CN215221934U - Linear motor - Google Patents

Abstract

The utility model relates to the technical field of transmission, a linear electric motor is provided, include: the outer surface of the fixed screw rod is provided with a first external thread; the driving screw rod is hollow, a first internal thread is arranged on the inner surface of the driving screw rod, the driving screw rod is sleeved on the fixed screw rod, and the first internal thread is matched with the first external thread; the outer surface of the driving screw rod is provided with a second external thread; and the power output end of the driving mechanism is connected with the driving screw rod and is used for driving the driving screw rod to rotate relative to the fixed screw rod. The device has the advantages that the rapid lifting or stretching of the device adopting the linear motor is realized, the lifting or stretching efficiency is effectively improved, and the occupied space is small.

Description

Linear motor

Technical Field

The utility model relates to the technical field of transmission, especially, relate to a linear electric motor.

Background

The linear motor usually adopts a screw rod and nut matching mode to realize the lifting or stretching of components such as a sleeve and the like, and is usually applied to devices needing lifting or stretching, such as a lifting upright post, an electric push rod and the like.

The existing lifting upright posts, electric push rods and other devices are usually set to be multi-level lifting or multi-level telescopic, and the linear motors of the lifting upright posts and the electric push rods are usually sequentially driven step by step, so that parts such as sleeves are sequentially lifted or stretched step by step, and the lifting or stretching efficiency is low.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a linear electric motor to improve among the prior art technical problem that goes up and down or flexible inefficiency.

In order to achieve the above object, the utility model adopts the following technical scheme: there is provided a linear motor including: the outer surface of the fixed screw rod is provided with a first external thread; the driving screw rod is hollow, a first internal thread is arranged on the inner surface of the driving screw rod, the driving screw rod is sleeved on the fixed screw rod, and the first internal thread is matched with the first external thread; the outer surface of the driving screw rod is provided with a second external thread; and the power output end of the driving mechanism is connected with the driving screw rod and is used for driving the driving screw rod to rotate relative to the fixed screw rod.

In one embodiment, the drive mechanism is disposed on the stationary lead screw.

In one embodiment, the fixing screw rod is hollow, the driving mechanism is arranged inside the fixing screw rod, and a power output end of the driving mechanism extends to the outside of the fixing screw rod and is connected with the driving screw rod.

In one embodiment, the second external thread has a direction of rotation opposite to the direction of rotation of the first external thread.

In one embodiment, the first internal thread is provided on a portion of an inner surface of the active screw near an end of the active screw.

In one embodiment, the inner surface of the driving screw is provided with a first limit portion along the axial direction of the driving screw, and the driving mechanism includes: the power part is fixed on the fixed screw rod and is provided with a power output shaft; the linkage piece is fixed on the power output shaft and is positioned inside the driving screw rod, and the linkage piece is provided with a first limiting matching part which is in sliding fit with the first limiting part; wherein the power part is a first motor; or, the power section includes: the second motor is fixed on the fixed screw rod; and the first gear box is connected with an output shaft of the second motor, and is provided with the power output shaft.

In one embodiment, the drive mechanism comprises: the third motor is fixed on the fixed screw rod; and the second gear box is connected with an output shaft of the third motor and is provided with a power output end which is matched with the inner surface of the driving screw rod to drive the driving screw rod to rotate relative to the fixed screw rod.

In one embodiment, the linear motor further comprises a plurality of lead screw layer assemblies, each lead screw layer assembly is sequentially sleeved and assembled from inside to outside, and the lead screw layer assembly at the innermost layer is sleeved on the active lead screw; the driving screw rod can drive each screw rod layer assembly to rotate and move along the axial direction of the driving screw rod; the linear motor further comprises a lead screw nut, and the lead screw nut is in threaded fit with the outermost lead screw layer assembly.

In one embodiment, the linear motor further comprises a screw nut, the screw nut is in threaded fit with the second external thread of the active screw rod, and the active screw rod can drive the screw nut to move along the axial direction of the active screw rod through the second external thread.

In one embodiment, the linear motor further comprises a fixing portion, and one end of the fixing screw rod is fixed to the fixing portion.

In one embodiment, the fixing part is provided with a protruding part, one end of the fixing screw rod is provided with a cavity, and the cavity is sleeved on the protruding part; the shape of the outer surface of the protruding part is matched with the shape of the inner surface of the cavity, so that the fixed screw rod and the protruding part are limited to rotate relatively.

