linear motors

Abstract

This invention relates to the field of transmission technology and provides a linear motor, comprising: a fixed lead screw with a first external thread on its outer surface; a driving lead screw, hollow inside with a first internal thread on its inner surface, the driving lead screw being sleeved on the fixed lead screw, and the first internal thread engaging with the first external thread; a second external thread on the outer surface of the driving lead screw; and a drive mechanism, the power output end of which is connected to the driving lead screw for driving the driving lead screw to rotate relative to the fixed lead screw. This enables rapid lifting or extension of the device using this linear motor, effectively improving lifting or extension efficiency, and occupying minimal space.

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 for multi-stage lifting or multi-stage extension. Their linear motors typically drive the components sequentially, causing the sleeves and other parts to lift or extend sequentially, resulting in low lifting or extension efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a linear motor to improve the technical problem of low lifting or telescopic efficiency in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a linear motor is provided, the linear motor comprising: a fixed lead screw, the outer surface of which is provided with a first external thread; a driving lead screw, the interior of which is hollow, the inner surface of which is provided with a first internal thread, the driving lead screw being sleeved on the fixed lead screw, and the first internal thread engaging with the first external thread; the outer surface of which is provided with a second external thread; and a driving mechanism, the power output end of which is connected to the driving lead screw for driving the driving lead screw to rotate relative to the fixed lead screw.

[0006] In one embodiment, the drive mechanism is disposed on the fixed lead screw.

[0007] In one embodiment, the fixed lead screw is hollow inside, the drive mechanism is disposed inside the fixed lead screw, and the power output end of the drive mechanism extends to the outside of the fixed lead screw and is connected to the driving lead screw.

[0008] In one embodiment, the direction of rotation of the second external thread is opposite to that of the first external thread.

[0009] In one embodiment, the first internal thread is provided on the inner surface of the lead screw near the end of the lead screw.

[0010] In one embodiment, the inner surface of the drive screw is provided with a first limiting portion along the axial direction of the drive screw, and the driving mechanism includes: a power unit fixed to the fixed screw, the power unit having a power output shaft; and a linkage member fixed to the power output shaft and located inside the drive screw, the linkage member having a first limiting engagement portion, the first limiting engagement portion slidingly engaging with the first limiting portion; wherein, the power unit is a first motor; or, the power unit includes: a second motor fixed to the fixed screw; and a first gearbox connected to the output shaft of the second motor, the first gearbox having the power output shaft.

[0011] In one embodiment, the drive mechanism includes: a third motor fixed to the fixed lead screw; and a second gearbox connected to the output shaft of the third motor, the second gearbox having a power output end that engages with the inner surface of the drive lead screw to drive the drive lead screw to rotate relative to the fixed lead screw.

[0012] 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 drive lead screw; the drive lead screw can drive each of the lead screw layer assemblies to rotate and move along the axial direction of the drive lead screw; the linear motor further includes a lead screw nut, which is threaded onto the outermost lead screw layer assembly.

[0013] In one embodiment, the linear motor further includes a lead screw nut, which is threaded into the second external thread of the drive lead screw, and the drive lead screw can drive the lead screw nut to move axially along the drive lead screw through the second external thread.

[0014] In one embodiment, the linear motor further includes a fixing part, and one end of the fixing screw is fixed to the fixing part.

[0015] In one embodiment, the fixing part has a protruding part, and one end of the fixing screw has a cavity, which is sleeved on the protruding part; the outer surface shape of the protruding part matches the inner surface shape of the cavity to restrict the relative rotation of the fixing screw and the protruding part.

