Screw assembly, ball screw assembly and actuator

Abstract

The utility model provides a lead screw assembly, a ball screw assembly and an actuator. The lead screw assembly comprises a mandrel and a lead screw. A channel is formed in the periphery of the lead screw, a circulating roller path comprising the channel is arranged on the lead screw, and balls can circularly roll in the circulating roller path; at least one lead screw is a hollow lead screw, a through hole is formed in the center of the hollow lead screw, and the core shaft is sleeved with the hollow lead screw. The lead screw assembly and the ball screw assembly can flexibly adapt to various scenes, the machining difficulty can be reduced, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of linear actuators, in particular to a lead screw assembly, a ball screw assembly comprising the lead screw assembly, and an actuator comprising the ball screw assembly. BACKGROUND

[0002] A reverse ball screw is a ball screw in which balls are arranged on a lead screw, and the lead screw moves linearly by rotating a nut. The maximum load of the reverse ball screw is positively correlated with the number of balls arranged on the lead screw. After the lead screw is machined, the number of balls that can be arranged is determined, and the maximum load of the reverse ball screw is also determined accordingly. Therefore, in order to meet different load requirements, different specifications of reverse ball screws need to be designed and machined, which lacks flexibility and is not conducive to reducing machining difficulty and saving costs. SUMMARY

[0003] The present disclosure provides a lead screw assembly, a ball screw assembly comprising the lead screw assembly, and an actuator comprising the ball screw assembly.

[0004] In a first aspect, the present disclosure provides a lead screw assembly, comprising a mandrel and a lead screw; a groove is arranged on the outer periphery of the lead screw, and a circulating raceway comprising the groove is arranged on the lead screw, and balls can circulate and roll in the circulating raceway; at least one of the lead screws is a hollow lead screw, the center of the hollow lead screw is provided with a through hole, and the hollow lead screw is sleeved on the mandrel.

[0005] In some embodiments, the mandrel comprises a rod portion and a flange portion extending outwardly at one end of the rod portion; the outer diameter of the flange portion is greater than the diameter of the through hole of the hollow lead screw; and the hollow lead screw is sleeved on the rod portion.

[0006] In some embodiments, a groove is arranged on the outer periphery of the flange portion, and a circulating raceway comprising the groove is arranged on the flange portion, as one of the lead screws.

[0007] In some embodiments, the grooves on each of the lead screws are aligned.

[0008] In some embodiments, the lead screw assembly further comprises a limiting mechanism for positioning the lead screw and the mandrel, to prevent the lead screw and the mandrel from rotating relative to each other.

[0009] In some embodiments, the limiting mechanism comprises a locking nut and a locking thread arranged on the mandrel, and the locking nut and the locking thread cooperate to lock and position the lead screw and the mandrel.

[0010] In some embodiments, the limiting mechanism comprises a first limiting structure arranged in the through hole of the hollow screw rod, and a second limiting structure arranged on the outer periphery of the mandrel; the first limiting structure and the second limiting structure cooperate to limit the rotation of the hollow screw rod relative to the mandrel.

[0011] In some embodiments, the first limiting structure comprises at least one first protruding part and at least one first recessed part, the first protruding part extends in the axial direction, the first recessed part extends in the axial direction, and the first protruding part and the first recessed part are alternately distributed in the through hole of the screw rod; the second limiting structure comprises at least one second protruding part and at least one second recessed part, the second protruding part extends in the axial direction, the second recessed part extends in the axial direction, and the second protruding part and the second recessed part are alternately distributed on the outer periphery of the mandrel; the first protruding part matches the second recessed part, and the first recessed part matches the second protruding part.

[0012] In some embodiments, at least one of the screw rods is provided with a ball return channel, and the channel on the screw rod and the ball return channel are in communication with each other to form the circulating rolling track.

[0013] In some embodiments, the screw rod provided with the ball return channel comprises at least two first circulators; the ball return channel penetrates through the screw rod in the axial direction; the two first circulators are arranged at the two ends of the screw rod, and the channel on the screw rod and the ball return channel are in communication to form the circulating rolling track.

[0014] In some embodiments, the first circulator comprises a first surface, a second surface, and a third surface, the first surface, the second surface, and the third surface intersect with each other in pairs; the third surface is provided with a first port, the second surface is provided with a second port, and the first surface is provided with a first circulating channel; the first circulating channel penetrates through the first circulator to communicate the first port and the second port; the first port is connected with the ball return channel, the second port is connected with one end of the channel, and the ball return channel, the channel on the screw rod, and the first circulating channel in the two first circulators form the circulating rolling track.

[0015] In some embodiments, the first circulator comprises a main body part and a positioning block, the main body part comprises the first surface, the second surface, a fourth surface parallel to the third surface, the positioning block protrudes from the fourth surface, and the first circulation channel penetrates through the main body part and the positioning block; the two ends of the ball return channel are respectively provided with positioning grooves matching the shape of the positioning block, the two ends of the lead screw are provided with mounting grooves matching the shape of the main body part, and the positioning grooves are arranged in the mounting grooves; the main body part cooperates with the mounting grooves, the positioning block cooperates with the positioning grooves, and the first circulator is mounted on the lead screw.

