Linear motor

Abstract

The application relates to the field of transmission technology and provides a linear motor which comprises a fixed screw rod in a hollow structure, the outer surface of the fixed screw rod is provided with a first outer thread, a transmission assembly, the transmission assembly comprises a hollow transmission part and a transmission nut, the transmission assembly is sleeved on the fixed screw rod, the transmission nut is matched with the first outer thread and can move along the axis direction of the fixed screw rod, and a driving mechanism, the driving mechanism is arranged in the fixed screw rod, the power output end of the driving mechanism is connected with the transmission part, and the driving mechanism is used for driving the transmission assembly to rotate relative to the fixed screw rod. The driving device is arranged in the fixed screw rod in the hollow structure, space is saved, and the design is beneficial to miniaturization.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and more particularly to a linear motor. Background Technology

[0002] Linear motors often use a lead screw and nut combination to achieve the lifting or extension of components such as sleeves. They are commonly used in devices that require lifting or extension, such as lifting columns and electric push rods.

[0003] Existing lifting columns, electric push rods, and other devices are usually designed with multi-stage lifting or multi-stage telescopic movement, and the drive mechanism is placed at the end of the lifting assembly, resulting in excessive axial length or height, which cannot meet the user's minimum height requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a linear motor to improve the technical problem that the large overall size of existing linear motors limits their application scenarios.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a linear motor, the linear motor comprising:

[0006] A fixing screw, wherein the fixing screw is hollow inside and has a first external thread on its outer surface;

[0007] The transmission assembly includes a hollow transmission component and a transmission nut disposed at one end of the transmission component. Both the transmission component and the transmission nut are sleeved on the fixed lead screw, and the internal thread of the transmission nut mates with the first external thread.

[0008] A drive mechanism is provided, which is located inside the fixed lead screw, and the power output end of the drive mechanism is connected to the transmission component for driving the transmission component to rotate relative to the fixed lead screw.

[0009] In one embodiment, the transmission component is a lead screw, and the outer surface of the lead screw is provided with a second external thread for adaptation to an external transmission structure.

[0010] In one embodiment, the inner surface of the transmission member is provided with a first limiting portion along the axial direction of the transmission member, and the driving mechanism includes:

[0011] A power unit, fixed within the fixed lead screw, the power unit having a power output shaft extending out of the fixed lead screw; and

[0012] A linkage component is fixed to the power output shaft and located inside the transmission component. The linkage component has a first limiting engagement portion, which slides in conjunction with the first limiting portion.

[0013] In one embodiment, the power unit is a motor, the motor having the power output shaft connected to the linkage; or, the power unit includes a motor and a gearbox connected to the output shaft of the motor, the gearbox having the power output shaft connected to the linkage.

[0014] In one embodiment, the transmission nut has a mounting section and a base section connected to the mounting section, the mounting section extending into the transmission member.

[0015] In one embodiment, a limiting groove structure adapted to the first limiting portion is formed on the outer surface of the mounting section; and / or, the base section is connected to the transmission member by screws.

[0016] In one embodiment, the direction of rotation of the second external thread is opposite to that of the first external thread.

[0017] In one embodiment, the linear motor further includes a lead screw nut, which is threaded into the second external thread of the transmission component.

[0018] In one embodiment, the linear motor further includes a plurality of lead screw layer assemblies, each of which is sequentially assembled from the inside out, with the innermost lead screw layer assembly fitted onto the transmission member; the transmission member is capable of driving each lead screw layer assembly to rotate and move along the axial direction of the transmission member, and the linear motor further includes a lead screw nut, which is fitted onto the outermost layer of the lead screw layer assembly.

[0019] In one embodiment, the linear motor further includes a fixing part, one end of the fixing screw is fixed to the fixing part; the fixing part has a protruding part, and the fixing screw is sleeved on the protruding part; the outer surface shape of the protruding part matches the inner surface shape of the fixing screw to restrict the relative rotation between the fixing screw and the protruding part.