[0016] The above-described technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0017] The linear motor provided in this embodiment of the invention comprises a fixed lead screw, a hollow driving lead screw fitted inside the fixed lead screw, and a drive mechanism connected to the driving lead screw at its power output end. The fixed lead screw has a first external thread on its outer surface, the driving lead screw has a first internal thread on its inner surface, and a second external thread on its outer surface. The drive mechanism drives the driving lead screw to rotate relative to the fixed lead screw, allowing the driving lead screw to simultaneously move linearly along the axial direction of the fixed lead screw under the engagement of the first internal and first external threads. Simultaneously, the rotation of the driving lead screw can be driven by its second external thread to engage with the external thread of the second external thread. The object moves linearly along the axis of the drive screw, causing the external object threaded to the second external thread to move axially relative to the drive screw while simultaneously moving axially relative to the fixed screw. This enables rapid lifting or extension of the external object threaded to the second external thread, thereby enabling rapid lifting or extension of devices that require lifting or extension functions using this linear motor, effectively improving lifting or extension efficiency. Furthermore, the first internal thread is directly provided on the inner surface of the drive screw, while the first external thread threaded to the fixed screw allows for rotational and linear motion relative to the fixed screw, resulting in a small footprint for the linear motor. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a schematic diagram of the structure of a linear motor provided in an embodiment of the present invention;

[0020] Figure 2 An exploded view of the linear motor provided in an embodiment of the present invention;

[0021] Figure 3 This is a top view of the linear motor provided in an embodiment of the present invention;

[0022] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure along the AA direction;

[0023] Figure 5 This is a schematic diagram of the linear motor after removing the lead screw and lead screw nut, provided in an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of the active lead screw provided in an embodiment of the present invention;

[0025] Figure 7 A top view of the active lead screw provided in an embodiment of the present invention;

[0026] Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure in the middle BB direction.

[0027] The following are the labeling elements in the figure:

[0028] 100. Linear motor; 10. Fixed lead screw; 101. First external thread; 20. Driving lead screw; 201. First internal thread; 202. Second external thread; 30. Lead screw nut; 40. Drive mechanism; 50. Fixed part; 51. Protruding part; 203. First limiting part; 41. Power part; 410. Power output shaft; 42. Linkage component; 420. First limiting mating part; 411. Second motor; 412. First gearbox. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] Please see Figures 1 to 4 This 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, lifting devices, and lifting tables, but is not limited thereto; the linear motor 100 includes a fixed lead screw 10, a driving lead screw 20, and a drive mechanism 40, wherein:

[0034] The fixed lead screw 10 can be fixed, that is, it does not rotate or move linearly. The outer surface of the fixed lead screw 10 is provided with a first external thread 101.

[0035] The drive screw 20 is hollow inside, and its inner surface is provided with a first internal thread 201. This first internal thread 201 can be provided on all inner surfaces of the drive screw 20 along its axial direction (i.e., the axial direction of the drive screw 20), or it can be provided only on a portion of the inner surface of the drive screw 20. The first internal thread 201 can be directly machined onto the inner surface of the drive screw 20, meaning it is integrally formed with the drive screw 20. The drive screw 20 is fitted onto the fixed screw 10, and the first internal thread 201 engages or screws with the first external thread 101, so that when the drive screw 20 rotates relative to the fixed screw 10, it can move linearly relative to the fixed screw 10 through the engagement of the first internal thread 201 and the first external thread 101; the outer surface of the drive screw 20 is provided with a second external thread 202, which can be used to engage with an external object to drive the external object to move, wherein the external object can be a screw nut, a hollow screw, or other components that need to be driven.

[0036] The power output end of the drive mechanism 40 is connected to the drive screw 20 and is used to drive the drive screw 20 to rotate relative to the fixed screw 10. The drive mechanism 40 refers to a mechanism or device that can provide driving force and drive the drive screw 20 to rotate relative to the fixed screw 10. For example, the drive mechanism 40 may include a motor and a transmission component connected to the output end of the motor. The motor provides driving force, which drives the drive screw 20 to rotate relative to the fixed screw 10.