[0016] In some embodiments, at least one of the lead screws comprises a surface circulator, the surface circulator connects two adjacent channels on the lead screw, and forms the circulation raceway.

[0017] In some embodiments, the outer periphery of the lead screw is provided with mounting holes, and a plurality of the mounting holes are distributed in the circumferential direction; the surface circulator comprises a second circulator, the second circulator is mounted in the mounting hole; the second circulator is provided with a second circulation channel penetrating through the second circulator, the second circulation channel connects two adjacent channels on the lead screw, and forms the circulation raceway.

[0018] In some embodiments, the second circulator is composed of two half circulators, and the two half circulators are centrally symmetrically arranged; the half circulator is provided with a guide groove, the guide groove comprises a concave section recessed inward and a convex section protruding outward; the concave section of the guide groove of one half circulator is complementary to the convex section of the guide groove of the other half circulator, and forms the second circulation channel.

[0019] In some embodiments, the surface circulator comprises a third circulator, the third circulator comprises a groove surface and a connecting surface, the groove surface is an arch surface, and a plurality of third circulation channels extending in the circumferential direction are arranged on the groove surface; the outer periphery of the lead screw comprises a mounting surface and a threaded surface, and channels are arranged on the threaded surface; the connecting surface cooperates with the mounting surface, the groove surface matches the outer periphery of the threaded surface, the third circulation channels connect two adjacent channels on the threaded surface, and form the circulation raceway.

[0020] In the second aspect, the embodiments of the present disclosure provide a ball screw assembly, which comprises a nut, balls, and the lead screw assembly of the first aspect of the embodiments of the present disclosure, and the balls are arranged in the circulation raceway of the lead screw assembly.

[0021] In the third aspect, the embodiments of the present disclosure provide an actuator, which comprises the ball screw assembly of the second aspect of the embodiments of the present disclosure.

[0022] In the embodiments of the present disclosure, the number of hollow leadscrews in the leadscrew assembly can be selected according to different application scenarios. For example, for different load requirements of different application scenarios, a corresponding number of hollow leadscrew sleeves can be arranged on the mandrel, so that the maximum load of the ball screw assembly meets the load requirement, and the ball screw assembly can be flexibly adapted to various scenarios, without the need to design and process multiple specifications of ball screw assemblies, which is conducive to reducing processing difficulty and saving cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a perspective view of a ball screw assembly in the embodiments of the present disclosure.

[0024] Figure 2 is a perspective view of a leadscrew assembly in the embodiments of the present disclosure.

[0025] Figure 3 is a sectional view of a ball screw assembly in the embodiments of the present disclosure.

[0026] Figure 4 is a sectional view of another ball screw assembly in the embodiments of the present disclosure.

[0027] Figure 5 is a structural schematic view of a first circulator.

[0028] Figure 6 is a structural schematic view of a leadscrew assembly using the first circulator.

[0029] Figure 7 is a structural schematic view of a second circulator. Figure 6 is a side view of a leadscrew in

[0030] Figure 8 is a structural schematic view of a leadscrew assembly using the second circulator in the embodiments of the present disclosure.

[0031] Figure 9 is a structural schematic view of a second circulator in the embodiments of the present disclosure.

[0032] Figure 10 is a structural schematic view of a half circulator. Figure 9 is a structural schematic view of an opening side of the second circulator in

[0033] Figure 11 is a structural schematic view of a third circulator in the embodiments of the present disclosure.

[0034] Figure 12 is a structural schematic view of a third circulator in the embodiments of the present disclosure.

[0035] Figure 13 is a structural schematic view of a leadscrew assembly using the third circulator in the embodiments of the present disclosure.

[0036] Reference Signs List:

[0037] 1, nut; 2, screw assembly; 21, mandrel; 211, rod portion; 212, flange portion; 213, locking thread; 22, lead screw; 221, hollow lead screw; 222, primary lead screw; 223, mounting slot; 224, positioning slot; 23, locking nut; 3, ball; 4, first circulator; 401, first surface; 402, second surface; 403, third surface; 404, fourth surface; 411, first port; 412, second port; 42, first circulation channel; 43, main body portion, 431, hollow hole; 44, positioning block; 441, hollow hole; 45, ball return spade; 46, protruding wing; 5, second circulator; 51, second circulation channel; 511, port; 512, port; 52, ball return spade; 53, half circulator; 531, guide slot; 6, third circulator; 61, third circulation channel. DETAILED DESCRIPTION

[0038] For those skilled in the art to better understand the technical solutions of the present disclosure, the technical solutions of the present disclosure will be described in detail below in combination with the drawings.

[0039] In the following, example embodiments will be described more fully with reference to the accompanying drawings, in which example embodiments can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0040] In the case of no conflict, each embodiment of the present disclosure and each feature in the embodiments can be combined with each other.