The embodiment of the present invention provides one or more technical solutions, which at least have the following technical effects or advantages:

the embodiment of the utility model provides a linear motor, through setting up the fixed screw rod, the inside is hollow and the initiative lead screw of locating the fixed screw rod is located to the cover, the actuating mechanism that power take off end and initiative lead screw are connected, and the surface of fixed screw rod is equipped with first external screw thread, the internal surface of initiative lead screw is equipped with first internal thread, the surface of initiative lead screw is equipped with second external screw thread, drive the initiative lead screw through actuating mechanism and make rotary motion relative to the fixed screw rod, can make the initiative lead screw rod make linear motion along the fixed screw rod axial simultaneously under the cooperation of first internal thread and first external screw thread, meanwhile, the rotation of initiative lead screw rod can make linear motion along the initiative lead screw rod axial through its second external screw thread drive external object of screw thread cooperation second external screw thread, thereby make the external object of screw thread cooperation second external screw thread move relative to the initiative lead screw rod axial while being relative to the fixed screw rod axial displacement along with the initiative lead screw rod, the fast lifting or stretching of an external object in threaded fit with the second external thread is realized, the fast lifting or stretching of a device which adopts the linear motor and needs to realize the lifting or stretching function is further realized, and the lifting or stretching efficiency is effectively improved; and the inner surface of the driving screw rod is directly provided with a first internal thread which is in threaded fit with the first external thread of the fixed screw rod so as to perform rotary motion and linear motion relative to the fixed screw rod, so that the linear motor occupies small space.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a linear motor according to an embodiment of the present invention;

fig. 2 is an exploded schematic view of a linear motor according to an embodiment of the present invention;

fig. 3 is a schematic top view of a linear motor according to an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view taken along line A-A of FIG. 3;

fig. 5 is a schematic structural view of the linear motor provided in the embodiment of the present invention after the driving screw rod and the screw rod nut are removed;

fig. 6 is a schematic structural diagram of an active screw rod according to an embodiment of the present invention;

fig. 7 is a schematic top view of an active screw according to an embodiment of the present invention;

fig. 8 is a schematic sectional view in the direction B-B in fig. 7.

Wherein, in the figures, the respective reference numerals:

100. a linear motor; 10. fixing the screw rod; 101. a first external thread; 20. an active screw rod; 201. a first internal thread; 202. a second external thread; 30. a feed screw nut; 40. a drive mechanism; 50. a fixed part; 51. a protruding part; 203. a first limiting part; 41. a power section; 410. a power take-off shaft; 42. a linkage member; 420. a first limit matching part; 411. a second motor; 412. a first gearbox.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating 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 the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1 to 4, the embodiment of the present invention provides a linear motor 100 for lifting or telescopic transmission, which can be applied to devices that need to realize lifting or telescopic functions, such as a lifting column, an electric push rod, a lifter, a lifting table, etc., but is not limited thereto; the linear motor 100 includes a fixing screw 10, a driving screw 20, and a driving mechanism 40, wherein:

the stationary screw 10 may be fixedly arranged, i.e. not rotating nor moving linearly, and the outer surface of the stationary screw 10 is provided with a first external thread 101.

The driving screw 20 is hollow, the inner surface of the driving screw 20 is provided with a first internal thread 201, the first internal thread 201 may be provided on the inner surface of the driving screw 20 along the axial direction of the driving screw 20 (i.e. the axial direction of the driving screw 20), or the first internal thread 201 may be provided only on a certain part of the inner surface of the driving screw 20, wherein the first internal thread 201 may be directly formed on the inner surface of the driving screw 20, that is, the first internal thread 201 and the driving screw 20 are integrally formed; the driving screw rod 20 is sleeved on the fixed screw rod 10, and the first internal thread 201 is matched with or screwed with the first external thread 101, so that the driving screw rod 20 can make linear motion relative to the fixed screw rod 10 through the screwing of the first internal thread 201 and the first external thread 101 when making rotary motion relative to the fixed screw rod 10; the outer surface of the active screw rod 20 is provided with a second external thread 202, which can be used to cooperate with an external object to drive the external object to move, wherein the external object can be a screw nut, a hollow screw rod or other components to be driven.

The power output end of the driving mechanism 40 is connected with the driving screw rod 20 and is used for driving the driving screw rod 20 to rotate relative to the fixed screw rod 10; the driving mechanism 40 is a mechanism or a device capable of providing a driving force and driving the driving screw 20 to rotate relative to the fixed screw 10, for example, the driving mechanism 40 may include a motor and a transmission member connected to an output end of the motor, and the driving force is provided by the motor, so that the transmission member drives the driving screw 20 to rotate relative to the fixed screw 10.

