KR20230166866A - Swivel Actuator of Hollow Type - Google Patents

Abstract

In the present invention, a drive motor is arranged inside the lower housing, and three gear trains and three pinion gear units for deceleration are arranged in the upper housing at intervals of 120 degrees, and the rotor worm gear, which is the output of the drive motor, is integrated with the rotary table. It relates to an internal hollow swivel actuator in which gears are coupled to transmit reduced rotational power between formed ring gears.
The internal hollow swivel actuator according to the present invention provides primary deceleration between the rotor worm gear of the drive motor and the first to third worm wheels of the first to third gear trains, the first to third worm gears, and the first to third pinions. A large reduction ratio can be obtained through the secondary reduction between the fourth to sixth worm wheels of the gear unit and the third reduction between the first to third pinion gears and the ring gear, resulting in a large increase in torque.

Description

Internal hollow swivel actuator {Swivel Actuator of Hollow Type}

The present invention relates to an actuator, and in particular, an internal hollow type that can increase breaking strength by minimizing backlash and increasing brake torque by combining three gear trains with the rotor worm gear of the drive motor at 120-degree intervals. It's about swivel actuators.

An electric actuator serves to rotate or linearly move a driven object with high-torque torque obtained by converting the rotational force generated from a rotational power source into torque.

In general, conventional actuators use a DC motor as a rotational power source, and the rotor output of the DC motor is generated by a gear train (worm gear formed integrally with the rotor output end and a plurality of spur gears combined). Torque is converted through a gear train to generate high torque rotation output from the actuator output end.

Since these conventional electric actuators use a DC motor with an external casing as a rotational power source, the magnet for sensing the rotational position of the rotor cannot be built into the casing, but is attached separately to the outside and senses the rotor rotational position using an external Hall sensor. The structure of connecting the Hall sensor from the printed circuit board (PCB) with the motor drive circuit built in is complex.

If the actuator does not use a Hall sensor, only forward and reverse rotation movements are possible.

In general, due to the characteristics of the actuator, the overall housing height is low and the product is configured to be long either horizontally or vertically, so it is difficult to adopt a structure in which a DC motor with an external casing is mounted vertically on the inner floor of the housing.

When using a DC motor, the stopped position must be maintained when external pressure is applied to the output shaft that rotates forward or reverse, so the braking torque must be increased using a worm gear.

In order to use a worm gear and a worm wheel in a DC motor and transmit power to the location of the output shaft, a spur gear is generally used to connect. In this case, the following problems exist.

First, because the actuator's housing height is low, there is a problem in that DC motors are generally applied lying down, which makes assembly structure difficult and increases unit cost. In other words, there is a problem in securing assembly space due to the bearing that must hold the casing and worm shaft of the DC motor.

Second, the structure of connecting the motor power to the motor controller becomes complicated.

Third, information on the rotational position of the rotor is required for accurate position control in the actuator. For this purpose, a magnet for rotational position sensing is placed at the bottom of the worm gear of the DC motor, and a Hall sensor IC for rotational position sensing is applied, so DC power is used, and a Hall sensor is connected to the printed circuit board (PCB) to sense the rotational position. The structure is complex.

Fourth, in a gear train that uses multiple spur gears to generate the rotational power of the drive motor to obtain a large reduction ratio, the tolerance increases, resulting in increased backlash and difficult precise position control.

When holding a meeting inside a vehicle, a swivel actuator is being applied to the car seat so that the car seat can be rotated to a desired angle and the meeting can be held with the occupants facing each other.

Korean Patent Publication No. 10-2022-0056821 (Patent Document 1) includes a cylindrical housing with a central hollow cylindrical portion protruding from the bottom and first and second step portions protruding on the inner wall; a drive motor disposed on the bottom of the housing and having a first worm gear integrally formed around the outer periphery of an extension extending to the top of the rotor; It is disposed on the upper part of the second step and coupled to the outer periphery of the first worm gear, and a first worm wheel geared to the first worm gear is formed on one side of the power transmission shaft and a second worm gear is formed on the other side of the power transmission shaft. gear train; a pinion gear unit in which a second worm wheel coupled to the second worm gear is formed at the bottom and a pinion gear is integrally formed at the top; and a rotation table in which the pinion gear of the pinion gear unit is geared to a ring gear integrally formed on the inside of the side portion to rotate, and the driven body is fixed to the upper surface. A swivel actuator including a has been proposed.

The actuator of Patent Document 1 uses a single reduction gear train with a worm wheel and worm gear installed on the power transmission shaft and a single pinion gear unit to drive the rotary table by reducing the rotational speed of the drive motor, to the outer circumference of the rotor of the drive motor. It has a structure that connects the first worm gear formed on the and the ring gear formed on the rotary table.

The swivel actuator of Patent Document 1 has a structure that transmits rotational power using a single gear train between the drive motor and the pinion gear unit that drives the rotary table, so the tolerance between gears can be reduced, but cannot be completely reduced. , In addition, there is a problem that the occurrence of vibration cannot be suppressed because the brake torque that controls the left and right rotation of the driven body (i.e., car seat) rotating together with the rotary table is low.

As a result, the actuator of Patent Document 1 cannot minimize backlash and at the same time has a problem in that it is difficult to suppress the vibration of the rotary table.