[0041] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0042] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms "comprise" and / or "consist of, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0043] The embodiments described herein can be described with reference to plan views and / or cross-sectional views using the ideal schematic diagrams of this disclosure. Therefore, the example illustrations can be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to those shown in the drawings, but include modifications to configurations formed based on manufacturing processes. Therefore, the areas illustrated in the drawings are schematic in nature, and the shapes of the areas shown in the figures illustrate specific shapes of areas of an element, but are not intended to be limiting.

[0044] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning, unless expressly so defined herein.

[0045] Figure 1 This is a perspective view of a ball screw assembly according to an embodiment of the present disclosure. Figure 2 This is a perspective view of a lead screw assembly according to an embodiment of this disclosure. Figure 3 This is a cross-sectional view of a ball screw assembly according to an embodiment of this disclosure. Figure 4 This is a cross-sectional view of another ball screw assembly in an embodiment of this disclosure.

[0046] like Figures 1 to 4 As shown, the ball screw assembly includes a nut 1, a screw assembly 2, and balls 3. Figures 1 to 4 The image shows a reverse ball screw assembly where the balls 3 are mounted on the screw assembly 2.

[0047] The lead screw assembly 2 includes a spindle 21 and a lead screw 22. The lead screw 22 has a groove on its outer periphery, which is part of the circulating raceway on the lead screw 22. The balls 3 are disposed in the circulating raceway on the lead screw 22. When the nut 1 rotates, it drives the balls 3 to roll in the circulating raceway, thereby driving the lead screw assembly 2 to move linearly as a whole, converting the rotational motion into linear motion.

[0048] like Figure 3 As shown, the lead screw assembly 2 includes at least one lead screw 22, of which at least one is a hollow lead screw 221. The hollow lead screw 221 has a through hole at its center and is sleeved on the spindle 21.

[0049] The embodiments disclosed herein do not impose any special limitation on the number of hollow lead screws 221.

[0050] The number of the hollow lead screws 221 in the embodiments of the present disclosure can be selected according to different application scenarios. For example, a corresponding number of hollow lead screws 221 can be arranged on the mandrel according to the load requirements of different application scenarios, so that the maximum load of the ball screw assembly meets the load requirements. The ball screw assembly provided in the embodiments of the present disclosure can be flexibly adapted to various scenarios and meet different load requirements, without the need to design and process multiple specifications of ball screw assemblies, which is conducive to reducing the processing difficulty and saving costs.

[0051] In the embodiments of the present disclosure, the number of turns of the spiral groove on the lead screw 22 is not specially limited. In some embodiments, the number of turns of the groove on the lead screw 22 is not more than 6. For example, the number of turns of the groove on the lead screw 22 is 3, 4 or 5. In the embodiments of the present disclosure, the maximum load of the ball screw assembly is positively correlated with the total number of turns of the grooves of all the lead screws 22 in the lead screw assembly 2. However, for each lead screw 22, the load efficiency is not always positively correlated with the number of turns of the groove. Too many turns of the groove of a lead screw 22 can cause the load efficiency of the lead screw 22 to decrease. Therefore, in the embodiments of the present disclosure, the number of turns of the groove on each lead screw 22 is set to be not more than 6, which is conducive to ensuring the load requirements of the ball screw assembly as a whole while making each lead screw 22 have a relatively optimal load efficiency.

[0052] In some embodiments, as shown in Figure 3 The mandrel 21 includes a rod-shaped portion 211 and a flange portion 212 extending outwardly at one end of the rod-shaped portion 211; and the hollow lead screw 221 is arranged on the rod-shaped portion 211, that is, each lead screw 22 in the lead screw assembly 2 is a hollow lead screw 221. The outer diameter of the flange portion 212 is greater than the diameter of the through hole of the hollow lead screw 221, which can play a limiting role to prevent the hollow lead screw 221 from being detached from the mandrel 21.

[0053] In some embodiments, as shown in Figure 4 The flange portion 212 is provided with a groove on the outer periphery, and the flange portion 212 is also provided with a circulating raceway including the groove, and the ball can circulate and roll in the circulating raceway. That is, the flange portion 212 also serves as one of the lead screws 22 of the lead screw assembly 2; or one of the lead screws 22 of the lead screw assembly 2 is integrally formed with the rod-shaped portion 211 of the mandrel 21 and serves as the flange portion 212 of the mandrel 21. As shown in Figure 4 The lead screw assembly 2 includes one primary lead screw 222 integrally formed with the rod-shaped portion 211 of the mandrel 21 and one hollow lead screw 221.

[0054] In this embodiment of the disclosure, when the lead screw assembly 2 includes multiple lead screws 22, the channels on each lead screw 22 are aligned. Alignment of the channels on each lead screw 2 means that if the channels on each lead screw 2 are extended to both ends, the channels on each lead screw 22 can form a continuous spiral channel. For example, when all the lead screws 22 in the lead screw assembly 2 are hollow lead screws 221, the channels of each hollow lead screw 221 are aligned; when the lead screw 22 in the lead screw assembly 2 includes a primary lead screw 222 and a hollow lead screw 221, the channels of each hollow lead screw 221 are aligned with the channels of the primary lead screw 222.

[0055] The alignment of the grooves on each lead screw 22 in the lead screw assembly 2 enables each lead screw 22 to engage with the nut 1, thereby ensuring the smooth operation of the ball screw assembly.