The linear motor 100 provided in the embodiment of the present application includes a fixed screw rod 10, an active screw rod 20 having a hollow interior and sleeved on the fixed screw rod 10, and a driving mechanism 40 having a power output end connected to the active screw rod 20, wherein the outer surface of the fixed screw rod 10 is provided with a first external thread 101, the inner surface of the active screw rod 20 is provided with a first internal thread 201 matching with the first external thread 101, the outer surface of the active screw rod 20 is provided with a second external thread 202, the driving screw rod 20 is driven by the driving mechanism 40 to rotate relative to the fixed screw rod 10, under the matching of the first internal thread 201 and the first external thread 101, the active screw rod 20 can make a linear motion along the axial direction of the fixed screw rod 10 while making a rotational motion, thereby achieving the lifting or extension of the active screw rod 20, and at the same time, the rotation of the active screw rod 20 can make a linear motion along the axial direction of the active screw rod 20 by matching with an external object having a second external thread driving a thread driving the second external thread Therefore, an external object in threaded fit with the second external thread moves axially relative to the fixed screw rod 10 along with the active screw rod 20 and also moves axially relative to the active screw rod 20, namely, when the active screw rod 20 moves relative to the fixed screw rod 10, the external object in threaded fit with the second external thread moves relative to the active screw rod 20, so that the external object in threaded fit with the second external thread can be quickly lifted or stretched, and further, the lifting upright column, the electric push rod and other devices adopting the linear motor 100 can be quickly lifted or stretched, and the lifting or stretching efficiency can be effectively improved. And, first internal thread 201 sets up in the internal surface of initiative lead screw 20 integratively, can improve the steadiness and the removal uniformity between first internal thread 201 and the initiative lead screw 20, can prevent to produce relative motion between initiative lead screw 20 and the first internal thread 201 to improve the driven steadiness and the transmission uniformity of cooperation between initiative lead screw 20 and the fixed screw 10, simultaneously, need not to connect the nut with fixed screw 10 screw-thread fit in addition on initiative lead screw 20, can effectively simplify the structure, reduce the space, make linear electric motor 100 occupation space little.

In one embodiment, referring to fig. 1 and 2, the linear motor 100 further includes a fixing portion 50, and one end of the fixing screw 10 is fixed to the fixing portion 50; the fixing portion 50 may be a base, the fixing screw 10 may be vertically fixed to the fixing portion 50, the fixing portion 50 may also be a base, the fixing screw 10 may be transversely fixed to the fixing portion 50, and of course, the fixing portion 50 may also be other structures. So set up, the fixed part 50 can fix the lead screw 10, prevents that the lead screw 10 from removing, reinforcing stability.

It should be noted that, in some other embodiments, the fixing portion 50 may not be disposed on the linear motor 100, and the fixing screw 10 may be directly fixed to a device to which the linear motor 100 is applied, for example, the fixing screw 10 may be directly fixed to a housing of the lifting column.

Optionally, in an embodiment, referring to fig. 2 and fig. 4, the fixing portion 50 has a protruding portion 51, one end of the fixing screw 10 has a cavity, and the cavity is sleeved on the protruding portion 51, that is, the protruding portion 51 is inserted into the cavity; it is understood that the cavity may be a groove provided at one end of the fixing screw 10 when the fixing screw 10 is solid, and may be a part of the inner space of the fixing screw 10 when the inside of the fixing screw 10 is hollow. With such an arrangement, the protruding portion 51 is matched with the cavity of the fixing screw 10, so that the fixing screw 10 can be prevented from deflecting or moving relative to the fixing portion 50, and the stability of the fixing screw 10 is improved.

In other embodiments, the protruding portion 51 may not be provided, for example, the fixing screw 10 and the fixing portion 50 are directly fixedly connected by a screw, a bolt, a rivet, a welding, or the like.

Alternatively, in one embodiment, referring to fig. 2 and 4, the outer surface of the protruding portion 51 is shaped to match the inner surface of the cavity to limit the relative rotation between the fixing screw and the protruding portion 51; the protruding portion 51 is a non-cylindrical protruding portion, and the cavity and the protruding portion 51 can be restricted from rotating relatively at this time, for example, the protruding portion 51 may be a prism (e.g., a quadrangular prism), a convex column with an elliptical cross section, or other regular or irregular convex columns. So set up, protruding portion 51 of establishing and the cooperation of cavity can prevent that fixed screw 10 from taking place to rotate, further improves its steadiness, and then improves initiative lead screw 20 and makes rotary motion and linear motion's stability for fixed screw 10.

Alternatively, in one embodiment, referring to fig. 4, the fixing screw 10 is detachably fixed on the fixing portion 50, for example, the fixing screw 10 may be fixed on the fixing portion 50 by a screw or a bolt. So configured, the detachment and installation between the fixing screw 10 and the fixing portion 50 is facilitated.

In one embodiment, referring to fig. 2 and 4, the rotation direction of the second external thread 202 is opposite to that of the first external thread 101, so that the moving direction of the external object in threaded engagement with the second external thread 202 during linear motion is the same as that of the driving screw rod 20 during linear motion, and thus the external object in threaded engagement with the second external thread 202 and the driving screw rod 20 can be simultaneously lifted or retracted in the same direction, and the lifting column is very suitable for being applied to a lifting column to simultaneously lift a sleeve of the lifting column; the direction of rotation is the direction of the screw thread, and the screw thread that is rotated clockwise is called a right-hand screw thread, and the screw thread that is rotated counterclockwise is called a left-hand screw thread.