: Korean Patent Publication No. 10-2022-0056821

Therefore, the present invention has been proposed to solve the problems of the prior art described above, and its purpose is to provide three first to third gear trains integrally formed on the power transmission shaft with a worm wheel and a worm gear spaced apart from the rotor of the drive motor. It is coupled to a cylindrical rotor worm gear extending at intervals of 120 degrees and rotates the rotary table on which the ring gear is installed using the first to third pinion gear units to minimize backlash and increase brake torque to destroy it. The goal is to provide an internal hollow swivel actuator that can increase strength.

Another object of the present invention is to install a set screw in the bearing housing to suppress the left and right displacement of both ends of the three power transmission shafts in the bearing housing, thereby eliminating the tolerance that occurs when coupling between gears and zeroing backlash. The purpose is to provide an internal hollow swivel actuator.

Another object of the present invention is to combine three gear trains with a rotor worm gear inside the upper housing and suppress the left and right displacement of the three power transmission axes using a set screw to minimize backlash and at the same time improve the stability of the rotary table. The goal is to provide an internal hollow swivel actuator that can suppress the occurrence of vibration.

Another object of the present invention is to arrange the drive motor in the lower housing, and arrange the first to third gear trains and first to third pinion gear units in the upper housing that is stacked and assembled to the lower housing, so that the drive motor and the gear train The purpose is to provide an internal hollow swivel actuator that can easily organize the divisions between the parts and improve the productivity of assembly work.

In order to achieve the above object, the internal hollow swivel actuator according to one feature of the present invention includes a lower housing with a central hollow cylindrical portion protruding upward; an upper housing that is stacked and assembled on top of the lower housing and has a through hole formed in the center where the hollow cylindrical portion protrudes upward; a drive motor disposed on the bottom of the lower housing and having a cylindrical rotor worm gear integrally formed around the outer circumference of a cylindrical rotor support body extending to the upper part of the rotor; First to third worm wheels are arranged and coupled at 120-degree intervals on the outer periphery of the rotor worm gear protruding from the upper housing, and are gear-engaged with the rotor worm gear on one side of the first to third power transmission shafts to achieve primary deceleration. first to third gear trains having first to third worm gears formed on the other side of the first to third power transmission shafts; First to third pinion gears each having fourth to sixth worm wheels formed at the bottom that are gear-combined with the first to third worm gears to achieve secondary reduction, and first to third pinion gears formed integrally at the top. unit; and a rotary table in which the first to third pinion gears of the first to third pinion gear units are gear-coupled with a ring gear integrally formed on the inside of the side portion to achieve tertiary deceleration.

Both ends of the first to third power transmission shafts are rotatably supported by a plurality of bearings, and the bearing housing in which the plurality of bearings are built includes a plurality of plurality to suppress left and right displacement of the first to third power transmission shafts. A set screw can be installed.

The internal hollow swivel actuator according to the present invention is formed on the wall of the upper housing and has a plurality of through holes for adjusting the set screws used to fix the first to third power transmission shafts by pushing the plurality of set screws to one side from the outside. More may be included.

Additionally, the first reduction ratio of the primary reduction, the second reduction ratio of the secondary reduction, and the third reduction ratio of the tertiary reduction may be set to be sequentially smaller toward the rear end.

The drive motor includes a cylindrical rotor support body whose lower end is cup-shaped, and a rotor rotatably coupled to the outer periphery of the hollow cylindrical portion; a stator disposed on the outside of the rotor with an air gap and disposed on the bottom of the housing to generate a rotating magnetic field to rotate the rotor; first and second bearings disposed between the cup-shaped lower end of the rotor support and the lower end of the hollow cylindrical portion to rotatably support the rotor and stacked in series; And it may include a bearing support that is press-coupled with the outer periphery of the hollow cylindrical part and presses the second bearing.

The internal hollow swivel actuator according to the present invention is disposed between the lower end of the cylindrical rotor support and the lower end of the hollow cylindrical part of the lower housing to rotatably support the rotor, and includes first and second bearings stacked in series; And it may further include a third bearing for rotatably supporting the rotary table on the outer periphery of the upper end of the hollow cylindrical part.

In addition, the internal hollow swivel actuator according to the present invention may further include a bearing support disposed between the second bearing and the third bearing to press the outer circumference of the cylindrical rotor support and press the second bearing.

Moreover, the internal hollow swivel actuator according to the present invention further includes first to third support shafts whose lower ends are respectively fixedly installed through the bottom of the upper housing and rotatably support the first to third pinion gear units. can do.

The virtual circle formed by the first to third support shafts forms the same concentric circle as the rotary table, the first to third support shafts are arranged at intervals of 120 degrees on the virtual circle, and the first to third pinion gears Gear combination can be made at three points at 120-degree intervals on the ring gear.

Additionally, the rotor support, the cylindrical rotor worm gear, the first virtual circle formed by the first to third worm wheels, the second virtual circle formed by the first to third support shafts, and the rotary table may be arranged based on the same concentric circle.

As described above, the present invention provides a power transmission structure that can minimize backlash through a gear train change structure that minimizes the number of combined gears by forming a worm wheel and a worm gear integrally at a distance from the power transmission shaft. . As a result, the present invention reduces the overall size and secures space compared to a conventional gear train combining a plurality of spur gears, thereby increasing design freedom and reducing costs.

In addition, in the present invention, a BLDC drive motor is installed on the bottom of the lower housing, and three gear trains, in which a worm wheel and a worm gear are integrally formed at the top with an interval on the power transmission shaft, are connected to the rotor worm gear formed at the output of the rotor protruding inside the upper housing. By combining them at 120-degree intervals, backlash can be minimized and vibration of the rotary table can be suppressed. That is, in the present invention, backlash is minimized and brake torque ( The breaking strength can be increased by increasing the Brake Torque.