[0056] The lead screw assembly 2 also includes a limiting mechanism for positioning the lead screw 22 and the spindle 21 to prevent relative rotation between the lead screw 22 and the spindle 21. This embodiment does not impose any special limitations on the locking mechanism.

[0057] like Figures 1 to 4 As shown, the limiting mechanism includes a locking nut 23 and a locking thread 213 disposed on the spindle 21. The locking nut 23 and the locking thread 213 cooperate to lock and position the lead screw 22 to the spindle 21. For example, the locking nut 23 is disposed at the other end of all hollow lead screws 221 relative to the flange portion 212 of the spindle 21 or the other end of the first-stage lead screw 222. After aligning the grooves on each lead screw 22, the locking nut 23 is installed onto the locking thread 213, thereby locking and positioning each hollow lead screw 221 to the spindle 21.

[0058] In this embodiment, other fastening methods can also be used to position the lead screw 22 and the spindle 21, preventing relative rotation between them. For example, methods such as applying adhesive, using clips, or inserting pins can be employed for fastening and positioning. This embodiment does not impose any specific limitations on these methods.

[0059] In some embodiments, the limiting mechanism includes a first limiting structure disposed in the through hole of the hollow lead screw 221 and a second limiting structure disposed on the outer periphery of the spindle 21; the first limiting structure and the second limiting structure cooperate to restrict the hollow lead screw 221 from rotating relative to the spindle 21, and prevent the hollow lead screw 221 from rotating relative to the spindle 21, which would cause the channels of each lead screw 22 to become misaligned.

[0060] The embodiments disclosed herein do not impose any special limitations on the first limiting structure and the second limiting structure. For example, the first limiting structure and the second limiting structure may be a spline or a flat key.

[0061] In some embodiments, the first limiting structure comprises at least one first protruding part and at least one first recessed part, the first protruding part extends in the axial direction, the first recessed part extends in the axial direction, the first protruding part and the first recessed part are alternately distributed in the through hole of the lead screw 22; the second limiting structure comprises at least one second protruding part and at least one second recessed part, the second protruding part extends in the axial direction, the second recessed part extends in the axial direction, the second protruding part and the second recessed part are alternately distributed on the outer periphery of the mandrel 21; the first protruding part matches the second recessed part, and the first recessed part matches the second protruding part.

[0062] The structure of the circulating raceway on the lead screw 22 is not specially limited in the embodiments of the present disclosure. For example, the lead screw 22 can be internally circulating, a ball return channel is formed in the interior of the lead screw 22, and the ball return channel and the groove on the outer periphery of the lead screw 22 constitute the circulating raceway; the lead screw 22 can also be surface circulating, the ball circulating is realized on the outer periphery of the lead screw 22. In the case where the lead screw assembly 2 comprises a plurality of lead screws 22, the circulating raceways of the respective lead screws 22 can be the same or different. For example, all the lead screws 22 are internally circulating, or all the lead screws 22 are surface circulating, or part of the lead screws 22 are internally circulating and the other part of the lead screws 22 are surface circulating.

[0063] In some embodiments, at least one lead screw 22 is provided with a ball return channel, and the groove on the lead screw 22 and the ball return channel are in communication to constitute the circulating raceway.

[0064] In the embodiments of the present disclosure, the groove on the lead screw 22 can be in communication with the ball return channel through the through hole formed on the lead screw 22, or the groove and the ball return channel can be in communication through the setting of a circulating device.

[0065] Figures 1 to 4 The lead screw assembly 2 in FIG. 1 takes the internally circulating as an example. The interior of the lead screw 22 is provided with a ball return channel, the ball return channel penetrates the lead screw 22 in the axial direction; as shown in FIG. 2, two first circulating devices 4 are arranged at the two ends of the lead screw 22, the groove on the lead screw 22 and the ball return channel are in communication to constitute the circulating raceway. Figure 1 、 Figure 2 The groove on the lead screw 22 and the ball return channel are in communication to constitute the circulating raceway.

[0066] Figure 5 FIG. 3 is a structural schematic diagram of a first circulating device 4, Figure 6 FIG. 4 is a structural schematic diagram of a lead screw 22 using the first circulating device 4. Figure 6 The lead screw 22 shown in FIG. 1 can be a primary lead screw 222 or a hollow lead screw 221; Figure 6 The through hole in the center of the hollow lead screw 221 is not shown in FIG. 1.

[0067] As shown in FIG. 2, the first circulating device 4 comprises a first housing 41 and a first rotating shaft 42, the first rotating shaft 42 is arranged in the first housing 41 and is rotatable relative to the first housing 41, the first rotating shaft 42 is provided with a first rotating groove 421, the first rotating groove 421 is in communication with the groove on the lead screw 22 and the ball return channel to constitute the circulating raceway. Figure 5As shown, the first circulator 4 includes a first surface 401, a second surface 402, and a third surface 403, which intersect each other. In some embodiments, the second surface 402 and the third surface 403 are perpendicular. A first port 411 is provided on the third surface 403, a second port 412 is provided on the second surface 402, and a first circulation channel 42 is provided on the first surface 401. The first circulation channel 42 passes through the first circulator 4, connecting the first port 411 and the second port 412. After the first circulator 4 is installed on the lead screw 22, the first port 411 corresponds to the ball return channel inside the lead screw 22, and the second port 412 corresponds to the channel on the outer periphery of the lead screw 22. Depending on the rolling direction of the ball 3 in the circulation channel, the ball 3 can enter the first circulation channel 42 from the first port 411 or from the second port 412.