In one embodiment, referring to fig. 4 and 8, the first internal thread 201 is disposed on a portion of the inner surface of the driving screw 20 near the end of the driving screw 20, and for the orientation shown in fig. 4 and 8, the first internal thread 201 is disposed on a portion of the inner surface of the driving screw 20 near the lower end of the driving screw 20, and a gap may be formed between a portion of the inner surface of the driving screw 20 not disposed with the first internal thread 201 and the first external thread 101 of the fixing screw 10. So set up, only in the initiative lead screw 20 internal surface processing that is close to the tip position of initiative lead screw 20 first internal thread 201 can, and need not all to process the internal thread at the internal surface of initiative lead screw 20, can effectively reduce cost, raise the efficiency, if to the internal surface processing full thread of initiative lead screw 20 then the technology is complicated and the cost is higher.

In one embodiment, referring to fig. 2 and 4, the driving mechanism 40 is disposed on the fixing screw 10, specifically, the driving mechanism 40 may be disposed outside the fixing screw 10 and inside the driving screw 20, or the fixing screw 10 may be disposed with a hollow interior and the driving mechanism 40 may be disposed inside the fixing screw 10. So set up, because the fixed setting of stationary screw 10, set up actuating mechanism 40 on stationary screw 10, not only do benefit to actuating mechanism 40's fixed mounting, and actuating mechanism 40 does not directly expose in linear electric motor 100's outside promptly, not only be difficult for receiving external influence, and do benefit to the make full use of space, make actuating mechanism 40, stationary screw 10, install compacter between parts such as initiative lead screw 20, actuating mechanism 40 does not bulge in linear electric motor 100's outside, and is more elegant appearance, and be convenient for linear electric motor 100 to install on its device of using, can improve user experience and feel.

It should be noted that, in some other embodiments, the driving mechanism 40 may not be disposed on the fixed screw 10, and the driving mechanism 40 may be disposed outside the fixed screw 10 and the driving screw 20, for example, the driving mechanism 40 may be disposed on a device to which the linear motor 100 is applied, and the driving screw 20 is driven to rotate by connecting a transmission member of the driving mechanism 40 to the driving screw 20, and it is understood that any transmission member of the driving mechanism 40 may be any one of the existing transmission structures.

Alternatively, in an embodiment, referring to fig. 2 and 4, the fixing screw 10 is hollow, the driving mechanism 40 is disposed inside the fixing screw 10, and the power output end of the driving mechanism 40 extends to the outside of the fixing screw 10 to be connected with the driving screw 20, wherein the driving mechanism 40 may be partially disposed inside the fixing screw 10, or all of the driving mechanism 40 except the power output end of the driving mechanism 40 may be disposed inside the fixing screw 10. So set up, actuating mechanism 40 sets up in the inside of stationary screw 10, can improve actuating mechanism 40's arrangement steadiness and arrangement convenience, form hidden installation, and whole length when can suitably shortening linear electric motor 100 contracts, and, actuating mechanism 40 does not occupy the exterior space, can improve space utilization, and the cooperation distance between actuating mechanism 40's power take off end and the initiative lead screw 20 is shorter this moment and more do benefit to the rotation of drive initiative lead screw 20 for stationary screw 10, can shorten the connection cooperation length between actuating mechanism 40 and the initiative lead screw 20, improve transmission stability.

