Lift module and driving method thereof

Abstract

The lift module of the present invention comprises a motor providing rotational force, a worm gear drive unit including a worm shaft that rotates by receiving the rotational force of the motor, and a worm wheel configured to rotate in mesh with the worm shaft, an internal gear formed integrally with the worm wheel or coupled to rotate integrally with the worm wheel, a transmission gear unit disposed on the inner circumference of the internal gear and configured to rotate in mesh with the internal gear, and a lifting unit that performs a lifting operation in conjunction with the rotation of the transmission gear unit, wherein the lifting unit is coupled to the transmission gear unit and configured to rotate in conjunction with the rotation of the transmission gear unit, and comprises a screw coupling unit including a first screw section and a second screw section, a first shaft screw-coupled to the first screw section and configured to move linearly while rotation is restricted, a second shaft disposed spaced apart from the first shaft and screw-coupled to the second screw section and configured to move linearly while rotation is restricted, and a member coupled to the first shaft and moving in conjunction with the linear movement of the first shaft. It includes a first lifting plate and a second lifting plate coupled to the second shaft and moving in conjunction with the linear movement of the second shaft, wherein the first screw section and the second screw section include screw threads in opposite directions, and the first shaft and the second shaft move linearly in opposite directions due to the same rotational direction of the screw coupling part.

Description

Technology Field

[0001] The present invention relates to a lift module and a driving method thereof, and more specifically, to a lift module and a driving method thereof that transmits the rotational force of a motor to a plurality of lifting units through a worm gear driving unit, an internal gear and a transmission gear unit, and can move a first shaft and a second shaft in opposite directions linearly using screw sections provided in each lifting unit. Background Technology

[0003] Lift devices are used to lift or lower pallets, loads, or workpieces in logistics warehouses, manufacturing sites, and automation facilities. These lift devices can be applied not only to stationary equipment but also to AMRs (Autonomous Mobile Robots), AGVs (Automated Guided Vehicles), logistics transport robots, or various unmanned transport devices.

[0004] Conventional lift modules often adopt a structure that raises the top plate or support members around a single screw jack or a single lifting axis. However, a single lifting axis structure is vulnerable to eccentric loads when the load of the cargo acts off-center, and tilting or shaking of the support members may occur during lifting operation.

[0005] Furthermore, to secure a sufficient lifting stroke within a limited height, it is sometimes necessary to increase the length of the screw or add a separate link structure. In this case, the overall height of the lift module, the number of parts, and the assembly space increase, posing a problem that makes it difficult to apply to transfer devices requiring a low-profile structure.

[0006] On the other hand, when using multiple lifting axes, uniform rotational force must be transmitted to each axis. However, using separate motors complicates control, and imbalances in lifting may occur due to synchronization errors between axes. Furthermore, using separate, complex gear trains or chain drive structures can result in a larger device and make maintenance difficult.

[0007] Therefore, a lift module is required that can synchronously transmit the rotational force of a single motor to multiple lifting units, increase the relative amount of movement in the vertical direction at each lifting unit, and enable stable lifting operation even in a limited installation space. The problem to be solved

[0009] The present invention aims to solve the problem of providing a lift module capable of stably supporting pallets or loads at multiple points by simultaneously transmitting the rotational force of a single motor to a plurality of lifting units.

[0010] The present invention aims to solve the problem of providing a lift module capable of synchronously driving a plurality of lifting units.

[0011] The present invention aims to solve the problem of providing a lift module capable of increasing the lifting stroke.

[0012] The present invention aims to solve the problem of providing a lift module capable of stably supporting axial and radial loads.

[0013] The present invention aims to solve the problem of providing a lift module and a driving method thereof that can stably maintain a lifting position even when the motor is stopped. means of solving the problem

[0015] A lift module according to one embodiment of the present invention comprises a motor providing rotational force, a worm gear drive unit including a worm shaft that rotates by receiving the rotational force of the motor and a worm wheel configured to rotate in mesh with the worm shaft, an internal gear formed integrally with the worm wheel or coupled to rotate integrally with the worm wheel, a transmission gear unit disposed on the inner circumference of the internal gear and configured to rotate in mesh with the internal gear, and a lifting unit that performs a lifting operation in conjunction with the rotation of the transmission gear unit, wherein the lifting unit is coupled to the transmission gear unit and configured to rotate in conjunction with the rotation of the transmission gear unit, and comprises a screw coupling unit including a first screw section and a second screw section, a first shaft screw-coupled to the first screw section and configured to move linearly while rotation is restricted, a second shaft disposed spaced apart from the first shaft and screw-coupled to the second screw section and configured to move linearly while rotation is restricted, and coupled to the first shaft and coupled to the linear movement of the first shaft It includes a moving first lifting plate and a second lifting plate coupled to the second shaft and moving in conjunction with the linear movement of the second shaft, wherein the first screw section and the second screw section include screw threads in opposite directions, and the first shaft and the second shaft can move linearly in opposite directions by the same rotational direction of the screw coupling part.

[0016] According to one embodiment of the present invention, the first screw section and the second screw section of the lift module are female screw sections formed on the inner circumference of the screw coupling part, and the first shaft and the second shaft may each include a male screw section that is screw-coupled to the first screw section and the second screw section.

[0017] In the case where the first screw section of the lift module according to one embodiment of the present invention is formed as a right screw, the second screw section is formed as a left screw, and in the case where the first screw section is formed as a left screw, the second screw section can be formed as a right screw.

[0018] The screw threads of the first screw section and the second screw section of the lift module according to one embodiment of the present invention may be formed as trapezoidal screw threads.

[0019] The screw coupling portion of the lift module according to one embodiment of the present invention may include a first nut member having a first screw section formed therein and a second nut member having a second screw section formed therein and arranged coaxially with the first nut member to be coupled to rotate integrally with the first nut member.

[0020] The transmission gear portion of the lift module according to one embodiment of the present invention includes a transmission gear coupled coaxially to the screw coupling portion on the outer circumference side of the screw coupling portion, and the transmission gear and the screw coupling portion may be configured to rotate integrally.

[0021] The transmission gear portion of a lift module according to one embodiment of the present invention includes a plurality of transmission gears that are spaced apart from each other along the circumferential direction of the internal gear and rotate simultaneously by the rotation of the internal gear, and the lifting portion is provided in a plurality of such portions to correspond to each of the plurality of transmission gears, and each of the plurality of transmission gears may be coupled to rotate integrally with a screw coupling portion provided in each of the plurality of lifting portions.

[0022] A first shaft provided in each of the plurality of lifting parts of a lift module according to one embodiment of the present invention may be arranged to protrude upward relative to the internal gear, and a second shaft provided in each of the plurality of lifting parts may be arranged to protrude downward relative to the internal gear.

