Core body, ball screw and actuator

Abstract

The utility model provides a core body, a ball screw and an actuator. The core includes: a main body portion; the at least one ball return channel is arranged on the main body part; the core body is used for being arranged in an inner hole of a lead screw, so that the ball return channel is communicated with a channel in the periphery of the lead screw to form a circulation channel. According to the ball screw, the machining difficulty can be reduced, especially under the condition that the size of the lead screw of the ball screw is very small, the machining cost of the ball screw can be reduced, and the ball screw can further provide larger load density.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of transmission devices, in particular to a core, a ball screw and an actuator. BACKGROUND

[0002] Ball screws are the main components of electric linear actuators (such as electric cylinders), and the principle is to convert rotary motion into linear motion through a spiral raceway. At present, ball screws capable of meeting the demand for large load density of electric linear actuators have high processing difficulty and high cost. CONTENT OF THE INVENTION

[0003] The present disclosure provides a core, a ball screw and an actuator.

[0004] In a first aspect, the present disclosure provides a core, comprising: a main body part; and at least one ball return channel, the ball return channel being arranged on the main body part; the core is arranged in the inner hole of a screw rod, so that the ball return channel and the channel on the outer periphery of the screw rod form a circulation channel.

[0005] In some embodiments, the ball return channel comprises an axial channel extending along the axial direction of the core, a first circumferential channel and a second circumferential channel extending along the circumferential direction of the core, the first circumferential channel and the second circumferential channel are respectively arranged at both ends of the axial channel, and the first circumferential channel, the second circumferential channel and the axial channel are smoothly connected.

[0006] In some embodiments, the first circumferential channel and the second circumferential channel extend in different directions along the circumferential direction of the core from the axial channel.

[0007] In some embodiments, the main body part comprises a protruding part, the protruding part comprises an axial protrusion extending along the axial direction of the core, a first circumferential protrusion and a second circumferential protrusion extending along the circumferential direction of the core, the first circumferential protrusion and the second circumferential protrusion are respectively arranged at both ends of the axial protrusion; the ball return channel is arranged along the extension direction of the protruding part.

[0008] In some embodiments, the first circumferential protrusion and the second circumferential protrusion extend in different directions along the circumferential direction of the core from the axial protrusion.

[0009] In some embodiments, the main body part further comprises a cylindrical columnar part, and the protruding part is arranged on the outer peripheral surface of the columnar part.

[0010] In some embodiments, the main body part further comprises a first flange part arranged at one end of the main body part, and the outer peripheral surface of the first flange part is coplanar with the outer surface of the protruding part.

[0011] In some embodiments, the main body part is cylindrical, and the ball return channel is arranged on the outer circumferential surface of the main body part.

[0012] In some embodiments, the main body part comprises a pipe part, the pipe part comprising an axial pipe extending along the axial direction of the core, a first circumferential pipe and a second circumferential pipe extending along the circumferential direction of the core, the first circumferential pipe and the second circumferential pipe being arranged at two ends of the axial pipe respectively; the inner cavity of the pipe part constitutes the ball return channel.

[0013] In some embodiments, the first circumferential pipe and the second circumferential pipe extend in different directions along the circumferential direction of the core from the two ends of the axial pipe respectively.

[0014] In some embodiments, the pipe part further comprises a first connecting pipe arranged at one end of the first circumferential pipe and a second connecting pipe arranged at one end of the second axial pipe; the first connecting pipe and the second connecting pipe extend away from the axis of the core.

[0015] In some embodiments, the core further comprises a fixing part arranged at one end of the main body part, the fixing part being used for axially positioning the core.

[0016] In some embodiments, the fixing part is arranged at one end of the main body part as a second flange part extending outward from the main body part.

[0017] In some embodiments, the fixing part is arranged at one end of the main body part as at least one tab extending outward from the main body part.

[0018] In some embodiments, the fixing part is provided with a perforation for mounting a bolt.

[0019] In some embodiments, the main body part is further provided with a limiting bump protruding from the outer surface of the main body part.

[0020] In some embodiments, the material of the core comprises any one of plastic, resin, and metal.

[0021] In a second aspect, the embodiments of the present disclosure provide a ball screw, comprising a nut, a screw rod, balls, and the core of the first aspect of the embodiments of the present disclosure; the screw rod is internally provided with an inner hole extending along the axial direction, the core is arranged in the inner hole, and at least one pair of through holes are arranged in the groove on the outer circumferential surface of the screw rod; one ball return channel of the core communicates with the groove of the screw rod through the pair of through holes to form a circulation channel; the balls are arranged in the circulation channel.

[0022] In some embodiments, the ball screw further comprises a circulator arranged at the through hole for guiding the ball to pass through the through hole to and from the ball return groove of the core.

[0023] In some embodiments, the circulator comprises a ball return spade and a connecting portion; the ball return spade is internally provided with a curved inner raceway for contacting with the ball to guide the ball to roll; the connecting portion is arranged at one end of the circulator relative to the ball return spade for fixing the circulator into the groove of the screw rod.

