Motor drive system for swivel actuator

Abstract

The present invention relates to a motor drive system for a swivel actuator, capable of driving a sun gear of a reduction gear part by using a single motor drive circuit for two drive motors. A motor drive system according to the present invention comprises: a rotation shaft; a first and a second drive motor arranged on opposite ends of the rotation shaft; and a single motor drive circuit for applying U, V, and W three-phase motor drive signals to each of the first and the second drive motor, wherein the first and the second drive motor respectively comprise: a first and a second rotor arranged on outer circumferential parts of the opposite ends of the rotation shaft; and a first and a second stator respectively having a first and a second coil which are wound thereon in a U / V / W three-phase drive manner, the first coil is wound on multiple teeth provided on a stator core of the first stator in a first direction, and the second coil is wound on multiple teeth provided on a stator core of the second stator in a direction opposite to the first direction.

Description

Motor drive system for swivel actuator

[0001] The present invention relates to a motor drive system, and more particularly, to a motor drive system for a swivel actuator capable of driving a sun gear of a reduction gear section using a single motor drive circuit (controller) with two drive motors installed at both ends of a rotating shaft.

[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 actuators use a DC motor laid down inside a low-height housing, a swivel actuator having a compact and slim structure is proposed in Korean Patent Publication No. 10-2022-0056821 (Patent Document 1) by vertically installing a BLDC motor in the form of an Al motor on the bottom of the housing and installing a gear train for reduction at the top.

[0005] However, Patent Document 1 has a problem in that the housing structure is complex and it is impossible to realize an overall slim structure because the drive motor is placed at the bottom of the housing, the reducer is placed in the middle, and the rotary table 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] The present invention was devised in consideration of the fact that when a single drive motor is placed on one side of a reducer and rotational force is transmitted to the reducer through a worm gear integrally formed with a sun gear or an output shaft, the outer shape of the actuator becomes larger on one side, and when force is received, the rotational axis of the drive motor is tilted to one side, which may cause a problem in that it cannot support the force.

[0009] Accordingly, the present invention has been proposed to solve the problems of the above-mentioned prior art, and its purpose is to provide a motor drive system for a swivel actuator that can drive two drive motors using a single motor drive circuit (controller) when stably driving a sun gear of a reduction gear section by driving a worm gear disposed at the center of a rotational shaft by two drive motors installed at both ends of a single rotational shaft.

[0010] Another object of the present invention is to provide a motor drive system for a swivel actuator capable of driving two drive motors in a single direction using a single motor drive circuit (controller) by reversing the U and W lines among conductive connection wires formed on a printed circuit board (PCB) when applying a motor drive signal from an inverter, when the U, V, and W coils are wound in the same direction on the first and second stators of the first and second drive motors installed at both ends of a single rotation shaft.

[0011] Another object of the present invention is to provide a motor drive system for a swivel actuator capable of driving two drive motors in a single direction using a single motor drive circuit (controller) by winding the U, V, W coils of a first stator and the U, V, W coils of a second stator in different directions in the first and second drive motors installed at both ends of a single rotation shaft.

[0012] In order to achieve the above object, a motor drive system according to one embodiment of the present invention comprises: a single rotary shaft having a worm gear integrally formed at a central portion thereof, in which a rotational output of the motor is generated; first and second drive motors formed at opposite ends of the rotary shaft; and a single motor drive circuit for applying U, V, and W three-phase motor drive signals from an inverter to the first and second drive motors, respectively; wherein the first and second drive motors each have first and second rotors integrally formed at outer peripheries of opposite ends of the single rotary shaft; first and second stators, each having first and second coils formed of a U-phase coil, a V-phase coil, and a W-phase coil wound in a U, V, and W three-phase drive manner on a plurality of teeth provided on each stator core so as to drive the first and second rotors in accordance with the U, V, and W three-phase motor drive signals; And the start terminals of the U-phase coil, the V-phase coil, and the W-phase coil of the first and second coils are connected, and the U-phase, V-phase, and W-phase terminal terminals to which the U, V, and W three-phase motor drive signals are applied are formed on one side, and the common connection wiring is formed on the other side to which the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil are connected so as to form a neutral point (NP) required for Y-connection; It includes first and second auxiliary printed circuit boards; The first stator is characterized in that the first coil is wound in a first direction on a plurality of teeth provided on the stator core, and the second stator is characterized in that the second coil is wound in a direction opposite to the first direction on a plurality of teeth provided on the stator core.

[0013] A motor drive system according to another embodiment of the present invention comprises: a single rotary shaft having a worm gear integrally formed at a central portion thereof, in which a rotational output of the motor is generated; first and second drive motors formed at opposite ends of the rotary shaft; and a single motor drive circuit for applying U, V, and W three-phase motor drive signals from an inverter to the first and second drive motors, respectively; wherein the first and second drive motors each have first and second rotors integrally formed at outer peripheries of opposite ends of the single rotary shaft; first and second stators, each having first and second coils formed of a U-phase coil, a V-phase coil, and a W-phase coil wound on a plurality of teeth provided on each stator core in a U, V, and W three-phase drive manner so as to drive the first and second rotors in accordance with the U, V, and W three-phase motor drive signals; A first auxiliary printed circuit board having a U-phase coil, a V-phase coil, and a W-phase coil, each of which has a start terminal connected to the U-phase coil, a V-phase coil, and a W-phase terminal terminal formed on one side to which the U, V, and W three-phase motor drive signals are applied, and a common connection wiring formed on the other side to which the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil are connected to form a neutral point (NP) required for Y-connection; And a second auxiliary printed circuit board having a first U-phase, V-phase, and W-phase terminal terminal to which the start terminals of the U-phase coil, the V-phase coil, and the W-phase coil of the second coil are connected, a second U-phase, V-phase, and W-phase terminal terminal to which the U, V, and W three-phase motor drive signals are applied, a first connection wire connecting the second U-phase terminal terminal to the first W-phase terminal terminal, a second connection wire connecting the second W-phase terminal terminal to the first U-phase terminal terminal, and a third connection wire connecting the second V-phase terminal terminal to the first V-phase terminal terminal, formed on one side, and a common connection wire connecting the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil to form a neutral point (NP) required for Y-connection on the other side;, wherein the first and second stators are characterized in that the first and second coils are wound in the same direction on a plurality of teeth provided on each stator core.

[0014] A motor drive system according to an embodiment of the present invention may further include a Hall sensor assembly installed on one of the first auxiliary printed circuit board and the second auxiliary printed circuit board to detect a rotor position signal of one of the first rotor and the second rotor and transmit the signal to the motor drive circuit.

[0015] The above motor drive circuit includes a control unit that generates a drive control signal of the first and second drive motors by combining a seat control signal and a rotor position signal from the vehicle body; and an inverter that generates a U, V, W three-phase motor drive signal according to the drive control signal and outputs the U, V, W three-phase motor drive signal to the first and second coils of the first and second drive motors; and the control unit and the inverter can be mounted on a main printed circuit board arranged inside the actuator housing.

[0016] In this case, the worm gear can drive a sun gear for a reducer for a swivel actuator.

[0017] In addition, the sun gear for the above-mentioned reducer is rotatably supported on the outer periphery of the hollow cylindrical portion, and a worm wheel that is gear-coupled to the worm gear to perform primary reduction is arranged on the lower side, and a spur gear that transmits the rotational output of the worm wheel can be formed integrally on the upper side.

[0018] Moreover, the 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.

[0019] The first and second stators each include a stator core having a plurality of teeth each having a "T" shape and a back yoke interconnected with the plurality of teeth to form a magnetic circuit; a bobbin integrally formed to surround an outer surface on which coils of each of the plurality of teeth are wound; and a coil wound on an outer surface of the bobbin; wherein the plurality of teeth and the back yoke may have an asymmetrical structure.

[0020] The first and second stators can drive the rotational direction of the first rotor in the opposite direction to the rotational direction of the second rotor so that the common rotational axis of the first and second rotors rotates in the same direction.