[0023] The load acting on the plurality of lifting parts of the lift module according to one embodiment of the present invention can be distributed and supported by a plurality of screw coupling parts each coupled to the plurality of transmission gears.

[0024] The worm wheel and the internal gear of the lift module according to one embodiment of the present invention may be formed as a single member or formed as separate members and combined to rotate integrally with each other.

[0025] A lifting module according to one embodiment of the present invention may include a bearing portion that rotatably supports the screw coupling portion.

[0026] The bearing portion of the lift module according to one embodiment of the present invention may include a thrust bearing portion that supports an axial load of the screw coupling portion and a radial bearing portion that supports a radial load of the screw coupling portion.

[0027] The bearing portion of the lift module according to one embodiment of the present invention includes a first bearing portion disposed on one axial side of the screw coupling portion and a second bearing portion disposed on the other axial side of the screw coupling portion, and the first bearing portion and the second bearing portion can support axial loads in opposite directions acting on the screw coupling portion according to the linear movement of the first shaft and the second shaft.

[0028] According to one embodiment of the present invention, at least one of the first bearing portion and the second bearing portion of the lift module is provided as a composite bearing including a needle roller portion and a thrust ball bearing portion, wherein the needle roller portion supports a radial load of the screw coupling portion and the thrust ball bearing portion supports an axial load of the screw coupling portion.

[0029] At least one of the first lifting plate and the second lifting plate of the lift module according to one embodiment of the present invention may be coupled to an external load support member that supports a pallet or load.

[0030] According to one embodiment of the present invention, the first shaft of the lift module may have its rotation restricted by the first lifting plate, and the second shaft may have its rotation restricted by the second lifting plate.

[0031] A lift module according to one embodiment of the present invention includes a support frame that supports at least a portion of the worm gear drive unit, the internal gear, the transmission gear unit, and the lifting unit, and the support frame may include a bearing block on which a bearing unit that rotatably supports the screw coupling unit is mounted, a motor-side bearing block that supports the motor or the worm shaft, a first fixed plate, and a second fixed plate spaced apart from the first fixed plate.

[0032] A lift module according to one embodiment of the present invention includes a power transmission unit that connects the output shaft of the motor and the worm shaft to transmit the rotational force of the motor to the worm shaft, and the power transmission unit may include a driving pulley coupled to the output shaft of the motor, a driven pulley coupled to the worm shaft, and a timing belt that is stretched between the driving pulley and the driven pulley to transmit rotational force.

[0033] In one embodiment of the present invention, the lead angle between the worm shaft and the worm wheel of the lift module may be formed to be less than or equal to the friction angle, thereby limiting the reverse rotation of the worm wheel by the load acting on the lifting part.

[0034] A method according to one embodiment of the present invention may include the steps of: transmitting the rotational force of a motor of a lift module to a worm shaft; rotating a worm wheel engaged with the worm shaft; rotating an internal gear that rotates integrally with the worm wheel; rotating a transmission gear portion engaged with the internal gear; rotating a screw coupling portion including a first screw portion and a second screw portion having screw threads in the opposite direction to the first screw portion in conjunction with the rotation of the transmission gear portion; moving a first shaft screw-coupled to the first screw portion in a first linear direction while rotation is restricted; moving a second shaft screw-coupled to the second screw portion in a second linear direction opposite to the first linear direction while rotation is restricted; and moving a first lifting plate and a second lifting plate in conjunction with the linear movement of the first shaft and the second shaft. Effects of the invention

[0036] The present invention has the effect of providing a lift module capable of stably supporting pallets or loads at multiple points by simultaneously transmitting the rotational force of a single motor to a plurality of lifting units.

[0037] The present invention has the effect of providing a lift module capable of synchronously driving a plurality of lifting units.

[0038] The present invention has the effect of providing a lift module capable of increasing the lifting stroke.

[0039] The present invention has the effect of providing a lift module capable of stably supporting axial and radial loads.

[0040] The present invention has the effect of providing a lift module and a driving method thereof that can stably maintain a lifting position even when the motor is stopped. Brief explanation of the drawing

[0042] FIG. 1 is an overall perspective view of a lift module according to one embodiment of the present invention. FIG. 2 is a perspective view illustrating the arrangement structure of a motor, a power transmission unit, a worm gear driving unit, and a lifting unit according to an embodiment of the present invention. FIG. 3 is a drawing for explaining the meshing structure of a worm gear driving part, an internal gear, and a transmission gear part according to an embodiment of the present invention. FIG. 4 is a perspective view illustrating the combined structure of an internal gear, a transmission gear section, and a lifting section according to one embodiment of the present invention. FIG. 5 is a diagram illustrating the disassembled structure of the lifting part and the bearing part according to one embodiment of the present invention. Specific details for implementing the invention

[0043] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. In this specification, identical or similar reference numbers are assigned to identical or similar components even if they are different embodiments, and the description thereof is replaced by the first description. Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the embodiments disclosed in this specification. Additionally, it should be noted that the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and should not be interpreted as limiting the technical concept disclosed in this specification.

[0044] FIG. 1 is an overall perspective view of a lift module according to one embodiment of the present invention.

[0045] Referring to FIG. 1, a lift module (100) according to one embodiment of the present invention may include a motor (110) that provides rotational force, a power transmission unit (120) that transmits the rotational force of the motor (110), a worm gear drive unit (130) that is driven by receiving the rotational force of the motor (110), an internal gear (140) that rotates in conjunction with the rotation of the worm gear drive unit (130), a transmission gear unit (150) that is provided to rotate in conjunction with the internal gear (140), a lifting unit (160) that performs a lifting operation in conjunction with the rotation of the transmission gear unit (150), a bearing unit (170) that rotatably supports at least a part of the lifting unit (160), and a support frame (180) that supports at least a part of the worm gear drive unit (130), the internal gear (140), the transmission gear unit (150), the lifting unit (160), and the bearing unit (170).

[0046] The motor (110) can provide rotational force for the lifting operation of the lift module (100). In one embodiment, the motor (110) may be an electric motor. For example, the motor (110) may be a DC motor, a BLDC motor, a servo motor, a stepper motor, an AC motor, or a geared motor with a reduction gear integrated therein. The motor (110) may be selected with various output specifications depending on the required load, lifting speed, control method, and installation space of the lift module (100).