In general, a swivel actuator is rotatably supported on a fixed frame fixed to a floor panel inside a vehicle, and a car seat is installed on a rotating table installed on top of the swivel actuator.

In this case, the swivel actuator is driven electrically and can operate the rotary table to rotate in a desired direction with respect to the fixed frame according to the user's switch operation. The operation of the swivel actuator rotates by a preset angle in conjunction with the operation (turn-on) of the operation switch, or when the operation of the operation switch is stopped while rotation is made in conjunction with the operation (turn-on) of the operation switch (turn-on). -Off) It can be driven by stopping in the rotated position.

When the user drives the swivel actuator electrically and stops it after rotating to the desired rotation angle, a predetermined brake torque is applied between the output part of the drive motor, that is, the rotor worm gear and the rotary table, depending on the operation (turn-on) of the operation switch. (Brake Torque) is required.

Since the rotating table has rotational inertia, in order to stop it at the desired position, brake torque is determined by the power transmission mechanism of the gear train and pinion gear unit coupled between the rotor worm gear and the ring gear of the rotary table. It is necessary to increase .

The rotary table on which the user's car seat is installed cannot withstand large forces because the number of meshing gears between the ring gear and pinion gear arranged on the outside of the rotary table is small. In this case, since the pinion gear, which is a spur gear, has a smaller gear diameter than the ring gear, the number of meshing gears between the ring gear and the pinion gear is about 1ea to 1.5ea per pinion gear.

Therefore, in order to increase the brake torque between the ring gear and the pinion gear, it is desirable to increase the number of meshing gears (number of gear teeth in contact) as much as possible.

In this case, three gear trains on the rotor worm gear are arranged to form an equilateral triangle at 120-degree intervals, and the three pinion gears of the three pinion gear units are evenly arranged at 120-degree intervals at three points on the ring gear of the rotary table. The power transmission mechanism that is gear-coupled at one or two points of the rotor worm gear and the ring gear of the rotary table uses a single or a pair of gear train and a single or a pair of pinion gear units. Large brake torque can be obtained.

That is, the present invention adopts a power transmission mechanism in which three gear trains are arranged on the rotor worm gear and three pinion gears of the three pinion gear units are gear-coupled at three points on the ring gear of the rotary table, making the transmission faster than before. Greater brake torque can be obtained.

As the brake torque increases as described above, the degree of freedom in selecting the material of the gear increases.

If SUS-processed products were previously used as gear materials, it is possible to use products made of sintered metal or plastic-processed products, which can be more competitive in terms of unit cost and mass production, so they mesh when combining gears. A design that increases the number of gear teeth is desirable.

In the present invention, three gear trains are arranged concentrically along the circumference of the hollow rotor worm gear to form equilateral triangles at 120-degree intervals, and the three pinion gears of the three pinion gear units are also arranged concentrically with respect to the hollow rotor worm gear. They are evenly spaced at 120-degree intervals and engage with balanced force at three points on the ring gear of the rotary table, which is advantageous in suppressing vibration of the rotary table. For this purpose, in the present invention, for the hollow rotor worm gear, the virtual circle formed by the three worm wheels of the three gear trains, the virtual circle formed by the three pinion gears of the three pinion gear unit, and the rotary table are all arranged in a concentric circle. It is done.

In addition, it is possible to reduce the tolerance between gears by arranging three gear trains in an equilateral triangle structure inside the upper housing as described above, but it is difficult to completely reduce it. In other words, the gap between the tiles and the gears is minimized, but a clearance between the gears occurs, which may cause a problem in which the rotary table coupled with the pinion gear unit and the gears shakes left and right.

This problem may be due to left and right displacement occurring at both ends of the power transmission shaft forming the gear train in the bearing housing. Accordingly, in the present invention, a set screw is added to the rear end of the bearing housing to suppress left and right displacement of both ends of the power transmission shaft, thereby suppressing left and right displacement of the power transmission shaft, thereby controlling the worm gear and pinion gear of the gear train. It is possible to eliminate the tolerance (gap) that occurs when coupling gears between the worm wheels of the unit. As a result, backlash can be reduced to zero by eliminating the gap between the pinion gear of the pinion gear unit and the ring gear of the rotary table.

1 to 3 are a perspective view, a plan view, and a cross-sectional view taken along the line AA of FIG. 2, respectively, of an internal hollow swivel actuator according to a preferred embodiment of the present invention.
Figure 4 is a perspective view of the rotary table of the internal hollow swivel actuator according to a preferred embodiment of the present invention.
Figure 5 is a plan view with the rotary table of the internal hollow swivel actuator according to a preferred embodiment of the present invention removed.
FIGS. 6A to 6C are cross-sectional views taken along lines BB, CC, and DD of FIG. 5, respectively.
Figures 7 and 8 are respectively an exploded perspective view and a completely exploded perspective view of each module of the internal hollow swivel actuator according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described with reference to the attached drawings.

In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. Additionally, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be made based on the content throughout this specification.

The swivel actuator according to the present invention is used with a rotary table to rotate the driven body, that is, the car seat for a vehicle, left and right. In the following description, an internal hollow actuator that drives the driven body using a BLDC type drive motor as a power source is described below. The type swivel actuator is explained.

In the present invention, where BLDC is difficult to apply to general motors, the motor is placed vertically at the bottom of the housing and the motor torque is increased by increasing the size in the radial direction. The drive motor has a stator and rotor placed on the bottom of the housing, and uses an inner rotor type BLDC motor.