[0021] The motor drive system according to an embodiment of the present invention may further include: first and second motor housings for accommodating first and second rotors and first and second stators at opposite ends of the rotational shaft, respectively; and first and second set screws that are assembled by screwing to opposite ends of the first and second motor housings and have tip ends that press and support the ends of the rotational shaft to suppress movement of the rotational shaft.

[0022] In addition, a motor drive system according to another embodiment of the present invention includes a single rotary shaft having a worm gear integrally formed at a central portion thereof, in which a rotational output of the motor is generated; first and second drive motors formed at opposite ends of the rotary shaft; and a single motor drive circuit for applying U, V, and W three-phase motor drive signals to the first and second drive motors, respectively; wherein the first and second drive motors each include first and second rotors integrally formed at the outer periphery of opposite ends of the single rotary shaft, respectively; And the first and second stators each include first and second coils, each consisting of a U-phase coil, a V-phase coil, and a W-phase coil, wound in a U, V, W three-phase drive manner on a plurality of teeth provided on each stator core to drive the first and second rotors according to the U, V, W three-phase motor drive signals, wherein the first stator winds a first coil in a first direction on a plurality of teeth provided on the stator core, and the second stator winds a second coil in a direction opposite to the first direction on a plurality of teeth provided on the stator core.

[0023] A motor drive system according to another embodiment of the present invention comprises: a single rotary shaft having a worm gear integrally formed at a central portion thereof, wherein a rotational output of the motor is generated; first and second drive motors formed at opposite ends of the rotary shaft; and a single motor drive circuit for applying U, V, and W three-phase motor drive signals to the first and second drive motors, respectively; wherein the first and second drive motors each have first and second rotors integrally formed at the outer periphery of opposite ends of the single rotary shaft, respectively; And the first and second stators each having first and second coils composed of a U-phase coil, a V-phase coil, and a W-phase coil wound on a plurality of teeth provided on each stator core to drive the first and second rotors according to the U, V, and W three-phase motor drive signals, respectively, in a U, V, and W three-phase drive manner, wherein the first and second stators each wind the first and second coils in the same direction on a plurality of teeth provided on each stator core, and when the U, V, and W three-phase motor drive signals are applied to the second coil composed of the U-phase coil, the V-phase coil, and the W-phase coil of the second stator of the second drive motor, the U-phase motor drive signal is applied to the W-phase coil, the W three-phase motor drive signal is applied to the U-phase coil, and the V-phase motor drive signal is applied to the V-phase coil.

[0024] The first and second driving motors may be BLDC motors driven in a 6-step manner.

[0025] As described above, in the present invention, when the worm gear disposed at the center of the rotational shaft is driven by two motors installed at both ends of a single rotational shaft to stably drive the sun gear of the reduction gear unit, the two drive motors can be driven using a single motor drive circuit (controller).

[0026] In addition, in the present invention, when the U, V, and W coils are wound in the same direction on the first and second stators of the first and second drive motors installed at both ends of a single rotation shaft, respectively, when a motor drive signal is applied from an inverter, by connecting the U and W lines among the conductive connection wires formed on a printed circuit board (PCB) in reverse, two drive motors can be driven in a single direction using a single motor drive circuit (controller).

[0027] Moreover, in the present invention, by winding the U, V, W coils of the first stator and the U, V, W coils of the second stator in different directions in the first and second drive motors installed at both ends of a single rotation shaft, two drive motors can be driven in a single direction using a single motor drive circuit (controller).

[0028] In the past, when one drive motor was placed on one side of a reducer to transmit rotational force to the reducer through a sun gear or a worm gear integrally formed with the output shaft, the actuator's outer shape became larger on one side, and when force was applied, the rotational axis of the drive motor was tilted to one side, which may cause a problem in that it could not support the force. However, in the present invention, by driving the worm gear placed in the center of the rotational axis by two drive motors installed on both ends of the rotational axis to stably drive the sun gear, it is possible to support a large load.

[0029] In addition, the present invention has a structure in which the length of one motor is divided into two parts and two bearings are placed at both ends of the rotation shaft to ensure even distribution of force and stable acceptance of force.

[0030] In addition, in the present invention, a worm gear is placed at the center of a rotating shaft driven by the first and second driving motors to drive the sun gear, thereby providing a structure that is more stable against vibration and noise.

[0031] The first and second driving motors are formed inside first and second motor housings that are fixedly installed on one side of the actuator housing, and both ends of the rotation shaft are rotatably supported by a pair of bearings arranged inside the first and second motor housings, thereby providing stability when driving the worm gear.

[0032] FIG. 1 is a perspective view of an internal hollow swivel actuator to which a motor driving device according to a preferred embodiment of the present invention is applied.

[0033] FIG. 2 and FIG. 3 are a perspective view of a rotary table of a swivel actuator to which a motor drive device according to a preferred embodiment of the present invention is applied, and a plan view of FIG. 2 with the rotary table removed, respectively.

[0034] Figure 4 is an exploded perspective view of each module of an internal hollow swivel actuator to which a motor driving device according to a preferred embodiment of the present invention is applied.

[0035] FIGS. 5 and 6 are a perspective view of a rotary table of another swivel actuator to which a motor drive device according to a preferred embodiment of the present invention is applied, and a plan view of FIG. 5 with the rotary table removed, respectively.

[0036] FIGS. 7A to 7C are a plan view, a cross-sectional view taken along line EE of FIG. 7A, and a cross-sectional view taken along line FF of FIG. 7A, respectively, of a motor driving device according to a preferred embodiment of the present invention.

[0037] FIG. 7d is a cross-sectional view of a drive motor having an asymmetric stator core according to a preferred embodiment of the present invention;

[0038] Figures 7e and 7f are exploded perspective views of a motor drive device and an exploded perspective view of a rotation shaft and a magnet, respectively, according to a preferred embodiment of the present invention.

[0039] Figure 8 is a schematic block diagram showing a motor drive system according to a preferred embodiment of the present invention.

[0040] FIG. 9 is a circuit diagram of a motor drive system for driving two drive motors installed at both ends of a single rotary shaft according to a preferred first embodiment of the present invention.

[0041] FIG. 10 is a circuit diagram of a motor drive system for driving two drive motors installed at both ends of a single rotary shaft according to a preferred second embodiment of the present invention.

[0042] Hereinafter, a preferred embodiment according to the present invention will be described with reference to the attached drawings.

[0043] 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.

[0044] 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 together with a rotary table. By installing the swivel actuator on a lower plate fixed to the floor of a vehicle and fixing the car seat to the rotary table, the car seat can also rotate according to the rotation of the rotary table.

[0045] 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.

[0046] The internal hollow swivel actuator according to the present invention is configured as an integrated unit in which a single actuator housing, a motor driving device, a sun gear, and a plurality of pinion gears are arranged inside the actuator housing, and a rotary table in which a ring gear is integrally formed on the upper portion is arranged, thereby solving the problems of the prior art and promoting miniaturization and slimming.

[0047] In addition, the internal hollow swivel actuator according to the present invention is formed in a disk shape, and has a through hole for cable withdrawal formed in the center of the internal hollow, and a plurality of, for example, 3 to 6, coupling holes are formed on the upper part of the rotating body (rotary table) to connect with a driven body, and the lower part of a fixing bolt passes through the coupling hole and can be fixed by screwing it to a stud nut fixedly installed on the inner surface of the rotary table.