[0037] The linear motor 100 provided in this application embodiment comprises a fixed lead screw 10, a hollow drive lead screw 20 sleeved within the fixed lead screw 10, and a drive mechanism 40 connected to the drive lead screw 20 at its power output end. The outer surface of the fixed lead screw 10 is provided with a first external thread 101, the inner surface of the drive lead screw 20 is provided with a first internal thread 201 that mates with the first external thread 101, and the outer surface of the drive lead screw 20 is provided with a second external thread 202. The drive mechanism 40 drives the drive lead screw 20 to rotate relative to the fixed lead screw 10. With the engagement of the first internal thread 201 and the first external thread 101, the drive lead screw 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 extension of the drive screw 20 is achieved simultaneously. The rotation of the drive screw 20 drives an external object threaded to the second external thread to move linearly along the axial direction of the drive screw 20. This allows the external object to move axially relative to the drive screw 20 while simultaneously moving axially with the drive screw 20 relative to the fixed screw 10. In other words, while the drive screw 20 moves relative to the fixed screw 10, the external object threaded to the second external thread also moves relative to the drive screw 20. This enables rapid lifting or extension of the external object threaded to the second external thread, thereby achieving rapid lifting or extension of devices such as lifting columns and electric push rods using the linear motor 100, effectively improving lifting or extension efficiency. Furthermore, the first internal thread 201 is integrally formed on the inner surface of the drive screw 20, which can improve the stability and movement consistency between the first internal thread 201 and the drive screw 20, and prevent relative movement between the drive screw 20 and the first internal thread 201. This improves the stability and transmission consistency of the cooperation and transmission between the drive screw 20 and the fixed screw 10. At the same time, there is no need to connect a nut that is threaded to the fixed screw 10 on the drive screw 20, which can effectively simplify the structure, reduce space, and make the linear motor 100 occupy less space.

[0038] In one embodiment, see 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.

[0039] 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.

[0040] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4 The fixing part 50 has a protruding part 51, and one end of the fixing screw 10 has a cavity. The cavity is fitted into the protruding part 51, that is, the protruding part 51 is inserted into the cavity. It can be understood that when the fixing screw 10 is solid, the cavity can be a groove provided at one end of the fixing screw 10; when the fixing screw 10 is hollow inside, the cavity can be part of the internal space of the fixing screw 10. With this arrangement, the protruding part 51 cooperates with the cavity of the fixing screw 10, which can prevent the fixing screw 10 from swaying or moving relative to the fixing part 50, thereby improving the stability of the fixing screw 10.

[0041] 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.

[0042] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4 The outer surface shape of the protrusion 51 matches the inner surface shape of the cavity to restrict the relative rotation between the fixed lead screw and the protrusion 51. The protrusion 51 is a non-cylindrical protrusion, which further restricts the relative rotation between the cavity 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 and the cavity fitting together, prevents the fixed lead screw 10 from rotating, further improving its stability, and consequently enhancing the stability of the driving lead screw 20 relative to the fixed lead screw 10 in rotational and linear motion.

[0043] 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.

[0044] In one embodiment, see Figure 2 and Figure 4The direction of rotation of the second external thread 202 is opposite to that of the first external thread 101. This allows the external object that is threaded to the second external thread 202 to move in the same direction as the active screw 20 when it is moving in a straight line. This enables the external object that is threaded to the second external thread 202 and the active screw 20 to move up and down or extend and retract in the same direction at the same time. This is very suitable for use on lifting columns to achieve simultaneous lifting and lowering of the sleeve of the lifting column. The direction of rotation refers to the direction of thread insertion. 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.

[0045] In one embodiment, see Figure 4 and Figure 8 The first internal thread 201 is provided on the inner surface of the drive screw 20 near the end of the drive screw 20, for... Figure 4 and Figure 8 In the indicated orientation, the first internal thread 201 is provided on the inner surface of the driving screw 20 near the lower end of the driving screw 20. A gap may exist between the portion of the inner surface of the driving screw 20 without the first internal thread 201 and the first external thread 101 of the fixed screw 10. This arrangement allows the first internal thread 201 to be machined only on the inner surface of the driving screw 20 near its end, eliminating the need to machine internal threads on the entire inner surface of the driving screw 20. This effectively reduces costs and improves efficiency. Machining a full thread on the inner surface of the driving screw 20 would be complex and costly.