[0047] The power transmission unit (120) can connect the output shaft of the motor (110) and the worm shaft (131) of the worm gear drive unit (130) to transmit the rotational force of the motor (110) to the worm shaft (131). In one embodiment, the power transmission unit (120) may include a driving pulley (121), a driven pulley (122), and a timing belt (123). Accordingly, the rotational force of the motor (110) can be transmitted to the worm shaft (131) at a set transmission ratio, and the position of the motor (110) can be designed to be spaced apart from the worm shaft (131), thereby improving the degree of freedom for the planar and height-direction positioning of the lift module (100).

[0048] The worm gear drive unit (130) may include a worm shaft (131) that rotates by receiving rotational force from the motor (110) through the power transmission unit (120), and a worm wheel (132) configured to rotate in mesh with the worm shaft (131). The worm gear drive unit (130) can perform deceleration and torque increase while switching the direction of the rotation axis of the motor (110). Accordingly, even when using a motor (110) of a relatively small size, the driving force required to lift a load or a work object can be secured.

[0049] The internal gear (140) may be formed integrally with the worm wheel (132) or coupled to rotate integrally with the worm wheel (132). Accordingly, when the worm wheel (132) rotates by the worm shaft (131), the internal gear (140) may also rotate together with the worm wheel (132). The internal gear (140) may include a gear tooth portion (141) on its inner side, and the gear tooth portion (141) may mesh with the transmission gear portion (150).

[0050] The transmission gear unit (150) may be positioned on the inner circumference of the internal gear (140) and configured to rotate by the rotation of the internal gear (140). In one embodiment, the transmission gear unit (150) may include a plurality of transmission gears (151) spaced apart from each other along the circumferential direction of the internal gear (140). Since the plurality of transmission gears (151) can mesh with one internal gear (140) and rotate simultaneously, the rotational force of the one motor (110) can be distributed and transmitted to a plurality of lifting units (160).

[0051] The lifting unit (160) can perform a lifting operation in conjunction with the rotation of the transmission gear unit (150). In one embodiment, the lifting unit (160) may be provided in multiple units, and the multiple lifting units (160) may be arranged to correspond to each of the multiple transmission gear units (150). Accordingly, the load of the load or work object can be distributed to the multiple lifting units (160), and the tilting of the work object can be reduced even when an eccentric load is applied.

[0052] The lifting unit (160) may include a first shaft (161), a second shaft (162), a screw coupling part (163), a first lifting plate (164), and a second lifting plate (165). The screw coupling part (163) is coupled to the transmission gear unit (150) and can rotate in conjunction with the rotation of the transmission gear unit (150). The first shaft (161) can be screw-coupled to the first screw section (1631) of the screw coupling part (163), and the second shaft (162) can be screw-coupled to the second screw section (1632) having screw threads in the opposite direction to the first screw section (1631). Accordingly, even if the screw coupling part (163) rotates in the same rotational direction, the first shaft (161) and the second shaft (162) can move linearly in opposite directions.

[0053] The first lifting plate (164) can move in conjunction with the linear movement of the first shaft (161), and the second lifting plate (165) can move in conjunction with the linear movement of the second shaft (162). Accordingly, an external load support, work object support, support, or lifting object can be raised by the movement of the first lifting plate (164) and the second lifting plate (165).

[0054] The bearing portion (170) can rotatably support the screw coupling portion (163) of the lifting portion (160). In one embodiment, the bearing portion (170) may be provided to support axial and radial loads acting on the screw coupling portion (163). Accordingly, the rotational center of the screw coupling portion (163) can be stably maintained, and shaking, eccentric rotation, and increased friction can be reduced during the repetitive lifting operation of the lifting portion (160).

[0055] The support frame (180) can function as a structure that supports each component of the lift module (100). In one embodiment, the support frame (180) may include a bearing block (181) on which the bearing part (170) is mounted, a motor-side bearing block (182) that supports the motor (110) or the worm shaft (131), a first fixed plate (183), and a second fixed plate (184) spaced apart from the first fixed plate (183). Since the relative positions of the worm gear drive part (130), the internal gear (140), the transmission gear part (150), the lifting part (160), and the bearing part (170) can be stably maintained by the support frame (180), a plurality of lifting parts (160) can be driven uniformly.

[0056] In one embodiment, the lift module (100) may be a lifting lift module mounted on an AMR (Autonomous Mobile Robot). The AMR may be a mobile robot equipped to transport pallets, containers, boxes, or loads in an autonomous manner in a logistics warehouse, manufacturing line, automation facility, or load storage space.

[0057] The lift module (100) may be placed inside or on top of the main body frame of the AMR. For example, the lift module (100) may be accommodated within the low-profile structure of the AMR, and at least one of the first lifting plate (164) and the second lifting plate (165) may be combined with a support member, support plate, base member, bracket, or fork-type support member for supporting a pallet or load.

[0058] The support member may be configured to protrude upward through the upper surface of the AMR or to be raised and lowered at a position adjacent to the upper surface of the AMR. Accordingly, the AMR can move to a target location after entering the lower space of a pallet or load by driving the lift module (100) to raise the support member and lifting the pallet or load.

[0059] The lift module (100) can be configured to distribute and transmit the rotational force of a single motor (110) to a plurality of lifting units (160), so that even when the load acts off-center during the process of the AMR supporting a pallet or load, the plurality of lifting units (160) can distribute and support the load. This limits the tilting of the pallet or load and reduces the possibility of the load shaking or falling while the AMR is in motion.

[0060] In addition, by configuring the first shaft (161) and the second shaft (162) of the lifting unit (160) to move in a straight line in opposite directions, the lift module (100) can secure a sufficient lifting stroke even within a limited installation height. Therefore, the lift module (100) can be suitablely applied to a low-profile AMR where a low vehicle body height is required.

[0061] In one embodiment, the AMR may include a drivable main body frame, a driving unit for moving the main body frame, a battery unit for supplying power to the driving unit and the lift module (100), a control unit for controlling the driving of the driving unit and the lift module (100), and a sensor unit for recognizing the surrounding environment or driving path. The driving unit may include a driving wheel, a driven wheel, a caster wheel, or a combination thereof, and the sensor unit may include at least one of a LiDAR sensor, a camera, an ultrasonic sensor, an infrared sensor, a bumper sensor, an encoder, or an IMU sensor.

[0062] The control unit can control the driving of the motor (110) based on the driving state of the AMR, pallet detection state, load state, or target lifting height. For example, when the AMR reaches a set position below the pallet or load, the control unit can drive the motor (110) in a first direction to raise the support member, and when it reaches a target position, drive the motor (110) in a second direction to lower the support member.

[0063] In one embodiment, the lift module (100) may further include a position detection unit for detecting the lifting position of the first lifting plate (164), the second lifting plate (165), or the support member. The position detection unit may include at least one of a limit switch, a proximity sensor, a Hall sensor, an encoder, a potentiometer, or a linear scale. The control unit may control the amount of rotation or the stopping point of the motor (110) based on the detection value of the position detection unit.

