CN106151430A - Ball screw device and bearing sleeve assembly thereof - Google Patents

Abstract

A ball screw device and a bearing sleeve assembly thereof. The bearing sleeve assembly is sleeved on the screw cap and comprises two bearing sleeves, a first bearing sleeve and a second bearing sleeve, wherein the two bearing sleeves are respectively provided with an inner positioning groove and an inner ball groove, the inner ball groove is arranged corresponding to a plurality of outer ball grooves of the screw cap, and each inner ball groove and each outer ball groove form a ball channel; the annular positioning assembly is clamped between the two bearing sleeves and is accommodated in the inner positioning groove; at least one ball retainer which is provided with an annular thin-wall body, is manufactured in a lamination manufacturing mode, is sleeved between the screw cap and the bearing sleeve and is provided with a plurality of fixing parts; a plurality of balls accommodated in the holding part and the ball passage, and the circumference of each holding part is not less than one half of the circumference of the largest section of each ball, and a preload adjustment assembly.

Description

Ball screw device and its bearing housing assembly

technical field

The invention relates to a ball screw device and a bearing sleeve assembly thereof.

Background technique

The rotary ball screw is a device widely used in many mechanical equipments. Its main purpose is to provide precise transmission function. With the help of rotary motion and linear motion in mechanical operation, it can make the loaded machine or object move in a straight line. Action on it.

The conventional rotary ball screw mainly includes a screw, a nut, a plurality of balls and a bearing sleeve. The surface of the screw has a spiral groove, and the inner surface of the nut also has a spiral inner groove, which can form a first ball channel with the screw. The bearing sleeve is sleeved on the outer peripheral edge of the nut, and the outer surface of the nut has an outer ball groove, and forms a second ball channel with the inner ball groove of the bearing sleeve. Both the first ball channel and the second ball channel are provided with a plurality of balls. The balls can respectively assist the relative rotation between the nut and the screw, and the bearing sleeve and the nut. In this way, the mechanical components carried by the rotary ball screw can move linearly along the axial direction of the screw, and because the rotary ball screw simultaneously realizes The movement behavior of rotation and linear movement provides two different setting options: the screw is not fixed, the nut is fixed, or the nut is not fixed, and the screw is fixed.

However, there are several circular holes in the ball retainer set in the bearing sleeve at present, and the circular holes are the positioning holes for fixing the rolling steel balls. into. However, in this manufacturing method, a four-axis numerical control CNC milling machine and wire-cut electric discharge machining are required in the process, and the processing steps are complicated and the manufacturing cost is relatively high. Especially for the configuration with reverse draft angle, CNC milling machine is difficult to process, but if special tools are used for processing, additional costs will be borne, and for small-sized ball cages with thinner thickness, CNC milling machine is not easy to clamp It is easy to deform, and the pass rate is low. In addition, if the injection molding technology is used to make plastic materials, it is necessary to additionally design a slider for radial movement, which is expensive. Moreover, the injection molded plastic ball cage has residual stress, so the amount of deformation is relatively large, which will also reduce the yield of finished products. However, if it is necessary to change the design due to customization, it is necessary to re-plan the cutting process path or re-make the fixture when using the cutting tool, and to modify the mold or even re-manufacture the mold if it is manufactured by injection molding. Both methods may increase the required cost.

Therefore, how to provide a ball screw device and its bearing sleeve assembly, which can be changed in design and manufactured according to customer needs without making molds, fixtures, or machining, has become one of the important issues.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a bearing sleeve assembly of a ball screw device, which is sleeved on a nut, including: two bearing sleeves, respectively having an inner positioning groove and an inner ball groove, and the inner ball groove Corresponding to the plurality of outer ball grooves of the nut, so that each inner ball groove and each outer ball groove form a ball channel; the ring positioning component is sandwiched between the two bearing sleeves, and the ring The positioning component is accommodated in the inner positioning groove; at least one ball retainer has an annular thin-walled body and is made by a laminated manufacturing method and is sleeved between the nut and the bearing sleeves, In addition, a plurality of holding parts are arranged on the annular thin-walled body; a plurality of balls are accommodated in these holding parts and the ball channel, and the circumference of each holding part is not less than the maximum cross-section of each ball accommodated therein One-half of the circumference of the bearing sleeve and the preload adjustment assembly are sandwiched between the two bearing sleeves.