Alternatively, in an embodiment, referring to fig. 2, 4, 5 and 6, the inner surface of the driving screw 20 is provided with a plurality of first limiting portions 203 along the axial direction of the driving screw 20, the driving mechanism 40 includes a power portion 41 and a linking member 42, the power portion 41 is fixed to the fixed screw 10, specifically, the power portion 41 may be fixed inside the fixed screw 10, for example, the power portion 41 may be fixed inside the fixed screw 10 by clamping, welding, screwing or bolting, but is not limited thereto, the power portion 41 may be partially or completely located inside the fixed screw 10, the power portion 41 is located at an end of the fixed screw 10 away from the fixing portion 50, the power portion 41 refers to a device capable of providing a rotational driving force, the power portion 41 has a power output shaft 410, the power output shaft 410 extends to the outside of the fixed screw 10, the linking member 42 is fixed on the power output shaft 410 and is located inside the driving screw 20, the linkage member 42 has a plurality of first limit matching parts 420, the first limit matching parts 420 are in sliding fit with the first limit parts 203, and can limit the relative rotation of the linkage member 42 and the driving screw rod 20 and only can do relative linear motion; the linkage 42 is an intermediate power transmission member capable of transmitting the rotation power of the power output shaft 410 to the driving screw 20, for example, the linkage 42 may be a spline, a cylindrical linkage, a fan-shaped linkage, a strip-shaped linkage, or other regular or irregular linkage; specifically, the first limiting portion 203 may be a protruding strip protruding from the inner surface of the driving lead screw 20 along the axial direction of the driving lead screw 20, the first limiting engaging portion 420 may be a sliding slot disposed on the outer peripheral surface of the linking member 42, or of course, the first limiting portion 203 may be a sliding slot recessed from the inner surface of the driving lead screw 20 along the axial direction of the driving lead screw 20, and the first limiting engaging portion 420 is a protruding strip or protrusion protruding from the outer peripheral surface of the linking member 42, and the sliding slot and the protruding strip or protrusion are slidably engaged with each other, so that the relative rotation between the linking member 42 and the driving lead screw 20 can be limited, the driving lead screw 20 can be driven to rotate when the linking member 42 rotates, and the driving lead screw 20 and the linking member 42 can perform a relative linear motion when performing a linear motion relative to the fixed lead screw 10; the first position-limiting portion 203 may also be a polygonal inner surface of the driving screw 20, for example, a polygonal inner surface with a quadrangular cross section, and correspondingly, the first position-limiting engaging portion 420 may be a polygonal outer peripheral surface, for example, a polygonal outer peripheral surface with a quadrangular cross section, and at this time, the shape of the link 42 may be a polygonal link, and the relative rotation between the link 42 and the driving screw 20 can be limited by the sliding engagement of the first position-limiting engaging portion 420 of the link 42, which is a polygonal outer peripheral surface, with the first position-limiting portion 203 of the driving screw 20, which is a polygonal inner surface. During operation, the power output shaft 410 drives the linkage member 42 to rotate through the action of the power portion 41, the linkage member 42 drives the driving screw rod 20 to rotate through the cooperation of the first limiting portion 203 and the first limiting matching portion 420, the driving screw rod 20 makes linear motion relative to the fixed screw rod 10 under the cooperation of the first internal thread 201 and the first external thread 101, the driving screw rod 20 and the linkage member 42 make linear motion relatively, and the linkage member 42 can play a role in supporting and stabilizing the driving screw rod 20 at the same time. So set up, do benefit to actuating mechanism 40 and stably drive initiative lead screw 20 and do rotary motion and linear motion simultaneously for stationary screw 10 for cooperation compact structure, stability is high between stationary screw 10, actuating mechanism 40 and the initiative lead screw 20.

Alternatively, in an embodiment, please refer to fig. 2 and fig. 4, the power part 41 includes a second motor 411 and a first gear box 412, the second motor 411 is fixed to the fixed screw 10, an input end of the first gear box 412 is connected to an output shaft of the second motor 411, the first gear box 412 has a power output shaft 410, specifically, the second motor 411 and the first gear box 412 may both be fixed inside the fixed screw 10, or only a part or all of the second motor 411 may be fixed inside the fixed screw 10 while the first gear box 412 is located outside the fixed screw 10, or of course, both the second motor 411 and the first gear box 412 may be located outside the fixed screw 10 and inside the driving screw 20; it is understood that the first gearbox 412 may take the form of any one of the existing gearboxes, such as, but not limited to, a planetary gearbox; in operation, the power unit 41 operates, and the power of the power unit 41 is transmitted from the output shaft thereof to the first gear case 412, transmitted from the gear train inside the first gear case 412 to the power output shaft 410, and transmitted to the link 42.

It should be noted that the structure of the power portion 41 is not limited to this, and in some other embodiments, the power portion 41 may be a first motor, the first motor has a power output shaft, and the link 42 is fixed to the power output shaft of the first motor, that is, the power portion 41 may not have the first gear box 412 and the link 42 is driven to rotate by the first motor, for example, the first motor may be a speed reduction motor, and the speed reduction motor has a power output shaft.

It should be further noted that the driving mechanism 40 may not have the linkage member 42, alternatively, in some other embodiments, the driving mechanism 40 includes a third motor and a second gear box, the third motor is fixed to the fixed screw rod, specifically, the third motor may be partially or completely located inside the fixed screw rod 10, the second gear box is connected to an output shaft of the third motor, the second gear box has a power output end which is matched with an inner surface of the driving screw rod 20 to drive the driving screw rod 20 to rotate relative to the fixed screw rod 10, wherein the power output end of the second gear box may be a rotatable outer shell of the second gear box, the inner surface of the outer shell may be provided with internal teeth engaged with internal transmission gears of the second gear box, the second gear box is driven by the third motor to operate, the outer shell of the second gear box is driven to rotate by the internal transmission gears of the second gear box, thereby enabling the second gearbox to drive the driving screw rod 20 to rotate; it will be appreciated that the second gearbox may be any of the prior art planetary gearboxes or a planetary gearbox modified from the prior art planetary gearboxes, the planetary gearboxes having a rotatable outer housing. Specifically, the inner surface of the driving screw 20 is provided with a first limiting portion 203 along the axial direction of the driving screw 20, the power output end of the second gearbox is provided with a gearbox limiting matching portion, the gearbox limiting matching portion is in sliding fit with the first limiting portion 203, the power output end of the second gearbox and the driving screw 20 can be limited to rotate relatively and can only do relative linear motion, wherein the gearbox limiting matching portion can adopt a structure the same as that of the first limiting matching portion 420, and details are not repeated herein.