[0068] like Figure 5 As shown, the first circulator 4 includes a main body 43 and a positioning block 44. The positioning block 44 protrudes from a fourth surface 404 parallel to the third surface 403 and is disposed on one side of the main body 43. In some embodiments, the first circulator 4 is generally L-shaped. Figure 5 As shown, the first port 411 is disposed on the third surface 403 of the positioning block 44.

[0069] In some embodiments, such as Figure 5 As shown, a hollow hole 441 is formed in the positioning block 44. The hollow hole 441 can be triangular, circular, or other shapes. This embodiment does not impose any particular limitation on this. Providing a hollow hole 441 in the positioning block 44 can save material while ensuring the supporting strength of the positioning block 44, which is beneficial for making components such as the first circulator 4 lighter.

[0070] In some embodiments, such as Figure 5 As shown, a hollow hole 431 is also formed on the main body 43 of the first circulator 4. The hollow hole 431 can be triangular, circular, or other shapes. Providing a hollow hole 431 on the main body 43 can save material while ensuring the supporting strength of the main body 43, which helps to make the first circulator 4 and other components lighter.

[0071] The shape of the first circulation channel 42 is not specifically limited in the embodiments disclosed herein.

[0072] In some embodiments, the radius of curvature of the geometry of the first circulation channel 42 is capable of withstanding Hertzian pressure related to the ball speed, thereby enabling the ball to roll at high speed in the first circulation channel 42.

[0073] In some embodiments, such as Figure 5As shown, the first circulation channel 42 is in the shape of an arcuate groove, and the curvature radius of the arcuate groove is greater than or equal to the width of the arcuate groove. For example, the curvature radius of the arcuate groove of the first circulation channel 42 is 1.2 times, 1.4 times, 1.6 times, 1.8 times, 2 times, etc. of the width of the arcuate groove. Such a structure of the first circulation channel 42 can effectively prevent the balls 3 from being stuck in the first circulation channel 42, thereby ensuring that the balls roll smoothly and at high speed in the first circulation channel 42.

[0074] As shown in FIG. 1, the first circulation device 4 is arranged on the screw 22. Figure 5 As shown, a ball return shovel 45 is arranged on the side of the second port 412 of the first circulation channel 42, and the ball return shovel 45 is used to guide the balls 3 to enter and exit the first circulation channel 42, for example, to guide the balls 3 rolled from the channel of the screw 22 into the first circulation channel 42 to fall into the first circulation channel 42 correctly.

[0075] As shown in FIG. 1, the first circulation device 4 is arranged on the screw 22. Figure 5 As shown, the main body 43 further includes a protruding wing 46 arranged on at least one side of the second port 412, and the protruding wing 46 protrudes from the first surface 401. The protruding wing 46 can fix the rolling track of the balls 3, and ensure that the balls 3 roll smoothly between the channel of the screw 22 and the first circulation channel 42.

[0076] As shown in FIG. 1, the first circulation device 4 is arranged on the screw 22. Figure 6 As shown, the inside of the screw 22 is provided with a ball return channel, the ball return channel penetrates the screw 22 in the axial direction; two first circulation devices 4 are respectively arranged on both ends of the screw 22, the first port 411 of the first circulation device 4 is in position and engaged with the ball return channel, the second port 412 of the circulation device 4 is in position and engaged with one end of the channel of the screw 22, the ball return channel, the channel of the screw 22, and the first circulation channel 42 of the two first circulation devices 4 constitute a communication circulation rolling track, and the balls 3 are arranged in the circulation rolling track.

[0077] As shown in FIG. 1, the first circulation device 4 is arranged on the screw 22. Figure 7 As shown, mounting grooves 223 are arranged on both ends of the screw 22, and the shape of the mounting grooves 223 matches the shape of the main body 43 of the first circulation device 4; positioning grooves 224 are arranged in the mounting grooves 223, and the shape of the positioning grooves 224 matches the shape of the positioning block 44; the main body 43 cooperates with the mounting grooves 223, and the positioning block 44 cooperates with the positioning grooves 224, thereby mounting the first circulation device 4 on the screw 22.

[0078] When the first circulation device 4 is mounted on the screw 22, the positioning block 44 is clamped into the positioning groove 224 on the end side of the screw 22, the main body 43 is clamped into the mounting groove 223 on the end side of the screw 22, and the first circulation channel 42 in the first circulation device 4 is embedded with the ball return channel. The protruding wing 46 and the ball return shovel 45 are located in the channel of the screw 22, the first circulation channel 42 is embedded with the channel of the screw 22, and a communication circulation rolling track is formed.