[0064] Additionally, the AMR can be controlled to limit the driving of the driving unit during the lifting operation of the lift module (100), or to drive the driving unit after the support unit reaches a set height. Accordingly, shaking caused by the movement of the AMR during the lifting of the pallet or load can be reduced, and the stability of the pallet or load transfer operation can be improved.

[0065] In another embodiment, the lift module (100) can be applied not only to AMRs but also to AGVs, logistics transport robots, collaborative transport robots, transfer devices for automated warehouses, transfer trolleys for manufacturing lines, fixed lifting devices, or load lifting devices. That is, the lift module (100) can be applied to various lifting devices that require a low-profile structure, multi-point load support, or a large lifting stroke.

[0066] FIG. 2 is a perspective view illustrating the arrangement structure of a motor, a power transmission unit, a worm gear driving unit, and a lifting unit according to an embodiment of the present invention, and FIG. 3 is a drawing for explaining the meshing structure of a worm gear driving unit, an internal gear, and a transmission gear unit according to an embodiment of the present invention.

[0067] Referring to FIG. 2, the power transmission unit (120) may be configured to connect the output shaft of the motor (110) and the worm shaft (131) of the worm gear drive unit (130) to transmit the rotational force of the motor (110) to the worm shaft (131).

[0068] In one embodiment, the power transmission unit (120) may include a driving pulley (121) coupled to the output shaft of the motor (110), a driven pulley (122) coupled to the worm shaft (131), and a timing belt (123) that transmits rotational force by being stretched between the driving pulley (121) and the driven pulley (122).

[0069] The driving pulley (121) may be coupled to rotate integrally with the output shaft of the motor (110), and the driven pulley (122) may be coupled to rotate integrally with the worm shaft (131). The timing belt (123) may include inner teeth that mesh with the outer teeth of the driving pulley (121) and the driven pulley (122). Accordingly, the rotational force of the motor (110) can be transmitted to the worm shaft (131) with limited slip, and the rotation angle or amount of rotation of the motor (110) can be transmitted to the worm shaft (131) at a ratio set.

[0070] The diameter or dimensions of the driving pulley (121) and the driven pulley (122) may be formed to be the same or different from each other. For example, the diameter or number of teeth of the driven pulley (122) may be formed to be larger than the diameter or number of teeth of the driving pulley (121). In this case, the rotational force of the motor (110) may be reduced first before being transmitted to the worm shaft (131), and the torque transmitted to the worm shaft (131) may be increased. Conversely, by adjusting the diameter or number of teeth of the driving pulley (121) and the driven pulley (122), the lifting speed and driving torque of the lift module (100) can be set to meet the required conditions.

[0071] When the power transmission unit (120) is provided with a pulley and timing belt structure, the motor (110) can be positioned at a spaced-away location without being directly connected to the worm shaft (131). Accordingly, the position of the motor (110) can be placed on one side of the support frame (180) or in a flat space of the lift module (100), and the height dimension of the lift module (100) can be reduced.

[0072] In one embodiment, the motor (110), the driving pulley (121), the driven pulley (122), and the timing belt (123) may be disposed on one side of the support frame (180). The support frame (180) may include a motor-side bearing block (182) that supports the motor (110) or the worm shaft (131), and the motor-side bearing block (182) can stably maintain the rotational axis position of the worm shaft (131). Accordingly, the axial shaking of the worm shaft (131) caused by changes in the tension of the timing belt (123) or driving vibrations of the motor (110) can be reduced.

[0073] In another embodiment, the power transmission unit (120) may be replaced with a chain and sprocket, a gear train, a coupling, a flat belt, a V-belt, or a combination of belt pulleys. For example, when the motor (110) and the worm shaft (131) are arranged coaxially, the power transmission unit (120) may be provided as a coupling, and when the motor (110) and the worm shaft (131) are arranged spaced apart from each other, the power transmission unit (120) may be provided as a belt or chain. In this case as well, the power transmission unit (120) may be provided to transmit the rotational force of the motor (110) to the worm shaft (131).

[0074] In one embodiment, when the lift module (100) is mounted on the AMR, the motor (110) may be placed in a low-height space inside the main body frame of the AMR. The power transmission unit (120) can transmit rotational force while compensating for the gap between the placement position of the motor (110) and the placement position of the worm shaft (131). Accordingly, the rotational force required for the lifting operation of the lift module (100) can be stably transmitted while maintaining the low-height structure of the AMR.

[0075] In addition, when using the timing belt (123), the driving vibration or shock of the motor (110) can be mitigated from being directly transmitted to the worm shaft (131). Accordingly, even when the lift module (100) performs a lifting operation while driving or after stopping the AMR, the meshing stability of the worm gear drive unit (130) can be increased and driving noise can be reduced.

[0076] Referring to FIG. 3, the worm gear drive unit (130) may include the worm shaft (131) and the worm wheel (132). The worm shaft (131) may be a shaft member having a helical worm tooth profile formed on its outer surface, and the worm wheel (132) may include a gear tooth profile that meshes with the worm tooth profile of the worm shaft (131).

[0077] The rotation axis of the worm shaft (131) and the rotation axis of the worm wheel (132) may be arranged to intersect or be orthogonal to each other. Accordingly, the rotational force of the worm shaft (131) can be transmitted to the worm wheel (132) and the direction of the rotation axis can be changed. In addition, the worm gear drive unit (130) can perform a reduction function according to the ratio of the number of teeth of the worm shaft (131) and the number of teeth of the worm wheel (132), so that the rotational force of the motor (110) can be converted into a torque suitable for lifting operation.

[0078] The worm wheel (132) may be formed integrally with the internal gear (140) or may be coupled to rotate integrally with the internal gear (140). For example, the worm wheel (132) and the internal gear (140) may be formed integrally as a single member. In another embodiment, the worm wheel (132) and the internal gear (140) may be manufactured as separate members and then coupled to rotate integrally by key coupling, spline coupling, press fitting, bolt fastening, welding, or a combination thereof.

[0079] When the worm wheel (132) and the internal gear (140) are formed as a single component, the number of parts can be reduced and the assembly process can be simplified. Additionally, since the relative clearance between the worm wheel (132) and the internal gear (140) can be reduced, the rotational force of the worm shaft (131) can be transmitted to the internal gear (140) more precisely. On the other hand, when the worm wheel (132) and the internal gear (140) are formed as separate components and combined, the material, tooth profile precision, or heat treatment conditions of each component can be set differently, thereby improving manufacturability and maintainability.

