of the first and second rotation shafts, which are arranged separately on the same line, and rotate the first and second rotation shafts in opposite directions; and a first worm gear, which has both ends connected between the first and second rotation shafts and generates a joint rotational output of the first and second drive motors; and the second motor drive unit includes third and fourth drive motors formed at rear ends of the third and fourth rotation shafts, which are arranged separately on the same line, and rotate the third and fourth rotation shafts in opposite directions; and a second worm gear, which has both ends connected between the third and fourth rotation shafts and generates a joint rotational output of the third and fourth drive motors; wherein the first worm gear and the second worm gear can be rotated in opposite directions.

[0016] In this case, the first to fourth driving motors may each be configured as BLDC motors with an inner rotor-outer stator structure.

[0017] In addition, the first to fourth driving motors each include a rotation shaft; a rotor integrally formed on the outer periphery of the rotation shaft; a stator disposed outside the rotor with an air gap therebetween to rotate the rotor; a front end housing coupled to a front end of the stator; a rear end housing coupled to a rear end of the stator; and a bearing accommodated inside the rear end housing to rotatably support the rear end of the rotation shaft; wherein the front end housing, the stator, and the rear end housing are mutually fixed by fastening means coupled to through holes provided at each of the four corners, and the stator can be exposed to the outside.

[0018] Furthermore, the first to fourth drive motors may further include an auxiliary printed circuit board in which parallel or series circuit connections of the U, V, and W three-phase coils and a neutral point formation in a Y-connection manner are formed so that drive control can be performed in a U, V, and W three-phase drive manner, respectively.

[0019] A worm wheel drive device for a swivel actuator according to the present invention may further include an annular upper cover having a through hole formed in the center through which the upper end of the worm wheel protrudes, and an outer peripheral portion of which is fixed to the upper end of the actuator housing to cover the upper end of the actuator housing.

[0020] In the present invention, a car seat can be mounted on the upper part of the worm wheel.

[0021] According to another feature of the present invention, a worm wheel drive device for a swivel actuator comprises: an actuator housing having a hollow cylindrical portion protruding upward at the center; a first motor drive unit disposed on one side of the bottom surface of the actuator housing so as to face the hollow cylindrical portion, wherein first and second drive motors are formed at each end of a first rotational shaft, and a first worm gear that generates rotational output of the first and second drive motors is integrally formed at the center of the first rotational shaft; And a second motor drive unit is disposed opposite the hollow cylindrical portion on the other side of the bottom surface of the actuator housing, and third and fourth drive motors are formed at each end of the second rotation shaft, and a second worm gear that generates the rotational output of the third and fourth drive motors is integrally formed at the center of the second rotation shaft; wherein the first and second worm gears can be gear-coupled to opposite sides of a worm wheel that is rotatably supported on the outer periphery of the hollow cylindrical portion, respectively.

[0022] In this case, the first rotation axis is divided into three or two central portions in which the first and second rotors and the worm gear are formed, and can be assembled using a D-cut structure.

[0023] A worm wheel drive device for a swivel actuator according to the present invention further includes a ring-shaped upper cover having a through hole formed in the center through which the upper end of the worm wheel protrudes, and an outer peripheral portion of which is fixed to the upper end of the actuator housing to cover the upper end of the actuator housing, and a car seat for a vehicle can be mounted on the upper end of the worm wheel.

[0024] According to another feature of the present invention, an internal hollow swivel actuator comprises: an actuator housing having a hollow cylindrical portion protruding upward in the center; a first motor drive unit disposed on one side of the bottom surface of the actuator housing so as to face the hollow cylindrical portion, and having first and second drive motors formed at rear ends of first and second rotational shafts which are disposed separately from each other on the same line, respectively, and having both ends of a first worm gear which generates rotational output of the first and second drive motors between the first and second rotational shafts connected; a second motor drive unit disposed on the other side of the bottom surface of the actuator housing so as to face the hollow cylindrical portion, and having third and fourth drive motors formed at rear ends of third and fourth rotational shafts which are disposed separately from each other on the same line, respectively, and having both ends of a second worm gear which generates rotational output of the third and fourth drive motors connected between the third and fourth rotational shafts; A worm wheel rotatably supported on the outer periphery of the hollow cylindrical portion, the first and second worm gears being gear-engaged on the outer periphery to perform deceleration; and an annular upper cover having a through-hole formed in the center through which the upper end of the worm wheel protrudes, the outer end being fixed to the upper end of the actuator housing to cover the upper end of the actuator housing; wherein the worm wheel is characterized in that the first and second worm gears are gear-engaged on opposite sides to perform torque conversion according to deceleration, and a car seat for a vehicle is mounted on the upper end of the worm wheel.

[0025] The first motor drive unit includes first and second drive motors formed at rear ends of the first and second rotation shafts, which are arranged separately on the same line, and rotate the first and second rotation shafts in opposite directions; and a first worm gear, which has both ends connected between the first and second rotation shafts and generates a joint rotational output of the first and second drive motors; and the second motor drive unit includes third and fourth drive motors formed at rear ends of the third and fourth rotation shafts, which are arranged separately on the same line, and rotate the third and fourth rotation shafts in opposite directions; and a second worm gear, which has both ends connected between the third and fourth rotation shafts and generates a joint rotational output of the third and fourth drive motors; wherein the first worm gear and the second worm gear can be rotated in opposite directions.

[0026] In addition, the first to fourth driving motors each include a rotation shaft; a rotor integrally formed on the outer periphery of the rotation shaft; a stator disposed outside the rotor with an air gap therebetween to rotate the rotor; a front end housing coupled to a front end of the stator; a rear end housing coupled to a rear end of the stator; and a bearing accommodated inside the rear end housing to rotatably support the rear end of the rotation shaft; wherein the stator can be exposed to the outside.

[0027] Furthermore, the rear end housing includes a bearing housing portion in which the bearing is accommodated therein; and a set screw receiving portion that extends from the bearing housing portion and accommodates a set screw therein; wherein the set screw is screw-coupled to the set screw receiving portion, and when the rear end of the set screw is driven from the outside of the actuator housing, the front end presses the rotation shaft to suppress left-right displacement in the actuator housing.

[0028] The rear end housing is assembled so that a portion of the rear end is positioned over a groove formed in a circular wall of the actuator housing, and the set screw can be operated from the outside using a driver.

[0029] The internal hollow swivel actuator according to the present invention further includes first and second bearings installed between the inner circumference of the hollow cylindrical portion and the worm wheel to rotatably support the worm wheel; and the worm wheel may be inserted between the first and second bearings in the inner circumference and may have an annular protrusion for preventing the first bearing from coming off.

[0030] In this case, the bottom surfaces of the first to fourth driving motors are inserted into the first to fourth through holes formed on the bottom surface of the actuator housing so as to form the same plane as the back surface of the actuator housing, and can be fixed to the bottom surface of the actuator housing using a plurality of brackets protruding outward from each of the front end housing and the rear end housing.

[0031] As described above, in the present invention, the rotational power of the first and second motor drive units is transmitted to the worm wheel through the first and second worm gears, respectively, thereby stably driving the worm wheel and supporting a large load.