[0048] First, referring to FIGS. 1 to 4, an internal hollow swivel actuator (200) according to a preferred embodiment of the present invention comprises: an actuator housing (10) having a hollow cylindrical portion (11) protruding upward at the center; a motor drive device (100) disposed on one side of a bottom surface (10f) of the actuator housing (10), wherein first and second drive motors (101, 102) are formed at both ends of a rotation shaft (34), and a worm gear (35) integrally formed at the center of the rotation shaft (34) to generate rotational outputs of the first and second drive motors (101, 102); a printed circuit board (50) on which a motor drive circuit for rotationally driving the first and second drive motors (101, 102) is mounted; It includes a sun gear (70) that is rotatably supported on the outer periphery of the hollow cylindrical portion (11) and has a worm wheel formed on the outer periphery thereof to perform gear reduction by engaging the worm gear (35); and a rotary table (20) that is fixed at the center to the upper portion of the sun gear (70) and rotatably supported on the upper portion of the hollow cylindrical portion (11).

[0049] The internal hollow swivel actuator (200) is described in detail below.

[0050] First, the motor driving device (100) has first and second driving motors (101, 102) formed at each end of the rotation shaft (34), and a worm gear (35) that generates the rotational output of the first and second driving motors (101, 102) is integrally formed at the center of the rotation shaft (34).

[0051] The actuator housing (10) above has a hollow cylindrical portion (11) having a through hole (11a) formed in the center thereof, and a circular wall (10a) protruding on the outer periphery thereof. On both sides of the circular wall (10a), first and second grooves (10b, 10c) are arranged at intervals so that portions of the first and second motor housings (90a, 90b) are hung when the first and second drive motors (101, 102) of the motor drive device (100) are installed, and third and fourth grooves (13a, 13b) are arranged adjacent to the first and second grooves (10b, 10c) for fixing the first and second motor housings (90a, 90b) to the circular wall (10a) of the actuator housing (10) using fixing bolts (96).

[0052] In addition, steps are formed at both ends of the first and second motor housings (90a, 90b) so that the size thereof becomes smaller toward the rear end, and a step corresponding to the steps of the first and second motor housings (90a, 90b) is formed inwardly on the circular wall (10a) in which the first and second grooves (10b, 10c) are formed, thereby increasing the contact area between the first and second motor housings (90a, 90b) and the actuator housing (10), as shown in FIGS. 3 and 4, thereby stably supporting the first and second motor housings (90a, 90b).

[0053] When the first and second motor housings (90a, 90b) are installed in the actuator housing (10), first and second through-holes (12a, 12b) are formed in the bottom surface (10f) of the actuator housing (10), and the bottom surfaces of the first and second motor housings (90a, 90b) are assembled to the first and second through-holes (12a, 12b) 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.

[0054] First and second brackets (94a, 94b) protrude from one side of the first and second motor housings (90a, 90b), respectively, and the first and second brackets (94a, 94b) can be fastened with one fixing bolt (96) so as to be fixed to the third and fourth grooves (13a, 13b), respectively.

[0055] In addition, third and fourth brackets (95a, 95b) protrude from the other sides of the first and second motor housings (90a, 90b), respectively, and first and second protruding fixing parts (15a, 15b) for fixing the motor corresponding to the third and fourth brackets (95a, 95b) protrude from the bottom surface (10f) of the actuator housing (10). Through holes are formed in the third and fourth brackets (95a, 95b) so that at least two fixing bolts (96) can be fastened to the first and second protruding fixing parts (15a, 15b).

[0056] Moreover, as shown in Fig. 7b, a pair of bearings (65, 66) are built into the inside of both ends of the first and second motor housings (90a, 90b) to rotatably support the rotation shafts (34) of the first and second drive motors (101, 102).

[0057] In this case, when generating rotational output from the motor drive device (100), a worm gear (35) is used to increase brake torque, and it is desirable to prevent bending or damage of the first and second motor housings (90a, 90b) 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 first and second motor housings (90a, 90b) in the actuator housing (10) while distributing the external pressure.

[0058] In the present invention, in order to prevent the first and second motor housings (90a, 90b) from being bent or damaged due to a large external pressure, the first and second drive motors (101, 102) of the motor drive device (100) are assembled so that both ends of the first and second motor housings (90a, 90b) partially hang over the first and second grooves (10b, 10c), respectively, and the first and second brackets (94a, 94b) are fixed to the third and fourth grooves (13a, 13b) using fixing bolts (96), and the third and fourth brackets (95a, 95b) are fixed to the first and second protruding fixing parts (15a, 15b) using at least two fixing bolts (96).

[0059] The first and second drive motors (101, 102) of the above motor drive device (100) generate, for example, relatively high-speed rotational power, and when transmitted to the sun gear (70), the high-speed rotational power is received and the rotational speed is reduced, thereby converting the torque to generate rotational power with increased torque and reduced rotational speed by transmitting the received high-speed rotational power to the rotary table (20).

[0060] The above rotary table (20) includes a circular upper plate (21) and a side portion (23) extending downward from the outer periphery of the upper plate (21). A plurality of coupling holes (22) may be formed through the upper plate (21) for coupling with a main body (e.g., an electric seat) that is a passive body installed on the rotary table (20).

[0061] As shown in FIGS. 7a to 7f, the motor driving device (100) has first and second driving motors (101, 102) formed at each end of the rotation shaft (34), and a worm gear (35) that generates the rotational output of the first and second driving motors (101, 102) is integrally formed at the center of the rotation shaft (34). As a result, the worm gear (35) is formed at the center of the rotation shaft (34) that is rotationally driven by the first and second driving motors (101, 102) of a symmetrical structure, and is gear-coupled with a sun gear (70) whose outer periphery is formed as a worm wheel.

[0062] The worm gear (35) formed at the center of the rotation shaft (34) of the above motor driving device (100) is arranged on one side of the sun gear (70).

[0063] 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 assembling a single drive motor to 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.

[0064] However, in the present invention, the worm gear (35) disposed at the center of the rotation shaft (34) is driven by the first and second drive motors (101, 102) installed at both ends of the rotation shaft (34) to stably drive the sun gear (70), thereby supporting a large load.

[0065] In addition, the first and second driving motors (101, 102) are formed inside the first and second motor housings (90a, 90b) which are fixedly installed on one side of the actuator housing (10), and both ends of the rotation shaft (34) are rotatably supported by a pair of bearings (65, 66) arranged inside the first and second motor housings (90a, 90b), thereby providing stability when driving the worm gear (35).

[0066] 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 both ends of the rotation shaft (34) to ensure uniform distribution of force and stable acceptance of force.

[0067] In addition, in the present invention, a worm gear (35) is placed at the center of a rotary shaft (34) that is driven by the first and second driving motors (101, 102) to drive the sun gear (70) from both sides, thereby providing a structure that is more stable against vibration and noise.

[0068] Since the first and second driving motors (101, 102) are arranged inside one side of the actuator housing (10), the shape of the actuator housing (10) can form an overall cylindrical shape.

[0069] Moreover, in the present invention, as shown in Fig. 7b, both ends of the first and second motor housings (90a, 90b) can serve as bearing housings, and set screws (73a, 73b) can be added to the inside, respectively, to limit the left-right movement of the rotation shaft (34).

[0070] 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.

[0071] The rear ends of the first and second motor housings (90a, 90b) have a shape that gradually narrows to function as bearing housings, and female threads are formed in through holes that penetrate inward from both ends. The set screws (73a, 73b) can be screw-coupled to the rear ends of the first and second motor housings (90a, 90b) having female threads formed thereon, so that the tip ends of the two set screws (73a, 73b) push and compress both ends of the rotation shaft (34).

[0072] It is preferable that the above set screws (73a, 73b) be installed in both bearing housings of the two bearings (65, 66) that rotatably support both ends of the rotary shaft (34), and it is also possible to install them only in one bearing housing to support one end of the rotary shaft, thereby pushing the rotary shaft (34) in one direction and suppressing left-right movement.

[0073] The internal hollow swivel actuator (200) illustrated in FIGS. 1 to 4 has a structure in which the central portion of the rotary table (20) is fixed to the upper portion of the sun gear (70) and rotatably supported on the upper portion of the hollow cylindrical portion (11).

[0074] However, the swivel actuator (200) of the present invention may be connected to the upper part of the sun gear (70) through a reducer without the central portion of the rotary table (20) being fixed thereto, as shown in FIGS. 5 and 6.