[0024] In some embodiments, the circulator comprises at least one fin arranged at at least one side of the ball return spade, the fin being in a curved sheet shape.

[0025] In some embodiments, a limiting protrusion is arranged on the main body portion of the core, the limiting protrusion protruding from the outer surface of the main body portion; a limiting groove matched with the limiting protrusion is arranged on the inner wall of the inner hole, the limiting protrusion and the limiting groove cooperating to limit the arrangement orientation of the core relative to the screw rod.

[0026] In some embodiments, the core further comprises a fixing portion arranged at one end of the main body portion, the fixing portion being connected with one end of the inner hole opening of the screw rod.

[0027] In some embodiments, the number of groove turns of the screw rod between each pair of through holes can be one or more turns.

[0028] In a third aspect, the embodiments of the present disclosure provide an actuator, comprising the ball screw of the second aspect of the present disclosure and a driver.

[0029] By adopting the technical solutions of the present disclosure, the core has a simple structure and is easy to process, even for a small-sized ball screw; thus the processing difficulty is reduced, and the processing cost of the ball screw is reduced. On the other hand, by adopting the technical solutions of the present disclosure, the diameter direction is more compact, and the load density is greater than that of a conventional ball screw. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 is a structural schematic diagram of a core according to an embodiment of the present disclosure;

[0031] Figure 2 FIG. 2 is a structural schematic diagram of an inner hole of a screw rod of a ball screw according to an embodiment of the present disclosure;

[0032] Figure 3 FIG. 3 is a structural schematic diagram of a ball screw according to an embodiment of the present disclosure;

[0033] Figure 4A schematic view of a circulator of a ball screw according to an embodiment of the present disclosure;

[0034] Figure 5 A schematic view of a structure of a screw rod of a ball screw according to an embodiment of the present disclosure;

[0035] Figure 6 A perspective view of an assembled core and circulator of a ball screw according to an embodiment of the present disclosure;

[0036] Figure 7 A schematic view of a structure of another core according to an embodiment of the present disclosure;

[0037] Figure 8 A perspective view of an assembled core and circulator of another ball screw according to an embodiment of the present disclosure;

[0038] Figure 9 A schematic view of a structure of a pipe portion of a core according to an embodiment of the present disclosure.

[0039] BRIEF DESCRIPTION OF DRAWINGS

[0040] 10, core; 102, limiting bump; 12, main body portion; 121, columnar portion; 122, protruding portion; 123, fixed portion; 124, first flange portion; 125, through hole; 126, pipe portion; 1261, axial pipe; 1262, first circumferential pipe; 1263, second circumferential pipe; 1264, first connecting pipe; 1265, second connecting pipe; 127, groove; 129, bolt; 13, ball returning channel; 130, end face; 132, inlet and outlet; 14, outer surface; 20, ball; 30, screw rod; 302, limiting groove; 304, end face; 32, inner hole; 34, channel; 36, through hole; 325, opening; 327, push rod; 40, nut; 50, circulator; 52, ball returning shovel; 54, inner raceway; 56, fin portion; 56A, first fin portion; 56B, second fin portion; 58, connecting portion; 59, mounting hole. DETAILED DESCRIPTION

[0041] In order 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 with reference to the drawings.

[0042] 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 being 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.

[0043] The embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0044] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," 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.

[0046] Embodiments described herein can be described with reference to plan views and / or cross-sectional views by virtue of the fact that the present disclosure equally contemplates method embodiments taken with reference to plan views and / or cross-sectional views. Accordingly, the example illustrations are to be considered for what they are intended to represent and not as limitations of embodiments. As such, the embodiments are not limited to the illustrated examples and include modifications based on manufacturing processes and / or tolerances, which are intended to be subsistent with the spirit and scope of the present disclosure. Thus, the zones illustrated in the drawings are schematic and the shapes of the zones illustrated in the drawings are not intended to be limiting and represent specific shapes of the zones of the elements.

[0047] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an overly literal or overly formal sense unless expressly so defined herein.

[0048] The ball screw involved in the present disclosure is a mechanical linear actuator mainly composed of a screw rod, a nut and balls, wherein a plurality of balls are accommodated between the screw rod and the nut. Due to the rotation of the screw rod or the nut, the balls are transported to one end of the screw groove, and then returned to the other end of the screw groove through the circulating channel. The ball return groove connects the start and end points of the screw groove, so that the balls can circulate and roll. The main function of the ball screw is to convert rotary motion into linear motion, and in this conversion process, the nut can accurately and stably transmit force to static or dynamic loads.

[0049] In the art, the positive screw structure is driven by the rotation of the screw rod to linearly move the nut.

[0050] The present disclosure optimizes the conventional ball screw structure and proposes a reverse ball screw structure in which the nut is rotated to drive the screw to move linearly. The ball (steel ball) is installed on the screw, and a circulating channel or a circulator needs to be arranged on the screw to realize the ball returning. However, the radial size of the reverse ball screw structure is usually small, and the precision machining is required, and the precision requirement of the parts is high. Therefore, the machining difficulty of the circulating channel on the small-size screw is high, and the machining process requirement is high, resulting in high cost of the ball screw.