[0020] The above-described technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0021] The linear motor provided in this embodiment of the invention comprises a fixed lead screw, a transmission assembly sleeved on the fixed lead screw, and a drive mechanism whose power output end is connected to the transmission assembly. The transmission assembly includes a hollow transmission component and a transmission nut located at one end of the transmission component. The inner surface of the transmission nut has an internal thread, and the outer surface of the fixed lead screw has a first external thread; that is, the internal thread of the transmission nut is adapted to the first external thread.

[0022] The external transmission mechanism is mounted on the outer surface of the transmission component. Through the engagement of the internal thread of the transmission nut and the first external thread, the transmission assembly can rotate while simultaneously moving linearly along the axial direction of the fixed lead screw, achieving lifting or extension of the transmission assembly. Furthermore, the fixed lead screw is hollow internally, and the drive mechanism is located inside it. The power output end of the drive mechanism extends to the outside of the fixed lead screw and connects to the transmission assembly. This configuration eliminates the need for external space for the drive mechanism, improving space utilization and facilitating the rotation of the transmission assembly relative to the fixed lead screw. It also shortens the connection length between the drive mechanism and the transmission assembly, enhancing transmission stability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 An exploded view of a linear motor provided in an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a linear motor provided in an embodiment of the present invention;

[0026] Figure 3 This is a top view of the linear motor provided in an embodiment of the present invention;

[0027] Figure 4 for Figure 3 A cross-sectional view along the AA direction;

[0028] Figure 5 This is a schematic diagram of the linear motor after removing the transmission components and the lead screw nut, as provided in an embodiment of the present invention.

[0029] Figure 6 An exploded view of the transmission assembly of a linear motor provided in an embodiment of the present invention.

[0030] The following are the labeling elements in the figure:

[0031] 100. Linear motor; 10. Fixed lead screw; 101. First external thread; 20. Transmission assembly; 20a. Transmission component; 20b. Transmission nut; 20b1. Mounting section; 20b2. Base section; 20c. Limiting groove structure; 201. Second external thread; 30. Lead screw nut; 40. Drive mechanism; 41. Power unit; 42. Linkage component; 50. Fixing part; 51. Protruding part; 202. First limiting part; 410. Power output shaft; 420. First limiting mating part; 411. Motor; 412. Gearbox. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] Please refer to Figures 1 to 4This application provides a linear motor 100 for lifting or telescopic transmission, which can be applied to devices that require lifting or telescopic functions, such as lifting columns, electric push rods, lifters, and lifting tables, but is not limited thereto; the linear motor 100 includes a fixed lead screw 10, a transmission assembly 20, and a drive mechanism 40, wherein:

[0037] The fixed lead screw 10 is fixedly installed, that is, it does not rotate or move linearly. The fixed lead screw 10 is hollow inside and its outer surface is provided with a first external thread 101.

[0038] The transmission assembly 20 includes a transmission component 20a with a hollow structure and a transmission nut 20b located at one end of the transmission component 20a. The transmission component 20a and the transmission nut 20b are both sleeved on the fixed lead screw 10. The transmission nut 20b is engaged or screwed into the first external thread 101, so that when the transmission component 20a and the transmission nut 20b rotate relative to the fixed lead screw 10, they can move linearly relative to the fixed lead screw 10 through the engagement of the internal and external threads.

[0039] The drive mechanism 40 is housed within the hollow fixed lead screw 10, and its power output end is connected to the transmission component 20a of the transmission assembly 20, for driving the transmission assembly 20 to rotate relative to the fixed lead screw 10. The drive mechanism 40 refers to a mechanism or device capable of providing driving force and driving the transmission assembly 20 to rotate relative to the fixed lead screw 10. For example, the drive mechanism 40 may include a motor and a transmission component connected to the output end of the motor, with the motor providing driving force to drive the transmission assembly 20 to rotate relative to the fixed lead screw 10. Alternatively, the drive mechanism 40 may also be a motor, with the output end of the motor directly driving the transmission assembly 20.