[0032] In addition, in the present invention, the first and second worm gears of the first and second motor drive units are gear-coupled to face the worm wheel located at the center of the actuator housing, and the car seat is directly connected to the upper part of the worm wheel, thereby simplifying the overall structure and realizing a slim structure.

[0033] As a result, in the present invention, the rotational power of the motor drive unit can be directly transmitted to the car seat through the worm wheel without going through a complex reduction gear train, and the upper part of the actuator housing can be used to block foreign substances from penetrating inside by covering the internal parts with an upper cover without a ring gear.

[0034] Moreover, in the present invention, a slim structure can be realized by arranging the motor drive unit and the worm wheel on the same plane inside a cylindrical housing.

[0035] In addition, in the present invention, the housings of the first and second motor driving units are stably accommodated and supported in the actuator housing, thereby preventing damage even when a large external force is applied.

[0036] In the present invention, by using set screws at both ends of the rotational shaft of the motor drive unit to suppress left-right displacement in the housing, the tolerance occurring when gears are coupled can be eliminated and backlash can be made zero.

[0037] Furthermore, the present invention has a structure that enables even distribution of force and stable acceptance of force by dividing the length of one motor into two halves and arranging two bearings at both ends of the rotational shaft. Furthermore, it is also possible to configure the rotational shaft of the motor drive unit as a rotational shaft assembled with two motor rotational shafts and a worm gear at the center.

[0038] In addition, in the present invention, a worm gear is placed at the center of the first and second rotary shafts that are driven by the first and second motor driving units to drive the worm wheel, thereby providing a structure that is more stable with respect to vibration and noise.

[0039] The first to fourth drive motors have rear end housings fixedly installed in four parts of the actuator housing, and both ends of the first and second rotary shafts are rotatably supported by four bearings arranged inside the rear end housing, thereby providing stability when driving the worm gear.

[0040] Moreover, in the present invention, the number of drive motors for driving the worm wheel can be freely increased according to the size of the required torque, and for example, it can be composed of two pairs of motors (i.e., four motors) or one pair of motors (i.e., two motors).

[0041] In addition, the present invention provides a motor drive circuit that drives multiple drive motors using a single motor drive circuit (i.e., a motor controller). The main printed circuit board (PCB) on which the motor drive circuit is mounted may be vertically arranged within the housing or horizontally arranged above or below the first and second motor drive units.

[0042] FIG. 1 and FIG. 2 are a perspective view and a plan view, respectively, of an internal hollow swivel actuator according to a first preferred embodiment of the present invention.

[0043] Figures 3a to 3d are cross-sectional views taken along line AA, line BB, line CC, and line DD of Figure 2, respectively.

[0044] FIG. 4a and FIG. 4b are exploded perspective views illustrating a module-by-module internal hollow swivel actuator and a worm wheel support structure according to a preferred first embodiment of the present invention, respectively.

[0045] FIGS. 5 to 7 are plan views showing the state in which the upper cover of the internal hollow swivel actuator according to the first to third preferred embodiments of the present invention is removed, respectively.

[0046] FIGS. 8A to 8E are a plan view, a cross-sectional view taken along line EE of FIG. 8A, a cross-sectional view taken along line FF of FIG. 8A, an exploded view by module, and a completely exploded perspective view, respectively, of a worm wheel drive device according to a preferred embodiment of the present invention.

[0047] Hereinafter, a preferred embodiment according to the present invention will be described with reference to the attached drawings.

[0048] In this process, the sizes and shapes of components depicted in the drawings may be exaggerated for clarity and convenience. Furthermore, terms specifically defined in consideration of the structure and operation of the present invention may vary depending on the intent or custom of the user or operator. Definitions of these terms should be based on the content throughout this specification.

[0049] The internal hollow swivel actuator according to the present invention is used to rotate a passive body, i.e., a car seat, left and right. By installing the swivel actuator on a lower plate fixed to the floor of the vehicle and fixing the car seat to the upper portion of a worm wheel, the car seat can rotate in accordance with the rotation of the worm wheel.

[0050] The following description describes an internal hollow swivel actuator that uses a BLDC type drive motor as a power source to drive a car seat as a driven body.

[0051] The internal hollow swivel actuator according to the present invention comprises a single actuator housing, a worm wheel drive device, and a worm wheel, and is configured as an integrated body in which a vehicle seat is directly connected to the upper portion of the worm wheel, thereby solving the problems of the prior art while achieving miniaturization and slimming.

[0052] In addition, the internal hollow swivel actuator according to the present invention is formed in a disk shape, and has a hollow cylindrical portion for cable extraction formed in the center of the internal hollow portion, from which a cable is extracted, and a plurality of assembly screw taps, for example, 3 to 6, are formed on the upper portion of the worm wheel to connect with a driven body (car seat), so that the actuator can be fixed to the car seat by fastening a fixing bolt.

[0053] In the present invention, a plurality of driving motors are arranged inside an actuator housing, and a large-diameter worm wheel arranged in the center is rotated by the rotational force of the driving motors, and a car seat is directly connected to the upper end of the worm wheel, thereby eliminating a spur gear or planet gear for reduction or power transmission arranged in the middle stage of a conventional swivel actuator, and instead of a rotary table arranged at the upper end and having a ring gear integrally formed on the inner outer periphery, an upper plate or upper cover for simply covering the upper part of the actuator housing can be applied.

[0054] First, referring to FIGS. 1 and 2, an internal hollow swivel actuator (200) according to a first preferred embodiment of the present invention comprises: an actuator housing (10) having a hollow cylindrical portion (11) protruding upward in the center; first and second motor drive units (100a, 100b) which are arranged on both sides of a bottom surface (10f) of the actuator housing (10), and in which first to fourth drive motors (101-104) are formed at both ends of first and second rotation axes (34; 34a, 34b), respectively, and first and second worm gears (35a, 35b) which generate rotational outputs of the first to fourth drive motors (101-104) are integrally formed at the centers of the first and second rotation axes (34; 34a, 34b), respectively; It includes a worm wheel (70) that is rotatably supported on the outer periphery of the hollow cylindrical portion (11) and gear-coupled to the first and second worm gears (35a, 35b) on the outer periphery to perform deceleration; and an annular upper cover (20) that has a through hole formed in the center and has an outer periphery that is fixed to the upper portion of the actuator housing (10) to cover the upper portion of the actuator housing (10).

[0055] The internal hollow swivel actuator (200) is described in detail below.

[0056] First, the worm wheel driving device (110) according to the present invention includes first and second motor driving units (100a, 100b) arranged oppositely on both sides of a large-diameter worm wheel (70) arranged at the center of the bottom surface (10f) of the actuator housing (10), as shown in FIGS. 4a to 5.

[0057] The first and second motor drive units (100a, 100b) may each be configured using one common rotational axis, or, as shown in FIG. 8d, one common rotational axis may be divided to use one first and second rotational axis (34a, 34b) for each of the first to fourth drive motors (101-104), and the first rotational axis (34a) and the second rotational axis (34b) may be connected using the first or second worm gear (35a, 35b).