In an embodiment, each holding portion has a concave conical surface on a radial section.

In an embodiment, each holding portion has a C-shaped notch, and the angle at which each C-shaped notch covers each ball is greater than 180 degrees.

In an embodiment, the angle at which each C-shaped notch covers each ball is 200 degrees to 270 degrees.

In an embodiment, each C-shaped notch has a crowned top and a bottom, the crowned top having a greater radial thickness than the bottom.

In an embodiment, the stacking method is selected from one of the following groups: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), inkjet printing (Ink jet printing, IJP), and melt extrusion molding (Fused deposition modeling, FDM).

In an embodiment, the material of the ball cage is selected from nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastic, carbon nanotube reinforced plastic, glass fiber reinforced plastic, polyfluorinated A group consisting of divinyl (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyimide (PI).

In an embodiment, the ball cage is further added with zirconia powder, alumina powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes, carbon powder, glass fiber, carbon fiber, carbonized Silica fibers, or whiskers fibers.

Another object of the present invention is to provide a ball screw device, comprising: a screw; a nut sleeved on the screw, and there is a first ball channel between the nut and the screw, and the outer surface of the nut has a plurality of The first outer ball groove; a plurality of first balls accommodated in the first ball channel; and the bearing sleeve assembly, including: two bearing sleeves, respectively having an inner positioning groove and an inner ball groove, and the inner ball groove Corresponding to the outer ball grooves of the nut, each of the inner ball grooves and each of the outer ball grooves form a second ball channel; the ring positioning component is sandwiched between the two bearing sleeves, and the ring The positioning component is accommodated in the inner positioning groove; at least one ball retainer has an annular thin-walled body and is made by a laminated manufacturing method and is sleeved between the nut and the bearing sleeves, And the ring-shaped thin-walled body is provided with a plurality of holding parts; a plurality of second balls are accommodated in these holding parts and the second ball channel, and the circumference of each holding part is not less than each holding part accommodated therein. One-half of the circumference length of the largest cross-section of the second ball and the preload adjusting component are sandwiched between the two bearing sleeves.

In an embodiment, each holding portion has a concave conical surface on a radial section.

Another object of the present invention is to provide a ball screw device, comprising: a screw; a nut sleeved on the screw, and there is a first ball channel between the nut and the screw, and the outer surface of the nut has a plurality of Outer ball grooves; a plurality of first balls are accommodated in these first ball passages; a bearing sleeve is sleeved on the nut, and the inner surface of the bearing sleeve is at least provided with an inner ball groove, and the inner ball groove and The corresponding outer ball groove forms a second ball channel; at least one ball retainer, the ball retainer has a ring-shaped thin-walled body and is made by a laminated manufacturing method and is sleeved on the nut, and on the ring A plurality of holding parts are provided on the thin-walled body; a plurality of second balls are accommodated in these holding parts and the second ball channel, and the circumference of each holding part is not less than the length of each second ball accommodated therein. One-half of the circumference of the largest section.

In an embodiment, each holding portion has a C-shaped notch, and an angle at which each C-shaped notch covers each second ball is larger than 180 degrees.

In an embodiment, the angle at which each C-shaped notch covers each second ball is 200 degrees to 270 degrees.

In an embodiment, each C-shaped notch has a crowned top and a bottom, the crowned top having a greater radial thickness than the bottom.

In an embodiment, the stacking method is selected from one of the following groups: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), inkjet printing (Ink jet printing, IJP), and melt extrusion molding (Fused deposition modeling, FDM).