[0079] In some embodiments, at least one lead screw 22 includes a second circulator 5 that connects two adjacent channels on the lead screw 22 to form the circulating raceway.

[0080] In this embodiment of the disclosure, the second circulator 5 may be a groove structure disposed on the lead screw 22 and connecting two adjacent channels on the lead screw 22, or it may be an independent component mounted on the lead screw 22.

[0081] Figure 8 This is a schematic diagram of the structure of a lead screw 22 according to an embodiment of this disclosure. Figure 8 The lead screw 22 shown can be a single-stage lead screw 222 or a hollow lead screw 221; Figure 8 The through hole at the center of the hollow lead screw 221 is not shown in the figure.

[0082] like Figure 8 As shown, mounting holes are provided between two adjacent channels on the outer periphery of the lead screw 22, and multiple mounting holes are distributed along the circumferential direction. The second circulator 5 is installed in the mounting holes.

[0083] Figure 9 , Figure 10 This is a schematic diagram of the structure of a second circulator 5 according to an embodiment of this disclosure. Figure 9 , Figure 10 As shown, the second circulator 5 is provided with a second circulation channel 51 that runs through the second circulator 5. The second circulation channel connects two adjacent channels on the lead screw 22 to form a circulation raceway.

[0084] like Figure 9 , Figure 10 As shown, the upper surface of the second circulator 5 is an arc surface. A return ball shovel 52 is respectively provided on the upper surface of the second circulator 5 at positions corresponding to ports 511 and 512 of the second circulation channel 51. The return ball shovel 52 guides the ball's path. After the second circulator 52 is mounted on the lead screw 22 to form a circulation raceway, when the ball 3 rolls in the circulation raceway to port 511 or port 512 of the second circulator 5, the return ball shovel 52 guides the ball 3 smoothly into the second circulation channel 51, thus allowing the ball 3 to circulate within the raceway.

[0085] In this embodiment of the disclosure, the second circulation channel 51 in the second circulator 5 can connect two adjacent channels on the lead screw 22, so that the ball 3 can return on the surface of the lead screw 22 without the need to process the return channel in the lead screw 22. Especially when the lead screw 22 is small and requires precision machining, it reduces the machining difficulty of the lead screw 22 and saves costs.

[0086] like Figure 9 , Figure 10As shown, the shape of the upper surface of the ball return shovel 52 matches the channel shape of the nut 1, and the connecting parts of the two ball return shovels 52 are arranged at intervals on the upper surface of the second circulating device 5, and the positions of the two ball return shovels 52 correspond to two adjacent channels respectively, so that the second circulating device 5 can be installed on the lead screw 22, and the two ball return shovels 52 are arranged in two adjacent channels of the nut 1 respectively.

[0087] The shape and structure of the second circulating channel 51 are not specially limited in the embodiments of the present disclosure.

[0088] As shown in Figure 8 , Figure 9 , the second circulating channel 51 includes a first arc segment and a second arc segment in the axial direction of the lead screw 22, the bending direction of the first arc segment is opposite to that of the second arc segment, and the first arc segment and the second arc segment are smoothly connected, so that the positions and orientations of the ports 511 and 512 correspond to two adjacent channels on the lead screw 22 respectively.

[0089] In some embodiments, the geometric design of the second circulating channel 51 enables its radius of curvature to withstand the Hertz pressure related to the speed of the ball, so that the ball can roll at high speed in the second circulating channel 51.

[0090] In some embodiments, the second circulating device 5 is composed of two half circulating devices 53, and the two half circulating devices 53 are arranged in a central symmetry.

[0091] Figure 11 is a structural schematic diagram of a half circulating device 53 in the embodiments of the present disclosure. As shown in Figure 11 , the half circulating device 53 is provided with a guide groove 531, and the guide groove 531 includes a concave segment and a convex segment; the concave segment of the guide groove 531 of one half circulating device 53 is complementary to the convex segment of the guide groove 531 of the other half circulating device 53. In the embodiments of the present disclosure, the shape of the concave segment is complementary to the shape of the convex segment, which means that the shapes of the concave segment and the convex segment can be matched in geometry, so as to be spliced into a complete raceway, and the ball can be accommodated in the raceway and roll in the raceway. After the two half circulating devices 53 which are completely the same are spliced in a central symmetry, the second circulating channel 51 is formed.

[0092] Figure 12 is a structural schematic diagram of a third circulating device 6 in the embodiments of the present disclosure. As shown in Figure 12 , the third circulating device 6 also functions to realize the circulation of the ball 3 on the surface of the lead screw 22. Figure 13 is a structural schematic diagram of a lead screw 22 using the third circulating device 6. As shown in Figure 13 , the lead screw 22 can be a primary lead screw 222 or a hollow lead screw 221; in Figure 13The through hole in the center of the hollow screw 221 is not shown.

[0093] As shown in Figure 12 , the third circulator 6 has a plurality of third circulation channels 61; as shown in Figure 13 , the third circulator 6 is installed on the mounting surface of the screw 22, and the third circulation channels 61 of the third circulator 6 replace a part of the channels on the screw 22.