[0075] Referring to FIGS. 5 and 6, an internal hollow swivel actuator (200) according to a preferred embodiment of the present invention comprises: an actuator housing (10) having a hollow cylindrical portion (11) protruding upward at the center; a motor drive device (100) disposed on one side of a bottom surface (10f) of the actuator housing (10), in which first and second drive motors (101, 102) are formed at each end of a common rotation shaft (34), and a worm gear (35) that generates rotational output of the drive motors (101, 102) is integrally formed at the center of the rotation shaft (34); A sun gear (70) that is rotatably supported on the outer periphery of the hollow cylindrical portion (11), has a worm wheel (71) that is gear-engaged with the worm gear (35) on the lower side to perform primary reduction, and is integrally formed with a spur gear (72) that transmits the rotational output of the worm wheel (71) on the upper side; a plurality of pinion gears (81a-81d) that are each arranged at intervals on the same circumference with the sun gear (70) at the other side of the bottom surface (10f) of the actuator housing (10) and are gear-engaged with the spur gear (72) of the sun gear (70) to rotate; And it includes a rotary table (20) in which the central part is rotatably supported on the outer periphery of the hollow cylindrical part (11), and the plurality of pinion gears (81a-81d) are gear-coupled to a ring gear integrally formed on the inner side of the side part to perform secondary reduction.

[0076] In this case, the above-mentioned sun gear (70) and a plurality of pinion gears (81a-81d) can form a reducer.

[0077] In the following description of the internal hollow swivel actuator (200), the same parts as those shown in the embodiments of FIGS. 1 to 4 are given the same reference numerals and detailed descriptions thereof are omitted.

[0078] On one side of the bottom surface (10f) of the actuator housing (10), first and second drive motors (101, 102) are formed at both ends of a common rotation shaft (34), and a motor drive device (100) is arranged in which a worm gear (35) that generates the rotational output of the drive motors (101, 102) is integrally formed at the center of the rotation shaft (34). On the other side of the bottom surface (10f), a plurality of support shafts (82a-82d) are installed to rotate a plurality of pinion gears (81a-81d) that are spaced apart on the same circumference centered on the sun gear (70), and the plurality of support shafts (82a-82d) are fixed to a plurality of protrusions (13a-13d) that protrude from the bottom surface (10f) of the actuator housing (10).

[0079] In this case, the plurality of support shafts (82a-82d) are assembled through the through-holes of the plurality of protrusions (13a-13d) from the bottom surface (10f) of the actuator housing (10), and a stopper insertion groove (84) is formed on the upper end of the support shafts (82a-82d), so that a plurality of stopper rings (83a-83d) can be combined in the stopper insertion groove (84) to prevent the pinion gear (81a-81d) from being detached after the pinion gear (81a-81d) is assembled.

[0080] The above-mentioned sun gear (70) is rotatably supported on the outer periphery of the above-mentioned hollow cylindrical portion (11), and a worm wheel (71) is arranged on the lower side to be gear-coupled to the worm gear (35) to perform primary reduction, and a spur gear (72) is formed integrally on the upper side to transmit the rotational output of the worm wheel (71) to a plurality of pinion gears (81a-81d).

[0081] A cylindrical needle roller bearing is inserted between the lower part of the hollow cylindrical portion (11) and the sun gear (70) to rotatably support the sun gear (70), and a table support bearing (62) is inserted between the upper part of the hollow cylindrical portion (11) and the center of the rotary table (20).

[0082] In addition, a bearing support is inserted between the needle roller bearing and the table support bearing (62) and is press-fitted to the outer periphery of the hollow cylindrical portion (11) to prevent the table support bearing (62) from descending.

[0083] Moreover, a damper ring is inserted into the lower side of the bearing support to absorb shock that may be applied to the needle roller bearing when the bearing support is press-fitted to the outer periphery of the hollow cylindrical portion (11).

[0084] In addition, the table support bearing (62) may be configured as a ball bearing having a plurality of balls inserted between the inner ring and the outer ring, the inner ring being fixed to the outer periphery of the hollow cylindrical portion (11) and the outer ring being fixed to a bearing housing protruding downwards in the center of the rotary table (20).

[0085] In addition, the hollow type swivel actuator (200) has a stopper insertion groove formed in the upper part of the hollow cylindrical portion (11), and a stopper ring (68) made of a snap ring is combined in the stopper insertion groove to prevent the rotary table (20) from being detached.

[0086] The above rotary table (20) includes a circular upper plate (21) and a side portion (23) extending downward from the outer periphery of the upper plate (21). A plurality of coupling holes (22) may be formed through the upper plate (21) for coupling with a main body (e.g., an electric seat) that is a passive body installed on the rotary table (20).

[0087] The above rotary table (20) is rotatably supported on the outer periphery of the hollow cylindrical portion (11) by a table support bearing (62) at the central portion, and the plurality of pinion gears (81a-81d) are gear-coupled to a ring gear (not shown) integrally formed on the inner side portion to achieve secondary reduction, thereby rotating at a low speed.

[0088] The above plurality of pinion gears (81a-81d) are arranged eccentrically with a gap on the same circumference centered on the sun gear (70) except for one side on the bottom surface (10f) of the actuator housing (10) where the motor driving device (100) is arranged.

[0089] In the present invention, the degree of design freedom can be increased by arranging the plurality of pinion gears (81a-81d) eccentrically and positioning the motor driving device (100) to one side.

[0090] In addition, in the present invention, a plurality of pinion gears (81a-81d) constituting the motor driving device (100) and the reduction gear unit can be arranged on the same plane inside the cylindrical actuator housing (10), thereby realizing a slim structure for the entire swivel actuator (200).

[0091] The above plurality of pinion gears (81a-81d) are each rotatably installed on a plurality of support shafts (82a-82d) that are spaced apart on the same circumference with the sun gear (70) as the center on the other side of the bottom surface (10f) of the actuator housing (10).

[0092] The lower ends of the above plurality of support shafts (82a-82d) are fixed to a plurality of protrusions (13a-13d) protruding from the bottom surface (10f) of the actuator housing (10).

[0093] Accordingly, the plurality of pinion gears (81a-81d) are each gear-coupled to a spur gear (72) formed on the upper portion of the sun gear (70) to rotate, and are also gear-coupled to a ring gear (24) of the rotary table (20) to transmit rotational force, thereby performing secondary deceleration to rotate the rotary table (20) at a low speed.

[0094] The above motor driving device (100) generates, for example, a relatively high-speed rotational power, and the sun gear (70) and a plurality of pinion gears (81a-81d) receive the high-speed rotational power, reduce the rotational speed, and transmit it to the rotary table (20), thereby converting the torque to generate a reduced rotational power with increased torque.

[0095] The internal hollow swivel actuator (200) according to the present invention generates a high-speed rotational output through a worm gear (35) of a motor driving device (100), and a stable high-torque output can be obtained as a large torque conversion is achieved through a two-stage reduction that rotates the ring gear of the rotary table (20) through a sun gear (70) and a plurality of pinion gears (81a-81d).

[0096] Below, the motor driving device (100) is described in detail with reference to FIGS. 7a to 7f.

[0097] Referring to FIGS. 7a to 7f, the motor driving device (100) has first and second driving motors (101, 102) formed at each end of the rotation shaft (34) and arranged inside the first and second motor housings (90a, 90b).

[0098] The first and second motor housings (90a, 90b) are assembled so that both ends partially hang over the first and second grooves (10b, 10c) of the actuator housing (10), and both ends are exposed to the outside. As a result, the set screws (73a, 73b) can be operated from the outside using a driver, thereby limiting the left and right movement of the rotation shaft (34).