In an embodiment, the material of the ball cage is selected from nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastic, carbon nanotube reinforced plastic, glass fiber reinforced plastic, polyfluorinated A group consisting of divinyl (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyimide (PI).

In an embodiment, the ball cage is further added with zirconia powder, alumina powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes, carbon powder, glass fiber, carbon fiber, carbonized Silica fibers, or whiskers fibers.

Based on the above, the ball screw device and its bearing sleeve assembly of the present invention, because the ball retainer has a ring-shaped thin-walled body and is made by an additive manufacturing method, compared with the traditional use of CNC milling machines and wire-cut electric discharge machining And other processing methods, the pass rate is higher. At the same time, because the circumference of the plurality of holding parts provided on the ring-shaped thin-walled body is not less than half of the circumference of the largest section of each ball accommodated therein, it has an inverted draft configuration, if Using traditional tools or injection molding for processing requires the design of special tools or an additional slider for radial movement, which is expensive. However, the present invention adopts the method of additive manufacturing (3D printing), so that the ball retainer with reverse draft configuration can be directly manufactured, so the cost is lower.

In addition, since the ball cage of the present invention can be made of plastic resin, it has the advantages of light weight, low noise, and good lubricity.

Description of drawings

FIG. 1A is a schematic diagram of a ball screw device shown in an embodiment of the present invention.

FIG. 1B is an exploded schematic view of the ball screw device shown in FIG. 1A .

FIG. 1C is a schematic cross-sectional view of the ball screw device shown in FIG. 1A .

FIG. 1D is a schematic diagram of a ball cage of the ball screw device shown in FIG. 1A .

FIG. 1E is a partially exploded diagram of a radial section of the ball screw device shown in FIG. 1A .

FIG. 2A is a schematic diagram of a ball screw device according to a second embodiment of the present invention.

FIG. 2B is an exploded schematic diagram of the ball screw device shown in FIG. 2A .

FIG. 2C is a schematic cross-sectional view of the ball screw device shown in FIG. 2A along the section line A-A.

FIG. 2D is a schematic diagram of a ball cage in the ball screw device shown in FIG. 2A .

2E and 2F are schematic diagrams of another ball cage in the ball screw device shown in FIG. 2A .

detailed description

A ball screw device according to a preferred embodiment of the present invention will be described below with reference to related drawings, wherein the same components will be described with the same reference symbols.

FIG. 1A is a schematic diagram of a ball screw device according to an embodiment of the present invention, and FIG. 1B is an exploded schematic diagram of the ball screw device shown in FIG. 1A . Please refer to Figure 1A and Figure 1B at the same time, the ball screw device 1 includes a screw 11, a nut 12, two bearing sleeves 13a, 13b, an annular positioning assembly 19, a ball retainer 14, a preload adjustment assembly 15, a plurality of first A ball 16b and a plurality of second balls 16a. The screw 11 is a cylindrical rod body, and its outer surface has a helical groove 111 wound continuously along the longitudinal axis. The nut 12 is an annular cylinder with a plurality of outer ball grooves 121, and the center of the nut 12 has a through hole 122, and the inner surface of the nut 12 near the through hole 122 has a first inner ball groove 123, and The lead pitch and groove surface configuration of the first inner ball groove 123 are the same or similar to the helical groove 111 of the screw 11 . When the nut 12 is sleeved on the screw 11 through the through hole 122 , the helical first inner ball groove 123 of the nut 12 and the helical groove 111 of the screw 11 can correspond to each other to form a first ball channel. The plurality of first balls 16b are accommodated in the first ball channel.

1A, 1B, and FIG. 1D, wherein FIG. 1D is a schematic diagram of the ball retainer 14 of the ball screw device shown in FIG. 1A. The ball retainer 14 has an annular thin-walled body and is made by a laminated manufacturing method, and is sleeved between the nut 12 and the bearing sleeves 13a, 13b, and the ball retainer 14 is provided with a ring-shaped thin-walled body. a plurality of holding parts 141 . A plurality of second balls 16a are accommodated in the holding portion 141 , and the circumference of each holding portion 141 is not less than half of the circumference of the largest section of each second ball 16a accommodated therein.