[0058] In the following description of the embodiment, an example is given in which one common rotation axis is divided into a first rotation axis (34a) and a second rotation axis (34b) for each of the first and second motor drive units (100a, 100b), as shown in FIG. 8d.

[0059] The first motor drive unit (100a) has first and second drive motors (101, 102) formed at the rear ends of first and second rotation axes (34a, 34b) that are arranged separately from each other on the same line, and both ends of a first worm gear (35a) that generates a joint rotational output of the first and second drive motors (101, 102) are connected between the first and second rotation axes (34a, 34b).

[0060] The second motor drive unit (100b) has third and fourth drive motors (103, 104) formed at the rear ends of the first and second rotation axes (34a, 34b) that are arranged separately from each other on the same line as the first motor drive unit (100a), and the two ends of the second worm gear (35b) that generates the joint rotational output of the third and fourth drive motors (103, 104) are connected between the first and second rotation axes (34a, 34b).

[0061] The above first to fourth driving motors (101-104) may be configured as BLDC motors having an inner rotor-outer stator structure, as described below. In this case, the exterior of the stator is configured such that the motor housing is excluded for slimming and heat dissipation, and the stator core is exposed to the outside. At the front and rear ends of the stator, the front end housing and the rear end housing may be assembled to the stator (i.e., the stator core) using fixing bolts or the like.

[0062] Accordingly, the first to fourth driving motors (101-104) are provided with a front housing (91a) that covers the front ends of the first and second stators (40a, 40b) arranged in the central portion, as shown in FIGS. 8a and 8d, respectively, and a rear housing (91b) that covers the rear ends of the first and second stators (40a, 40b).

[0063] The actuator housing (10) above has a hollow cylindrical portion (11) with a through hole (11a) formed in the center thereof protruding and a circular wall (10a) protruding on the outer periphery thereof. On both sides of the circular wall (10a), first to fourth grooves (10b-10e) are arranged at intervals so that a portion of the rear end housing (91b) of each of the first to fourth drive motors (101-104) of the first and second motor drive units (100a, 100b) is cut to hang over them when the first to fourth drive motors (101-104) are installed.

[0064] In addition, the rear end housing (91b) has a stepped portion formed so that the size thereof becomes smaller as it goes toward the rear end, and a stepped portion corresponding to the stepped portion of the rear end housing (91b) is formed on the inner side of the circular wall (10a) in which the first to fourth grooves (10b-10e) are formed, thereby increasing the contact area between the rear end housing (91b) and the actuator housing (10), thereby stably supporting the rear end housing (91b).

[0065] When the first to fourth driving motors (101-104) are installed in the actuator housing (10), the first to fourth through holes (12a-12d) are formed in the bottom surface (10f) of the actuator housing (10), and the bottom surfaces of the first to fourth driving motors (101-104) are assembled so as to form the same plane as the back surface of the actuator housing (10), so that the thickness of the swivel actuator (200) can be designed to be reduced as much as possible.

[0066] The first to fourth drive motors (101-104) above have first and second brackets (94a, 94b) formed with fixing through holes on the outside of the front housing (91a) and the rear housing (91b), respectively, protruding, and the first and second brackets (94a, 94b) can be fixed to the bottom surface (10f) of the actuator housing (10) by fastening a fixing bolt (96) to the fixing through holes.

[0067] In addition, a third bracket (95) having a fixing through hole formed therein protrudes from the inside of the rear housing (91b), and a motor fixing protruding fixing part (15) corresponding to the third bracket (95) protrudes from the bottom surface (10f) of the actuator housing (10). A fixing bolt (96) can be fastened to the protruding fixing part (15) through the fixing through hole of the third bracket (95).

[0068] Moreover, as shown in Fig. 8b, a pair of bearings (65, 66) are built into the interior of the rear housing (91b) to rotatably support the first and second rotation axes (34a, 34b) of the first to fourth driving motors (101-104).

[0069] In this case, when the first and second motor drive units (100a, 100b) generate rotational output, the first and second worm gears (35a, 35b) are used to increase the brake torque, and it is desirable to prevent bending or damage of the rear housing (91b) supporting a pair of bearings (65, 66) due to the large external pressure. To this end, the present invention is designed to firmly support the rear housing (91b) on the actuator housing (10) while distributing the external pressure.

[0070] The swivel actuator according to the present invention may be provided with a pair of cable guides (74) to prevent interference between the cable discharged to the outside of the housing through a through hole formed in the bottom surface (10f) of the actuator housing (10) and the worm wheel (70), as shown in FIG. 4a.

[0071] As shown in FIGS. 8a to 8e, the first motor drive unit (100a) according to the present invention has a first worm gear (35a) connected between the first drive motor (101) and the second drive motor (102), and the second motor drive unit (100b) has a second worm gear (35b) connected between the third drive motor (103) and the fourth drive motor (104).

[0072] Specifically, a first rotation shaft (34a) extended from a first drive motor (101) and a second rotation shaft (34b) extended from a second drive motor (102) may be coupled to both ends of a first worm gear (35a) having a hollow shape, and a first rotation shaft (34a) extended from a third drive motor (103) and a second rotation shaft (34b) extended from a fourth drive motor (104) may be coupled to both ends of a second worm gear (35b) having a hollow shape.

[0073] In the present invention, in order to prevent the first to fourth drive motors (101-104) from being bent or damaged by a large external pressure, the rear end housing (91b) of each of the first to fourth drive motors (101-104) is assembled so that a portion thereof hangs over the first to fourth grooves (10b-10e), and the first and second brackets (94a, 94b) are fixed to the outside of the bottom surface (10f) of the actuator housing (10) using a fixing bolt (96), and the third bracket (95) is fastened to the protruding fixing member (15) located on the inside of the bottom surface (10f) by using a fixing bolt (96).

[0074] When the first drive motor (101) and the second drive motor (102) of the first motor drive unit (100a) rotate in, for example, a CW (clockwise) direction, the first worm gear (35a) also rotates in a CW (clockwise) direction, and when the third drive motor (103) and the fourth drive motor (104) of the second motor drive unit (100b) located on the opposite side of the worm wheel (70) rotate in a CCW (counterclockwise) direction, the second worm gear (35b) also rotates in a CCW (counterclockwise) direction.

[0075] As a result, the rotational forces of the first worm gear (35a) and the second worm gear (35b) arranged opposite to one side and the other side of the worm wheel (70) are transmitted to the worm wheel (70), thereby rotating the worm wheel (70) in the same direction.

[0076] In this case, the rotation speeds of the first to fourth drive motors (101-104) and the rotation speeds of the first worm gear (35a) and the second worm gear (35b) are set to relatively high speeds, and the rotation speed of the worm wheel (70) is greatly reduced by the rotational force transmitted to the worm wheel (70), resulting in torque conversion and reduced rotational power with increased torque.

[0077] Accordingly, the vehicle seat (not shown) having the lower part connected to the upper part of the worm wheel (70) is rotated at low speed by the reduced rotational power with increased torque in the same manner as the worm wheel (70).