[0099] The first and second motor housings (90a, 90b) include, as shown in FIG. 7e, first and second motor housing bodies (91a, 91b) forming internal spaces in which the first and second rotors (30a, 30b) and the first and second stators (40a, 40b) are accommodated, respectively, and first and second motor housing covers (92a, 92b) coupled to the entrances of the first and second motor housing bodies (91a, 91b), and are fixed by fastening a plurality of fixing bolts (93).

[0100] As shown in FIGS. 7e and 7f, the first and second drive motors (101, 102) are formed integrally with first and second rotors (30a, 30b) at both ends of the rotation shaft (34), and are arranged with an air gap on the outside of the first and second rotors (30a, 30b), and first and second stators (40a, 40b) for generating a rotating magnetic field to rotate and drive the first and second rotors (30a, 30b) are arranged inside the first and second motor housing bodies (91a, 91b).

[0101] The first and second rotors (30a, 30b) are each composed of magnets (31a, 31b) attached to the outer periphery of both ends of the rotation shaft (34), as illustrated in FIGS. 7e and 7f, respectively. The magnets (31a, 31b) 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 multi-polarly split and magnetized may be used.

[0102] When the first and second rotors (30a, 30b) are formed of a plurality of N-pole and S-pole split magnet pieces, a plurality of protrusions (32a, 32b) are formed protruding along the outer periphery at both ends of the rotation shaft (34), and a plurality of grooves (33a, 33b) are formed between the plurality of protrusions (32a, 32b) to which a plurality of magnets (31a, 31b) can be attached, and a plurality of magnets (31a, 31b) are fixed to the plurality of grooves (33a, 33b).

[0103] As shown in FIGS. 7a to 7f, the rotation axis (34) of the first and second rotors (30a, 30b) is formed as an integral body with a worm gear (35) machined in the center and magnets (31a, 31b) fixedly positioned at both ends, so that two magnets can be magnetized simultaneously.

[0104] In addition, the above-mentioned rotation shaft (34) can be manufactured by dividing it into three or two parts in the central portion where the first and second rotors (30a, 30b) and the worm gear (35) are formed, and then assembled using a D-cut structure or another connecting method.

[0105] The first and second stators (40a, 40b) each include a stator core (45) having a plurality of teeth (41) each having a "T" shape and a back yoke (42) interconnected with the plurality of teeth (41) to form a magnetic circuit; a bobbin (44) made of an insulating material integrally formed to surround an outer circumferential surface on which a coil (43) of each of the plurality of teeth is wound; and a coil (43) wound on the outer circumferential surface of the bobbin (44). The bobbin (44) may be integrally formed with the stator core (45) as a stator support.

[0106] In this case, the bobbin (44) may be composed of upper and lower insulators assembled to surround the back yoke (42) with a plurality of teeth (41) on the left and right sides or the upper and lower sides of the rotation axis (34).

[0107] In this case, the first and second stators (40a, 40b) 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. 7c, and may have a stator core (45a) of an asymmetrical structure in which a plurality of teeth (41) protrude toward the center from an asymmetric back yoke (42) of an asymmetrical structure with different lengths, as shown in FIG. 7d.

[0108] The embodiment illustrated in Fig. 7c is one in which the magnet (31b) of the rotor (30b) is formed of a plurality of N-pole and S-pole split magnet pieces, and the embodiment illustrated in Fig. 7d is one in which the magnet (31b) of the rotor (30b) uses a ring-shaped magnet in which the N-pole and S-pole are split into multiple poles and magnetized.

[0109] The first and second stators (40a, 40b) having the stator core (45a) of the above-described asymmetrical structure can be used when providing a motor structure for maximizing the use of space within the actuator housing (10). That is, as shown in Fig. 7a, 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 space outside the rotation shaft (34) (i.e., the lower side in Fig. 7a).

[0110] As shown in FIGS. 2 to 4, the motor driving device (100) may have a printed circuit board (PCB) (50) having a motor driving circuit (i.e., a motor controller) mounted thereon vertically placed in the middle portion of the first and second driving motors (101, 102).

[0111] The swivel actuator (200) according to the present invention may be configured such that the first and second drive motors (101, 102) constituting the motor drive device (100) are BLDC motors having an 8-pole-6-slot structure, as illustrated in FIG. 7c, for example. In this case, the first and second stators (40a, 40b) of the first and second drive motors (101, 102) may have a 9-slot structure having a multiple of 3 as illustrated in FIGS. 9 and 10, or another slot structure having a multiple of 3, instead of a stator core having a 6-slot structure.

[0112] The first and second driving motors (101, 102) above can be wound with the first and second coils (43a, 43b) of the first and second stators (40a, 40b) in a three-phase driving manner on a plurality of teeth (41) of the stator core (45), respectively, by winding the first and second coils (43a, 43b) in a U, V, W three-phase structure, and the other ends of the U, V, W three-phase coils (43) can be connected in a Y-connection (see FIGS. 8 and 9) or star-connection manner.

[0113] The first and second driving motors (101, 102) can be driven using a single motor driving circuit (i.e., a motor controller). In this case, the motor driving circuit is mounted on a printed circuit board (PCB) (50) arranged in the middle portion of the first and second driving motors (101, 102), and the first and second coils (43a, 43b) wound on the stator cores (45) of the first and second stators (40a, 40b) provided in the first and second driving motors (101, 102) are connected to the motor driving circuit of the printed circuit board (PCB) (50) using wire harnesses.

[0114] FIG. 8 is a schematic block diagram showing a motor drive system for driving two drive motors according to a preferred embodiment of the present invention, FIG. 9 is a circuit diagram of a motor drive system for driving two drive motors installed at both ends of a single rotation shaft according to a preferred first embodiment of the present invention, and FIG. 10 is a circuit diagram of a motor drive system for driving two drive motors installed at both ends of a single rotation shaft according to a preferred second embodiment of the present invention.

[0115] Referring to FIG. 8, a motor drive system (500) according to a preferred embodiment of the present invention includes a control unit (51) that generates a drive control signal for the first and second drive motors (101, 102) (M1, M2) by combining a seat control signal (SCS) and a rotor position signal (H1-H3) from an automobile body; an inverter (52) that generates a U, V, W three-phase motor drive signal (Us, Vs, Ws) composed of AC power according to the drive control signal of the control unit (51) and outputs the U, V, W three-phase motor drive signal (Us, Vs, Ws) to the first and second coils (43a, 43b) of the first and second drive motors (101, 102); And it includes a Hall sensor assembly (56) for detecting a rotor position signal (H1-H3) of one of the first and second driving motors (101, 102) and disposed in one of the motor housings (90a, 90b) of the first and second driving motors (101, 102).

[0116] When driving the first and second drive motors (101, 102) using a single motor drive circuit and a single Hall sensor assembly (56) according to the present invention, it is preferable that the positions of the first and second rotors (30a, 30b), the positions of the stator cores of the first and second drive motors (101, 102), etc., be positioned on the same line. That is, when using one Hall sensor IC (i.e., Hall sensor assembly) for detecting the rotational positions of the first and second rotors (30a, 30b), the rotational positions of the rotor, the positions of the stator cores, and the U, V, and W lines must be arranged in accordance with the rotational direction.

[0117] The above control unit (51) and inverter (52) form a single motor drive circuit and are mounted on a main printed circuit board (PCB) (50) arranged inside an actuator housing (10), and the Hall sensor assembly (56) has two or three Hall sensors for detecting the magnetic poles of the magnets (31a, 31b) of the rotating first and second rotors (30a, 30b) to generate a rotor position signal (H1-H3), and is mounted on one of the motor housings (90a, 90b) of the first and second drive motors (101, 102), for example, a first auxiliary printed circuit board (PCB) (54a) provided inside the motor housing (90a).