[0040] The linear motor 100 provided in this embodiment comprises a fixed lead screw 10, a transmission assembly 20 sleeved on the fixed lead screw 10, and a drive mechanism 40 whose power output end is connected to the transmission assembly 20. The transmission assembly 20 includes a hollow transmission member 20a and a transmission nut 20b located at one end of the transmission member 20a. The inner surface of the transmission nut 20b has an internal thread, and the outer surface of the fixed lead screw 10 has a first external thread 101, meaning the internal thread of the transmission nut 20b is compatible with the first external thread. The drive mechanism 40 drives the transmission assembly 20 to rotate relative to the fixed lead screw 10. With the cooperation of the internal thread of the transmission nut 20b and the first external thread 101, the transmission assembly 20 can rotate while simultaneously moving linearly along the axial direction of the fixed lead screw 10 (i.e., the axial direction of the fixed lead screw 10), thus achieving the lifting or extending / retracting of the transmission assembly 20. Furthermore, the fixed lead screw 10 is hollow inside, and the drive mechanism 40 is disposed inside the fixed lead screw 10. The power output end of the drive mechanism 40 extends to the outside of the fixed lead screw 10 and is connected to the transmission assembly 20. This arrangement, with the drive mechanism 40 disposed inside the fixed lead screw 10, does not occupy external space, improving space utilization. It also facilitates the rotation of the transmission assembly 20 relative to the fixed lead screw 10, shortens the connection length between the drive mechanism 40 and the transmission assembly 20, and improves transmission stability.

[0041] Please refer to Figure 1 and Figure 2 The transmission component 20a is a transmission screw, and the outer surface of the transmission screw is provided with a second external thread 201 for matching the external transmission structure. The drive mechanism 40 drives the transmission assembly 20 to rotate relative to the fixed lead screw 10. With the cooperation of the internal thread of the transmission nut 20b and the first external thread 101, the transmission assembly 20 can rotate while simultaneously moving linearly along the axial direction of the fixed lead screw 10 (i.e., the axial direction of the fixed lead screw 10), thus realizing the lifting or extension of the transmission assembly 20. At the same time, the rotation of the transmission lead screw can drive the external transmission mechanism threaded to the second external thread 201 to move linearly along the axial direction of the transmission lead screw. This allows the external transmission mechanism threaded to the second external thread 201 to move axially relative to the transmission lead screw while moving axially with the transmission lead screw relative to the fixed lead screw 10. That is, while the transmission lead screw 20 moves relative to the fixed lead screw 10, the external transmission mechanism threaded to the second external thread moves relative to the transmission lead screw, thus realizing the rapid lifting or extension of the external transmission mechanism threaded to the second external thread 201. This, in turn, enables the rapid lifting or extension of devices such as lifting columns and electric push rods using the linear motor 100, effectively improving the lifting or extension efficiency.

[0042] In another embodiment, the transmission component 20a is a hollow tube, and the external transmission structure is fixedly connected to the hollow tube. Understandably, in this case, the external transmission structure or the mechanism to be transmitted is directly fixed to the outside of the hollow tube, that is, it moves telescopically along the axial direction of the fixed lead screw 10 under the drive of the hollow tube. At this time, the first-stage transmission of the external transmission structure is achieved.

[0043] In one embodiment, please refer to Figure 1 and Figure 2 The linear motor 100 also includes a fixing part 50, to which one end of the fixing screw 10 is fixed. The fixing part 50 can be a base, and the fixing screw 10 can be vertically fixed to the fixing part 50. Alternatively, the fixing part 50 can be a base, and the fixing screw 10 can be horizontally fixed to the fixing part 50. Of course, the fixing part 50 can also be other structures. With this configuration, the fixing part 50 can fix the fixing screw 10, preventing it from moving and enhancing stability.

[0044] It should be noted that in some other embodiments, the linear motor 100 may not have a fixing part 50, and the fixing screw 10 may be directly fixed to the device on which the linear motor 100 is applied. For example, the fixing screw 10 may be directly fixed to the outer shell of the lifting column.