[0078] In addition, an upper cover (20) is fixedly joined to the upper portion of the actuator housing (10) to prevent foreign substances from penetrating into the housing. To this end, a plurality of through holes (22) for fastening fixing screws are formed on the outer periphery of the upper cover (20), and a protruding fixing portion (16) for fixing the cover, to which the tip of the fixing screw is fastened, is formed on the inside of the actuator housing (10).

[0079] In this case, the uppermost part of the worm wheel (70) needs to protrude a certain length outward through the through hole (21) of the upper cover (20) so that the lower part of the car seat (not shown) can be connected.

[0080] Below, a worm wheel driving device (110) for rotating the worm wheel (70) with torque conversion is described in detail with reference to FIGS. 8a to 8e.

[0081] The worm wheel driving device (110) according to the present invention includes first and second motor driving units (100a, 100b) arranged opposite to each other on one side and the other side with the worm wheel (70) as the center.

[0082] Referring to FIGS. 8a to 8e, the first and second motor driving units (100a, 100b) have the same structure and transmit rotational forces in opposite directions to the worm wheel (70).

[0083] The first motor drive unit (100a) has a first worm gear (35a) connected between the first drive motor (101) and the second drive motor (102), and the second motor drive unit (100b) has a second worm gear (35b) connected between the third drive motor (103) and the fourth drive motor (104).

[0084] Specifically, the first motor drive unit (100a) has a first rotation shaft (34a) extended from the first drive motor (101) and a second rotation shaft (34b) extended from the second drive motor (102) connected to both ends of a first worm gear (35a) having a hollow shape, so that when the first drive motor (101) and the second drive motor (102) rotate in, for example, a CW (clockwise) direction, the first worm gear (35a) also rotates in a CW (clockwise) direction.

[0085] The second motor drive unit (100b) has a first rotation shaft (34a) extended from the third drive motor (103) and a second rotation shaft (34b) extended from the fourth drive motor (104) connected to both ends of a second worm gear (35b) in a hollow shape, so that when the third drive motor (103) and the fourth drive motor (104) rotate in the CCW (counterclockwise) direction, the second worm gear (35b) also rotates in the CCW (counterclockwise) direction.

[0086] It is preferable that the first to fourth driving motors (101-104) above generate the same rotational force, and in this case, the first and second rotational forces of the same magnitude and in opposite directions of the first worm gear (35a) and the second worm gear (35b) arranged opposite to one side and the other side of the worm wheel (70) are transmitted to the worm wheel (70), and accordingly, the worm wheel (70) can be stably rotated in the same direction.

[0087] Conventionally, a single drive motor arranged on one side of a reducer is used to provide rotational force to the reducer gear stage through a worm gear formed integrally on the output shaft. Therefore, when the drive motor is assembled into the reducer gear module, the actuator's outer shape becomes larger on one side, and when force is applied, the output shaft of the drive motor is biased on one side, which may cause a problem in that it cannot support the force.

[0088] However, in the present invention, the first and second worm gears (35a, 35b) arranged in the center of the first and second rotation axes (34a, 34b) are driven by the first to fourth drive motors (101-104) installed at both ends of the first and second rotation axes (34a, 34b), thereby symmetrically driving the worm wheel (70) on both sides, thereby stably supporting a large load.

[0089] In addition, a pair of bearings (65, 66) are installed in the rear end housing (91b) arranged at the rear end of each of the first drive motor (101) and the second drive motor (102) of the first motor drive unit (100a) to rotatably support the first and second rotation shafts (34a, 34b), thereby providing stability when the first and second worm gears (35a, 35b) are rotatably driven.

[0090] Moreover, the third drive motor (103) and the fourth drive motor (104) of the second motor drive unit (100b) are also provided with a pair of bearings (65, 66) in the rear housing (91b) to rotatably support the first and second rotation axes (34a, 34b) in the same manner as the first drive motor (101) and the second drive motor (102) of the first motor drive unit (100a), thereby providing stability when the first and second worm gears (35a, 35b) are rotatably driven.

[0091] As described above, the present invention has a structure in which the length of one motor is divided into two sides and two bearings (65, 66) are placed at the rear ends of the first and second rotation axes (34a, 34b) to ensure uniform distribution of force and stable acceptance of force.

[0092] In addition, in the present invention, the first and second worm gears (35a, 35b) are arranged at the center of the first and second rotary shafts (34a, 34b) that are driven by the first to fourth driving motors (101-104) to drive the worm wheel (70) from both sides, thereby providing a structure that is more stable against vibration and noise.

[0093] Since the first to fourth driving motors (101-104) are arranged on both sides of the actuator housing (10), the shape of the actuator housing (10) can form an overall cylindrical shape.

[0094] Moreover, in the present invention, as illustrated in FIG. 8b, the rear end housing (91b) disposed at the rear end of each of the first to fourth driving motors (101-104) functions as a bearing housing, and by adding a set screw (73a, 73b) to the inside, the left and right movement of the first and second rotation axes (34a, 34b) connected to each other through the first and second worm gears (35a, 35b) can be restricted.

[0095] The above rear end housing (91b) includes a bearing housing portion in which a bearing (65, 66) is accommodated inside, and a set screw accommodation portion that extends into a cylindrical shape with a diameter smaller than the bearing housing portion and accommodates the set screw (73a, 73b) inside.

[0096] The set screw receiving portion of the rear end housing (91b) has a female thread formed in a through hole penetrating from the rear end to the inside. The set screws (73a, 73b) can be screw-connected to the set screw receiving portion of the rear end housing (91b) having the female thread formed therein, so that the tip ends of the two set screws (73a, 73b) push and compress both ends of the first and second rotary shafts (34a, 34b).

[0097] The above set screw (73a, 73b) has a male thread formed on the outer periphery of the body, and a “-” or “+” shaped groove formed on the rear end to accommodate the tip of the driver, and the tip may be formed in a curved or flat shape.

[0098] It is preferable that the above set screws (73a, 73b) be installed in the set screw receiving portions of a pair of rear end housings (91b) coupled to the rear ends of each of the first and second rotation axes (34a, 34b), and it is also possible to install them in only one of the rear end housings (91b) to push the first and second rotation axes (34a, 34b) in one direction to suppress left-right movement.

[0099] As shown in FIGS. 8a to 8e, the first and second motor drive units (100a, 100b) are connected to a first rotation shaft (34a) and a second rotation shaft (34b) via a first worm gear (35a) or a second worm gear (35b) between them, and first to fourth drive motors (101 to 104) are formed on the first rotation shaft (34a) and the second rotation shaft (34b).

[0100] The above first to fourth drive motors (101-104) can each be configured as BLDC motors with an inner rotor-outer stator structure, and since they have the same structure, the first drive motor (101) will be described as an example, and the description of the remaining second to fourth drive motors (102-104) will be omitted.

[0101] The first drive motor (101) includes a first rotation shaft (34a), a first rotor (30a) integrally formed on the outer periphery of the first rotation shaft (34a), a first stator (40a) disposed outside the first rotor (30a) with an air gap, a front end housing (91a) coupled to the front end of the first stator (40a), a rear end housing (91b) coupled to the rear end of the first stator (40a), and a bearing (65) accommodated inside the rear end housing (91b) to rotatably support the rear end of the first rotation shaft (34a).