[0118] Referring to FIG. 9, which illustrates a motor driving system (500) according to a first embodiment, a first auxiliary printed circuit board (PCB) (54a) has three-phase terminal terminals (Tu, Tv, Tw) arranged on one side to which start terminals of the U-phase coils (u1-u3), the V-phase coils (v1-v3), and the W-phase coils (w1-w3) of the first coil (43a) wound on a plurality of teeth (41) of the stator core (45) are connected, and three-phase end connection terminals (Gu, Gv, Gw) arranged at intervals from the three-phase terminal terminals (Tu, Tv, Tw) to which end terminals of the U-phase coils (u1-u3), the V-phase coils (v1-v3), and the W-phase coils (w1-w3) are connected.

[0119] In addition, a second auxiliary printed circuit board (PCB) (54b) provided inside a motor housing (90b) of a second drive motor (102) has three-phase terminal terminals (Tu1, Tv1, Tw1) arranged on one side to which start terminals of the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) of the second coil (43b) wound on a plurality of teeth (41) of a stator core (45) are connected, and three-phase end connection terminals (Gu1, Gv1, Gw1) arranged at intervals from the three-phase terminal terminals (Tu1, Tv1, Tw1) to which end terminals of the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) are connected.

[0120] The U, V, W three-phase motor drive signals (Us, Vs, Ws) generated from the inverter (52) are applied to the three-phase terminal terminals (Tu, Tv, Tw) of the first auxiliary printed circuit board (PCB) (54a) and the three-phase terminal terminals (Tu1, Tv1, Tw1) of the second auxiliary printed circuit board (PCB) (54b) using wire harnesses.

[0121] In addition, the three-phase end connection terminals (Gu, Gv, Gw) of the first auxiliary printed circuit board (PCB) (54a) and the three-phase end connection terminals (Gu1, Gv1, Gw1) of the second auxiliary printed circuit board (PCB) (54b) are connected to common connection wiring (58a, 58b), thereby forming a neutral point (NP) required for Y-connection.

[0122] The inverter (52) is configured with three pairs of power switching elements (FET1-FET6) each connected in a totem pole manner, and a three-phase motor drive signal (Us, Vs, Ws) of U, V, W of each phase is generated from the connection point between the upper FET (FET1, FET3, FET5) and the lower FET (FET4, FET6, FET2) and is applied to the three-phase terminal terminal (Tu, Tv, Tw) of the first auxiliary printed circuit board (PCB) (54a) and the three-phase terminal terminal (Tu1, Tv1, Tw1) of the second auxiliary printed circuit board (PCB) (54b).

[0123] The first and second drive motors (101, 102) are BLDC motors of a three-phase drive type driven by a single inverter (52), and detect a rotor position signal from a Hall element (H1-H3) every 12° of mechanical angle in a 6-step manner as shown in Table 1 below, and apply the current flowing in the U-phase coil (u1-u3), V-phase coil (v1-v3), and W-phase coil (w1-w3) of the first coil (43a) and the U-phase coil (u11-u13), V-phase coil (v11-v13), and W-phase coil (w11-w13) of the second coil (43b) by switching the direction of the current, thereby selectively activating the first coil (43a) and the second coil (43b) to generate a rotating magnetic field.

[0124] The first and second drive motors (101, 102) selectively drive two of the three pairs of totem pole-connected switching elements (FET1-FET6) based on the rotor position signal of the rotor (30a, 30b), thereby sequentially applying current to two of the U-phase coils (u1-u3), V-phase coils (v1-v3), and W-phase coils (w1-w3) of the first coil (43a) and the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) of the second coil (43b), thereby sequentially exciting the two-phase coils to generate a rotating magnetic field, thereby causing the rotors (30a, 30b) to rotate. In this case, a driving signal is applied from the output of the inverter (52) to one coil, and is applied to the other coil through the neutral point (NP).

[0125] When the control unit (51) of the motor drive circuit detects the rotor position signal of the rotor (30a, 30b) by the Hall element (H1-H3) at each rotor rotation angle, it generates a U, V, W three-phase motor drive signal (Us, Vs, Ws) to turn on a pair of switching elements (FET) in combination with a seat control signal (SCS) from the vehicle body, and the inverter (52) turns on a pair of switching elements (FET) according to Table 1 below to set a current flow path.

[0126] Electrical angle 0°60°120°180°240°300°360°0°Mechanical angle 0°12°24°36°48°60°72°0°H1NSSSNNNH2NNNSSSNH3SSNNNSSInput VVWWUUVOutput WUUVVWWUpper FETFET3FET3FET5FET5FET1FET1FET3Lower FETFET2FET4FET4FET6FET6FET2FET2

[0127] In the motor drive system (500) according to the first preferred embodiment of the present invention illustrated in FIG. 9, the first and second drive motors (101, 102) are positioned at opposite ends of a single rotational axis (35), so that, for example, the rotational direction of the second drive motor (102) located opposite to the rotational direction of the first drive motor (101) must be rotated in the opposite direction so that rotation is performed in the same direction from the perspective of the rotational axis.

[0128] To this end, the U-phase coils (u1-u3), V-phase coils (v1-v3), and W-phase coils (w1-w3) of the first coil (43a) in the first stator (40a) of the first drive motor (101) are wound in the forward direction on multiple teeth (41) of the stator core (45), and the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) of the second coil (43b) in the second stator (40b) of the second drive motor (102) are wound in the reverse direction.

[0129] In this state, when the same motor driving signal is applied to the first coil (43a) of the first drive motor (101) and the second coil (43b) of the second drive motor (102) using an inverter (52), the rotational direction of the first drive motor (101) and the rotational direction of the second drive motor (102) are opposite to each other, so the single rotational shaft (35) rotates in the same direction.

[0130] For example, when the first and second drive motors (101, 102) are driven in the 6-step manner shown in Table 1, first, when the rotor position of the second drive motor (102) is 0 degrees, the rotor position signal detected from the Hall element (H1-H3) is detected as N, N, S, and the U, V, W three-phase motor drive signal (Us, Vs, Ws) is input to the V-phase coil (v11-v13) of the inverter (52), and the V-phase motor drive signal (Vs) passes through the neutral point (NP) and sets a current flow path to the W-phase coil (w11-w13). For this purpose, among the switching elements (FET1-FET6), only the upper FET3 and the lower FET2 are set to turn-on. In this case, the second drive motor (102) rotates in the forward direction.

[0131] As with the second drive motor (102) described above, when the V-phase motor drive signal (Vs) is applied to the V-phase coil (v1-v3) of the first drive motor (101) and a current flow path is set to the W-phase coil (w1-w3), the first drive motor (101) rotates in the reverse direction because the winding direction of the coil is opposite to that of the second drive motor (102).

[0132] In the motor drive system (500) of the first embodiment, when the first coil (43a) of the first drive motor (101) and the second coil (43b) of the second drive motor (102) are wound around the stator core (45) of the first stator (40a) and the second stator (40b), the two first and second drive motors (101, 102) having opposite winding directions of the coils are installed at both ends of a single rotation shaft (35), a method is proposed in which the two drive motors rotate the single rotation shaft (35) in the same direction using a single motor drive circuit.

[0133] The above first embodiment is based on the premise that the first stator (40a) and the second stator (40b) of the first and second driving motors (101, 102) have different structures, but the present invention is not limited thereto and can also be applied to a case where the first stator (40a) and the second stator (40b) of the first and second driving motors (101, 102) have the same structure.

[0134] FIG. 10 is a circuit diagram of a motor drive system for driving two motors installed at both ends of a single rotary shaft according to a preferred second embodiment of the present invention.

[0135] Referring to FIG. 10, a motor driving system (500) according to a preferred second embodiment of the present invention includes a control unit (51), an inverter (52), and a hall sensor assembly (56) mounted on a main printed circuit board (50).

[0136] In the second embodiment, compared to the first embodiment, the control unit (51) and inverter (52) mounted on the main printed circuit board (50) are identical to those of the first embodiment. Therefore, when describing the second embodiment, the same parts as those of the first embodiment are assigned the same reference numerals and a detailed description thereof is omitted.