[0094] As shown in Figure 12 , the third circulator 6 includes a groove surface and a connecting surface, the groove surface is an arch surface, and the groove surface has a plurality of third circulation channels 61, and each of the third circulation channels 61 is in communication with two adjacent channels on the screw 22. For example, the first circle channel is in communication with the second circle channel, and after the ball 3 rolls from the first circle channel to the second circle channel, it should continue to roll to the third circle channel, but due to the communication between the first circle channel and the second circle channel, the ball 3 returns to the first circle channel from the second circle channel, so that the ball 3 circulates and rolls within 360 degrees, and each 360 degrees is a circulation channel. Referring to Figure 12 、 Figure 13 , the third circulator 6 of the embodiment has three circulation channels. Through such a structure, the ball circulation channel does not need to be arranged inside the screw 22, and the ball circulation can be performed on the outer peripheral surface of the screw 22. The number of circulation channels of the embodiment is not specially limited. The number of third circulation channels 61 opened on the third circulator 6 is the number of circulation channels. In some embodiments, the number of circulation channels depends on the required dynamic load, and the load is proportional to the number of turns. In some embodiments, the number of circulation channels depends on the load efficiency, and the number of circulation channels is not more than 6, for example, the circulation channel can be 3 or 6, which can meet the load demand while realizing the optimal load efficiency.

[0095] As shown in Figure 13 , the connecting surface of the third circulator 6 is matched and connected with the mounting surface of the screw 22, and the groove surface of the third circulator 6 is matched with the outer periphery of the threaded surface, that is, after the third circulator 6 is installed on the mounting surface of the screw 22, the groove surface of the third circulator 6 is on the same cylindrical surface with the threaded surface of the screw 22, so as to ensure that the screw 22 with the third circulator 6 installed can be assembled in the nut 1. The third circulation channel 61 provided on the groove surface of the third circulator 6 is in communication with two adjacent channels on the threaded surface, forming a circulation channel; the ball 3 is arranged in the circulation channel

[0096] In some embodiments, the connecting surface of the third circulator 6 is a plane, and the first connecting mechanism is arranged on the connecting surface; the mounting surface of the screw 22 is a plane matched with the connecting surface, and the second connecting mechanism is arranged on the mounting surface; the first connecting mechanism and the second connecting mechanism are matched and connected, so as to install the third circulator 6 on the mounting surface of the screw 22.

[0097] In some embodiments, the first connecting mechanism comprises a limiting piece protruding from the connecting surface of the third circulator 6; the second connecting mechanism comprises a limiting groove arranged on the mounting surface of the lead screw 22; the limiting piece and the limiting groove are connected in cooperation. In some embodiments, the limiting piece and the limiting groove are interference fit. In some embodiments, the limiting piece and the limiting groove are inserted fit, constituting a mortise and tenon structure.

[0098] In some embodiments, the first connecting mechanism is a groove structure arranged on the connecting surface of the third circulator 6, and the second connecting mechanism is a protruding structure arranged on the mounting surface of the lead screw 22; the groove structure and the protruding structure are interference fit or inserted fit, mounting the third circulator 6 on the mounting surface of the lead screw 22.

[0099] The embodiments of the present disclosure further provide an actuator comprising the ball screw assembly described in the embodiments of the present disclosure.

[0100] In some embodiments, the actuator is an electric cylinder.

[0101] Example embodiments have been disclosed herein and, although the use of specific terms is expressly used herein, they are intended in the sense only of general descriptive purpose and should not be taken as limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics or / and elements described in connection with a particular embodiment can be used in conjunction with other embodiments unless otherwise explicitly stated. As such, those skilled in the art will appreciate that a variety of changes can be made without departing from the scope of the present disclosure as set forth in the claims appended hereto.

Claims

1. A lead screw assembly, comprising: The core shaft (21) and the lead screw (22) are included; A groove is arranged on the outer periphery of the lead screw (22), and a circulating raceway including the groove is arranged on the lead screw (22), and the ball can circulate and roll in the circulating raceway; At least one of the lead screws (22) is a hollow lead screw (221), and a through hole is arranged in the center of the hollow lead screw (221), and the hollow lead screw (221) is sleeved on the core shaft (21).

2. The lead screw assembly of claim 1, wherein, The core shaft (21) includes a rod-shaped portion (211) and a flange portion extending outward at one end of the rod-shaped portion (211); the outer diameter of the flange portion (212) is greater than the diameter of the through hole of the hollow lead screw (221); and the hollow lead screw (221) is sleeved on the rod-shaped portion (211).

3. The lead screw assembly of claim 2, wherein, A groove is arranged on the outer periphery of the flange portion (212), and a circulating raceway including the groove is arranged on the flange portion (212) as one of the lead screws (22).

4. The lead screw assembly of any one of claims 1 to 3, wherein, The grooves on each of the lead screws (22) are aligned.

5. The lead screw assembly of any one of claims 1 to 3, wherein, The screw rod assembly further includes a limiting mechanism for positioning the lead screw (22) and the core shaft (21) to prevent relative rotation of the lead screw (22) and the core shaft (21).