[0102] In this case, a through hole is formed in the center of the shear housing (91a) to rotatably support the outer circumference of the first rotation shaft (34a).

[0103] The first stator (40a) includes a stator core (45) having a plurality of teeth (41) each having a "T" shape at the front end and a back yoke (42) interconnected with the rear ends of the plurality of teeth (41) to form a magnetic circuit, as shown in FIGS. 8a to 8c; upper and lower insulators (44a, 44b) assembled so as to surround the outer circumference of each of the plurality of teeth (41) from the top and bottom while wrapping around the outer circumference on which the coil (43) is wound; and a coil (43) wound on the outer circumference of the upper and lower insulators (44a, 44b).

[0104] The first stator (40a) is positioned with an air gap between it and the first rotor (30a) and generates a rotating magnetic field to rotate the first rotor (30a).

[0105] In this case, the upper and lower insulators (44a, 44b) may be formed as a bobbin of insulating material that is integrally formed by wrapping the outer surface of each of the plurality of teeth (41) around which the coil (43) is wound, and the bobbin may be integrally formed as a stator support.

[0106] The above first stator (40a) may have a stator core (45) of a symmetrical structure in which a plurality of teeth (41) protrude toward the center from an annular back yoke (42), as shown in FIG. 8c, and may also have a stator core of an asymmetrical structure in which a plurality of teeth protrude toward the center from an asymmetrical back yoke with different lengths, as needed.

[0107] A stator having a stator core of the above-described asymmetrical structure can be used when providing a motor structure for maximizing the use of space within an actuator housing (10). That is, it can be applied when extending the length of a plurality of teeth (41) of the stator and increasing the number of turns of the coil (43) by utilizing the outer space of the first and second rotation axes (34a, 34b).

[0108] The first stator (40a) is formed in such a manner that no housing is formed on the outside of the stator core (45), as shown in FIG. 8c, and the back yoke (42) of the stator core (45) is formed in a rectangular shape overall with each of the four corners (45a) protruding instead of the circular outer periphery, and a through hole (45b) for fastening a fixing bolt is formed in each of the four corners (45a).

[0109] In addition, as shown in Fig. 8e, through holes (92a, 92b) corresponding to the through holes (45b) formed in the four corners (45a) of the stator core (45) are formed in the four corners of the front end housing (91a) and the rear end housing (91b), respectively.

[0110] Accordingly, the first drive motor (101) can be fixed by fastening four fastening means, i.e., fixing bolts (93), so that the front housing (91a), the stator core (45) of the first stator (40a) and the rear housing (91b) pass through the through holes (45b) formed at the four corners (45a) of the stator core (45).

[0111] The first rotor (30a) is composed of a magnet (31a) attached to the outer periphery of the first rotation shaft (34a). The magnet (31a) may be composed of a plurality of N-pole and S-pole split magnet pieces, or a ring-shaped magnet in which the N-pole and S-pole are split into multiple poles and magnetized may be used.

[0112] When the first rotor (30a) is formed of a plurality of N-pole and S-pole split magnet pieces, a plurality of protrusions (32) are formed protruding along the outer periphery of the first rotation shaft (34a), and a plurality of grooves are formed between the plurality of protrusions (32) to which a plurality of magnets (31a) can be attached, and a plurality of magnets (31a) are attached to the plurality of grooves.

[0113] The first and second rotation axes (34a, 34b) on which the first and second rotors (30a, 30b) are formed are manufactured in a divided manner, and then a first worm gear (35a) is connected between the first rotation axes (34a) and the second rotation axes (34b). The connection between the first rotation axes (34a) and the second rotation axes (34b) and the first worm gear (35a) can be assembled using, for example, a keyway connection (press-fitting or inserting a structure for preventing rotation) or a D-cut structure, or another connection method.

[0114] An example of a coupling between the first and second rotation axes (34a, 34b) and the first worm gear (35a) is, for example, as shown in FIG. 8d, a key groove coupling structure in which a key (36) formed on the outer periphery of the first and second rotation axes (34a, 34b) and a key groove formed on the inner periphery of the first worm gear (35a) are coupled.

[0115] In addition, the first and second rotation axes (34a, 34b) of the first and second rotors (30a, 30b) are formed as a single integral body, and the first worm gear (35a) is machined at the center of the single rotation axle, a plurality of magnets (31a, 31b) are fixedly installed at both ends, and the first and second rotors (30a, 30b) can be formed by simultaneously magnetizing two magnets.

[0116] Moreover, when the first to fourth drive motors (101-104) are configured as BLDC motors having an inner rotor-outer stator structure, as shown in FIG. 8e, the coils (43) of the stator may be wound around the stator core (45) in a U, V, W three-phase drive manner, and an auxiliary printed circuit board (PCB) (50a, 50b) necessary for parallel or series circuit connection of the U, V, W three-phase coils and formation of a neutral point in a Y-connection manner may be provided so that drive control can be performed in a 6-step manner.

[0117] In order to form a neutral point of the above Y-connection method, the end wires of each of the U, V, and W three-phase coils are connected in common on an auxiliary printed circuit board (PCB) (50a, 50b), and after the parallel or series circuit connection of the U, V, and W three-phase coils is made, the start wires of each of the U, V, and W three-phase coils are connected to a main printed circuit board (PCB) on which a motor drive circuit (i.e., a motor controller) described below is mounted.

[0118] Additionally, each of the auxiliary printed circuit boards (PCBs) (50a, 50b) may be equipped with a Hall sensor assembly for detecting rotor position information.

[0119] In the present invention, a main printed circuit board (PCB) having a motor drive circuit (i.e., a motor controller) mounted thereon to drive the first and second motor drive units (100a, 100b) may be horizontally placed above or below the first and second motor drive units (100a, 100b), or may be placed in an empty space between the first motor drive unit (100a) and the second motor drive unit (100b).

[0120] The swivel actuator (200) according to the present invention may be configured such that the first to fourth drive motors (101-104) constituting the first and second motor drive units (100a, 100b) may be configured as BLDC motors having an 8-pole-6-slot structure, or as 10-pole-9-slot BLDC motors, as illustrated in FIG. 8c, for example. In this case, when the coils (43) of the first and second stators (40a, 40b) of the first to fourth drive motors (101-104) are wound around six teeth (41), the coils (43) may be wound in a U, V, W three-phase structure, and the end wires of the U, V, W three-phase coils (43) may be connected in a Y-connection or star-connection manner.

[0121] Moreover, the first to fourth drive motors (101-104) may be driven in a 6-step radio wave drive manner using an inverter after receiving a rotor position signal from two or three Hall sensors mounted on a Hall sensor assembly installed on the auxiliary printed circuit board (PCB) (50a, 50b) in a motor drive circuit implemented on the main printed circuit board (PCB), for example.

[0122] In this case, the first and second drive motors (101, 102) arranged in the first motor drive unit (100a) and the third and fourth drive motors (103, 104) arranged in the second motor drive unit (100b) have the same structure and are driven in the same manner, so the following description will describe the operation of the first and second drive motors (101, 102) arranged in the first motor drive unit (100a).