[0051] In order to realize the ball returning in the reverse ball screw structure, the present disclosure proposes a special core body installed in the inner hole of the screw, which is positioned by the groove of the screw to realize the ball returning in the screw. The structure is more compact in the diameter direction, has a larger load density than the conventional ball screw, and has fewer parts than the planetary ball screw, is easier to process, and has a lower cost.

[0052] Figure 1 FIG. 1 is a structural schematic diagram of the core body 10 of the embodiment of the present disclosure, and some balls 20 are exemplarily shown in the figure. Figure 2 FIG. 2 is a structural schematic diagram of the inner hole of the screw 30 of the ball screw 1 of the embodiment of the present disclosure.

[0053] With reference to Figure 1 and 2 the embodiment of the present disclosure provides a core body 10, which comprises a main body part 12 and at least one ball returning groove 13 arranged on the main body part 12, wherein the core body 10 is arranged in the inner hole 32 of the screw 30, so that the ball returning groove 13 and the groove 34 on the outer periphery of the screw 30 form a circulating channel.

[0054] In the present disclosure, the core body 10 (which can also be referred to as a circulating core rod) comprises a main body part 12 and a ball returning groove 13 on the outer surface. By using such a core body 10, the ball returning groove 13 does not need to be machined inside the screw 30, and only the inner hole 32 needs to be arranged on the screw 30, thereby reducing the machining difficulty; especially in the case of a small-size screw 30, it is more difficult to machine the ball returning groove 13 inside the screw 30 by precision machining, and the use of the core body 10 of the embodiment of the present disclosure is beneficial to further reduce the machining difficulty, and enables the ball to circulate inside the small-size screw 30 and realize the reverse ball screw. The core body 10 of the embodiment of the present disclosure has a simple structure and is easy to process, and allows the use of a relatively simple mold (such as a coreless mold) for machining and manufacturing, and only the inner hole needs to be arranged in the screw 30 to realize the ball circulation, thereby solving the problem of high machining difficulty and high machining process requirement of the circulating channel on the small-size screw, and being beneficial to reducing the machining cost of the ball screw. Since the core body 10 is arranged in the inner hole 32 of the screw 30, the overall structure is more compact in the diameter direction, and has a larger load density than the conventional ball screw.

[0055] In Figure 1 , two ball return channels 13 are exemplarily shown on the core 10. However, the number of the ball return channels 13 provided on the core 10 is not specially limited in the embodiments of the present disclosure, and can be specifically set according to actual needs. For example, the more the number of the ball return channels 13, the more the circulating channels formed on the screw rod 30, and the greater the load of the ball screw. The number of the ball return channels 13 on the core 10 can be set according to the needs of the load of the ball screw. In the case of providing two ball return channels 13 as shown in Figure 1 , the two ball return channels 13 respectively form two independent circulating channels with two sections of the channels 34 on the outer periphery of the screw rod 30.

[0056] Referring to Figure 2 , the screw rod 30 is further provided with a plurality of through holes 36 penetrating the screw rod 30 in the radial direction, and the plurality of through holes 36 are paired two by two, and each pair of through holes 36 corresponds to one ball return channel 13 on the core 10. The through holes 36 are used to communicate the channels 34 on the outer periphery of the screw rod 30 with the ball return channels 13 on the core 10 inside the screw rod 30. When the nut 40 (refer to Figure 3 ) is rotated, the balls 20 roll in the channels 34 on the outer periphery of the screw rod 30, pass through the through holes 36 on the screw rod 30 to enter the ball return channels 13 on the core 10, and continue to roll on the ball return channels 13, and then pass through another through hole 36 to return to the channels 34 on the outer periphery of the screw rod 30. Thus, the circulating rolling of the balls 20 is realized. As long as the nut 40 is long enough, the rotation of the nut 40 can drive the screw rod 30 to move linearly.

[0057] Referring to Figure 1 , the ball return channel 13 includes an axial channel extending in the axial direction of the main body portion 12, a first circumferential channel and a second circumferential channel extending in the circumferential direction of the main body portion 12, the first circumferential channel and the second circumferential channel are respectively provided at both ends of the axial channel, and the first circumferential channel and the second circumferential channel are in smooth communication with the axial channel. That is, the ball return channel 13 includes an axial extending portion and a circumferential extending portion, the circumferential extending portion is in communication with the channels 34 on the outer periphery of the screw rod 30 through the through holes of the screw rod 30, and can make the balls smoothly enter the ball return channel 13 from the channels 34 or enter the channels 34 from the ball return channel 13; the axial extending portion corresponds to the span between the start point and the end point of the channels 34, and can make the balls return from the start point of the channels 34 to the end point of the channels 34, thereby realizing circulation.

[0058] As Figure 1As shown, the first circumferential channel and the second circumferential channel extend in different directions along the circumference of the main body 12 from the axial channel. The fact that the first circumferential channel and the second circumferential channel extend in different directions in the circumferential direction enables the ball 20 to roll in one direction in the circumferential direction when it rolls from the inlet to the outlet of the return ball channel 13, for example, along the direction in which the ball 20 rolls in the channel 34, thereby making the ball 20 roll smoothly in the circulation channel.