In one embodiment, referring to fig. 1 and 4, the linear motor 100 further includes a lead screw nut, the lead screw nut 30 is sleeved on the driving lead screw 20, an inner thread is disposed on an inner surface of the lead screw nut 30, the lead screw nut 30 can be limited by a device to which the linear motor 100 is applied to limit the rotation of the lead screw nut 30, and the driving lead screw 20 can drive the lead screw nut 30 to move along the axial direction of the driving lead screw 20 through the second outer thread 202; the lead screw nut 30 is sleeved on the active lead screw 20, which means that the lead screw nut 30 is directly sleeved on the active lead screw 20 or sleeved on the active lead screw 20 through an intermediate component; in one way, the lead screw nut 30 can be directly sleeved on the driving lead screw 20 and is in threaded fit with the second external thread 202, when the driving lead screw 20 rotates, the lead screw nut 30 is directly driven to make linear motion through the second external thread 202, in this case, the fixed lead screw 10 can be regarded as a first stage, the driving lead screw 20 can be regarded as a second stage, and the lead screw nut 30 can be regarded as a third stage, so that three-stage lifting or stretching is realized; alternatively, the lead screw nut 30 may be sleeved on the active lead screw 20 through an intermediate member, and the active lead screw 20 drives the intermediate member to linearly move through the second external thread 202 when rotating, so as to indirectly drive the lead screw nut 30 to linearly move, for example, the intermediate member may be a hollow lead screw sleeved on the active lead screw 20, and the lead screw nut 30 may be in threaded fit with the hollow lead screw, in this case, the fixed lead screw 10 may be regarded as a first stage, the active lead screw 20 may be regarded as a second stage, the hollow lead screw may be regarded as a third stage, and the lead screw nut 30 may be regarded as a fourth stage, so as to achieve four-stage lifting or stretching, and so on, the plurality of hollow lead screws may be arranged, each hollow lead screw may be sequentially sleeved from inside to outside, and the lead screw nut 30 is in threaded fit with the outermost hollow lead screw, so as to achieve multiple-stage lifting or stretching.

Alternatively, in an embodiment, referring to fig. 1 and fig. 4, the lead screw nut 30 is in threaded fit with the second external thread 202 of the active lead screw 20, that is, the internal thread of the lead screw nut 30 is matched or screwed with the second external thread 202, the driving lead screw 20 is driven to rotate and linearly move relative to the fixed lead screw 10 by the linkage 42 of the driving mechanism 40, the driving lead screw 20 drives the lead screw nut 30 to linearly move relative to the active lead screw 20, at this time, the fixed lead screw 10 can be regarded as a first stage, the active lead screw 20 can be regarded as a second stage, and the lead screw nut 30 can be regarded as a third stage, so that three-stage lifting or extension is realized, the stability is high, and the driving lead screw 20 and the lead screw nut 30 can be lifted or extended simultaneously, and the efficiency can be improved.

Illustratively, when the linear motor 100 is applied to a lifting column, the lifting column has a first cylinder, the first cylinder may be fixed to the fixing portion 50, and serves as a first-stage lifting cylinder, the second cylinder may be located inside the first cylinder and rotatably connected (e.g., via a bearing) to one end of the active screw rod, and serves as a second-stage lifting cylinder, the third cylinder may be located inside the second cylinder and fixed to the screw nut 30, and serves as a third-stage lifting cylinder, an outer circumferential surface of the screw nut 30 may be matched with an inner surface of the second cylinder to limit rotation of the screw nut 30 (e.g., an outer circumferential surface of the screw nut 30 may be non-circular, such as polygonal, and the screw nut 30 may also be matched with the inner surface of the second cylinder in a manner similar to the manner that the first limiting portion 203 is slidably matched with the first limiting matching portion 420). During operation, the driving screw rod 20 is driven to rotate and linearly move through the driving mechanism 40, the driving screw rod 20 drives the second cylinder, the screw rod nut 30 and the third cylinder to simultaneously linearly move, meanwhile, the driving screw rod 20 rotates to drive the screw rod nut 30 to linearly move, the screw rod nut 30 drives the third cylinder to linearly move, simultaneous lifting or stretching of the second cylinder and the third cylinder is achieved, and lifting or stretching efficiency can be effectively improved.