[0123] In order for two drive motors implemented on one rotational axis to drive the rotational axis in the same direction, one of the first and second drive motors (101, 102) must have an opposite rotational direction, so the U-line and the W-line must be changed for one of the first and second stators (40a, 40b).

[0124] This can be solved by equally winding U, V, and W coils (43) on the first and second stators (40a, 40b) of the first and second driving motors (101, 102), respectively, and connecting the U and W lines among the conductive patterns formed on the auxiliary printed circuit board (PCB) (50a, 50b) in reverse.

[0125] First, when two drive motors are positioned symmetrically, the rotation direction of one drive motor and the rotation direction of the other drive motor located on the opposite side must rotate in the opposite direction, so they must rotate in the same direction from the perspective of one rotation axis.

[0126] When two driving motors are positioned symmetrically and the coils are wound in the same winding direction, in order to share the motors, the windings are wound in the same direction and the U-phase, V-phase, and W-phase are connected using the conductive patterns formed on two auxiliary printed circuit boards (PCBs) (50a, 50b) so that the rotation shafts can be driven in the same direction.

[0127] When two driving motors are positioned symmetrically, one driving motor is wound in reverse, and the conductive patterns formed on the auxiliary printed circuit board (PCB) (50a, 50b) are connected to the U phase and the W phase, the W phase and the U phase, and the V phase to the V phase, thereby rotating the rotation shaft in the same direction.

[0128] At this time, the positions of the first and second rotors (30a, 30b), the position of the stator core, etc. must be located on the same line. That is, by using one Hall sensor IC (i.e., Hall sensor assembly) to detect the rotational positions of the first and second rotors (30a, 30b), the positions of the rotor or the stator core, and the U, V, and W lines must be arranged in accordance with the rotational direction.

[0129] The internal hollow swivel actuator (200) according to the present invention generates a high-speed rotational output through the first and second worm gears (35a, 35b) of the first and second motor driving units (100a, 100b), and then transmits the high-speed rotational output to the worm wheel of the worm wheel (70), thereby achieving a large torque conversion by deceleration, thereby obtaining a stable high-torque output, and a car seat directly coupled to the upper portion of the worm wheel (70) can also perform low-speed rotation in the same manner as the worm wheel (70).

[0130] Between the inner circumference of the hollow cylindrical portion (11) and the worm wheel (70), first and second bearings (61, 62) made of ball bearings are inserted to rotatably support the worm wheel (70).

[0131] As shown in FIGS. 3a and 3b, an annular protrusion (70a) is formed on the inner circumference of the worm wheel (70) to prevent the first bearing (61) from coming off, and the annular protrusion (70a) for preventing coming off is inserted between the first and second bearings (61, 62). In addition, a spacer ring (63) necessary for maintaining a gap is inserted between the first bearing (61) and the second bearing (62).

[0132] Furthermore, an upper stopper (64) made of a snap ring is coupled to a groove on the outer periphery of the hollow cylindrical portion (11) to prevent the second bearing (62) from coming off.

[0133] The first and second bearings (61, 62) above may be configured as ball bearings having a plurality of balls inserted between the inner and outer rings, the inner ring being fixed to the outer periphery of the hollow cylindrical portion (11) and the outer ring being fixed to the worm wheel (70).

[0134] The above worm wheel (70) can be formed by having a plurality of coupling holes (72) formed with screw taps inside for coupling with a main body (e.g., an electric seat) that is a passive body installed on the worm wheel (70).

[0135] In addition, an upper cover (20) is fixedly joined to the upper portion of the actuator housing (10) to prevent foreign substances from penetrating into the housing. A plurality of through holes (22) are formed on the outer periphery of the upper cover (20), and when a fixing screw is fastened to the through holes (22), the tip portion is fastened to a protruding fixing member (16) for fixing the cover inside the actuator housing (10).

[0136] A central through hole (11a) is formed in the inner portion of the hollow cylindrical portion (11) above, through which a cable passes to transmit an actuator driving command according to the user's operation of the car seat control button to the main printed circuit board (PCB) of the motor driving circuit installed inside the actuator housing (10).

[0137] The above cable can be introduced downward through the hollow cylindrical portion (11) of the actuator housing (10) and then connected to the main printed circuit board (PCB) through a through hole formed in the bottom of the actuator housing (10).

[0138] The motor drive circuit for driving the first to fourth drive motors (101-104) constituting the first and second motor drive units (100a, 100b) is mounted on a main printed circuit board (PCB) installed inside the actuator housing (10), and the first to fourth drive motors (101-104) are each provided with auxiliary printed circuit boards (PCBs) (50a, 50b) necessary for parallel or series circuit connection of U, V, W three-phase coils (43) and formation of a neutral point in a Y-connection manner.

[0139] The operation of the internal hollow swivel actuator (200) according to the present invention will be described below with reference to FIGS. 1 to 8e.

[0140] In the internal hollow swivel actuator (200) of the present invention, when an actuator driving command is transmitted from the outside via a cable, a motor driving signal is generated from a motor driving circuit of a main printed circuit board (PCB) to operate the first and second motor driving units (100a, 100b) installed on both sides of the bottom surface (10f) of the actuator housing (10) via auxiliary printed circuit boards (PCB) (50a, 50b), and the first to fourth driving motors (101-104) of the BLDC type are driven to generate rotational output from the first and second worm gears (35a, 35b) arranged at the center of the first and second rotation axes (34a, 34b).

[0141] The first and second worm gears (35a, 35b) are gear-coupled on opposite sides of the worm wheel (70) and drive the worm wheel (70) rotatably supported on the outer periphery of the hollow cylindrical portion (11) to rotate on both sides, thereby achieving deceleration.

[0142] When the above worm wheel (70) is driven to rotate, the vehicle seat attached to the upper portion of the worm wheel (70) also rotates at the same low speed. As a result, the worm wheel (70) can rotate at a low speed with stable high torque output as a large torque conversion is achieved through torque conversion according to deceleration.

[0143] In the present invention, the first stage reduction ratio (R1) between the first and second worm gears (35a, 35b) of the first to fourth drive motors (101-104) and the worm wheel (70) can be set to 165:1.

[0144] Accordingly, in the swivel actuator (200) of the present invention, for example, when the first to fourth driving motors (101-104) rotate at 330 rpm, if the reduction ratio of the reducer is 165:1, the speed is reduced to 165:1, so that the rotation speed of the worm wheel (70) and the car seat is lowered to a low speed of 2 rpm, and the rotation torque is increased by 165 times, resulting in a large torque increase.

[0145] When the swivel actuator (200) of the present invention is applied to drive a car seat, when conducting a meeting or the like inside a vehicle, it is possible to rotate the car seat to a desired angle so that the passengers can conduct the meeting while facing each other.

[0146] As described above, in the present invention, the first and second motor driving units (100a, 100b) and the worm wheel (70) are arranged on the same plane inside the cylindrical housing (10), and the car seat is directly connected to the upper part of the worm wheel (70), thereby realizing an internal hollow swivel actuator (200) having an overall simplified and slim structure.

[0147] Figures 6 and 7 are plan views showing the state in which the upper cover of the internal hollow swivel actuator according to the second and third preferred embodiments of the present invention is removed, respectively.