[0059] It should be noted that in some embodiments, the first circumferential channel and the second circumferential channel may also extend from the axial channel in the same direction along the circumference of the main body 12. This disclosure does not impose any special limitations on this aspect.

[0060] This disclosure does not impose any particular limitation on how the ball return channel 13 is provided on the main body 12. In some embodiments, the main body 12 is cylindrical, and the ball return channel 13 is formed on the cylindrical outer surface of the main body 12.

[0061] In some embodiments, such as Figure 1 As shown, the main body 12 includes a cylindrical columnar portion 121, and a protrusion 122 is provided on the outer peripheral surface 14 of the columnar portion 121; a ball return groove 13 is formed on the protrusion 122. That is, the protrusion 122 is only provided on the outer peripheral surface of the columnar portion 121 at the position where the ball return groove 13 needs to be provided, and the ball return groove 13 is formed on the protrusion 122, which helps to save materials and also reduces the weight of the core 10, thereby achieving the lightweighting of the ball screw.

[0062] The shape of the protrusion 122 is not particularly limited in the embodiments disclosed herein. For example, the protrusion 122 may be an arc-shaped protrusion on the outer peripheral surface of the columnar portion 121, or the protrusion 122 may be a shape that matches the extending direction of the ball return channel 13.

[0063] In some embodiments, such as Figure 1 As shown, the protrusion 122 includes an axial protrusion extending along the axial direction of the columnar portion 121, a first circumferential protrusion and a second circumferential protrusion extending circumferentially along the columnar portion 121, with the first circumferential protrusion and the second circumferential protrusion respectively disposed at both ends of the axial protrusion; the ball return channel 13 is disposed along the extending direction of the protrusion 122. In this embodiment of the present disclosure, the protrusion 122 is configured with a shape matching the extending direction of the ball return channel 13, which is beneficial for further saving materials and reducing weight.

[0064] In this embodiment of the present disclosure, the extension directions of the first circumferential protrusion and the second circumferential protrusion of the protrusion 122 are consistent with the extension directions of the first circumferential channel and the second circumferential channel of the ball return channel 13, respectively.

[0065] like Figure 1As shown, the first circumferential protrusion and the second circumferential protrusion extend from the axial protrusion in different directions along the circumference of the columnar portion 121, respectively.

[0066] In some embodiments, the main body portion 12 can also only include the protrusion portion 122 without the columnar portion 121. As shown in FIG. 2, the main body portion 12 includes the protrusion portion 122, which includes an axial protrusion extending along the axial direction of the core 10, a first circumferential protrusion and a second circumferential protrusion extending along the circumferential direction of the core 10, and the first circumferential protrusion and the second circumferential protrusion are arranged at two ends of the axial protrusion, respectively. Figure 7 As shown, the main body portion 12 includes the protrusion portion 122, which includes an axial protrusion extending along the axial direction of the core 10, a first circumferential protrusion and a second circumferential protrusion extending along the circumferential direction of the core 10, and the first circumferential protrusion and the second circumferential protrusion are arranged at two ends of the axial protrusion, respectively; the ball return channel 13 is arranged along the extension direction of the protrusion portion 122.

[0067] In some embodiments, the first circumferential protrusion and the second circumferential protrusion extend from the two ends of the axial protrusion in different directions along the circumferential direction of the core 10, respectively.

[0068] In the embodiments of the present disclosure, the ball return channel 13 can be an open groove structure arranged on the main body portion 12, or a closed pipeline structure. The embodiments of the present disclosure do not make special limitations on this.

[0069] In some embodiments, the main body portion 12 is composed of a pipeline structure.

[0070] In some embodiments, as shown in FIG. 2, the main body portion 12 includes the pipeline portion 126, which includes an axial pipeline 1261 extending along the axial direction of the core 10, a first circumferential pipeline 1262 and a second circumferential pipeline 1263 extending along the circumferential direction of the core 10, and the first circumferential pipeline 1262 and the second circumferential pipeline 1263 are arranged at two ends of the axial pipeline 1261, respectively; the inner cavity of the pipeline portion 126 constitutes the ball return channel 13. Figure 8 、 Figure 9 In some embodiments, as shown in FIG. 2, the main body portion 12 includes the pipeline portion 126, which includes an axial pipeline 1261 extending along the axial direction of the core 10, a first circumferential pipeline 1262 and a second circumferential pipeline 1263 extending along the circumferential direction of the core 10, and the first circumferential pipeline 1262 and the second circumferential pipeline 1263 are arranged at two ends of the axial pipeline 1261, respectively; the inner cavity of the pipeline portion 126 constitutes the ball return channel 13.

[0071] In some embodiments, the first circumferential pipeline 1262 and the second circumferential pipeline 1263 extend from the two ends of the axial pipeline 1261 in different directions along the circumferential direction of the core 10, respectively.