[0046] In one embodiment, see Figure 2 and Figure 4 The drive mechanism 40 is mounted on the fixed lead screw 10. Specifically, the drive mechanism 40 can be located outside the fixed lead screw 10 but inside the drive lead screw 20, or the fixed lead screw 10 can be hollow inside, and the drive mechanism 40 can be located inside the fixed lead screw 10. With this configuration, since the fixed lead screw 10 is fixedly mounted, mounting the drive mechanism 40 on it not only facilitates the fixed installation of the drive mechanism 40, but also prevents the drive mechanism 40 from being directly exposed to the outside of the linear motor 100. This makes it less susceptible to external influences and allows for full utilization of space, resulting in a more compact installation among the drive mechanism 40, fixed lead screw 10, and drive lead screw 20. The drive mechanism 40 does not protrude from the outside of the linear motor 100, making it more aesthetically pleasing and facilitating the installation of the linear motor 100 on its application device, thus improving the user experience.

[0047] It should be noted that in some other embodiments, the drive mechanism 40 may not be disposed on the fixed lead screw 10. The drive mechanism 40 may be disposed outside the fixed lead screw 10 and the driving lead screw 20. For example, the drive mechanism 40 may be disposed on the device to which the linear motor 100 is applied. The drive mechanism 40 is connected to the driving lead screw 20 through the transmission component of the drive mechanism 40 to drive the driving lead screw 20 to rotate. It can be understood that the transmission component of the drive mechanism 40 may adopt any of the existing transmission structures.

[0048] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4 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 connects with the driving lead screw 20. The drive mechanism 40 can be partially disposed inside the fixed lead screw 10, or all of it except for its power output end can be disposed inside the fixed lead screw 10. This arrangement, with the drive mechanism 40 disposed inside the fixed lead screw 10, improves the stability and ease of installation of the drive mechanism 40, creating a concealed installation. It also appropriately shortens the overall length of the linear motor 100 when retracted. Furthermore, the drive mechanism 40 does not occupy external space, improving space utilization. In this configuration, the shorter engagement distance between the power output end of the drive mechanism 40 and the driving lead screw 20 facilitates the rotation of the driving lead screw 20 relative to the fixed lead screw 10, shortening the connection length between the drive mechanism 40 and the driving lead screw 20 and improving transmission stability.

[0049] Alternatively, in one embodiment, please refer to Figure 2 , Figure 4 , Figure 5 and Figure 6The inner surface of the drive screw 20 is provided with several first limiting portions 203 along the axial direction of the drive screw 20. The drive mechanism 40 includes a power unit 41 and a linkage member 42. The power unit 41 is fixed to the fixed screw 10. Specifically, the power unit 41 can be fixed inside the fixed screw 10. For example, the power unit 41 can be fixed inside the fixed screw 10 by means of snap-fit, welding, threaded connection, screw or bolt connection, etc., but it is not limited to this. The power unit 41 can be partially or completely located inside the fixed screw 10. The power unit 41 is located on the fixed screw 10 at one end opposite to the fixed part 50. The power unit 41 refers to a device that can provide rotational driving force. 1. A power output shaft 410 extends to the outside of the fixed lead screw 10. A linkage 42 is fixed to the power output shaft 410 and located inside the drive lead screw 20. The linkage 42 has several first limiting engagement portions 420, which slide with first limiting portions 203 to restrict relative rotation between the linkage 42 and the drive lead screw 20, allowing only relative linear motion. The linkage 42 is an intermediate power transmission component that transmits the rotational power of the power output shaft 410 to the drive lead screw 20. For example, the linkage 42 can be a spline, a cylindrical, fan-shaped, or strip-shaped linkage, or... The linkage can be any other regular or irregular shape; specifically, the first limiting part 203 can be a protrusion on the inner surface of the driving screw 20 along the axial direction of the driving screw 20, and the first limiting mating part 420 can be a groove on the outer peripheral surface of the linkage 42. Of course, the first limiting part 203 can also be a groove recessed on the inner surface of the driving screw 20 along the axial direction of the driving screw 20, and the first limiting mating part 420 can be a protrusion or a protrusion on the outer peripheral surface of the linkage 42. By slidingly engaging the groove and the protrusion or protrusion, the relative rotation between the linkage 42 and the driving screw 20 can be restricted, so that when the linkage 42 rotates, it can drive the driving screw 20 to rotate, and at the same time... When the driving screw 20 moves linearly relative to the fixed screw 10, it can move linearly relative to the linkage 42. The first limiting part 203 can also be the polygonal inner surface of the driving screw 20, such as the polygonal inner surface with a quadrilateral cross-section. Correspondingly, the first limiting mating part 420 can be the polygonal outer peripheral surface, such as the polygonal outer peripheral surface with a quadrilateral cross-section. In this case, the linkage 42 can be a polygonal linkage. By slidingly mating the first limiting mating part 420 of the linkage 42 (which is the polygonal outer peripheral surface) with the first limiting part 203 of the driving screw 20 (which is the polygonal inner surface), the relative rotation between the linkage 42 and the driving screw 20 can be restricted.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 203 and the first limiting mating part 420, drives the drive screw 20 to rotate. Under the engagement of the first internal thread 201 and the first external thread 101, the drive screw 20 moves linearly relative to the fixed screw 10. Thus, the drive screw 20 and the linkage 42 undergo relative linear motion, and the linkage 42 also serves to support and stabilize the drive screw 20. This configuration facilitates the drive mechanism 40 to stably drive the drive screw 20 to simultaneously perform rotational and linear motion relative to the fixed screw 10, resulting in a compact and highly stable structure among the fixed screw 10, drive mechanism 40, and drive screw 20.