In another embodiment, the linear motor 100 further includes a plurality of lead screw layer assemblies, each of which is sequentially sleeved from inside to outside, and the innermost lead screw layer assembly is sleeved on the active lead screw 20; the driving screw rod 20 can drive each screw rod layer assembly to rotate and move along the axial direction of the driving screw rod 20, and multi-stage lifting or stretching can be achieved.

Optionally, in one embodiment, the screw rod layer assembly includes a hollow screw rod, the hollow screw rod is hollow inside, the inner surface of the hollow screw rod is provided with a second internal thread, the outer surface of the hollow screw rod is provided with a fourth external thread, each hollow screw rod is sleeved from inside to outside in sequence, and the second internal thread of the hollow screw rod of the outer layer of two adjacent hollow screw rods is matched or screwed with the fourth external thread of the hollow screw rod of the inner layer; the hollow screw rod at the innermost layer is sleeved on the active screw rod 20, and the second internal thread of the hollow screw rod at the innermost layer is matched or screwed with the second external thread 202 of the active screw rod 20. The driving screw rod 20 rotates to drive each hollow screw rod to do linear movement and/or rotary movement through the second external thread 202, so that multi-stage lifting or stretching is realized. For those skilled in the art, the parameters such as the lead angle of the second external thread 202 and the fourth external thread of each hollow screw rod can be set according to the actual application requirement. Further, the lead screw nut 30 may be screw-fitted to the fourth external thread of the outermost hollow lead screw.

Optionally, in one embodiment, the lead screw layer assemblies include a transmission lead screw and a nut fixedly connected to the transmission lead screw, the transmission lead screw and the nut may be coaxially arranged, the transmission lead screw is hollow, the outer surface of the transmission lead screw is provided with a fifth external thread, the transmission lead screw of each lead screw layer assembly is sequentially sleeved from inside to outside, and the nut of the lead screw layer assembly on the outer layer of the two adjacent lead screw layer assemblies is in threaded fit or screwed fit with the fifth external thread of the lead screw layer assembly on the inner layer; the driving screw rod of the innermost screw rod layer assembly is sleeved on the driving screw rod 20, and the nut of the innermost screw rod layer assembly is matched or screwed with the second external thread 202 of the driving screw rod 20. The nuts and the transmission screw rods of the screw rod layer assemblies are driven to do linear movement and/or rotary movement through the rotation of the driving screw rod 20 and the second external threads 202, so that multi-stage lifting or stretching is realized. For those skilled in the art, the parameters such as the lead angle of the second external thread 202 and the internal thread of the nut of each lead screw layer assembly can be set according to the actual application.

Optionally, in an embodiment, the screw layer assembly includes a driven screw, a transmission nut and a driven member, the driven screw is hollow inside, the inner surface of the driven screw is provided with a second limiting portion along the axial direction of the driven screw, the outer surface of the driven screw is provided with a third external thread, the transmission nut is rotatably connected with one end of the driven screw, specifically, the transmission nut may be connected with one end of the driven screw through a bearing, so that the driven screw and the transmission nut can rotate relatively, and of course, the transmission nut may also be directly rotatably fitted with the driven screw without passing through the bearing; the driven part is provided with a second limit matching part which is matched with the second limit part in a sliding way, specifically, the second limit part can be a raised line which is convexly arranged on the inner surface of the driven screw rod along the axial direction of the driven screw rod, the second limit matching part can be a sliding groove which is arranged on the outer peripheral surface of the driven part, of course, the second limit part may be a sliding groove recessed in the inner surface of the driven screw rod along the axial direction of the driven screw rod, the second limit matching part may be a convex strip or a protrusion protruding from the outer peripheral surface of the driven member, the driven member is an intermediate power transmission member capable of transmitting the rotation force of the driving screw rod to the driven screw rod or transmitting the rotation force of the driven screw rod to another driven screw rod, for example, the driven member may be a spline, the driven member can be a driven member in a cylindrical shape, a fan shape or a strip shape, or can be other driven members in a regular or irregular shape, and the function of the driven member is similar to that of the linkage member 42; the driven screw rod of the innermost screw rod layer assembly is sleeved on the driving screw rod 20, the transmission nut of the innermost screw rod layer assembly is in threaded fit with the second external thread 202, and the driven piece of the innermost screw rod layer assembly is fixed on the driving screw rod 20; the screw rod nut 30 can be in threaded fit with a third external thread of a driven screw rod of the screw rod layer assembly on the outermost layer, and when the number of the screw rod layer assemblies is one, the screw rod layer assembly on the outermost layer and the screw rod layer assembly on the innermost layer are the same; the driving screw rod 20 can drive each screw rod layer assembly to rotate and move along the axial direction of the driving screw rod 20, so that four-stage and more than four-stage multi-stage lifting or stretching is realized.