[0072] In some embodiments, the pipeline portion 126 further includes a first connecting pipeline 1264 arranged at one end of the first circumferential pipeline 1262 and a second connecting pipeline 1265 arranged at one end of the second axial pipeline 1263; the first connecting pipeline 1264 and the second connecting pipeline 1265 extend in a direction away from the axis of the core 10. The first connecting pipeline 1264 and the second connecting pipeline 1265 are used to communicate the pipeline portion 126 with the through hole 36 on the lead screw 30.

[0073] In some embodiments, as shown in FIG. 2, the main body portion 12 includes the pipeline portion 126, which includes an axial pipeline 1261 extending along the axial direction of the core 10, a first circumferential pipeline 1262 and a second circumferential pipeline 1263 extending along the circumferential direction of the core 10, and the first circumferential pipeline 1262 and the second circumferential pipeline 1263 are arranged at two ends of the axial pipeline 1261, respectively; the inner cavity of the pipeline portion 126 constitutes the ball return channel 13. Figure 1As shown, the main body 12 further comprises a first flange portion 124 arranged at one end of the columnar portion 121, and the outer circumferential surface of the first flange portion 124 is coplanar with the outer surface of the protruding portion 122. The diameter of the outer circumferential surface of the first flange portion 124 matches the diameter of the inner hole 32 of the screw rod 30, and when the core 10 is installed in the inner hole 32, the outer circumferential surface of the first flange portion 124 and the outer surface of the protruding portion 122 can cooperate with the inner wall of the inner hole 32 to position the core 10.

[0074] Referring to Figure 1 In some embodiments, the core 10 further comprises a fixing portion 123 arranged at one end of the main body 12, and the fixing portion 123 is used to fix the core 10 to the screw rod 30 to axially position the core 10. In some embodiments, as shown in Figure 1 , the fixing portion 123 is arranged at one end of the columnar portion 121 relative to the first flange portion 124.

[0075] In some embodiments, the columnar portion 121 can be a tubular portion with a central hole as shown in Figure 1 . The specific structure of the columnar portion 121 can be designed as needed, and the specific structure is not limited.

[0076] In some embodiments, as shown in Figure 1 , the fixing portion 123 is arranged as a flange portion extending outwardly from the columnar portion 121 at one end of the columnar portion 121. The flange portion is annular.

[0077] In some embodiments, the fixing portion 123 is arranged as at least one tab extending outwardly from the columnar portion 121 at one end of the columnar portion 121. The number of tabs is not particularly limited in the embodiments of the present disclosure. When the tabs are multiple, the multiple tabs are arranged at intervals, for example, uniformly distributed in the circumferential direction. When the tabs are two, the two tabs are oppositely arranged.

[0078] In some embodiments, the fixing portion 123 is provided with perforations 125 for installing bolts 129.

[0079] Referring to Figure 1 , when the fixing portion 123 is a flange portion, the flange portion is used to connect and fix the core 10 to the screw rod 30, and perforations 125 are arranged on the flange portion, and the core 10 is fixed to the screw rod 30 by bolts 129 (refer to Figure 3 ) passing through the perforations 125. The number of perforations 125 can be more than two; however, the specific number of perforations 125 can be designed as needed without any limitation.

[0080] In addition, in some embodiments, a groove 127 is provided on the end surface 130 of the fixing portion 123 opposite to the cylindrical portion 121 at a position corresponding to the through hole 125 to accommodate the head of the bolt, so that the head of the bolt does not protrude from the end surface 130 to prevent interference with other components or damage.

[0081] When the fixing portion 123 is a tab (not shown), the through hole is provided on the tab, and the bolt 129 passes through the through hole on the tab to fix the core 10 to the lead screw 30.

[0082] In some embodiments, a limiting protrusion 102 is further provided on the core 10 to cooperate with a corresponding limiting groove 302 on the lead screw 30 to limit the setting orientation of the core 10 relative to the lead screw 302. By adopting such a setting, the rotation of the core 10 relative to the lead screw 30 can be prevented, so that the through hole 36 on the lead screw 30 is not misaligned with the entrance 132 of the ball return channel 13 on the core 10.

[0083] As shown in Figure 1 , in some embodiments, the limiting protrusion 102 of the core 10 can protrude from the end surface of the fixing portion 123 opposite to the end surface 130, i.e., the end surface facing the cylindrical portion 121. As shown in Figure 2 , the limiting groove 302 of the lead screw 30 can be recessed from the inner hole 32 to the outside on one end surface 304 of the lead screw 30. However, the specific structure of the limiting protrusion 102 of the core 10 and the limiting groove 302 of the lead screw 30 is not limited thereto, as long as they can position the orientation of the core 10 relative to the lead screw 302.

[0084] The material of the core 10 is not particularly limited in the embodiments of the present disclosure. For example, the core 10 can be made of metal, resin, plastic, etc.

[0085] The manufacturing process of the core 10 is also not particularly limited in the embodiments of the present disclosure. For example, the core 10 can be manufactured by molding processes including but not limited to injection molding, casting, powder metallurgy, 3D printing, etc.

[0086] In some embodiments, the core 10 can be made of plastic by an injection molding process. By adopting the injection molding process to make the core 10 from plastic, the processing difficulty and cost are reduced.