In this embodiment, as shown in FIG. 1D , it is taken as an example that each holding portion 141 is a closed gourd hole holder. Because the ball retainer 14 has the retaining portion 141 in the gourd-shaped arc-shaped hole configuration, the second ball 16a can be nested into the embedded combination, so that the ball retainer can use the retaining portion 141 with a large covering angle to provide Each second ball 16a is stably positioned and combined. And because the retaining portion 141 of the gourd-shaped arc-shaped hole configuration has local deformation capability, the second ball 16 a can be easily inserted into the retaining portion 141 of the ball retainer 14 .

The lamination manufacturing method adopted by the ball cage 14 can be one of the following methods: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), inkjet printing (Ink jet printing). printing, IJP), or melt extrusion molding (Fused deposition modeling, FDM). The material of the ball cage 14 can be nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastics, carbon nanotube reinforced plastics, glass fiber reinforced plastics, polyvinyl fluoride ( PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or polyimide (PI), or any combination of the above materials.

In addition, in order to improve the wear resistance and lubricity of the ball cage 14 to increase its service life, composite materials can be used to make it, that is, ceramic powder (such as: zirconia powder, oxide Aluminum powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes) or graphite powder, carbon powder, solid lubricant and other lubricating materials. In addition, in order to enhance the structural strength of the ball cage 14 , glass fibers, carbon fibers, silicon carbide fibers, or whiskers fibers may also be added.

FIG. 1C is a schematic cross-sectional view of the ball screw device shown in FIG. 1A . Please also refer to FIG. 1A to FIG. 1C . The bearing sleeves 13a, 13b are sleeved on both sides of the nut 12 respectively, and the nut 12 has a plurality of outer ball grooves 121. In this embodiment, the nut 12 has two outer ball grooves 121, and the bearing sleeves 13a, 13b respectively has second inner ball grooves 131a, 131b, and the configuration of the surrounding way, guide distance and grooves is corresponding to the outer ball groove 121, so that when the bearing sleeves 13a, 13b are sleeved on the nut 12, The second inner ball grooves 131a, 131b and the outer ball grooves 121 can form a second ball channel for accommodating a plurality of second balls 16a so that the nut 12 can rotate relative to the bearing sleeves 13a, 13b. The forming direction of the outer ball groove 121 is perpendicular to the axial direction of the screw rod 11. Of course, in other embodiments, the outer ball groove 121 can also be arranged in an inclined manner relative to the axial direction of the screw rod 11 with an included angle. The invention is not limited here.

In addition, as shown in Figure 1C, as mentioned above, the second ball channel is the main part of the ball circulation channel between the screw 11 and the nut 12, and accommodates a plurality of second balls 16a (Figure 1B and Figure 1C only show Some balls are represented), so that the nut 12 can rotate with the axis of the screw rod 11 as the longitudinal axis, so as to convert the rotary motion into linear motion. It needs to be further explained that the ball return method of the present invention is not limited to the external circulation type, the internal circulation type or the end cap circulation type. In this embodiment, the end cap circulation type is only used as an example, but it is not limited to this , as for the detailed description, please refer to the following. The assembling of the screw and the nut and the formation of the grooves are understood by those skilled in the art, so details are not repeated here.

Please refer to FIG. 1E , which is a partially exploded view of the radial section of the ball screw device shown in FIG. 1A . As shown in the figure, the holding portion 141 has a concave conical surface on the radial section, which is consistent with the outer contour surface of the second ball 16a. Cooperating with each other, the second ball 16a can further maintain its position when rolling.