[0080] The internal gear (140) may include a gear tooth portion (141) and a coupling portion (142). The gear tooth portion (141) is formed on the inner circumference of the internal gear (140) and may mesh with the transmission gear (151) of the transmission gear portion (150). The coupling portion (142) may be formed integrally with the worm wheel (132) or may be a part coupled to rotate integrally with the worm wheel (132). Accordingly, when the worm wheel (132) rotates, the internal gear (140) can rotate together with the worm wheel (132) through the coupling portion (142).

[0081] The transmission gear unit (150) may be positioned on the inner circumference of the internal gear (140) and may be configured to rotate in mesh with the internal gear (140). The transmission gear unit (150) may include a transmission gear (151) and a transmission gear shaft (152). The transmission gear (151) may mesh with the gear tooth portion (141) of the internal gear (140) and may rotate around the transmission gear shaft (152).

[0082] In one embodiment, the transmission gear shaft (152) may be positioned on the same axis as the rotation axis of the screw coupling part (163) of the lifting part (160). In this case, the transmission gear (151) may be coaxially coupled to the outer circumference of the screw coupling part (163), and the transmission gear (151) and the screw coupling part (163) may rotate as a single unit. Accordingly, the rotational force transmitted from the internal gear (140) can be directly transmitted to the screw coupling part (163) without a separate intermediate gear, thereby reducing power loss and reducing the height and number of parts of the device.

[0083] In one embodiment, the transmission gear unit (150) may include a plurality of transmission gears (151) spaced apart from each other along the circumferential direction of the internal gear (140). The plurality of transmission gears (151) may rotate simultaneously by the rotation of the internal gear (140). In this case, each of the plurality of transmission gears (151) may be coupled to rotate integrally with a screw coupling unit (163) provided on each of the plurality of lifting units (160).

[0084] By simultaneously engaging the plurality of transmission gears (151) with a single internal gear (140), the rotational force of the single motor (110) can be evenly distributed to the plurality of lifting units (160). Accordingly, compared to the case where the plurality of lifting units (160) are each driven by a separate motor, the control configuration becomes simpler and the driving synchronization error between each lifting unit (160) can be reduced.

[0085] The plurality of transmission gears (151) may be arranged radially with respect to the center of the internal gear (140). For example, the plurality of transmission gears (151) may be arranged at equal angular intervals along the circumferential direction of the internal gear (140). Accordingly, the plurality of lifting members (160) may be distributed along the circumferential direction of the internal gear (140), and the load of a pallet, load, or work object may be distributed to multiple points.

[0086] In another embodiment, the plurality of transmission gears (151) may be arranged at different angular intervals depending on the load distribution or installation space acting on the lift module (100). For example, a larger number of transmission gears (151) and lifting members (160) may be arranged in the direction where eccentric load is expected, or the spacing of the transmission gears (151) may be adjusted to increase the load-bearing capacity in a specific direction. Accordingly, load-bearing characteristics can be adjusted to suit various load shapes or the body structure of the AMR.

[0087] The internal gear (140) and the transmission gear (151) may be provided as spur gears, helical gears, or a combination thereof. When using spur gears, tooth profile machining and assembly are easy, and when using helical gears, meshing impact and noise can be reduced. Additionally, the internal gear (140) and the transmission gear (151) may be formed from carbon steel, alloy steel, stainless steel, sintered metal, engineering plastic, or a composite of metal and resin. Accordingly, an appropriate material can be selected based on the required load, noise conditions, wear resistance, or manufacturing cost.

[0088] The lead angle between the worm shaft (131) and the worm wheel (132) can be formed to be less than or equal to the friction angle. In this case, the reverse rotation of the worm wheel (132) can be restricted by the load acting on the lifting part (160). Accordingly, even when the driving of the motor (110) is stopped, the reverse rotation of the internal gear (140), the transmission gear part (150), and the screw coupling part (163) can be restricted, and the positions of the first shaft (161), the second shaft (162), the first lifting plate (164), and the second lifting plate (165) can be stably maintained.

[0089] In one embodiment, when the lift module (100) is mounted on the AMR, the reverse rotation limiting characteristic of the worm gear drive unit (130) is advantageous for maintaining the lifting position while the AMR is driving or stopping with the pallet or load lifted. For example, even if the load of the pallet or load acts on the lifting unit (160) due to vibration or movement on an inclined surface while the AMR is driving, the reverse rotation of the worm wheel (132) is limited, so the lowering or position change of the lifting unit (160) can be reduced.

[0090] In addition, since the plurality of transmission gears (151) are driven simultaneously by a single internal gear (140), the plurality of lifting members (160) can rise uniformly during the process of the AMR lifting the pallet. Accordingly, the tilting of the pallet to one side can be reduced, and the possibility of the load shaking or falling off during the operation of the AMR can be reduced.

[0091] According to the structure of FIGS. 2 and 3, the rotational force of the motor (110) can be transmitted sequentially through the power transmission unit (120), the worm shaft (131), the worm wheel (132), the internal gear (140), and the transmission gear unit (150) to the screw coupling unit (163) of the lifting unit (160). Thus, multiple lifting units (160) can be driven simultaneously using a single motor (110), and large lifting loads and stable synchronous driving can be achieved within a limited installation space.

[0092] FIG. 4 is a perspective view illustrating the combined structure of an internal gear, a transmission gear section, and a lifting section according to one embodiment of the present invention, and FIG. 5 is a drawing illustrating the disassembled structure of a lifting section and a bearing section according to one embodiment of the present invention.

[0093] Referring to FIG. 4, the lifting unit (160) may be configured to perform a lifting operation in conjunction with the rotation of the transmission gear unit (150). The lifting unit (160) may include a first shaft (161), a second shaft (162), a screw coupling unit (163), a first lifting plate (164), and a second lifting plate (165).

[0094] The above screw coupling portion (163) may be configured to be coupled to the transmission gear portion (150) and rotate in conjunction with the rotation of the transmission gear portion (150). In one embodiment, the transmission gear portion (150) may include a transmission gear (151) coupled coaxially with the screw coupling portion (163) on the outer circumference of the screw coupling portion (163). The transmission gear (151) and the screw coupling portion (163) may be provided to rotate as a single unit.

[0095] The coaxial coupling structure of the transmission gear (151) and the screw coupling part (163) may be configured to directly transmit the rotational force transmitted from the internal gear (140) to the screw coupling part (163). Accordingly, the rotational force of the transmission gear (151) can be converted into rotation of the screw coupling part (163) without adding a separate intermediate link or a complex gear train. This allows for a reduction in the number of parts and a reduction in the height dimension of the lift module (100).