[0045] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4 The fixing part 50 has a protruding part 51, and the fixing screw 10 is sleeved on the protruding part 51, that is, the protruding part 51 is inserted into it. The protruding part 51 cooperates with the cavity of the fixing screw 10 to prevent the fixing screw 10 from swaying or moving relative to the fixing part 50, thereby improving the stability of the fixing screw 10.

[0046] It should be noted that in some other embodiments, the protrusion 51 may not be provided. For example, the fixing screw 10 and the fixing part 50 may be directly fixedly connected by screws, bolts, riveting, welding or other means.

[0047] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4The outer surface shape of the protrusion 51 matches the inner surface shape of the cavity of the fixing screw 10 to restrict the relative rotation between the fixing screw 10 and the protrusion 51. The protrusion 51 is a non-cylindrical protrusion, which further restricts the relative rotation between the fixing screw 10 and the protrusion 51. For example, the protrusion 51 can be prismatic (e.g., quadrangular prism), an elliptical cross-section, or other regular or irregular shapes. This arrangement, with the protrusion 51 fitting into the cavity of the fixing screw 10, prevents the fixing screw 10 from rotating, further enhancing its stability and improving the stability of the transmission assembly 20 relative to the fixing screw 10 in rotational and linear motion.

[0048] Alternatively, in one embodiment, please refer to Figure 4 The fixing screw 10 is detachably fixed to the fixing part 50, for example, by means of screws or bolts. This arrangement facilitates the disassembly and installation of the fixing screw 10 and the fixing part 50.

[0049] In one embodiment, please refer to Figure 2 and Figure 4 The direction of rotation of the second external thread 201 is opposite to that of the first external thread 101, which allows the external transmission mechanism connected to the second external thread 201 to move in the same direction as the transmission screw when it moves in a straight line. This enables the external transmission mechanism connected to the second external thread 201 and the transmission component 20a to move up and down or extend and retract in the same direction simultaneously. The direction of rotation refers to the direction of the thread. A thread that is screwed in when rotated clockwise is called a right-hand thread, and a thread that is screwed in when rotated counterclockwise is called a left-hand thread.

[0050] In one embodiment, referring to the figure, the inner surface of the transmission member 20a is provided with a plurality of first limiting portions 202 along the axial direction of the transmission member 20a. The drive mechanism 40 includes a power unit 41 and a linkage member 42. The power unit 41 is fixed to the fixed lead screw 10. Specifically, the power unit 41 can be fixed inside the fixed lead screw 10. For example, the power unit 41 can be fixed inside the fixed lead screw 10 by means of snap-fit, welding, threaded connection, screw or bolt connection, etc., but is not limited to this. The power unit 41 is located on the fixed lead screw 10 at one end opposite to the fixed portion 50. The power unit 41 has a power output shaft 410, which extends to the outside of the fixed lead screw 10. The linkage member 42 is fixed to the power output shaft 410 and located inside the transmission assembly 20. The linkage member 42 has a plurality of first limiting engagement portions 420. The first limiting engagement portions 420 slide with the first limiting portions 202, which can restrict the linkage member 42 from relative rotation with the transmission assembly 20, and can only perform relative linear motion. The moving part 42 refers to the intermediate power transmission component that can transmit the rotational power of the power output shaft 410 to the transmission assembly 20. For example, the linkage 42 can be a spline, a cylindrical, fan-shaped, or strip-shaped linkage, or other regular or irregular shaped linkages. Specifically, the first limiting part 202 can be a protrusion on the inner surface of the transmission assembly 20 along the axial direction of the transmission assembly 20, and the first limiting mating part 420 can be a groove provided on the outer peripheral surface of the linkage 42. Of course, it can also be... The first limiting part 202 is a groove recessed along the axial direction of the transmission assembly 20 on the inner surface of the transmission assembly 20, while the first limiting mating part 420 is a protrusion or ridge protruding from the outer circumferential surface of the linkage 42. Through the sliding engagement of the groove and the protrusion or ridge, the relative rotation between the linkage 42 and the transmission assembly 20 is restricted, allowing the linkage 42 to rotate and drive the transmission assembly 20 to rotate. Simultaneously, when the transmission assembly 20 moves linearly relative to the fixed lead screw 10, it can also move linearly relative to the linkage 42. During operation, the power unit 41 actuates, and its power output shaft 410 drives the linkage 42 to rotate. The linkage 42, through the engagement of the first limiting part 202 and the first limiting mating part 420, drives the transmission assembly 20 to rotate. The transmission assembly 20, under the engagement of the second external thread 201 and the first external thread 101, moves linearly relative to the fixed lead screw 10. Thus, the transmission assembly 20 and the linkage 42 move linearly relative to each other. The linkage 42 also serves to support and stabilize the transmission assembly 20. This configuration allows the drive mechanism 40 to stably drive the transmission component 20 to perform both rotational and linear motion relative to the fixed lead screw 10, resulting in a compact and highly stable working structure among the fixed lead screw 10, the drive mechanism 40, and the transmission component 20.