[0050] Alternatively, in one embodiment, please refer to Figure 2 and Figure 4 The power unit 41 includes a second motor 411 and a first gearbox 412. The second motor 411 is fixed to the fixed lead screw 10. The input end of the first gearbox 412 is connected to the output shaft of the second motor 411. The first gearbox 412 has a power output shaft 410. Specifically, the second motor 411 and the first gearbox 412 can both be fixed inside the fixed lead screw 10, or only the second motor 411 can be partially or completely fixed inside the fixed lead screw 10 while the first gearbox 412 is located outside the fixed lead screw 10. Of course, the second motor 411 and the first gearbox 412 can both be located outside the fixed lead screw 10 and inside the drive lead screw 20. It is understood that the first gearbox 412 can be any type of existing gearbox, such as a planetary gearbox, but is not limited to this. During operation, the power of the power unit 41 is transmitted from its output shaft to the first gearbox 412 through the operation of the power unit 41, and then from the gear set inside the first gearbox 412 to the power output shaft 410, and then to the linkage 42.

[0051] 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 first motor with a power output shaft. The linkage 42 is fixed to the power output shaft of the first motor. That is, the power unit 41 may not have a first gearbox 412 and can drive the linkage 42 to rotate through the first motor. For example, the first motor can be a geared motor with a power output shaft.

[0052] It should also be noted that the drive mechanism 40 may not have the linkage 42. Optionally, in some other embodiments, the drive mechanism 40 includes a third motor and a second gearbox. The third motor is fixed to the fixed lead screw. Specifically, the third motor may be partially or entirely located inside the fixed lead screw 10. The second gearbox is connected to the output shaft of the third motor. The second gearbox has a power output end that cooperates with the inner surface of the drive lead screw 20 to drive the drive lead screw 20 to rotate relative to the fixed lead screw 10. The power output end of the second gearbox may be a rotatable outer shell of the second gearbox. The inner surface of the outer shell may be provided with internal teeth that mesh with the internal transmission gears of the second gearbox. The third motor drives the second gearbox to work, and the internal transmission gears of the second gearbox drive the outer shell of the second gearbox to rotate, thereby causing the second gearbox to drive the drive lead screw 20 to rotate. It can be understood that the second gearbox may be any planetary gearbox in the prior art or a planetary gearbox improved from the planetary gearbox in the prior art. The planetary gearbox has a rotatable outer shell. Specifically, the inner surface of the drive screw 20 is provided with a first limiting part 203 along the axial direction of the drive screw 20, and the power output end of the second gearbox has a gearbox limiting engagement part. The gearbox limiting engagement part slides with the first limiting part 203, which can restrict the relative rotation between the power output end of the second gearbox and the drive screw 20, and can only make relative linear motion. The gearbox limiting engagement part can adopt the same structure as the first limiting engagement part 420 mentioned above, which will not be described in detail here.