[0096] The transmission gear (151) and the screw connection part (163) may be integrally formed as a single member. In another embodiment, the transmission gear (151) and the screw connection part (163) may be manufactured as separate members and then joined to rotate as a single unit by means of key connection, spline connection, press fitting, screw fastening, welding, or fastening member connection. In this case, the material, heat treatment conditions, or machining precision of the transmission gear (151) and the screw connection part (163) can be set differently, thereby improving manufacturability and maintainability.

[0097] The above screw coupling portion (163) may be configured to include a first screw section (1631) and a second screw section (1632). The first screw section (1631) and the second screw section (1632) may include screw threads in opposite directions. For example, if the first screw section (1631) is formed as a right-hand screw, the second screw section (1632) may be formed as a left-hand screw, and if the first screw section (1631) is formed as a left-hand screw, the second screw section (1632) may be formed as a right-hand screw.

[0098] The first screw section (1631) and the second screw section (1632) may be female screw sections formed on the inner circumference of the screw coupling part (163). The first shaft (161) may include a male screw section that is screw-coupled to the first screw section (1631), and the second shaft (162) may include a male screw section that is screw-coupled to the second screw section (1632).

[0099] The first shaft (161) may be configured to move linearly by being screw-coupled to the first screw section (1631). The second shaft (162) may be configured to move linearly by being screw-coupled to the second screw section (1632) and spaced apart from the first shaft (161). The first shaft (161) and the second shaft (162) may each be provided to be movable in the axial direction while rotation is restricted.

[0100] The first lifting plate (164) may be configured to be coupled to the first shaft (161) and move in conjunction with the linear movement of the first shaft (161). The second lifting plate (165) may be configured to be coupled to the second shaft (162) and move in conjunction with the linear movement of the second shaft (162). Accordingly, the movement force of the first shaft (161) can be transmitted to the first lifting plate (164), and the movement force of the second shaft (162) can be transmitted to the second lifting plate (165).

[0101] The rotation of the first shaft (161) may be limited by the first lifting plate (164). The rotation of the second shaft (162) may be limited by the second lifting plate (165). For example, the first shaft (161) and the first lifting plate (164) may be joined integrally with each other, or may be joined through a joining surface, a flat section, a key joint section, a fastening section, or a guide structure that limits the rotation of the first shaft (161). Additionally, the second shaft (162) and the second lifting plate (165) may also be joined through the same or similar rotation limiting structure.

[0102] The above rotation limiting structure may be configured to convert the rotation of the screw coupling part (163) into linear movement. That is, even if the screw coupling part (163) rotates together with the transmission gear (151), the first shaft (161) and the second shaft (162) may be prevented from rotating together with the screw coupling part (163). Accordingly, the first shaft (161) and the second shaft (162) can move linearly along the first screw section (1631) and the second screw section (1632), respectively.

[0103] The movement of the first shaft (161) and the second shaft (162) in opposite directions may be an operation achieved by the thread directions of the first screw section (1631) and the second screw section (1632) being opposite to each other. When the screw coupling part (163) rotates in the same rotational direction, the first shaft (161) moves in the first straight direction, and the second shaft (162) can move in the second straight direction opposite to the first straight direction. Accordingly, the first lifting plate (164) and the second lifting plate (165) can move in a direction away from each other or in a direction closer to each other.

[0104] The relative movement of the first lifting plate (164) and the second lifting plate (165) may be configured to increase the lifting stroke of the lift module (100). For example, when the first lifting plate (164) moves upward and the second lifting plate (165) moves downward, the relative movement amount between the two plates may be formed by the sum of the movement amount of the first lifting plate (164) and the movement amount of the second lifting plate (165). Accordingly, a larger lifting stroke can be secured within a limited height compared to a structure in which only one shaft moves.

[0105] The screw coupling portion (163) may be composed of a plurality of members. In one embodiment, the screw coupling portion (163) may include a first nut member in which the first screw section (1631) is formed and a second nut member in which the second screw section (1632) is formed. The second nut member may be arranged coaxially with the first nut member and coupled to rotate integrally with the first nut member. In another embodiment, the first screw section (1631) and the second screw section (1632) may be formed in different inner regions of a single hollow screw coupling portion.

[0106] The split structure of the first nut member and the second nut member may be configured to improve manufacturing and assembly. Even if the first screw section (1631) and the second screw section (1632) have screw threads in opposite directions, the difficulty of processing can be reduced because the first nut member and the second nut member can be assembled after being processed separately. On the other hand, if the screw coupling part (163) is formed as a single hollow member, the number of parts can be reduced and coaxiality can be improved.

[0107] The threads of the first screw section (1631) and the second screw section (1632) may be trapezoidal threads. Since trapezoidal threads can stably transmit a relatively large axial load, they may be suitable for a lift module (100) for lifting pallets, loads, or work objects. In another embodiment, the first screw section (1631) and the second screw section (1632) may be formed as square threads, ACME threads, metric threads, multi-thread threads, or thread grooves for ball screws.

[0108] The plurality of lifting members (160) may be configured to correspond to each of the plurality of transmission gears (151). Each of the plurality of transmission gears (151) may be coupled to rotate integrally with a screw coupling member (163) provided on each of the plurality of lifting members (160). Accordingly, the plurality of screw coupling members (163) can rotate simultaneously by the rotation of a single internal gear (140), and the plurality of first shafts (161) and the plurality of second shafts (162) can move linearly simultaneously.

[0109] The arrangement structure of the plurality of lifting members (160) is configured for load distribution. The load acting on the plurality of lifting members (160) can be distributed and supported by a plurality of screw connection parts (163) each coupled to the plurality of transmission gears (151). Accordingly, compared to a structure that supports the load with only one central lifting shaft, stability against eccentric loads can be improved, and the horizontal state of the load or work object can be stably maintained.

[0110] The arrangement direction of the first shaft (161) may be a direction protruding upward relative to the internal gear (140). The arrangement direction of the second shaft (162) may be a direction protruding downward relative to the internal gear (140). In this case, the first lifting plate (164) and the second lifting plate (165) may be arranged in opposite directions relative to the internal gear (140), and the lift module (100) may utilize relative movement in both upward and downward directions simultaneously.

[0111] In one embodiment, when the lift module (100) is mounted on the AMR, at least one of the first lifting plate (164) and the second lifting plate (165) may be coupled to an external load support. The external load support may be a support plate, a base, a bracket, or a fork-type support for supporting a pallet or load. Accordingly, the AMR can lift the pallet or load by raising the external load support after entering the lower space of the pallet or load.