6. The lead screw assembly of claim 5, wherein, The limiting mechanism includes a locking nut (23) and a locking thread (213) arranged on the core shaft (21), and the locking nut (23) and the locking thread (213) cooperate to lock and position the lead screw (22) and the core shaft (21).

7. The lead screw assembly of claim 5, wherein, The limiting mechanism includes a first limiting structure arranged in the through hole of the hollow lead screw (221) and a second limiting structure arranged on the outer periphery of the core shaft (21); the first limiting structure and the second limiting structure cooperate to limit the rotation of the hollow lead screw (221) relative to the core shaft (21).

8. The lead screw assembly of claim 7, wherein, The first limiting structure includes at least one first protruding portion and at least one first recessed portion, the first protruding portion extends in the axial direction, the first recessed portion extends in the axial direction, and the first protruding portion and the first recessed portion are alternately distributed in the through hole of the lead screw (22); The second limiting structure includes at least one second protruding portion and at least one second recessed portion, the second protruding portion extends in the axial direction, the second recessed portion extends in the axial direction, and the second protruding portion and the second recessed portion are alternately distributed on the outer periphery of the core shaft (21); The first protruding portion matches the second recessed portion, and the first recessed portion matches the second protruding portion.

9. The lead screw assembly of any one of claims 1 to 3, wherein, At least one of the lead screws (22) is provided with a ball return channel, and the groove on the lead screw (22) and the ball return channel are in communication with each other to form the circulating raceway.

10. The lead screw assembly of claim 9, wherein, The lead screw (22) provided with the ball return channel includes at least two first circulators (4); the ball return channel penetrates the lead screw (22) in the axial direction; two first circulators (4) are arranged at both ends of the lead screw (22) to communicate the groove on the lead screw (22) with the ball return channel to form the circulating raceway.

11. The lead screw assembly of claim 10, wherein, The first circulator (4) comprises a first surface (401), a second surface (402), and a third surface (403), the first surface (401), the second surface (402), and the third surface (403) intersect with each other in pairs; the third surface (403) is provided with a first port (411), the second surface (402) is provided with a second port (412), and the first surface (411) is provided with a first circulation channel (42); the first circulation channel (42) penetrates through the first circulator (4) and connects the first port (411) and the second port (412). The first port (411) is connected with the ball return channel, the second port (412) is connected with one end of the channel, and the ball return channel, the channel on the lead screw (22), and the first circulation channel (42) in the two first circulators (4) constitute the circulating track.

12. The lead screw assembly of claim 11, wherein, The first circulator (4) comprises a main body (43) and a positioning block (44), the main body (44) comprises the first surface (401), the second surface (402), and a fourth surface (404) parallel to the third surface (403), the positioning block (44) protrudes from the fourth surface (404), and the first circulation channel (42) penetrates through the main body (43) and the positioning block (44). Both ends of the ball return channel are provided with positioning grooves (224) matching the shape of the positioning block, both ends of the lead screw (22) are provided with mounting grooves (223) matching the shape of the main body (43), and the positioning grooves (224) are arranged in the mounting grooves (223); the main body (43) is matched with the mounting grooves (223), the positioning block (44) is matched with the positioning grooves (224), and the first circulator (4) is mounted on the lead screw (22).

13. The lead screw assembly of any one of claims 1 to 3, wherein, At least one of the lead screws (22) comprises a surface circulator, which connects two adjacent channels on the lead screw (22) and constitutes the circulating track.

14. The lead screw assembly of claim 13, wherein, The lead screw (22) is provided with mounting holes on the outer periphery, and a plurality of mounting holes are distributed in the circumferential direction; the surface circulator comprises a second circulator (5) mounted in the mounting hole. The second circulator (5) is provided with a second circulation channel (51) penetrating through the second circulator (5), which connects two adjacent channels on the lead screw (22) and constitutes the circulating track.

15. The lead screw assembly of claim 14, wherein, The second circulator (5) is composed of two half circulators (53) arranged in a central symmetry. The half circulator (53) is provided with a guide groove (531), which comprises a concave section and a convex section; the concave section of the guide groove (531) of one half circulator (53) is complementary to the convex section of the guide groove (531) of the other half circulator (53), and the second circulation channel (51) is formed.

16. The lead screw assembly of claim 13, wherein, The surface circulator comprises a third circulator (6), the third circulator (6) comprises a groove surface and a connecting surface, the groove surface is an arch surface, and a plurality of third circulation grooves (61) extending in the circumferential direction are arranged on the groove surface; The outer periphery of the screw rod (22) comprises a mounting surface and a threaded surface, and a groove is arranged on the threaded surface; the connecting surface is connected with the mounting surface, the groove surface matches the outer periphery of the threaded surface, and the third circulation groove (61) communicates two adjacent grooves on the threaded surface to form the circulation track.

17. A ball screw assembly, characterized in that, The ball screw assembly (2) according to any one of claims 1 to 16, wherein the ball screw assembly (2) comprises a nut (1) and a plurality of balls (3) arranged in the circulation track of the ball screw assembly (2).

18. An actuator comprising: The ball screw assembly according to claim 17.

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