[0051] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4The power unit 41 includes a motor 411 and a gearbox 412. The motor 411 is installed inside the fixed lead screw 10. The input end of the gearbox 412 is connected to the output shaft of the motor 411. The gearbox 412 has a power output shaft 410. Specifically, both the motor 411 and the gearbox 412 are fixed inside the fixed lead screw 10. It can be understood that the gearbox 412 can be any type of existing gearbox. During operation, the power of the motor 411 is transmitted to the gearbox 412 through its output shaft by the action of the power unit 41. The power is then transmitted to the power output shaft 410 through the gear set inside the gearbox 412, and then to the linkage 42.

[0052] It should be noted that the structure of the power unit 41 is not limited to this. In some other embodiments, the power unit 41 can be a geared motor with a power output shaft 410. In one embodiment, the drive mechanism 40 is a motor, and the power output shaft of the motor is connected to the linkage.

[0053] In one embodiment, please refer to Figure 1 , Figure 4 and Figure 6 The transmission nut 20b has a mounting section 20b1 and a base section 20b2 connected to the mounting section 20b1. The mounting section 20b1 extends into the transmission member 20a. Understandably, this is to improve the quick connection and stability between the transmission nut and the transmission member 20a. During installation, the mounting section 20b1 extends into the transmission member 20a to provide positioning and support.

[0054] In one embodiment, please refer to Figure 6 A limiting groove structure 20c adapted to the first limiting part 202 is formed on the outer surface of the mounting section 20b1. Understandably, the adaptation of the first limiting part 202 and the limiting groove structure 20c further improves the connection stability between the transmission member 20a and the transmission nut 20b. That is, when the transmission member 20a and the transmission nut 20b are connected by screws, the torsional force between them causes the screw to be subjected to shear force, making it prone to breakage. However, the first limiting part can be a rib provided along the axial direction of the transmission member 20a, and the limiting groove structure 20c is also provided along the axial direction of the mounting section 20b1. In this way, the nut section and the lead screw section form a bonding force in the circumferential direction, greatly improving the connection stability. Simultaneously, to further improve the stability between the transmission nut and the transmission member 20a, a screw is screwed into the end face of the base section 20b2 and connected to the end face of the transmission member 20a.

[0055] Optionally, in one embodiment, the lead screw layer assembly includes several hollow lead screws. Each hollow lead screw is hollow inside, with an internal thread on its inner surface and an external thread on its outer surface. The hollow lead screws are sequentially fitted from the inside out, and the internal thread of the outermost hollow lead screw in a pair of adjacent hollow lead screws engages or screws with the external thread of the innermost hollow lead screw. The innermost hollow lead screw is fitted onto the transmission member 20a, and its internal thread engages or screws with the second external thread 201 of the transmission member 20a. Rotation of the transmission member 20a causes the second external thread 201 to drive each hollow lead screw to perform linear movement and / or rotational motion, thereby achieving multi-stage lifting or extension / retraction. For those skilled in the art, parameters such as the helix angle of the second external thread 201 and the external threads of each hollow lead screw can be set according to actual application needs.