[0087] In other embodiments, the core 10 can be made of metal material. By adopting metal material to make the core 10, the rigidity of the core 10 can be improved, and the strength and durability thereof are enhanced.

[0088] In some embodiments, as shown in Figure 1 , Figure 2As shown, at both ends of the groove 34 on the outer periphery of the lead screw 30, a through hole 36 is provided; correspondingly, at both ends of the ball return groove 13 on the core 10, an entrance 132 is also provided; thus the ball 20 can pass in and out of the groove 34 through the through hole 36 and pass in and out of the ball return groove 13 through the entrance 132. Generally, two through holes 36 are provided corresponding to one groove 34, and two entrances 132 are provided corresponding to one ball return groove 13, and the positions of the through holes 36 and the entrances 132 are one-to-one corresponding so that the ball 20 can circulate in the groove 34 and the ball return groove 13. The positions of the through holes 36 and the entrances can also be provided in other ways, as long as the positions of the through holes 36 and the entrances are corresponding so as to connect the groove 34 and the ball return groove 13 to form a circulating channel.

[0089] In Figure 1 , two ball return grooves 13 and two entrances 132 of one of the ball return grooves 13 are exemplarily shown, but those skilled in the art should understand that although not shown, the other ball return groove 13 also has two entrances 132 to communicate with the groove 34 on the outer periphery of the lead screw 30. In addition, in Figure 2 , only one through hole 36 is exemplarily shown, and other through holes are not shown due to position blocking.

[0090] Referring to Figure 2 , the outer periphery of the lead screw 30 is provided with at least one groove 34. In each circulating channel formed by the communication of the groove 34 and the ball return groove 13, the number of turns of the groove 34 outside the lead screw 30 can be one or more turns. The more the number of turns of the ball 20 on the lead screw 30 and the more the number of ball return grooves 13 provided on the core 10, the higher the total load. However, in each circulating channel, the load efficiency is not always positively correlated with the number of turns of the ball. In some embodiments, for example, as shown in Figure 2 , two circulating channels are provided, each of which includes 3 or 4 turns of the groove outside the lead screw 30, and the two circulating channels include a total of 6 or 8 turns of the groove, which can enable each circulating channel to have a higher load efficiency.

[0091] In some embodiments, the groove 34 on the lead screw 30 is continuous, and the plurality of circulating channels are provided adjacently or at intervals.

[0092] In some embodiments, the groove 34 on the lead screw 30 is segmented, and each segment corresponds to one circulating channel.

[0093] Continuing to refer to Figure 2, a plurality of openings 325 are provided on one end face 304 of the screw rod 30, the openings 325 correspond to the through holes 125 on the fixed part 123 of the core 10 respectively, so that the bolts 129 passing through the through holes 125 enter the openings 325, thereby connecting the screw rod 30 and the core 10 together. As mentioned above, the one end face 304 of the screw rod 30 is also provided with the limiting groove 302 matched with the limiting block 102 of the core 10 and is provided with the inner hole 32 for accommodating the core 10. The other end face of the inner hole 32 of the screw rod 30 is connected with the push rod 327.

[0094] Figure 3 A structure diagram of the ball screw 1 of the embodiment of the present disclosure, in which a part of the nut 40 is intercepted to better show the internal structure thereof.

[0095] With reference to Figure 3 , the ball screw 1 comprises: a core 10; a screw rod 30, which is internally provided with an inner hole 32 extending along the axial direction, the core 10 is arranged in the inner hole 32 of the screw rod 30, the outer periphery of the screw rod 30 is provided with a channel 34, the end of the channel 34 is provided with at least one pair of through holes 36; one return ball channel 13 of the core 10 is communicated with the channel 34 of the screw rod 30 through the pair of through holes 36, to form a circulation channel; the ball 20 is arranged in the circulation channel

[0096] As Figure 3 shown, the ball screw 1 further comprises a circulator 50 arranged at the through hole 36, wherein the circulator 50 makes the ball 20 arranged in the channel 34 enter and exit the return ball channel 13 of the core 10.

[0097] In the embodiment of the present disclosure, the installation of the circulator 50 at the through hole 36 also means that it is installed at the position corresponding to the entrance and exit 132 of the return ball channel 13, so that the ball 20 coming out of the entrance and exit 132 can enter the channel 34 through the through hole 36 by means of the circulator 50, and vice versa.

[0098] More specifically, the circulator 50 is installed at the position corresponding to the through hole 36 in the channel 34 outside the screw rod 30, and two circulators 50 are arranged correspondingly to form one circulation channel to make the ball 20 circulate inside and outside the screw rod 30.

[0099] Figure 4 A structure diagram of the circulator 50 of the ball screw 1 of the embodiment of the present disclosure. Figure 5 A structure diagram of the screw rod 30 of the ball screw 1 of the embodiment of the present disclosure, in which the nut 40 is removed to better show the internal structure of the ball screw 1. Figure 6FIG. 1 is a perspective view of a ball screw 1 according to an embodiment of the present disclosure. The ball screw 1 includes a nut 40, a lead screw 30, and a core 10. The core 10 includes a circulation device 50. The circulation device 50 includes a ball return shoveling device 52. The ball return shoveling device 52 includes an inner raceway 54 in contact with balls 20. The inner raceway 54 is curved to ensure that the balls 20 correctly enter and exit a ball return channel 13 at high speed.