Specifically, when the number of the screw layer assemblies is one, the driving screw 20 is driven to perform rotary motion and linear motion through the driving mechanism 40, the driven screw is driven to rotate through the driven member when the driving screw 20 performs rotary motion, and the transmission nut of the screw layer assembly is driven to perform linear motion relative to the driving screw 20 through the second external thread 202, so that the driven screw performs linear motion and rotary motion simultaneously, and the driven screw performs rotary motion, i.e., the screw nut 30 is driven to perform linear motion through the third external thread thereof, in this case, the fixed screw 10 can be regarded as a first stage, the driving screw 20 can be regarded as a second stage, the driven screw can be regarded as a third stage, and the screw nut 30 can be regarded as a fourth stage, thereby realizing four-stage lifting or stretching, and the driving screw 20, the driven screw and the screw nut 30 can simultaneously lift or stretch, thereby effectively improving efficiency.

Specifically, when the number of the screw rod layer assemblies is two or more, the driving screw rod 20 is arranged in a sleeved mode on the innermost screw rod layer assembly, the driven screw rod of the sub-inner screw rod layer assembly is sleeved on the driven screw rod of the innermost screw rod layer assembly, the transmission nut of the sub-inner screw rod layer assembly is in threaded fit with the third external thread of the driven screw rod of the innermost screw rod layer assembly, the driven member of the sub-inner screw rod layer assembly is fixed on the driven screw rod of the innermost screw rod layer assembly, and by analogy, all the screw rod layer assemblies are sequentially sleeved from inside to outside and assembled, the driving screw rod 20 can be in rotary motion and linear motion to drive all the screw rod layer assemblies to rotate and move along the axial direction of the driving screw rod 20, and multistage lifting or stretching of five stages or more can be achieved.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A linear motor, characterized in that the linear motor comprises:

the outer surface of the fixed screw rod is provided with a first external thread;

the driving screw rod is hollow, a first internal thread is arranged on the inner surface of the driving screw rod, the driving screw rod is sleeved on the fixed screw rod, and the first internal thread is matched with the first external thread; the outer surface of the driving screw rod is provided with a second external thread; and

and the power output end of the driving mechanism is connected with the driving screw rod and is used for driving the driving screw rod to rotate relative to the fixed screw rod.

2. A linear motor according to claim 1, wherein: the driving mechanism is arranged on the fixed screw rod.

3. A linear motor according to claim 2, wherein: the driving mechanism is arranged in the fixing screw rod, and a power output end of the driving mechanism extends to the outside of the fixing screw rod and is connected with the driving screw rod.

4. A linear motor according to claim 1, wherein: the second external thread has a direction of rotation opposite to the direction of rotation of the first external thread.

5. A linear motor according to claim 1, wherein: the first internal thread is arranged on the inner surface of the driving screw rod and close to the end part of the driving screw rod.

6. The linear motor according to any one of claims 1 to 5, wherein a first stopper is provided on an inner surface of the driving screw in an axial direction of the driving screw, and the driving mechanism includes:

the power part is fixed on the fixed screw rod and is provided with a power output shaft; and

the linkage piece is fixed on the power output shaft and is positioned inside the driving screw rod, the linkage piece is provided with a first limiting matching part, and the first limiting matching part is in sliding fit with the first limiting part;

wherein the power part is a first motor; or, the power section includes:

the second motor is fixed on the fixed screw rod; and

the first gear box is connected with an output shaft of the second motor and is provided with the power output shaft.

7. A linear motor according to any one of claims 1 to 5, the drive mechanism comprising:

the third motor is fixed on the fixed screw rod; and

and the second gear box is connected with an output shaft of the third motor and is provided with a power output end which is matched with the inner surface of the driving screw rod to drive the driving screw rod to rotate relative to the fixed screw rod.

8. A linear motor according to any one of claims 1 to 5, characterized in that: the linear motor also comprises a plurality of screw rod layer assemblies, each screw rod layer assembly is sequentially sleeved and assembled from inside to outside, and the screw rod layer assembly at the innermost layer is sleeved on the active screw rod; the driving screw rod can drive each screw rod layer assembly to rotate and move along the axial direction of the driving screw rod; the linear motor further comprises a lead screw nut, and the lead screw nut is in threaded fit with the outermost lead screw layer assembly.

9. A linear motor according to any one of claims 1 to 5, characterized in that: the linear motor further comprises a screw nut, the screw nut is in threaded fit with the second external thread of the active screw rod, and the active screw rod can drive the screw nut to move along the axial direction of the active screw rod through the second external thread.

10. A linear motor according to any one of claims 1 to 5, characterized in that: the linear motor also comprises a fixing part, and one end of the fixing screw rod is fixed on the fixing part; the fixing part is provided with a convex part, one end of the fixing screw rod is provided with a cavity, and the cavity is sleeved on the convex part; the shape of the outer surface of the protruding part is matched with the shape of the inner surface of the cavity, so that the fixed screw rod and the protruding part are limited to rotate relatively.

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