[0056] Optionally, in one embodiment, the lead screw layer assembly includes a driven lead screw and a nut body. The driven lead screw is hollow inside and has an external thread on its outer surface. The nut body is fixedly connected to one end of the driven lead screw. That is, the structure of this lead screw layer assembly is the same as that of the transmission assembly 20. Specifically, the driven lead screw of the innermost lead screw layer assembly is sleeved on the transmission member 20a, the nut body of the innermost lead screw layer assembly is threaded into the second external thread 201, and the driven lead screw of the innermost lead screw layer assembly is engaged with the transmission member 20a. When there is only one lead screw layer assembly, the outermost lead screw layer assembly and the innermost lead screw layer assembly are the same lead screw layer assembly. The transmission member 20a can drive each lead screw layer assembly to rotate and move along the axial direction of the transmission member 20a, thereby achieving four or more levels of multi-stage lifting or telescopic movement.

[0057] Specifically, when there is only one lead screw layer assembly, the drive mechanism 40 drives the transmission member 20a to perform rotational and linear motion. When the transmission member 20a rotates, it drives the driven lead screw to rotate. At the same time, the second external thread 201 drives the nut of the lead screw layer assembly to perform linear motion relative to the transmission member 20a, so that the driven lead screw performs both linear and rotational motions. In this case, the fixed lead screw 10 can be regarded as the first stage, the transmission member 20a as the second stage, and the driven lead screw as the third stage, thereby realizing three-stage lifting or extension. The transmission member 20a, the driven lead screw, and the lead screw nut 30 can lift or extend simultaneously, which can effectively improve efficiency.

[0058] Specifically, when there are two or more lead screw layer assemblies, the innermost lead screw layer assembly is sleeved on the transmission member 20a, the driven lead screw of the next innermost lead screw layer assembly is sleeved on the driven lead screw of the innermost lead screw layer assembly, the nut thread of the next innermost lead screw layer assembly is threaded into the external thread of the driven lead screw of the innermost lead screw layer assembly, the driven member of the next innermost lead screw layer assembly is fixed to the driven lead screw of the innermost lead screw layer assembly, and so on. Each lead screw layer assembly is sleeved and assembled sequentially from the inside out. The rotational and linear motion of the transmission member 20a can drive each lead screw layer assembly to rotate and move along the axial direction of the transmission member 20a, which can realize five or more levels of multi-stage lifting or telescopic movement.

[0059] In one embodiment, see Figure 1 and Figure 4 The linear motor 100 also includes a lead screw nut 30, which is sleeved on the transmission member 20a. The inner surface of the lead screw nut 30 is provided with an internal thread. The lead screw nut 30 can be limited by the device to which the linear motor 100 is applied to restrict the rotation of the lead screw nut 30. The transmission member 20a can drive the lead screw nut 30 to move axially along the transmission member 20a through the second external thread 201. Wherein, the lead screw nut 30 is sleeved on the transmission member 20a, which means that the lead screw nut 30 is directly sleeved on the transmission member 20a or sleeved on the transmission member 20a through an intermediate component. In one way, the lead screw nut 30 can be directly sleeved on the transmission member 20a and threaded into the second external thread 201. When the transmission member 20a rotates, it directly drives the lead screw nut 30 to make linear motion through the second external thread 201. In this case, the fixed lead screw 10 can be regarded as the first stage, the transmission member 20a can be regarded as the second stage, and the lead screw nut 30 can be regarded as the third stage, thereby realizing three-stage lifting or telescopic movement.

[0060] In another embodiment, or in another manner, the lead screw nut 30 is sleeved on the lead screw layer assembly. When the transmission member 20a rotates, it drives the lead screw layer assembly to make linear motion through the second external thread 201, thereby indirectly driving the lead screw nut 30 to make linear motion. For example, the lead screw layer assembly can be a hollow lead screw sleeved on the transmission member 20a, and the lead screw nut 30 can be threaded onto the outermost hollow lead screw. In this case, when there is one hollow lead screw, the fixed lead screw 10 can be regarded as the first stage, the transmission member 20a as the second stage, the hollow lead screw as the third stage, and the lead screw nut 30 as the fourth stage, thereby realizing four stages of lifting or telescopic movement. Similarly, multiple hollow lead screws can be provided, and each hollow lead screw can be sleeved sequentially from the inside out, with the lead screw nut 30 threaded onto the outermost hollow lead screw, thereby realizing multi-stage lifting or telescopic movement.