The actuator according to the prior art consists of a motor part made of a DC motor, a gear part, and a rotating part as separate parts, so there are many problems such as assembly tolerances and parts supply when assembling the actuator product into a main body.

The swivel actuator according to the present invention can be applied to rotate a driven body installed on a rotary table together with the rotary table.

The swivel actuator according to the present invention includes a BLDC type drive motor, a gear train that transmits the rotation power of the drive motor to the rotary table and increases torque by deceleration, and a rotary table that rotates by the output of the gear train, and the rotary table The driven body is coupled and rotates together with the rotary table. In this case, the drive motor, gear train, and rotary table are integrated into the housing.

The swivel actuator according to the present invention has a disk shape, is hollow on the inside, and has a through hole for cable extraction in the central part, and a driven body (e.g., electric motor) at the top of the rotating body (rotary table). A plurality of, for example, four coupling holes are formed to connect the seat to the seat, and for example, a fixing bolt for fixing to the electric seat may be coupled to the coupling hole.

In the actuator according to the present invention, an annular stator is disposed on the bottom of a housing, and a rotor with a worm gear integrally formed on the upper side is disposed inside the stator. The rotor worm gear is coupled with the worm wheel of the power transmission shaft forming the gear train, the worm gear formed on the other end of the power transmission shaft is coupled to the worm wheel located at the bottom of the pinion gear unit, and the pinion gear located at the top of the pinion gear unit is coupled to the rotor worm gear. It is coupled to a ring gear formed on the inside of the side part of the rotary table to rotate the rotary table.

In this case, the rotor worm gear has three gear trains arranged at 120-degree intervals to form an equilateral triangle, so that each worm wheel of the power transmission shaft forming the three gear trains is gear-coupled, and each worm gear formed on the other end of the power transmission shaft has three gear trains. The three pinion gears, which are coupled to the worm wheel located at the bottom of the two pinion gear units and located at the top of the three pinion gear units, are coupled to the ring gear formed on the inside of the side part of the rotary table at three points at 120-degree intervals to ensure even The rotary table is driven to rotate by force.

As described above, the three gear trains on the rotor worm gear are arranged to form an equilateral triangle at 120-degree intervals, and the three pinion gears of the three pinion gear units are evenly arranged at 120-degree intervals, so that the three gear trains of the rotary table's ring gear are arranged equally at 120-degree intervals. A power transmission mechanism geared at one point is better than a power transmission mechanism geared at one or two points between the rotor worm gear and the ring gear of the rotary table using a single or paired gear train and a single or paired pinion gear unit. When combining gears, the brake torque can be increased by increasing the number of meshing gear teeth.

In the present invention, with respect to the hollow rotor worm gear, the virtual circle formed by the three worm wheels of the three gear trains, the virtual circle formed by the three pinion gears of the three pinion gear units, and the rotary table can be arranged concentrically. Vibration of the rotary table can be suppressed.

Referring to Figures 1 to 8, the internal hollow swivel actuator 200 according to a preferred embodiment of the present invention includes a lower housing 10 with a central hollow cylindrical portion 11 protruding upward; An upper housing (15) that is stacked and assembled on top of the lower housing (10) and has a through hole (15c) formed in the center through which the hollow cylindrical portion (11) protrudes upward; A drive motor 100 disposed on the bottom 10b of the lower housing 10 and having a rotor worm gear 35 integrally formed around the outer periphery of an extension extending to the top of the rotor 30; Each is disposed on the bottom (15b) of the upper housing (15) and coupled to the outer periphery of the rotor worm gear (35), and the rotor worm gear (35) is located on one side of the first to third power transmission shafts (71a-71c). First to third worm wheels (72a-72c) are formed on the other side of the first to third power transmission shafts (71a-71c) and first to third worm gears (73a-73c) are formed on the other side of the first to third power transmission shafts (71a-71c). 3 gear train (70a-70c); Fourth to sixth worm wheels (81a-81c) geared to the first to third worm gears (73a-73c) are formed at the bottom, respectively, and first to third pinion gears (82a-82c) are formed at the top. First to third pinion gear units (80a-80c) formed of; And the first to third pinion gears (82a-82c) of the first to third pinion gear units (80a-80c) are gear-coupled with the ring gear (24) integrally formed on the inside of the side portion (23). It includes a rotary table 20 that rotates.

A hollow cylindrical part 11 protrudes at the center of the lower housing 10, and a drive motor 100 is installed in the space of the floor 10b between the hollow cylindrical part 11 and the circular wall 10a. .

In addition, the upper housing 15 is stacked and assembled on the upper part of the lower housing 10, and is fixed by fastening a plurality of fixing bolts or screws 17. The bottom 15b of the upper housing 15 accommodates the first to third gear trains 70a-70c and the first to third pinion gear units 80a-80c, and rotates at the top thereof. The table 20 is installed to be rotatable.

The drive motor 100 generates rotational power, and the first to third gear trains 70a-70c receive the rotational power and convert it into torque by reducing the speed to generate the reduced rotational power with increased torque. Occurs.

In addition, the first to third pinion gear units (80a-80c) are installed perpendicular to the first to third worm gears (73a-73c) of the first to third gear trains (70a-70c), respectively. After receiving the reduced rotational power with increased torque, it serves to transmit it to the ring gear 24 formed integrally with the rotary table 20.