[0053] In one embodiment, see Figure 1 and Figure 4The linear motor 100 also includes a lead screw nut 30, which is sleeved on the drive lead screw 20. 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 drive lead screw 20 can drive the lead screw nut 30 to move axially along the drive lead screw 20 through the second external thread 202. The lead screw nut 30 being sleeved on the drive lead screw 20 means that the lead screw nut 30 is directly sleeved on the drive lead screw 20 or sleeved on the drive lead screw 20 through an intermediate component. In one method, the lead screw nut 30 can be directly sleeved on the drive lead screw 20 and threaded into the second external thread 202. When the drive lead screw 20 rotates, it directly drives the lead screw nut 30 to perform linear motion through the second external thread 202. In this case, the fixed lead screw 10 can be regarded as the first stage, and the drive lead screw 20... The first method can be considered as the second stage, and the second method as the third stage, thus achieving three-stage lifting or telescopic movement. Alternatively, the screw nut 30 can be fitted onto the drive screw 20 via an intermediate component. When the drive screw 20 rotates, it drives the intermediate component to move linearly via the second external thread 202, thereby indirectly driving the screw nut 30 to move linearly. For example, the intermediate component can be a hollow screw fitted onto the drive screw 20, and the screw nut 30 can be threaded onto this hollow screw. In this case, the fixed screw 10 can be considered as the first stage, the drive screw 20 as the second stage, the hollow screw as the third stage, and the screw nut 30 as the fourth stage, thus achieving four-stage lifting or telescopic movement. Similarly, multiple hollow screws can be provided, and each hollow screw can be fitted sequentially from the inside out. The screw nut 30 is threaded onto the outermost hollow screw, thus achieving multi-stage lifting or telescopic movement.

[0054] Alternatively, in one embodiment, please refer to Figure 1 and Figure 4 The lead screw nut 30 is threaded into the second external thread 202 of the drive lead screw 20, that is, the internal thread of the lead screw nut 30 is engaged with or screwed into the second external thread 202. Through the linkage 42 of the drive mechanism 40, the drive lead screw 20 is driven to rotate and move linearly relative to the fixed lead screw 10. The drive lead screw 20 drives the lead screw nut 30 to move linearly relative to the drive lead screw 20. At this time, the fixed lead screw 10 can be regarded as the first stage, the drive lead screw 20 as the second stage, and the lead screw nut 30 as the third stage, thereby realizing three-stage lifting or extension, which has high stability. Moreover, the simultaneous lifting or extension of the drive lead screw 20 and the lead screw nut 30 can improve efficiency.

[0055] For example, when the linear motor 100 is applied to a lifting column, the lifting column has a first cylinder, a second cylinder, and a third cylinder. The first cylinder can be fixed to the fixing part 50 as a first-stage lifting cylinder. The second cylinder can be located inside the first cylinder and rotatably (e.g., via a bearing) connected to one end of the drive screw as a second-stage lifting cylinder. The third cylinder can be located inside the second cylinder and fixed to the screw nut 30 as a third-stage lifting cylinder. The outer peripheral surface of the screw nut 30 can cooperate with the inner surface of the second cylinder to restrict the rotation of the screw nut 30 (for example, the outer peripheral surface of the screw nut 30 can be polygonal or non-circular, and the screw nut 30 can also cooperate with the inner surface of the second cylinder in a manner similar to the sliding cooperation between the first limiting part 203 and the first limiting cooperation part 420 described above). During operation, the drive mechanism 40 drives the active lead screw 20 to perform rotational and linear motion. The active lead screw 20 drives the second cylinder, the lead screw nut 30, and the third cylinder to perform linear motion simultaneously. At the same time, the rotation of the active lead screw 20 drives the lead screw nut 30 to perform linear motion, which in turn drives the third cylinder to perform linear motion. This enables the second and third cylinders to lift or extend simultaneously, effectively improving the lifting or extension efficiency.