[0112] In the above AMR application embodiment, the plurality of lifting members (160) are configured to distribute and support the load of a pallet or load at multiple points. Accordingly, even if the pallet or load is placed at a position off-center from the external load support member, the plurality of lifting members (160) can distribute and support the load and moment. This reduces the possibility of tilting, shaking, or falling of the pallet or load while the AMR is in motion.

[0113] Referring to FIG. 5, the bearing portion (170) is configured to rotatably support the screw coupling portion (163). The bearing portion (170) can support the radial load generated during the rotation of the screw coupling portion (163) and the axial load generated during the linear movement of the first shaft (161) and the second shaft (162).

[0114] The bearing portion (170) may include a composite bearing (171), a thrust bearing portion (172), a radial bearing portion (173), or a bearing washer (174). In one embodiment, the bearing portion (170) may include a thrust bearing portion (172) that supports an axial load of the screw portion (163) and a radial bearing portion (173) that supports a radial load of the screw portion (163).

[0115] The thrust bearing portion (172) may be configured to support an axial load acting on the screw coupling portion (163) during the linear movement of the first shaft (161) or the second shaft (162). The radial bearing portion (173) may be configured to support a radial load or an eccentric load occurring during the rotation of the screw coupling portion (163). Accordingly, the rotational center of the screw coupling portion (163) can be stably maintained, and the eccentric load acting on the screw coupling portion between the screw coupling portion (163) and the first shaft (161) or the second shaft (162) can be reduced.

[0116] The bearing washer (174) may be configured to support the axial position of the thrust bearing portion (172) or the composite bearing (171). The bearing washer (174) may be positioned between the bearing portion (170) and the bearing block (181), between the bearing portion (170) and the screw coupling portion (163), or on one axial side of the bearing portion (170). Accordingly, the axial clearance of the bearing portion (170) can be reduced, and the bearing position may be restricted from deviating during repetitive lifting operations.

[0117] The bearing portion (170) may include a first bearing portion and a second bearing portion. The first bearing portion may be configured to be positioned on one axial side of the screw coupling portion (163), and the second bearing portion may be configured to be positioned on the other axial side of the screw coupling portion (163). The first bearing portion and the second bearing portion may support axial loads in opposite directions acting on the screw coupling portion (163) according to the linear movement of the first shaft (161) and the second shaft (162).

[0118] The arrangement structure of the first bearing portion and the second bearing portion on both sides may be configured to support the axial load of the screw coupling portion (163) in both directions. When the first shaft (161) and the second shaft (162) move in opposite directions, axial reaction forces in different directions may act on the screw coupling portion (163). Since the first bearing portion and the second bearing portion can distribute and support such bidirectional axial loads, the positional stability and rotational precision of the screw coupling portion (163) can be improved.

[0119] The above composite bearing (171) may be a bearing comprising a needle roller section and a thrust ball bearing section. The needle roller section can support a radial load of the screw connection section (163), and the thrust ball bearing section can support an axial load of the screw connection section (163). Accordingly, since a single bearing configuration can support both a radial load and an axial load, the bearing placement space can be reduced.

[0120] The above composite bearing (171) may be configured to be advantageous for thinning the lift module (100). That is, compared to the case where the radial bearing and the thrust bearing are separately arranged in an axially elongated manner, the above composite bearing (171) can support a composite load within a limited axial space. Accordingly, sufficient bearing support performance can be secured even when the lift module (100) is applied to a low-profile AMR or a transfer device with a height limit.

[0121] The bearing block (181) is part of a support frame (180) on which the bearing portion (170) is mounted. The bearing block (181) supports the rotation axis of the screw portion (163) and can transmit the load transmitted through the bearing portion (170) to the support frame (180). The bearing block (181) may be formed from a metal block, a cast member, a machined member, a plate assembly, or a composite block.

[0122] The motor-side bearing block (182) may be configured to support the motor (110) or the worm shaft (131). The motor-side bearing block (182) can maintain the rotational axis position of the worm shaft (131) and stably maintain the meshing position between the worm shaft (131) and the worm wheel (132). Accordingly, the driving noise, tooth wear, and rotational resistance of the worm gear drive unit (130) can be reduced.

[0123] The first fixed plate (183) and the second fixed plate (184) may be components that form the basic framework of the support frame (180). The first fixed plate (183) and the second fixed plate (184) may be spaced apart from each other and may maintain the relative positions of the worm gear drive unit (130), the internal gear (140), the transmission gear unit (150), the lifting unit (160), and the bearing unit (170).

[0124] The support frame (180) may be configured to stabilize the synchronous drive of a plurality of lifting units (160). By combining the first fixed plate (183), the second fixed plate (184), the bearing block (181), and the motor-side bearing block (182), the axial alignment of a plurality of transmission gears (151), a plurality of screw coupling parts (163), and a plurality of bearing parts (170) can be maintained. Accordingly, a plurality of lifting units (160) can move to a uniform height, and tilting of the load or work object can be reduced.

[0125] In one embodiment, the main body frame of the AMR may support the support frame (180) or function as part of the support frame (180). For example, the first fixing plate (183) or the second fixing plate (184) may be fastened to the body frame of the AMR, and the bearing block (181) may be positioned inside the body of the AMR. Accordingly, the lift module (100) can be stably accommodated in the internal space of the AMR, and the low-profile structure of the AMR can be maintained.

[0126] According to the structure of FIGS. 4 and FIGS. 5, the rotation of the transmission gear unit (150) is transmitted to the rotation of the screw coupling unit (163), and the rotation of the screw coupling unit (163) can be converted into the opposite linear movement of the first shaft (161) and the second shaft (162). In addition, the bearing unit (170) and the support frame (180) can stably support the rotation of the screw coupling unit (163) and the load transmission of the lifting unit (160). Thus, the lift module (100) can achieve a large lifting stroke, support for loads at multiple points, and stable synchronous lifting operation within a limited height.