Please refer to Figure 1C. The two bearing sleeves 13a, 13b respectively have inner positioning grooves 132a, 132b, and the ball screw device 1 further has an annular positioning component 19 . Wherein, the annular positioning assembly 19 is interposed between the two bearing sleeves 13a, 13b, and the annular positioning assembly 19 is accommodated in the inner positioning grooves 132a, 132b. Preferably, the outer surface of the annular positioning assembly 19 abuts against the side walls of the inner positioning grooves 132a, 132b, and the annular positioning assembly 19 is accommodated in the inner positioning grooves 132a, 132b in a manner concentric with the two bearing sleeves 13a, 13b , so that the bearing sleeve 13a and the bearing sleeve 13b are mutually positioned, because there is an annular positioning component 19, the alignment tolerance between the bearing sleeves 13a, 13b can be further significantly reduced. Because the relative position between the annular positioning assembly 19 and the bearing sleeves 13a, 13b is preferably concentric, at this time, the annular positioning assembly 19 can also be called a concentric ring.

In addition, the preload adjustment assembly 15 is also sandwiched between the two bearing sleeves 13a, 13b, and the inner diameter of the preload adjustment assembly 15 is larger than the outer diameter of the annular positioning assembly 19, as shown in Figure iC, the annular positioning assembly 19 and the preload The adjustment assembly 15 is sandwiched between the two bearing sleeves 13a, 13b, and the preload adjustment assembly 15 is arranged on the outer periphery of the annular positioning assembly 19, but the preload adjustment assembly 15 and the annular positioning assembly 19 are not in contact.

Preferably, the above-mentioned components are fixed to each other in a screw-locking manner. Therefore, the bearing sleeves 13a, 13b and the preload adjustment component 15 can have a plurality of screw holes S1 respectively, and the positions of the screw holes S1 correspond to each other, and the screws S2 The bearing sleeves 13a, 13b and the preload adjustment assembly 15 are mutually locked. The preload adjustment assembly 15 is preferably made of rigid iron to provide preferred rigidity and toughness, which is beneficial to control the pressure between the bearing sleeves 13a, 13b during the manufacturing process and increase the overall operational stability of the ball screw device 1 . The bearing sleeve assembly B is formed after assembling the two bearing sleeves 13a, 13b, the annular positioning assembly 19, the ball retainer 14, the second ball 16a and the preload adjustment assembly 15.

In addition, the present invention further provides a bearing sleeve assembly of a ball screw device, which is sleeved on a nut. The bearing sleeve assembly includes two bearing sleeves, a ring positioning assembly, a ball retainer, a plurality of balls, and a preload adjustment assembly. The two bearing sleeves respectively have inner positioning grooves and inner ball grooves, and the inner ball grooves are set corresponding to the plurality of outer ball grooves of the nut, so that each inner ball groove and each outer ball groove form a ball channel. The annular positioning component is sandwiched between the two bearing sleeves, and the annular positioning component is accommodated in the inner positioning groove. The ball retainer has a ring-shaped thin-walled body and is made by a laminated manufacturing method, and is sheathed between the nut and two bearing sleeves, and a plurality of holding parts are arranged on the ring-shaped thin-walled body. A plurality of balls are accommodated in the holding portion and the ball channel, and the circumference of each holding portion is not less than half of the circumference of the largest section of each ball accommodated therein. The preload adjusting component is sandwiched between the two bearing sleeves. For the specific structure and features of the components, reference can be made to the description in the previous embodiment, and details will not be repeated here.

In addition, the present invention further provides another ball screw device, please refer to FIG. 2A to FIG. 2F . 2A is a schematic diagram of a ball screw device according to an embodiment of the present invention; FIG. 2B is an exploded schematic diagram of the ball screw device shown in FIG. 2A; FIG. 2C is a schematic cross-sectional view of the ball screw device shown in FIG. 2A is a schematic diagram of the ball retainer in the ball screw device, and FIG. 2E and FIG. 2F are schematic diagrams of another ball retainer in the ball screw device shown in FIG. 2A.