[0100] Referring to Figure 4 to Figure 6 , the circulation device 50 includes the ball return shoveling device 52. The ball return shoveling device 52 includes the inner raceway 54 in contact with the balls 20. The inner raceway 54 is curved to ensure that the balls 20 correctly enter and exit the ball return channel 13 at high speed.

[0101] More specifically, the middle ball return shoveling device 52 ensures that the balls 20 correctly fall back to the circulation channel at high speed. For example, the curved shape of the inner raceway 54 of the ball return shoveling device 52 causes the balls 20 in the channel 34 outside the lead screw 30 to vertically pass through the through hole 36 along the inner raceway 54 of the ball return shoveling device 52 to enter the ball return channel 13 on the core 10 under the action of centrifugal force; and causes the balls 20 in the ball return channel 13 on the core 10 to vertically pass through the through hole 36 and correctly fall back to the channel 34 outside the lead screw 30 along the inner raceway 54 of the ball return shoveling device 52.

[0102] In some embodiments, the shape of the protrusion on the outer side of the ball return shoveling device 52 matches the channel on the nut 40.

[0103] In some embodiments, the circulation device 50 includes at least one fin 56 disposed on at least one side of the ball return shoveling device 52. The fin 56 is curved and in the shape of a sheet. The fin 56 is used to position the circulation device 50 in the channel on the nut 40 and also used to assist the balls 20 to correctly enter and exit the circulation device 50. In Figure 4 two fins 56 are exemplarily shown in FIG. 1, but the fin 56 can also be provided only one. For example, considering the force on both sides of the circulation device 50 when the balls 20 are in operation, the fin 56 can be provided only on the side of the circulation device 50 that is subjected to force. For example, referring to Figure 4 , the ball return shoveling device 52 includes a first fin 56A and a second fin 56B. In some cases, the ball return shoveling device 52 can include only the first fin 56A.

[0104] The circulation device 50 further includes a connecting portion 58 disposed at one end of the circulation device 50 to fix the circulation device 50 to the outer periphery of the lead screw 30.

[0105] Referring to Figure 4 , in some embodiments, the connecting portion 58 of the circulation device 50 can include a mounting hole 59. The circulation device 50 can be mounted to the outer periphery of the lead screw 30 by passing a connecting member such as a bolt through the mounting hole 59.

[0106] In the present disclosure, the ball 20 is circulated to the center of the screw rod 30 by adopting the circulator 50 configured in the above manner, and the ball 20 is allowed to return several turns by adopting the core 10 with the ball return channel 13, so that several cycles can be realized on one ball screw 1, and the circulation operation of the ball is not limited to end-side circulation. The number of turns depends on the required ball screw load. The number of circulation channels also depends on the required ball screw load.

[0107] The structure of the core 10 and the circulator 50 in the present disclosure is simple and has low processing difficulty. In addition, the limiting block 102 provided on the core 10 makes the assembly positioning difficult. The circulator 50 only needs to be installed at the through hole 36 through the connecting part 50, and also has the advantage of low assembly positioning difficulty.

[0108] The present disclosure also provides an actuator. The actuator comprises the ball screw of the present disclosure and a driver.

[0109] In some embodiments, the actuator is an electric linear actuator, such as an electric cylinder, etc. The driver is an electric motor, which converts electric energy into mechanical motion energy through a transmission device such as a ball screw 1.

[0110] Example embodiments have been disclosed herein and, although the use of specific terms is expressly used herein, they are intended in a generic sense only and are not intended to limit the scope of the present disclosure. 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. Therefore, those skilled in the art will appreciate that various changes can be made in form and detail without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. A core body, characterized by, The core (10) comprises: a main body portion (12); and at least one ball return channel (13) provided on the main body portion (12); The core (10) is arranged in the inner hole of the lead screw, so that the ball return channel (13) and the channel on the outer periphery of the lead screw form a circulation channel.

2. The core of claim 1, wherein The ball return channel (13) comprises an axial channel extending in the axial direction of the core (10), a first circumferential channel and a second circumferential channel extending in the circumferential direction of the core (10), the first circumferential channel and the second circumferential channel are respectively arranged at both ends of the axial channel, and the first circumferential channel, the second circumferential channel and the axial channel are smoothly communicated.

3. The core of claim 2, wherein The first circumferential channel and the second circumferential channel respectively extend in different directions from both ends of the axial channel along the circumferential direction of the main body portion (12).

4. The core according to claim 2 or 3, characterized in that The main body portion (12) comprises a protruding portion (122), the protruding portion (122) comprises an axial protrusion extending in the axial direction of the core (10), a first circumferential protrusion and a second circumferential protrusion extending in the circumferential direction of the core (10), the first circumferential protrusion and the second circumferential protrusion are respectively arranged at both ends of the axial protrusion; the ball return channel (13) is arranged along the extension direction of the protruding portion (122).