The drive motor 100 may be configured as an inner rotor type in which the rotor 30 is disposed inside the stator 40, and is rotatable around the outer circumference of the hollow cylindrical portion 11 of the lower cover 11. The rotor 30 is combined with the stator, which is disposed with an air gap on the outside of the rotor 30 and disposed on the upper surface of the lower cover 11 to generate a rotating magnetic field to rotate the rotor 30. It includes (40), and a rotor worm gear 35 is integrally formed on the outer periphery of the extension portion extending upward from the rotor 30.

The magnet 31 disposed on the outer periphery of the back yoke 32 located on the inside of the rotor 30 is made of a plurality of divided magnet pieces of N and S poles, or a ring-shaped magnet with N and S poles. A multi-pole split magnetized magnet can be used, and the back yoke 32 is installed on the back of the magnet 31 to form a magnetic circuit.

The stator 40 includes a stator core 45 including 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; upper and lower insulators (44a, 44b) made of an insulating material integrally formed to surround an outer peripheral surface on which the coils (43) of each of the plurality of teeth are to be wound; and a coil 43 wound around the outer peripheral surface of the insulators 44a and 44b.

In this case, the insulators 44a and 44b may be integrally formed as a bobbin and stator support body surrounding the back yoke 42 along with a plurality of teeth 41.

In the swivel actuator 200 according to the present invention, the drive motor 100 may be configured as, for example, a BLDC motor with a 20 pole-18 slot structure. In addition, when the coil 43 of the stator 40 is wound around a plurality of teeth 41, the drive motor 100 winds the coil 43 in a three-phase structure of U, V, and W, and U, V, The other end of the W three-phase coil 43 may be connected, for example, in a Y-connection method. Moreover, the drive motor 100, for example, can be driven in a 6-step radio wave drive method using an inverter after receiving rotor position signals from two or three Hall sensors in the motor drive circuit. .

First and second bearings 61 and 62 are installed on the outer periphery of the hollow cylindrical portion 11 of the lower cover 11 to rotatably support the rotor 30.

The upper housing 15 has first to third grooves 16a-16c disposed on the bottom 15b at 120-degree intervals around a through hole 15c located in the center of the circular wall 15a.

The first to third gear trains (70a-70c) are respectively disposed with first to third grooves (16a-16c) of the upper housing (15) and have hollow holes protruding upward through the through hole (15c). They are evenly arranged at 120-degree intervals around the rotor worm gear 35, and are gear-coupled with the rotor worm gear 35 on one side of the first to third power transmission shafts 71a-71c. Worm wheels (72a-72c) are formed, and first to third worm gears (73a-73c) are formed on the other side of the first to third power transmission shafts (71a-71c).

The first to third grooves 16a-16c have a groove shape that accommodates not only the first to third gear trains 70a-70c but also the first to third pinion gear units 80a-80c.

The first to third gear trains (70a-70c) are evenly spaced at 120 degree intervals centered on the hollow rotor worm gear (35) protruding above the upper housing (15), respectively. 3 Both ends of the power transmission shafts 71a-71c are rotatably supported by three pairs of bearings 74a-74f.

In this case, in the present invention, the first to third power transmission shafts 71a-71c are provided with a bearing housing to suppress left-right displacement from occurring in the bearing housings 75a-75f that support the three pairs of bearings 74a-74f. Set screws (77a-77f) were added to the rear ends of (75a-75f), respectively, to limit left and right movement of the first to third power transmission shafts (71a-71c).

The set screws (76a-76f) have male threads formed on the outer periphery of the body, and a groove in the shape of "-" or "+" that can accommodate the tip of the driver is formed at the rear end, and the tip is curved or flat. It can be done in the form

The set screws (76a-76f) form female threads in through-holes penetrating inward from the rear end of the bearing housing (75a-75f), and the set screws (76a-76f) are screwed together to form six set screws (76a-76a-76f). The front end of 76f) is coupled to both ends of the first to third power transmission shafts 71a-71c by pushing and compressing them.

The set screws (76a-76d) are installed in all six bearing housings (75a-75f) of the six bearings (74a-74f) that rotatably support both ends of the first to third power transmission shafts (71a-71c). It is preferable to install it only on one side of the bearing housing (75a-75f) to support one end of the first to third power transmission shafts (71a-71c). It is also possible to suppress left and right flow by pushing in one direction.

The set screws (76a-76f) may have distal ends protruding in a spherical shape to minimize contact with the ends of the first to third power transmission shafts (71a-71c), or the distal ends may have a planar shape. In the present invention, since the rpm of the drive motor 100 is small and the gear ratio is large, the shape of the tip of the set screws 76a-76f does not have a significant influence.

The first to third pinion gear units (80a-80c) are installed on first to third support shafts (83a-83c) whose lower ends penetrate the bottom (15b) of the upper housing (15), respectively. Fourth to sixth worm wheels (81a-81c), which are gear-coupled with the first to third worm gears (73a-73c), are rotatably coupled to the lower ends of the first to third support shafts (83a-83c), and are rotatably coupled to the upper ends of the first to third support shafts (83a-83c). The first to third pinion gears 82a-82c are formed integrally with the fourth to sixth worm wheels 81a-81c.

In this case, the fourth to sixth worm wheels (81a-81c) and the first to third pinion gears (82a-82c) may be integrally formed by injection molding using synthetic resin, and may be manufactured separately. It is also possible to use them by assembling them and rotatably coupling them to the support shaft 83.

The 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 top plate 21 for coupling with a main body (eg, an electric car seat) installed on the rotary table 20.

At the center of the top plate 21, the stator coil 43 of the drive motor 100 and a plurality of Hall sensors provided in the Hall sensor assembly are connected to a motor drive circuit installed outside the swivel actuator 200. A central through hole 25 through which the cable passes is formed.