[0056] In another embodiment, the linear motor 100 further includes several lead screw layer assemblies, which are sequentially assembled from the inside out, with the innermost lead screw layer assembly fitted onto the drive lead screw 20; the drive lead screw 20 can drive each lead screw layer assembly to rotate and move along the axial direction of the drive lead screw 20, thereby realizing multi-stage lifting or telescopic movement.

[0057] Optionally, in one embodiment, the lead screw layer assembly includes a hollow lead screw. The hollow lead screw is hollow inside, with a second internal thread on its inner surface and a fourth external thread on its outer surface. The hollow lead screws are sequentially sleeved from the inside out, and the second internal thread of the outermost hollow lead screw in a pair of adjacent hollow lead screws engages or screws into the fourth external thread of the innermost hollow lead screw. The innermost hollow lead screw is sleeved on the drive lead screw 20, and its second internal thread engages or screws into the second external thread 202 of the drive lead screw 20. The rotation of the drive lead screw 20 drives each hollow lead screw to perform linear and / or rotational movements via the second external thread 202, 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 202 and the fourth external thread of each hollow lead screw can be set according to actual application needs. Furthermore, the lead screw nut 30 can be threaded into the fourth external thread of the outermost hollow lead screw.

[0058] Optionally, in one embodiment, the lead screw layer assembly includes a transmission lead screw and a nut fixedly connected to the transmission lead screw. The transmission lead screw and the nut can be coaxially arranged. The transmission lead screw is hollow inside, and its outer surface is provided with a fifth external thread. The transmission lead screws of each lead screw layer assembly are sequentially sleeved from the inside out. The nut of the outermost lead screw layer assembly in two adjacent lead screw layer assemblies is threaded or screwed into the fifth external thread of the innermost lead screw layer assembly. The transmission lead screw of the innermost lead screw layer assembly is sleeved on the driving lead screw 20, and the nut of the innermost lead screw layer assembly is threaded or screwed into the second external thread 202 of the driving lead screw 20. The rotation of the driving lead screw 20 drives the nuts and transmission lead screws of each lead screw layer assembly to perform linear and / or rotational movements via the second external thread 202, 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 202 and the internal threads of the nuts of each lead screw layer assembly can be set according to actual application needs.

[0059] Optionally, in one embodiment, the lead screw layer assembly includes a driven lead screw, a transmission nut, and a driven member. The driven lead screw is hollow inside, and its inner surface along the axial direction is provided with a second limiting portion. The outer surface of the driven lead screw is provided with a third external thread. The transmission nut is rotatably connected to one end of the driven lead screw. Specifically, the transmission nut can be connected to one end of the driven lead screw via a bearing, allowing the driven lead screw and the transmission nut to rotate relative to each other. Alternatively, the transmission nut can be directly rotatably engaged with the driven lead screw without a bearing. The driven member has a second limiting engagement portion, which slides in conjunction with the second limiting portion. Specifically, the second limiting portion can be a protrusion extending along the axial direction of the driven lead screw on its inner surface, or a groove on the outer circumferential surface of the driven member. Alternatively, the second limiting portion can be a groove recessed along the axial direction of the driven lead screw on its inner surface, and the second limiting engagement portion can be a protrusion or a raised portion extending on the outer circumferential surface of the driven member. The driven member refers to a member capable of... An intermediate power transmission component capable of transmitting the rotational force of the driving screw to the driven screw or the rotational force of the driven screw to another driven screw. For example, the driven component can be a spline, a cylindrical, fan-shaped, or strip-shaped driven component, or other regular or irregular shaped driven components. The function of the driven component is similar to that of the linkage component 42 mentioned above. The driven screw of the innermost screw layer assembly is sleeved on the driving screw 20, and the transmission nut of the innermost screw layer assembly is threaded... The driven component of the innermost lead screw layer assembly is fixed to the driving lead screw 20 via the second external thread 202; the lead screw nut 30 can be threaded into the third external thread of the driven lead screw of the outermost lead screw layer assembly. 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 driving lead screw 20 can drive each lead screw layer assembly to rotate and move along the axial direction of the driving lead screw 20, thereby realizing four or more levels of multi-stage lifting or telescopic movement.