[0127] The present invention may be modified and implemented in various forms, and its scope of rights is not limited to the embodiments described above. Therefore, if a modified embodiment includes the components of the claims of the present invention, it should be considered to fall within the scope of the present invention. Explanation of the symbols

[0129] 100 lift modules 110 motors 120 Power transmission unit 121 drive pulley 122 Driven Pulley 123 Timing Belt 130 Worm gear drive unit 131 Worm Shaft 132 worm wheel 140 internal gear 141 Gear tooth profile 142 connecting part 150 transmission gear section 151 transmission gear 152 transmission gear shaft 160: Elevator 161: 1st shaft 162: Second shaft 163: Screw connection 1631: First screw section 1632: Second screw section 164: First lifting plate 165: Second lifting plate 170: Bearing section 171: Composite Bearing 172: Thrust bearing section 173: Radial bearing section 174: Bearing washer 180: Support Frame 181: Bearing block 182: Motor-side bearing block 183: First fixed plate 184: Second fixed plate 190: External cargo support

Claims

Claim 1 A motor providing rotational force; a worm gear drive unit comprising a worm shaft that rotates by receiving rotational force from the motor, and a worm wheel configured to rotate in mesh with the worm shaft; an internal gear formed integrally with the worm wheel or coupled to rotate integrally with the worm wheel; and a transmission gear unit disposed on the inner circumference of the internal gear and configured to rotate in mesh with the internal gear. A lift module comprising: a lifting unit that performs a lifting operation in conjunction with the rotation of the transmission gear unit; wherein the lifting unit comprises: a screw coupling unit coupled to the transmission gear unit and configured to rotate in conjunction with the rotation of the transmission gear unit, and comprising a first screw section and a second screw section; a first shaft coupled to the first screw section and configured to move linearly while rotation is restricted; a second shaft disposed spaced apart from the first shaft and coupled to the second screw section and configured to move linearly while rotation is restricted; a first lifting plate coupled to the first shaft and moving in conjunction with the linear movement of the first shaft; and a second lifting plate coupled to the second shaft and moving in conjunction with the linear movement of the second shaft; wherein the first screw section and the second screw section comprise screw threads in opposite directions, and the first shaft and the second shaft move linearly in opposite directions due to the same rotational direction of the screw coupling unit. Claim 2 A lift module according to claim 1, wherein the first screw section and the second screw section are female screw sections formed on the inner circumference of the screw coupling part, and the first shaft and the second shaft each include a male screw section that is screw-coupled to the first screw section and the second screw section. Claim 3 A lift module according to claim 1, characterized in that when the first screw section is formed as a right screw, the second screw section is formed as a left screw, and when the first screw section is formed as a left screw, the second screw section is formed as a right screw. Claim 4 A lift module according to claim 1, characterized in that the threads of the first screw section and the second screw section are formed as trapezoidal threads. Claim 5 A lift module according to claim 1, wherein the screw coupling portion comprises: a first nut member having a first screw section formed therein; and a second nut member having a second screw section formed therein, arranged coaxially with the first nut member, and coupled to rotate integrally with the first nut member. Claim 6 A lift module according to claim 1, wherein the transmission gear portion includes a transmission gear coupled coaxially to the outer circumference of the screw coupling portion, and the transmission gear and the screw coupling portion are configured to rotate as a single unit. Claim 7 A lift module according to claim 6, wherein the transmission gear unit comprises a plurality of transmission gears spaced apart from each other along the circumferential direction of the internal gear and rotating simultaneously by the rotation of the internal gear, and the lifting unit is provided in a plurality such that each of the plurality of transmission gears corresponds to each of the plurality of transmission gears, and each of the plurality of transmission gears is coupled to rotate integrally with a screw coupling unit provided in each of the plurality of lifting units. Claim 8 A lift module according to claim 7, characterized in that a first shaft provided in each of the plurality of lifting parts is positioned to protrude upward relative to the internal gear, and a second shaft provided in each of the plurality of lifting parts is positioned to protrude downward relative to the internal gear. Claim 9 A lift module according to claim 7, characterized in that the load acting on the plurality of lifting parts is distributed and supported by a plurality of screw coupling parts each coupled to the plurality of transmission gears. Claim 10 A lift module according to claim 1, characterized in that the worm wheel and the internal gear are formed as a single member or are formed as separate members and joined to rotate integrally with each other. Claim 11 A lift module according to claim 1, characterized by including a bearing portion that rotatably supports the screw coupling portion. Claim 12 A lift module according to claim 11, wherein the bearing portion comprises: a thrust bearing portion supporting an axial load of the screw coupling portion; and a radial bearing portion supporting a radial load of the screw coupling portion. Claim 13 A lift module according to claim 11, wherein the bearing portion comprises: a first bearing portion disposed on one axial side of the screw coupling portion; and a second bearing portion disposed on the other axial side of the screw coupling portion; wherein the first bearing portion and the second bearing portion support axial loads in opposite directions acting on the screw coupling portion according to the linear movement of the first shaft and the second shaft. Claim 14 A lift module according to claim 13, wherein at least one of the first bearing portion and the second bearing portion is provided as a composite bearing including a needle roller portion and a thrust ball bearing portion, wherein the needle roller portion supports a radial load of the screw coupling portion and the thrust ball bearing portion supports an axial load of the screw coupling portion. Claim 15 A lift module according to claim 1, characterized in that at least one of the first lifting plate and the second lifting plate is provided to be coupled to an external load support. Claim 16 A lift module according to claim 1, characterized in that the rotation of the first shaft is restricted by the first lifting plate, and the rotation of the second shaft is restricted by the second lifting plate. Claim 17 A lift module according to claim 1, comprising a support frame that supports at least a portion of the worm gear drive unit, the internal gear, the transmission gear unit, and the lifting unit, wherein the support frame comprises: a bearing block on which a bearing unit that rotatably supports the screw coupling unit is mounted; a motor-side bearing block that supports the motor or the worm shaft; a first fixed plate; and a second fixed plate disposed spaced apart from the first fixed plate. Claim 18 A lift module according to claim 1, comprising a power transmission unit that connects the output shaft of the motor and the worm shaft to transmit the rotational force of the motor to the worm shaft, wherein the power transmission unit comprises: a driving pulley coupled to the output shaft of the motor; a driven pulley coupled to the worm shaft; and a timing belt that spans between the driving pulley and the driven pulley to transmit rotational force. Claim 19 A lift module according to claim 1, characterized in that the lead angle between the worm shaft and the worm wheel is formed to be less than or equal to the friction angle, thereby limiting the reverse rotation of the worm wheel by the load acting on the lifting part. Claim 20 A method for driving a lift module, characterized by comprising: a step of transmitting rotational force of a motor to a worm shaft; a step of rotating a worm wheel engaged with the worm shaft; a step of rotating an internal gear that rotates integrally with the worm wheel; a step of rotating a transmission gear portion engaged with the internal gear; a step of rotating a screw coupling portion including a first screw section and a second screw section having screw threads in the opposite direction to the first screw section in conjunction with the rotation of the transmission gear portion; a step of moving a first shaft screw-coupled to the first screw section in a first linear direction while rotation is restricted; a step of moving a second shaft screw-coupled to the second screw section in a second linear direction opposite to the first linear direction while rotation is restricted; and a step of moving a first lifting plate and a second lifting plate in conjunction with the linear movement of the first shaft and the second shaft.

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