Accordingly, the cable is introduced into the lower part through the central through hole 25 provided in the center of the upper plate and the hollow cylindrical portion 11 of the lower housing 10, and then through the through hole formed in the bottom of the lower housing 10. It is connected to the stator coil 43 and the hall sensor assembly 50 through (19a). The through hole (19a) is finished by assembling the through hole cover (19).

In this case, the printed circuit board (PCB) on which the motor driving circuit is implemented is installed on the outside of the swivel actuator 200 and then connected to the stator coil 43 and the Hall sensor assembly 50 of the driving motor 100 installed inside through the cable. ) can be connected to. However, the printed circuit board (PCB) on which the motor driving circuit is implemented can also be built into the space formed in the lower part of the lower housing 10 or the lower side of the upper housing 15.

When connected from the outside to the stator coil 43 of the internally installed drive motor 100 and the Hall sensor assembly 50 through the cable, the cable includes the U, V, and W output terminals of the inverter circuit and three Hall sensors. It is necessary to have 8 wires consisting of (Hall sensor) (H1~H3), Vcc, and GND.

As described above, in the present invention, the hollow cylindrical portion 11 protruding at the center of the lower housing 10 extends upward through the through hole 15c of the upper housing 15 and penetrates the rotary table 20. It is exposed through the hole 25. As a result, the operation control cable of the drive motor 100 is connected to the stator coil 43 and the Hall sensor assembly 50 disposed in the lower housing 10 from the outside through the through hole 11a of the hollow cylindrical portion 11. It can be easily connected to and does not interfere with the cable even when the car seat installed on the top of the rotary table is rotated.

In addition, the upper end of the hollow cylindrical part 11 of the lower housing 10 is located in the central through hole 25, and the rotary table 20 is installed at the center of the inner peripheral surface of the upper plate 21. A third bearing 63 may be installed on the outer periphery to rotatably support it.

The third bearing 63 may be composed of a ball bearing with balls inserted between the inner ring and the outer ring. In this case, the outer ring of the third bearing 63 is supported on the bearing housing 26 protruding from the lower part of the rotary table 20, and the lower end of the inner ring of the third bearing 63 is at the upper end of the bearing support 64. It is supported on the hollow cylindrical portion 11 of the lower housing 10.

In addition, the hollow type swivel actuator 200 has a stopper insertion groove formed at the upper end of the hollow cylindrical portion 11, and the stopper insertion groove is provided with a stopper ring 13 to prevent the rotary table 20 from being separated. This is combined.

A ring gear 24 is integrally formed on the inside of the side portion 23 of the rotary table 20, and the ring gear 24 includes the first to third pinion gear units 80a-80c. To third pinion gears (82a-82c) are gear-coupled.

As described above, in the present invention, first to third worm wheels (72a-72c) and first to third worm gears (73a-73c) are provided at intervals on each of the first to third power transmission shafts (71a-71c). It provides a power transmission structure that can minimize backlash through a gear train change structure that is integrated and minimizes the number of gears combined. As a result, the present invention reduces the overall size and secures space compared to a conventional gear train combining a plurality of spur gears, thereby increasing design freedom and reducing costs.

In addition, in the present invention, the BLDC drive motor 100 is installed on the bottom 10b of the lower housing 10, and the first to the first to the bottom 15b of the upper housing 15 assembled on the upper part of the lower housing 10. First to third gear trains (70a) in which third worm wheels (72a-72c) and first to third worm gears (73a-73c) are formed integrally with the first to third power transmission shafts (71a-71c) at intervals. By arranging -70c) evenly at 120-degree intervals inside the upper housing 15, backlash can be minimized and vibration occurrence can be suppressed.

In the present invention, as described above, the three first to third gear trains 70a-70c are evenly arranged and coupled to the rotor worm gear 35 of the drive motor 100 at 120-degree intervals, and the first to third pinions are connected to each other. Gear coupling at three points to the ring gear 24 using the three fourth to sixth worm wheels (81a-81c) and first to third pinion gears (82a-82c) of the gear unit (80a-80c) This is being done.

Therefore, in the present invention, by adopting a power transmission mechanism that combines three first to third gear trains (70a-70c) and first to third pinion gear units (80a-80c), three gears arranged at equal intervals The rotary table 20 is driven to rotate by rotating the ring gear 24 using the first to third pinion gears 82a-82c, and as a result, the number of meshing gears (number of gear teeth in contact) is increased to apply the brake. The breaking strength can be increased by increasing the brake torque.

In addition, in the present invention, with respect to the hollow rotor worm gear 35, a virtual circle formed by the three first to third worm wheels (72a-72c) of the three first to third gear trains (70a-70c), three The virtual circle formed by the three first to third pinion gears (82a-82c) of the first to third pinion gear units (80a-80c) and the rotary table (20) can all be arranged in a concentric circle, Vibration of the rotary table can be suppressed.

It is possible to reduce the tolerance between gears by arranging the first to third gear trains 70a-70c inside the upper housing as described above, but it is difficult to completely reduce it. In other words, the gap between gears is minimized, but clearance between gears occurs and clearance occurs, so the rotary table 20 and the driven animal that are gear-coupled with the first to third pinion gears 82a-82c shake left and right. Problems may arise.

This problem may be due to left and right displacement occurring at both ends of the power transmission shaft forming the gear train in the bearing housing. In the present invention, both ends of the first to third power transmission shafts 71a-71c are rotatably supported by six bearings 74a-74f, respectively.