[0148] Referring to FIGS. 6 and 7, an internal hollow swivel actuator according to a second and third preferred embodiment of the present invention will be described.

[0149] The difference between the internal hollow swivel actuator (200a, 200b) according to the second and third preferred embodiments of the present invention and the internal hollow swivel actuator (200) according to the first embodiment lies in the number of drive motors (101-104) for rotating the worm wheel (70).

[0150] The internal hollow swivel actuator (200) according to the first embodiment described above has first and second motor drive units (100a, 100b) on both sides of the bottom surface (10f) of the actuator housing (10), and the first motor drive unit (100a) has first and second drive motors (101, 102) formed at both ends of the first and second rotation shafts (34a, 34b), respectively, and a first worm gear (35a) assembled at the center of the first and second rotation shafts (34a, 34b), and the second motor drive unit (100b) has third and fourth drive motors (103, 104) formed at both ends of the first and second rotation shafts (34a, 34b), respectively, similar to the first motor drive unit (100a), and first and second A second worm gear (35b) is assembled at the center of the rotation shaft (34a, 34b).

[0151] The internal hollow swivel actuator (200) according to the first embodiment described above is different in that it configures the first and second motor drive units (100a, 100b) using four drive motors (101-104), but the internal hollow swivel actuator (200a) according to the second embodiment uses two drive motors (102, 104) on opposite sides of the worm wheel (70) to drive the worm wheel (70) by the first and second worm gears (35a, 35b), and the internal hollow swivel actuator (200b) according to the third embodiment uses two drive motors (101, 102) on one side of the worm wheel (70) to drive the worm wheel (70) by one worm gear (35a), and the remaining parts are different in that It is the same as the first embodiment.

[0152] Therefore, when describing the second and third embodiments, descriptions of the same parts as the first embodiment are omitted and only the differences are described.

[0153] First, as shown in FIG. 6, the internal hollow swivel actuator (200a) according to the second embodiment has third and fourth motor driving units (100c, 100d) arranged on opposite sides of the worm wheel (70) to drive rotation of the worm wheel (70) installed in the center of the bottom surface (10f) of the actuator housing (10).

[0154] The third motor drive unit (100c) is gear-coupled with one side of the worm wheel (70) through the first worm gear (35a) connected to the rotation shaft (34b) by the output of the second drive motor (102), and the fourth motor drive unit (100d) is gear-coupled with the other side of the worm wheel (70) through the second worm gear (35b) connected to the rotation shaft (34b) by the output of the fourth drive motor (104).

[0155] In this case, the internal hollow swivel actuator (200a) according to the second embodiment has the second drive motor (102) and the fourth drive motor (104) arranged on one side of the actuator housing (10), so that the first worm gear (35a) connected to the rotational shaft (34b) of the second drive motor (102) rotates in the CW direction, and the second worm gear (35b) connected to the rotational shaft (34b) of the fourth drive motor (104) rotates in the CCW direction, so that the worm wheel (70) rotates in the same direction by the rotational forces of the first worm gear (35a) and the second worm gear (35b) arranged oppositely on one side and the other side.

[0156] The internal hollow swivel actuator (200a) according to the second embodiment of the present invention can be applied when the required torque is not large by reducing the number of driving motors from four to two.

[0157] The internal hollow swivel actuator (200b) according to the third embodiment is provided with a first motor drive unit (100a) on one side of the worm wheel (70) to drive rotation of the worm wheel (70) installed in the center of the bottom surface (10f) of the actuator housing (10), as shown in FIG. 7.

[0158] As described in the first embodiment illustrated in FIG. 5, the first motor drive unit (100a) has first and second drive motors (101, 102) formed at both ends of the first and second rotation shafts (34a, 34b), respectively, and a first worm gear (35a) assembled at the center of the first and second rotation shafts (34a, 34b).

[0159] The internal hollow swivel actuator (200b) according to the third embodiment of the present invention can be applied when the required torque is not large by reducing the number of driving motors from four to two, similar to the third embodiment.

[0160] The internal hollow swivel actuator (200b) according to the third embodiment of the present invention rotates the worm wheel (70) using the first worm gear (35a) provided in the first motor driving unit (100a).

[0161] The above first worm gear (35a) is gear-coupled to the worm wheel (70), and when the first and second driving motors (101, 102) rotate at high speed, deceleration occurs and the vehicle seat installed on the top of the worm wheel (70) also rotates at low speed at the same speed through torque conversion.

[0162] As described above, in the present invention, a large diameter worm wheel (70) is rotatably installed in the central portion, and the number of driving motors can be increased or decreased without increasing the height according to the torque required.

[0163] In the case where the driving motor is placed only in one space of the housing, such as in the internal hollow swivel actuator (200a, 200b) according to the second and third embodiments described above, a main printed circuit board (PCB) with a motor driving circuit mounted thereon may be installed in the empty space, or a height motor, etc. required for driving the seat may be mounted thereon.

[0164] In addition, in the present invention, since there is a lot of empty space on the periphery of the actuator housing, it is possible to form the overall shape of the swivel actuator into a square or asymmetrical structure rather than a circle.

[0165] As described above, in the present invention, a plurality of driving motors are arranged at the bottom of the housing, a worm wheel arranged at the center is rotated by the rotational force of the driving motors, and a car seat is directly connected to the top of the worm wheel, thereby eliminating the spur gear or planet gear for reduction arranged at the middle stage in a conventional swivel actuator, and instead of a rotary table arranged at the top and having a ring gear integrally formed on the inner outer periphery, an upper plate or upper cover without a ring gear can be applied to cover the upper part of the actuator housing.

[0166] As a result, in the present invention, the reducer placed in the middle of the actuator housing can be removed, thereby reducing the height by half compared to the conventional one, and implementing a slim structure with an overall height of 35 mm.

[0167] Additionally, the spur gear or planet gear of the reduction stage can be removed and the ring gear of the rotary table coupled thereto can be removed, thereby increasing the overall assembly productivity.

[0168] Although the present invention has been described and illustrated with specific preferred embodiments as examples, the present invention is not limited to the above embodiments, and various changes and modifications may be made by a person having ordinary skill in the art to which the invention pertains within a scope that does not depart from the spirit of the present invention.

[0169] The swivel actuator according to the present invention can be applied for the purpose of rotating a driven body, such as a car seat, directly connected to the top of a worm wheel left and right.

Claims

1. Actuator housing with a hollow cylindrical portion protruding upward in the center; A first motor drive unit in which first and second drive motors are formed at the rear ends of first and second rotation axes which are arranged opposite to the hollow cylindrical portion on one side of the bottom surface of the actuator housing and are separated from each other on the same line, and both ends of a first worm gear which generates rotational output of the first and second drive motors are connected between the first and second rotation axes; and A second motor drive unit is provided, in which third and fourth drive motors are formed at the rear ends of third and fourth rotation axes, which are arranged opposite to the hollow cylindrical portion on the other side of the bottom surface of the actuator housing and are arranged separately from each other on the same line, and both ends of a second worm gear that generates rotational output of the third and fourth drive motors are connected between the third and fourth rotation axes; A worm wheel drive device for a swivel actuator in which the first and second worm gears are gear-coupled to opposite sides of a worm wheel rotatably supported on the outer periphery of the hollow cylindrical portion, respectively, to convert torque according to deceleration.