5. The core of claim 4, wherein The first circumferential protrusion and the second circumferential protrusion respectively extend in different directions from both ends of the axial protrusion along the circumferential direction of the core (10).

6. The core of claim 4, wherein The main body portion (12) further comprises a cylindrical columnar portion (121), and the protruding portion (122) is arranged on the outer peripheral surface of the columnar portion (121).

7. The core of claim 4, wherein The main body portion (12) further comprises a first flange portion (124) arranged at one end of the main body portion (12), and the outer peripheral surface of the first flange portion (124) is coplanar with the outer surface of the protruding portion (122).

8. The core according to claim 2 or 3, characterized in that The main body portion (12) is cylindrical, and the ball return channel (13) is arranged on the outer peripheral surface of the main body portion (12).

9. The core according to claim 2 or 3, characterized in that The main body portion (12) comprises a pipe portion (126), the pipe portion (126) comprises an axial pipe (1261) extending in the axial direction of the core (10), a first circumferential pipe (1262) and a second circumferential pipe (1263) extending in the circumferential direction of the core (10), the first circumferential pipe (1262) and the second circumferential pipe (1263) are respectively arranged at both ends of the axial pipe (1261); the inner cavity of the pipe portion (126) constitutes the ball return channel (13).

10. The core of claim 9, wherein The first circumferential pipe (1262) and the second circumferential pipe (1263) respectively extend in different directions from both ends of the axial pipe (1261) along the circumferential direction of the core (10).

11. The core of claim 10, wherein The pipe part (126) further comprises a first connecting pipe (1264) arranged at one end of the first circumferential pipe (1262) and a second connecting pipe (1265) arranged at one end of the second circumferential pipe (1263); the first connecting pipe (1264) and the second connecting pipe (1265) extend away from the axis of the core body (10).

12. The core according to any one of claims 1 to 3, characterized in that The core body (10) further comprises a fixing part (123) arranged at one end of the main body part (12), which is used for axially positioning the core body (10).

13. The core of claim 12, wherein The fixing part (123) is arranged at one end of the main body part (12) as a second flange part extending outward from the main body part (12).

14. The core of claim 12, wherein The fixing part (123) is arranged at one end of the main body part (12) as at least one tab extending outward from the main body part (12).

15. The core of claim 12, wherein The fixing part (123) is provided with a perforation (125) for mounting a bolt.

16. The core of any one of claims 1 to 3, wherein The main body part (12) is further provided with a limiting bump (102) protruding from the outer surface of the main body part (12).

17. The core of any one of claims 1 to 3, wherein The material of the core body (10) comprises any one of plastic, resin and metal.

18. A ball screw comprising a nut (40), a screw shaft (30), and balls (20), characterized by The ball screw further comprises the core body (10) according to any one of claims 1 to 17; The inner part of the screw rod (30) is provided with an inner hole (32) extending along the axial direction, the core body (10) is arranged in the inner hole (32), and at least one pair of through holes (36) are arranged in the channel (34) on the outer periphery of the screw rod (30); one ball return channel (13) of the core body (10) communicates with the channel (34) of the screw rod (30) through a pair of through holes (36), forming a circulation channel; The ball (20) is arranged in the circulation channel.

19. The ball screw of claim 18, wherein, The ball screw further comprises: A circulator (50) arranged at the through hole (36) for guiding the ball (20) to enter and exit the ball return channel (13) of the core body (10) through the through hole (36).

20. The ball screw of claim 19, wherein, The circulator (50) comprises a ball return shovel (52) and a connecting part (58); The inner part of the ball return shovel (52) is provided with a curved inner raceway for contacting the ball (20) to guide the ball (20) to roll; The connecting part (58) is arranged at one end of the circulator (50) relative to the ball return shovel (52) for fixing the circulator (50) in the channel (34) of the screw rod (30).

21. The ball screw of claim 20, wherein, The circulator (50) comprises at least one fin 56 arranged at least one side of the ball return shovel (52), and the fin 56 is in the shape of a curved sheet.

22. The ball screw according to any one of claims 18 to 21, characterized in that, The main body part (12) of the core body (10) is provided with a limiting bump (102) protruding from the outer surface of the main body part (12); An inner wall of the inner hole (32) is provided with a limiting groove (302) matched with the limiting protrusion, and the limiting protrusion (102) cooperates with the limiting groove (302) to limit the setting orientation of the core (10) relative to the lead screw (30).

23. The ball screw according to any one of claims 18 to 21, characterized in that, The core (10) further comprises a fixing portion (123) arranged at one end of the main body portion (12), and the fixing portion (123) is connected with an opening end of the inner hole (32) of the lead screw (30).

24. The ball screw according to any one of claims 18 to 21, characterized in that, The number of turns of the channel (34) of the lead screw (30) between each pair of the through holes (36) can be one or more turns.

25. An actuator comprising: The actuator comprises the ball screw according to any one of claims 18 to 24 and a driver.

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