Six bearings (74a-74f) are built into bearing housings (75a-75f) fixed to the bottom (15b) of the upper housing (15). In the present invention, both ends of the first to third power transmission shafts (71a-71c) are provided with a set screw (76a) at the rear end of the bearing housing (75a-75f) to suppress left and right displacement from occurring in the bearing housing (75a-75f). -76f) was added.

As a result, by suppressing the left-right displacement of the first to third power transmission shafts 71a-71c, the first to third worm gears 73a-73c of the first to third gear trains 70a-70c and the first Eliminates the tolerance (gap) that occurs when engaging gears between the fourth to sixth worm wheels (81a-81c) of the first to third pinion gear units (80a-80c), and also eliminates the gap between the first to third pinion gear units (80a-80c). Backlash is also reduced to zero by eliminating the gap between the first to third pinion gears (82a-82c) of (80a-80c) and the ring gear (24) of the rotary table (20). can do.

Compression between the set screws (76a-76f) and the first to third power transmission shafts (71a-71c) as described above is performed by assembling the first to third power transmission shafts (71a-71c) inside the upper housing (15). After that, the set screws (76a-76f) are advanced in one direction from the outside through the set screw adjustment through hole (12) formed in the wall (15a) of the upper housing (15) to move the first to third power transmission shafts. By pushing (71a-71c), the left and right flow of the first to third power transmission shafts (71a-71c) can be suppressed.

Below, the operation of the internal hollow swivel actuator 200 according to the present invention will be described with reference to FIGS. 1 to 8.

The internal hollow swivel actuator 200 of the present invention first operates the BLDC drive motor 100 installed on the bottom of the lower housing 10, so that the rotor 30 rotates and moves to the upper side of the rotor 30. The integrally formed rotor worm gear 35 also rotates in the same direction.

When the rotor worm gear 35 rotates, the first to third worm wheels 72a of the first to third gear trains 70a to 70c are arranged and geared at intervals of 120 degrees on the outer periphery of the rotor worm gear 35. As -72c) rotates, primary deceleration occurs and the first to third power transmission shafts (71a-71c) also rotate.

As a result, the first to third worm gears (73a-73c) formed on the other side of the first to third power transmission shafts (71a-71c) are gear-coupled with the first to third pinion gear units (80a-80c). ) Secondary deceleration is achieved by rotating the fourth to sixth worm wheels (81a-81c).

Accordingly, the first to third pinion gears (82a-82c) located at the top of the first to third pinion gear units (80a-80c) are driven to rotate, and the first to third pinion gears (82a-82c) are driven to rotate. In 82c), the ring gear 24 provided on the rotary table 20 is engaged at intervals of 120 degrees and rotates in the same direction to achieve third deceleration.

Generally, the reduction ratio of a reduction device is calculated as (number of driven gear teeth/number of drive pinion gear teeth), and when multi-stage gear combination is performed, the total reduction ratio is calculated as the product of each reduction ratio.

In this case, in the present invention, the gear ratio (reduction ratio) (R1) between the rotor worm gear 35 of the drive motor 100 and the first to third worm wheels 72a-72c of the first to third gear trains 70a-70c ) is 20:1, the gear ratio (reduction ratio) (R2) between the first to third worm gears (73a-73c) and the fourth to sixth worm wheels (81a-81c) is 10:1, the first to third pinion By setting the gear ratio (reduction ratio) (R3) between the gears 82a-82c and the ring gear 24 to 2:1, a total reduction ratio of 400:1 can be easily achieved.

In this case, by setting the gear ratio (reduction ratio) between gears to be smaller as the output increases (i.e., R1 > R2 > R3), a stable high torque output can be obtained even if a large torque conversion occurs at the final stage.

For example, when the BLDC drive motor 100 rotates at 800 rpm, the swivel actuator 200 of the present invention is decelerated to 400:1 in the case of a total reduction ratio of 400:1 by three-stage deceleration, so that the rotary table 20 The rotation speed is lowered to a low speed of 2 rpm and the rotation torque is increased by 400 times, resulting in a large increase in torque.

When the swivel actuator 200 of the present invention is applied to a car seat, when holding a meeting inside a vehicle, it is possible to rotate the car seat to a desired angle and hold the meeting with the occupants facing each other.

As described above, in the present invention, backlash is minimized and vibration generation is suppressed by arranging the first to third gear trains and the first to third pinion gear units at 120-degree intervals inside the upper housing. can do.

In addition, in the present invention, a set screw was added to the rear end of the bearing housing to prevent left and right displacement of both ends of the first to third power transmission shafts from occurring in the bearing housing. In the present invention, after assembling the first to third gear trains inside the upper housing, the set screw is advanced in one direction to push the first to third power transmission shafts to suppress left and right movement of the first to third power transmission shafts. You can do it.

As a result, the left and right displacement of the first to third power transmission shafts is suppressed by tightening the set screw, thereby reducing the first to third worm gears of the first to third gear trains and the fourth gears of the first to third pinion gear units. Eliminates the tolerance (gap) that occurs when engaging gears between the first to sixth worm wheels, and also eliminates the gap between the first to third pinion gears of the first to third pinion gear units and the ring gear of the rotary table. ) can be removed to reduce backlash to zero.

In addition, in the present invention, the gear train is formed integrally with a worm wheel and an output worm gear at intervals, the worm wheel is gear-coupled with the rotor worm gear integrally formed on the upper part of the rotor, and the worm gear is gear-coupled with the worm wheel of the pinion gear unit to generate rotational power. Torque conversion occurs as power is transmitted and decelerated by transmitting to the rotary table.