[0060] Specifically, when there is only one lead screw layer assembly, the drive mechanism 40 drives the active lead screw 20 to perform rotational and linear motion. When the active lead screw 20 rotates, it drives the driven lead screw to rotate through the driven member. At the same time, the transmission nut of the lead screw layer assembly is driven to perform linear motion relative to the active lead screw 20 through the second external thread 202, so that the driven lead screw performs both linear and rotational motion. The rotational motion of the driven lead screw can drive the lead screw nut 30 to perform linear motion through its third external thread. In this case, the fixed lead screw 10 can be regarded as the first stage, the active lead screw 20 as the second stage, the driven lead screw as the third stage, and the lead screw nut 30 as the fourth stage, thereby realizing four stages of lifting or extension. Moreover, the active lead screw 20, the driven lead screw, and the lead screw nut 30 can lift or extend simultaneously, which can effectively improve efficiency.

[0061] Specifically, when there are two or more lead screw layer assemblies, the innermost lead screw layer assembly is sleeved on the driving lead screw 20, 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 transmission nut of the next innermost lead screw layer assembly is threaded into the third external thread of the driven lead screw of the innermost lead screw layer assembly, the driven component 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 driving lead screw 20 can drive each lead screw layer assembly to rotate and move along the axial direction of the driving lead screw 20, which can realize five or more levels of multi-stage lifting or telescopic movement.

[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 outer surface of the fixing screw is provided with a first external thread; A driving screw, the driving screw being hollow inside, having a first internal thread on its inner surface, the first internal thread being integrally formed with the driving screw, the driving screw being sleeved on the fixed screw, and the first internal thread engaging with the first external thread; the driving screw having a second external thread on its outer surface; and A drive mechanism, wherein the power output end of the drive mechanism is connected to the active lead screw, and is used to drive the active lead screw to rotate relative to the fixed lead screw; The driving mechanism is mounted on the fixed lead screw; The fixed lead screw is hollow inside, and the drive mechanism is disposed inside the fixed lead screw. The power output end of the drive mechanism extends to the outside of the fixed lead screw and is connected to the driving lead screw. The inner surface of the drive screw is provided with a first limiting portion along the axial direction of the drive screw, and the driving mechanism includes: A power unit, fixed to the fixed lead screw, the power unit having a power output shaft; and A linkage component is fixed to the power output shaft and located inside the drive screw. The linkage component has a first limiting engagement portion, which slides with the first limiting portion to restrict relative rotation between the linkage component and the drive screw, while allowing relative linear motion. The linkage component is a spline.

2. The linear motor according to claim 1, characterized in that: The direction of rotation of the second external thread is opposite to that of the first external thread.

3. The linear motor according to claim 1, characterized in that: The first internal thread is provided on the inner surface of the lead screw near the end of the lead screw.

4. The linear motor according to any one of claims 1 to 3, It is characterized in that Wherein, the power unit is a first motor; or, the power unit includes: A second motor, the second motor being fixed to the fixed lead screw; and A first gearbox is connected to the output shaft of the second motor, and the first gearbox has the power output shaft.

5. The linear motor according to any one of claims 1 to 3, characterized in that, The drive mechanism includes: A third motor, the third motor being fixed to the fixed lead screw; and The second gearbox is connected to the output shaft of the third motor, and the second gearbox has a power output end that engages with the inner surface of the drive screw to drive the drive screw to rotate relative to the fixed screw.

6. The linear motor according to any one of claims 1 to 3, 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 drive lead screw; the drive lead screw can drive each lead screw layer assembly to rotate and move along the axial direction of the drive lead screw; the linear motor also includes a lead screw nut, which is threaded onto the outermost lead screw layer assembly.

7. The linear motor according to any one of claims 1 to 3, characterized in that: The linear motor also includes a lead screw nut, which is threaded into the second external thread of the drive lead screw. The drive lead screw can drive the lead screw nut to move axially along the drive lead screw through the second external thread.

8. The linear motor according to any one of claims 1 to 3, 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, one end of the fixing screw has a cavity, the cavity is sleeved on the protruding part; the outer surface shape of the protruding part matches the inner surface shape of the cavity to restrict the relative rotation of the fixing screw and the protruding part.

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