[0137] The above Hall sensor assembly (56) has two or three Hall sensors (H1-H3) for detecting the stimulation of the magnets (31a, 31b) of the rotating rotor (30a, 30b) to generate a rotor position signal, and is mounted on one of the motor housings (90a, 90b) of the first and second drive motors (101, 102), for example, the first auxiliary printed circuit board (PCB) (54a).

[0138] In the motor drive system (500) according to the second embodiment, the first and second drive motors (101, 102) are positioned at both ends of a single rotation shaft (35), and in order to commonize the motors of the two drive motors, the windings of the U-phase coils (u1-u3), V-phase coils (v1-v3), and W-phase coils (w1-w3) of the first coil (43a) of the first stator (40a) of the first drive motor (101) and the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) of the second coil (43b) of the second stator (40b) of the second drive motor (102) can be wound in the same manner.

[0139] In this case, in the first auxiliary printed circuit board (PCB) (54a), the start terminals of the U-phase coils (u1-u3), V-phase coils (v1-v3), and W-phase coils (w1-w3) of the first coil (43a) are connected to the three-phase terminal terminals (Tu, Tv, Tw), and the three-phase AC power (Us, Vs, Ws) generated from the inverter (52) is applied to the three-phase terminal terminals (Tu1, Tv1, Tw1), and the end terminals of the U-phase coils (u1-u3), V-phase coils (v1-v3), and W-phase coils (w1-w3) are connected to the three-phase end connection terminals (Gu, Gv, Gw) connected to the common connection wiring (58a) to form a neutral point (NP) for Y-connection.

[0140] However, in the second auxiliary printed circuit board (PCB) (54b), the start terminals of the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) of the second coil (43b) are connected to the first three-phase terminal terminal (Tu1, Tv1, Tw1), and the three-phase AC power (Us, Vs, Ws) generated from the inverter (52) is connected to the second three-phase terminal terminal (Tu2, Tv2, Tw2).

[0141] In addition, the first three-phase terminal terminal (Tu1) is connected to the second three-phase terminal terminal (Tw2) via the first connection wire (57a) formed on the second auxiliary printed circuit board (PCB) (54b), the first three-phase terminal terminal (Tw1) is connected to the second three-phase terminal terminal (Tu2) via the second connection wire (57b), and the first three-phase terminal terminal (Tv1) is connected to the second three-phase terminal terminal (Tv2) via the third connection wire (57c).

[0142] The end terminals of each of the U-phase coils (u11-u13), V-phase coils (v11-v13), and W-phase coils (w11-w13) are connected to the three-phase ground terminals (Gu1, Gv1, Gw1) connected to the common connection wiring (58b) to form a neutral point (NP) for Y-connection.

[0143] As described above, in the motor drive system (500) according to the second preferred embodiment of the present invention, the first and second coils (43a, 43b) of the first and second drive motors (101, 102) are wound in the same manner on the stator core, thereby facilitating motor sharing of the two drive motors.

[0144] In this case, the problem can be solved by a connection method in which the U-phase AC power (Us) is applied to the W-phase coil (w11-w13) and the W-phase AC power (Ws) is applied to the U-phase coil (u11-u13) using the first to third connection wires (57a-57c) formed on the second auxiliary printed circuit board (PCB) (54b).

[0145] In this state, when the same motor driving signal, i.e., three-phase AC power (Us, Vs, Ws), is applied to the first coil (43a) of the first drive motor (101) and the second coil (43b) of the second drive motor (102) using an inverter (52), the rotation of the first drive motor (101) and the rotation of the second drive motor (102) rotate in opposite directions, so that the single rotation shaft (35) rotates in the same direction.

[0146] In addition, the main printed circuit board (PCB) (50) is assembled using a printed circuit board (PCB) (50) formed in a donut shape on top of the drive motor instead of being assembled in a vertical manner as shown in FIG. 2, and the wire harnesses connected to the U, V, W three-phase coils (43a, 43b) of the first and second drive motors (101, 102) are drawn out to the upper side of the first and second drive motors (101, 102) and soldered to the main printed circuit board (PCB) (50) or assembled using a press fit.

[0147] In the illustrated embodiment, the main printed circuit board (PCB) (50) of the motor drive circuit is installed inside the actuator housing (10). However, the motor drive circuit is installed outside the actuator housing (10), and a Hall sensor assembly is mounted on an auxiliary printed circuit board (PCB) (54a) installed inside the motor housing, so that the U, V, W output signals of the inverter, Vcc, and GND are applied to the stator coils and Hall sensor assembly of the first and second drive motors (101, 102) through cables from the motor drive circuit installed outside, and it is also possible to receive signals from three Hall sensors (H1 to H3).

[0148] Accordingly, the cable can be introduced downward through the central through-hole (25) provided in the center of the upper plate (21) and the hollow cylindrical portion (11) of the actuator housing (10), and then connected to the main printed circuit board (PCB) (50) through the through-hole formed in the bottom of the actuator housing (10).

[0149] In the above-described embodiment, a Hall sensor assembly (56) is mounted on an auxiliary printed circuit board (PCB) (54a) to detect the stimulation of the magnets (31a, 31b) of the rotor (30a, 30b) and transmit the detected rotor position signal to the control unit (51). However, it is also possible to configure a sensorless motor drive circuit without mounting the Hall sensor assembly (56) on the auxiliary printed circuit board (PCB) (54a).

[0150] The operation of the internal hollow swivel actuator (200) according to the present invention will be described below with reference to FIGS. 1 to 10.

[0151] In the internal hollow swivel actuator (200) of the present invention, when the motor driving device (100) installed on one side of the bottom surface (10f) of the actuator housing (10) is first operated, the first and second driving motors (101, 102) of the BLDC type are driven, and a high-speed rotational output is generated from the worm gear (35) arranged at the center of the rotation shaft (34).

[0152] The above worm gear (35) is gear-coupled to one side of the sun gear (70) and drives the worm wheel of the sun gear (70) that is rotatably supported on the outer periphery of the hollow cylindrical portion (11) to rotate on one side.

[0153] When the above sun gear (70) is rotated, the rotary table (20) coupled to the upper part of the sun gear (70) also rotates at the same low speed.

[0154] As a result, the rotary table (20) can be rotated at low speed by stable high torque output as a large torque is converted by torque conversion according to deceleration while the central portion is rotatably supported by the table support bearing (62) on the outer periphery of the hollow cylindrical portion (11).

[0155] As described above, the internal hollow swivel actuator (200) according to the present invention generates a high-speed rotational output through the worm gear (35) of the motor driving device (100), and then transmits it to the worm wheel of the sun gear (70) so that a large torque is converted by deceleration, thereby obtaining a stable high-torque output, and the rotary table (20) can be coupled to the upper portion of the sun gear (70) or a pinion gear (81a-81d) and a ring gear can be used to drive the rotary table (20) so that a low-speed rotation can be achieved.

[0156] In addition, in the present invention, when the first and second coils (43a, 43b) of the first and second drive motors (101, 102) are wound in the same manner on the stator core (45) or the winding directions are set in reverse, the rotation of the first drive motor (101) and the rotation of the second drive motor (102) are configured to rotate in opposite directions, so that even if a single motor drive circuit is used, a single rotation shaft (35) can be driven to rotate in the same direction.

[0157] In the present invention, the first-stage reduction ratio (R1) between the worm gear (35) of the first and second driving motors (101, 102) and the worm wheel of the sun gear (70) can be set to 165:1.

[0158] In the swivel actuator (200) of the present invention, for example, when the first and second driving motors (101, 102) rotate at 330 rpm, if the reduction ratio of the reducer is 165:1, the rotation speed of the rotary table (20) is reduced to 165:1, and the rotation speed is lowered to a low speed of 2 rpm, and the rotation torque is increased by 165 times, resulting in a large torque increase.

[0159] When the swivel actuator (200) of the present invention is applied to 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.

[0160] 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.

[0161] The motor drive system according to the present invention can be applied to a swivel actuator that can drive a sun gear of a reduction gear section using a single motor drive circuit (controller) with two drive motors installed at both ends of a rotation shaft.