Moreover, in the present invention, the drive motor is placed in the lower housing, and the first to third gear trains and the first to third pinion gear units are stacked and assembled in the upper housing, making it easy to organize the partition between the drive motor and gear train. This can be achieved and the productivity of assembly work can be improved.

In the above, the present invention has been shown and described by taking specific preferred embodiments as examples, but the present invention is not limited to the above-described embodiments and is within the scope of the spirit of the present invention and is within the scope of common knowledge in the technical field to which the invention pertains. Various changes and modifications will be possible by those who have it.

The swivel actuator according to the present invention can be applied to rotate together with the rotary table to rotate a driven object such as a car seat installed on the rotary table to the left and right.

10: lower housing 10a, 15a: circular wall
10b, 15b: bottom 11: cylindrical part
11a: Through hole 12: Through hole for set screw adjustment
13: Stopper ring 15: Upper housing
15c, 19a: Through hole 16a-16c: Groove
17: Fixing bolt 19: Cover
20: Rotating table 21: Top plate
22,25: Through hole 23: Side part
24: ring gear 26: bearing housing
30: rotor 31: magnet
32: Back yoke 35,73a-73c: Worm gear
40: Stator 41: Teeth
42: back yoke 43: coil
44a, 44b: insulator 45: stator core
61~63,74a-74f: Bearing 75a~75f: Bearing housing
64: Bearing support 70a-70c: Gear train
71a-71c: Power transmission shaft 72a-72c, 81a-81c: Worm wheel
77a~77f: Set screw 80a-80c: Pinion gear unit
82a-82c: pinion gear 83a-83c: support shaft
100: Drive motor 200: Swivel actuator

Claims (10)

a lower housing with a central hollow cylindrical portion protruding upward;
an upper housing that is stacked and assembled on top of the lower housing and has a through hole formed in the center where the hollow cylindrical portion protrudes upward;
a drive motor disposed on the bottom of the lower housing and having a cylindrical rotor worm gear integrally formed around the outer circumference of a cylindrical rotor support body extending to the upper part of the rotor;
First to third worm wheels are arranged and coupled at 120-degree intervals on the outer periphery of the rotor worm gear protruding from the upper housing, and are gear-engaged with the rotor worm gear on one side of the first to third power transmission shafts to achieve primary deceleration. first to third gear trains having first to third worm gears formed on the other side of the first to third power transmission shafts;
First to third pinion gears each having fourth to sixth worm wheels formed at the bottom that are gear-combined with the first to third worm gears to achieve secondary reduction, and first to third pinion gears formed integrally at the top. unit; and
An internal hollow swivel actuator comprising a rotary table in which tertiary deceleration is achieved by gearing the first to third pinion gears of the first to third pinion gear units to a ring gear integrally formed on the inside of the side portion. According to paragraph 1,
Both ends of the first to third power transmission shafts are rotatably supported by a plurality of bearings, and the bearing housing in which the plurality of bearings are built includes a plurality of plurality to suppress left and right displacement of the first to third power transmission shafts. Internal hollow swivel actuator on which a set screw is installed. According to paragraph 2,
An internal hollow swivel actuator further comprising a plurality of through-holes for adjusting the set screws formed on the wall of the upper housing and used to fix the first to third power transmission shafts by pushing the plurality of set screws to one side from the outside. According to paragraph 1,
An internal hollow swivel actuator wherein the first reduction ratio of the primary reduction, the second reduction ratio of the secondary reduction, and the third reduction ratio of the tertiary reduction are sequentially set to be smaller toward the rear end. According to paragraph 1,
The driving motor is
A rotor including a cylindrical rotor support body whose lower end is cup-shaped and rotatably coupled to the outer periphery of the hollow cylindrical portion;
a stator disposed on the outside of the rotor with an air gap and disposed on the bottom of the housing to generate a rotating magnetic field to rotate the rotor;
first and second bearings disposed between the cup-shaped lower end of the rotor support and the lower end of the hollow cylindrical portion to rotatably support the rotor and stacked in series; and
A swivel actuator comprising a bearing support that is press-coupled to the outer periphery of the hollow cylindrical part and presses the second bearing. According to paragraph 1,
first and second bearings disposed between the lower end of the cylindrical rotor support and the lower end of the hollow cylindrical part of the lower housing to rotatably support the rotor and stacked in series; and
An internal hollow swivel actuator further comprising a third bearing for rotatably supporting the rotary table on an outer periphery of an upper end of the hollow cylindrical part. According to clause 6,
An internal hollow swivel actuator further comprising a bearing support that is press-coupled to the outer periphery of the cylindrical rotor support and disposed between the second bearing and the third bearing to press the second bearing. According to paragraph 1,
An internal hollow swivel actuator further comprising first to third support shafts, each of which has a lower end fixedly installed through the bottom of the upper housing and rotatably supports the first to third pinion gear units. According to clause 8,
The virtual circle formed by the first to third support shafts forms the same concentric circle as the rotary table, the first to third support shafts are arranged at intervals of 120 degrees on the virtual circle, and the first to third pinion gears is an internal hollow swivel actuator that engages gears at three points at 120-degree intervals on a ring gear. According to paragraph 1,
The rotor support, the cylindrical rotor worm gear, the first virtual circle formed by the first to third worm wheels, the second virtual circle formed by the first to third support shafts, and the rotary table are internal hollow swivel actuators arranged based on the same concentric circle. .

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