2. In paragraph 1, The above first motor drive unit First and second drive motors formed at the rear ends of the first and second rotation axes, which are arranged separately from each other on the same line, and drive the first and second rotation axes in opposite directions; and A first worm gear having both ends connected between the first and second rotational axes and generating a joint rotational output of the first and second driving motors; The above second motor drive unit Third and fourth drive motors formed at the rear ends of the third and fourth rotation axes, which are arranged separately from each other on the same line, and drive the third and fourth rotation axes to rotate in opposite directions; and A second worm gear having both ends connected between the third and fourth rotational axes and generating a joint rotational output of the third and fourth driving motors; A worm wheel drive device for a swivel actuator in which the first worm gear and the second worm gear rotate in opposite directions.

3. In paragraph 1, A worm wheel drive device for a swivel actuator, wherein the first to fourth drive motors are each composed of a BLDC motor with an inner rotor-outer stator structure.

4. In paragraph 1, The first to fourth driving motors are each axis of rotation; A rotor integrally formed on the outer periphery of the above rotating shaft; A stator disposed outside the rotor with an air gap therebetween, generating a rotating magnetic field to rotate the rotor; A front end housing coupled to the front end of the stator; A rear end housing coupled to the rear end of the stator; and A bearing is included inside the rear end housing to rotatably support the rear end of the above-mentioned rotary shaft; A worm wheel drive device for a swivel actuator, wherein the front end housing, the stator, and the rear end housing are mutually fixed by fastening means that are coupled to through holes provided at each of the four corners, and the stator is exposed to the outside.

5. In paragraph 4, A worm wheel drive device for a swivel actuator, wherein the first to fourth drive motors each further include an auxiliary printed circuit board in which parallel or series circuit connections of U, V, and W three-phase coils and a neutral point formation in a Y-connection manner are formed so that drive control can be performed in a U, V, and W three-phase drive manner.

6. In paragraph 1, A worm wheel drive device for a swivel actuator, comprising a through hole formed in the center through which the upper part of the worm wheel protrudes, and further comprising an annular upper cover having an outer peripheral portion fixed to the upper part of the actuator housing to cover the upper part of the actuator housing.

7. In paragraph 1, A worm wheel drive device for a swivel actuator in which a car seat is mounted on the upper part of the above worm wheel.

8. Actuator housing with a hollow cylindrical portion protruding upward in the center; A first motor drive unit is disposed opposite the hollow cylindrical portion on one side of the bottom surface of the actuator housing, and has first and second drive motors formed at each end of the first rotation shaft, and a first worm gear integrally formed at the center of the first rotation shaft to generate rotational output of the first and second drive motors; and A second motor drive unit is disposed opposite the hollow cylindrical portion on the other side of the bottom surface of the actuator housing, and has third and fourth drive motors formed at each end of the second rotation shaft, and a second worm gear that generates rotational output of the third and fourth drive motors is integrally formed at the center of the second rotation shaft. A worm wheel drive device for a swivel actuator in which the first and second worm gears are each gear-coupled to opposite sides of a worm wheel rotatably supported on the outer periphery of the hollow cylindrical portion.

9. In paragraph 8, A through hole is formed in the center through which the upper part of the worm wheel protrudes, and an outer peripheral part is fixed to the upper part of the actuator housing, and further includes an annular upper cover covering the upper part of the actuator housing. A worm wheel drive device for a swivel actuator in which a car seat is mounted on the upper part of the above worm wheel.

10. Actuator housing with a hollow cylindrical portion protruding upward in the center; A first motor drive unit in which first and second drive motors are formed at the rear ends of first and second rotation axes which are arranged opposite to the hollow cylindrical portion on one side of the bottom surface of the actuator housing and are separated from each other on the same line, and both ends of a first worm gear which generates rotational output of the first and second drive motors are connected between the first and second rotation axes; A second motor drive unit in which third and fourth drive motors are formed at the rear ends of third and fourth rotation axes that are arranged opposite to the hollow cylindrical portion on the other side of the bottom surface of the actuator housing and are separated from each other on the same line, and both ends of a second worm gear that generates rotational output of the third and fourth drive motors are connected between the third and fourth rotation axes; A worm wheel rotatably supported on the outer periphery of the hollow cylindrical portion, and having the first and second worm gears engaged with the outer periphery to achieve deceleration; and A through hole is formed in the center through which the upper part of the worm wheel protrudes, and an annular upper cover is fixed to the upper part of the actuator housing and covers the upper part of the actuator housing; The above worm wheel is an internal hollow swivel actuator in which the first and second worm gears are gear-engaged on opposite sides to convert torque according to deceleration, and a car seat is mounted on the upper part of the worm wheel.

11. In paragraph 10, The above first motor drive unit First and second drive motors formed at the rear ends of the first and second rotation axes, which are arranged separately from each other on the same line, and drive the first and second rotation axes in opposite directions; and A first worm gear having both ends connected between the first and second rotational axes and generating a joint rotational output of the first and second driving motors; The above second motor drive unit Third and fourth drive motors formed at the rear ends of the third and fourth rotation axes, which are arranged separately from each other on the same line, and drive the third and fourth rotation axes to rotate in opposite directions; and A second worm gear having both ends connected between the third and fourth rotational axes and generating a joint rotational output of the third and fourth driving motors; The above first worm gear and the second worm gear are an internal hollow swivel actuator that rotates in opposite directions.

12. In paragraph 10, The first to fourth driving motors are each axis of rotation; A rotor integrally formed on the outer periphery of the above rotating shaft; A stator positioned outside the rotor with an air gap between the rotor and the stator to rotate the rotor; A front end housing coupled to the front end of the stator; A rear end housing coupled to the rear end of the stator; and A bearing is included inside the rear end housing to rotatably support the rear end of the above-mentioned rotary shaft; The above stator is an internal hollow swivel actuator exposed to the outside of the front end housing and the rear end housing.

13. In paragraph 12, The above rear end housing A bearing housing portion in which the bearing is accommodated; and It includes a set screw receiving portion that extends from the above bearing housing portion and receives a set screw therein; An internal hollow swivel actuator in which the set screw is screw-connected to the set screw receiving portion and the front end of the set screw presses the rotation shaft when the rear end of the set screw is driven from the outside of the actuator housing, thereby suppressing left-right displacement in the actuator housing.

14. In paragraph 12, Further comprising first and second bearings installed between the inner circumference of the hollow cylindrical portion and the worm wheel to rotatably support the worm wheel; An internal hollow swivel actuator in which the worm wheel is inserted between the first and second bearings on the inner circumference and has an annular protrusion for preventing the first bearing from coming off.

15. In paragraph 10, The bottom surfaces of the first to fourth driving motors are inserted into the first to fourth through holes formed on the bottom surface of the actuator housing so as to form the same plane as the back surface of the actuator housing, An internal hollow swivel actuator that is fixed to the bottom surface of the actuator housing using a plurality of brackets protruding outward from each of the front end housing and the rear end housing.

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