Claims

1. A single rotary shaft with a worm gear integrally formed in the central portion to generate the rotational output of the motor; First and second driving motors formed at both ends of the above rotating shaft; and A single motor drive circuit for applying U, V, and W three-phase motor drive signals from an inverter to the first and second drive motors, respectively; The first and second driving motors are respectively First and second rotors formed integrally on the outer periphery of both ends of the single rotating shaft; First and second stators each having first and second coils consisting of a U-phase coil, a V-phase coil, and a W-phase coil wound in a U, V, W three-phase drive manner on a plurality of teeth provided on each stator core to drive the first and second rotors according to the U, V, W three-phase motor drive signals; and First and second auxiliary printed circuit boards, each of which has a start terminal of the U-phase coil, the V-phase coil, and the W-phase coil of the first and second coils connected, and a U-phase, V-phase, and W-phase terminal terminal formed on one side to which the U, V, and W three-phase motor drive signals are applied, and a common connection wiring formed on the other side to which the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil are connected to form a neutral point (NP) required for Y-connection; A motor driving system in which the first stator winds a first coil in a first direction on a plurality of teeth provided in the stator core, and the second stator winds a second coil in a direction opposite to the first direction on a plurality of teeth provided in the stator core.

2. In paragraph 1, The first and second driving motors each include first and second motor housings accommodating first and second rotors and first and second stators at opposite ends of the rotation shaft; and A motor drive system further comprising first and second set screws, which are assembled by screwing to both ends of the first and second motor housings and have a front end that presses and supports an end of the rotation shaft to suppress movement of the rotation shaft.

3. In paragraph 1, A motor drive system further comprising a Hall sensor assembly installed on one of the first auxiliary printed circuit board and the second auxiliary printed circuit board to detect a rotor position signal of one of the first rotor and the second rotor and transmit the signal to the motor drive circuit.

4. In paragraph 1, The above motor drive circuit A control unit that generates a driving control signal for the first and second driving motors by combining a seat control signal and a rotor position signal from the vehicle body; and An inverter is included that generates a U, V, W three-phase motor drive signal according to the above drive control signal and outputs the U, V, W three-phase motor drive signal to the first and second coils of the first and second drive motors. A motor drive system in which the above control unit and inverter are mounted on a main printed circuit board placed inside the actuator housing.

5. In paragraph 1, The above worm gear is a motor drive system that drives a sun gear for a reducer of a swivel actuator.

6. In paragraph 5, A motor drive system in which the above-mentioned sun gear for the reducer is rotatably supported on the outer periphery of a hollow cylindrical portion, a worm wheel is arranged on the lower side to perform primary reduction by being gear-coupled to the worm gear, and a spur gear that transmits the rotational output of the worm wheel is formed integrally on the upper side.

7. In paragraph 1, A motor drive system in which the above rotational axis is divided into three or two central portions in which the first and second rotors and the worm gear are formed, and is assembled using a D-cut structure.

8. In paragraph 1, The first and second stators are respectively A stator core having a plurality of teeth formed in a “T” shape and a back yoke interconnected with the plurality of teeth to form a magnetic circuit; A bobbin integrally formed to surround the outer surface on which each of the plurality of teeth coils is wound; and A coil wound on the outer surface of the above bobbin; A motor drive system in which the above-mentioned plurality of teeth and back yokes have an asymmetrical structure.

9. In paragraph 1, A motor drive system in which the first and second stators drive the rotational direction of the first rotor in the opposite direction to the rotational direction of the second rotor so that the common rotational axis of the first and second rotors rotates in the same direction.

10. A single rotary shaft with a worm gear integrally formed in the central part to generate the rotational output of the motor; First and second driving motors formed at both ends of the above rotating shaft; and A single motor drive circuit for applying U, V, and W three-phase motor drive signals from an inverter to the first and second drive motors, respectively; The first and second driving motors are respectively First and second rotors formed integrally on the outer periphery of both ends of the single rotating shaft; First and second stators each having first and second coils composed of a U-phase coil, a V-phase coil, and a W-phase coil wound in a U, V, W three-phase drive manner on a plurality of teeth provided on each stator core to drive the first and second rotors according to the U, V, W three-phase motor drive signals; A first auxiliary printed circuit board having a U-phase coil, a V-phase coil, and a W-phase coil, each of which has a start terminal connected to the U-phase coil, a V-phase coil, and a W-phase terminal terminal formed on one side to which the U, V, and W three-phase motor drive signals are applied, and a common connection wiring formed on the other side to which the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil are connected to form a neutral point (NP) required for Y-connection; and A second auxiliary printed circuit board having a first U-phase, V-phase, and W-phase terminal terminal to which the start terminals of the U-phase coil, V-phase coil, and W-phase coil of the second coil are connected, a second U-phase, V-phase, and W-phase terminal terminal to which the U, V, and W three-phase motor drive signals are applied, a first connection wire connecting the second U-phase terminal terminal to the first W-phase terminal terminal, a second connection wire connecting the second W-phase terminal terminal to the first U-phase terminal terminal, and a third connection wire connecting the second V-phase terminal terminal to the first V-phase terminal terminal, formed on one side, and a common connection wire connecting the end terminals of the U-phase coil, the V-phase coil, and the W-phase coil to form a neutral point (NP) required for Y-connection on the other side; A motor drive system in which the first and second stators are each provided with a plurality of teeth on the stator core, each of which winds the first and second coils in the same direction.

11. In paragraph 10, A motor drive system in which the first and second stators drive the rotational direction of the first rotor in the opposite direction to the rotational direction of the second rotor so that the common rotational axis of the first and second rotors rotates in the same direction.

12. In paragraph 10, A motor drive system in which the first and second stators drive the rotational direction of the first rotor in the opposite direction to the rotational direction of the second rotor so that the common rotational axis of the first and second rotors rotates in the same direction.

13. A single rotary shaft with a worm gear integrally formed in the central portion to generate the rotational output of the motor; First and second driving motors formed at both ends of the above rotating shaft; and A single motor drive circuit for applying U, V, and W three-phase motor drive signals to the first and second drive motors, respectively; The first and second driving motors include first and second rotors formed integrally on the outer periphery of both ends of the single rotating shaft, respectively; and first and second stators each having first and second coils formed of a U-phase coil, a V-phase coil, and a W-phase coil wound on a plurality of teeth provided on each stator core in a U, V, W three-phase driving manner so as to drive the first and second rotors according to the U, V, W three-phase motor driving signals. A motor driving system in which the first stator winds a first coil in a first direction on a plurality of teeth provided in the stator core, and the second stator winds a second coil in a direction opposite to the first direction on a plurality of teeth provided in the stator core.

14. In paragraph 13, A motor drive system in which the first and second drive motors are BLDC motors driven in a 6-step manner.

15. A single rotary shaft with a worm gear integrally formed in the center to generate the rotational output of the motor; First and second driving motors formed at both ends of the above rotating shaft; and A single motor drive circuit for applying U, V, and W three-phase motor drive signals to the first and second drive motors, respectively; The first and second driving motors include first and second rotors formed integrally on the outer periphery of both ends of the single rotating shaft, respectively; and first and second stators each having first and second coils formed of a U-phase coil, a V-phase coil, and a W-phase coil wound on a plurality of teeth provided on each stator core in a U, V, W three-phase driving manner so as to drive the first and second rotors according to the U, V, W three-phase motor driving signals. The first and second stators are each provided with a plurality of teeth on the stator core, and the first and second coils are wound in the same direction. A motor driving system in which, when the U, V, W three-phase motor driving signals are applied to a second coil consisting of a U-phase coil, a V-phase coil, and a W-phase coil of a second stator of a second driving motor, the U-phase motor driving signal is applied to the W-phase coil, the W three-phase motor driving signal is applied to the U-phase coil, and the V-phase motor driving signal is applied to the V-phase coil.

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