[0061] Alternatively, in one embodiment, please refer to Figure 1 and Figure 4The lead screw nut 30 is threaded into the second external thread 201 of the transmission component 20a, that is, the internal thread of the lead screw nut 30 is engaged with or screwed into the second external thread 201. Through the linkage 42 of the drive mechanism 40, the transmission component 20a is driven to rotate and move linearly relative to the fixed lead screw 10. The transmission component 20a drives the lead screw nut 30 to move linearly relative to the transmission component 20a. At this time, the fixed lead screw 10 can be regarded as the first stage, the transmission component 20a can be regarded as the second stage, and the lead screw nut 30 can be regarded as the third stage, thereby realizing three-stage lifting or extension, which has high stability. Moreover, the simultaneous lifting or extension of the transmission component 20a and the lead screw nut 30 can improve efficiency.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A linear motor, characterized in that, The linear motor includes: A fixing screw, wherein the fixing screw is hollow inside and has a first external thread on its outer surface; The transmission assembly includes a hollow transmission component and a transmission nut located at one end of the transmission component. Both the transmission component and the transmission nut are sleeved on the fixed lead screw. The internal thread of the transmission nut engages with the first external thread. The inner surface of the transmission component is provided with a first limiting portion along the axial direction of the transmission component. A driving mechanism is provided, which is located inside the fixed lead screw, and the power output end of the driving mechanism is connected to the transmission member for driving the transmission member to rotate relative to the fixed lead screw. The driving mechanism includes a power unit and a linkage member. The power unit is fixed inside the fixed lead screw and has a power output shaft extending out of the fixed lead screw. The linkage member is fixed to the power output shaft and located inside the transmission member. The linkage member has a first limiting engagement portion, and the first limiting engagement portion slides in conjunction with the first limiting portion.

2. The linear motor according to claim 1, characterized in that: The transmission component is a lead screw, and the outer surface of the lead screw is provided with a second external thread for matching the external transmission structure.

3. The linear motor according to claim 1, characterized in that: The power unit is an electric motor, which has the power output shaft connected to the linkage; or, the power unit includes an electric motor and a gearbox connected to the output shaft of the electric motor, the gearbox having the power output shaft connected to the linkage.

4. The linear motor according to claim 1, characterized in that: The transmission nut has a mounting section and a base section connected to the mounting section, the mounting section extending into the transmission member.

5. The linear motor according to claim 4, characterized in that: The outer surface of the mounting section is provided with a limiting groove structure that is adapted to the first limiting part; and / or, the base section is connected to the transmission component by screws.

6. The linear motor according to claim 2, characterized in that: The direction of rotation of the second external thread is opposite to that of the first external thread.

7. The linear motor according to claim 2, characterized in that: The linear motor also includes a lead screw nut, which is threaded into the second external thread of the transmission component.

8. The linear motor according to any one of claims 1 to 4, characterized in that: The linear motor further includes several lead screw layer assemblies, each of which is assembled sequentially from the inside out, with the innermost lead screw layer assembly fitted onto the transmission member; the transmission member can drive each lead screw layer assembly to rotate and move along the axial direction of the transmission member, and the linear motor further includes a lead screw nut, which is fitted onto the outermost layer of the lead screw layer assembly.

9. The linear motor according to claim 1, characterized in that: The linear motor further includes a fixing part, one end of the fixing screw is fixed to the fixing part; the fixing part has a protruding part, and the fixing screw is sleeved on the protruding part; the outer surface shape of the protruding part matches the inner surface shape of the fixing screw to restrict the relative rotation of the fixing screw and the protruding part.

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