First, please refer to FIGS. 2A to 2C together. In this embodiment, the ball screw device 2 includes a screw 21, a nut 22, a bearing sleeve 23, a plurality of first balls 26b, at least one ball retainer 24, A plurality of second balls 26 a, a plurality of return components 27 , a plurality of dust-proof components 28 and at least one reinforcement 29 .

The inner surface of the nut 22 has a plurality of first inner ball grooves 222 , and the outer surface of the screw 21 has a plurality of helical grooves 211 . In this embodiment, the first inner ball groove 222 and the spiral groove 211 are spiral grooves. When the nut 22 is sleeved on the screw rod 21 , the first inner ball groove 222 and the corresponding helical groove 211 jointly form the first ball channel P1 . The first ball 26b is accommodated in the first ball passage P1. In particular, to make the drawing simple and easy to understand, FIG. 2C only shows part of the second ball 26a and part of the first ball 26b. In this embodiment, the ball screw device 2 further includes two return components 27 , which can be sleeved on both ends of the nut 22 , and each return component 27 has two return channels 271 . Next, please refer to FIG. 2C together. When the first ball 26b rolls to the return assembly 27 in the first ball channel P1, the first ball 26b can turn from the return channel 271 to enter and correspond to the return channel 271 and The circulation channel 213 axially passes through the nut 22 . Therefore, the first ball channel P1 (ie, the first inner ball groove 222 and the spiral groove 211 ), the return channel 271 and the circulation channel 213 form a complete ball circulation path RP. When the first ball 26 b moves to the position of the return component 27 in the first ball channel P1 , it will generate repeated circular movement by means of the return channel 271 and the circulation channel 213 . In this embodiment, the number of circulation channels 213 preferably corresponds to the number of return channels 271 . The ball screw device 2 of this embodiment further includes four reinforcing members 29, which can be made of metal, and are respectively arranged on the return channel 271 of the return assembly 27, so that when the first ball 26b is returned through the return assembly 27, the first ball 26b is rolled on the reinforcing member 29 instead of directly rolling on the return component 27 to reduce wear of the return channel 271 .

The nut 22 has at least one outer ball groove 221 . However, those skilled in the art can understand that an outer ball groove 221 can be arranged on the nut 22 , and an outer ball groove 221 can also be provided on the nut 22 in order to increase the rotation stability of the bearing sleeve 23 and/or the bearing capacity of the ball screw device 2 . A plurality of outer ball grooves 221 are arranged on the top. In this embodiment, the nut 22 has two outer ball grooves 221 as an example for illustration. Two outer ball grooves 221 are disposed on the outer surface OS of the nut 22 . The bearing sleeve 23 has at least one inner ball groove 231 disposed on the inner surface IS of the bearing sleeve 23 . And for the same reason as the previous paragraph, those skilled in the art can understand that an inner ball groove 231 can be set on the bearing sleeve 23 corresponding to the outer ball groove 221 on the nut 22, and it can also be rotated in order to increase the bearing sleeve 23. stability and/or the bearing capacity of the ball screw device 2 , and a plurality of second inner ball grooves 231 are disposed on the bearing sleeve 23 . In this embodiment, the bearing sleeve 23 has two second inner ball grooves 231 as an example. When the bearing sleeve 23 is sleeved on the nut 22 , the second inner ball groove 231 of the bearing sleeve 23 and the corresponding outer ball groove 221 together form a second ball channel P2 , as shown in FIG. 2C .

Please refer to FIG. 2B again, the ball retainer 24 has a plurality of retaining portions 241, the shape of which preferably conforms to the arc shape of the second ball 26a, and its arc length is not less than one-half of the circumference length of the largest section of the second ball 26a . And when the second ball 26a is placed in the second ball channel P2, the ball retainer 24 can also be sleeved on the nut 22 and located between the bearing sleeve 23 and the nut 22, and the holding part 241 corresponds to the second ball 26a. snapping, so as to maintain and fix the positions of the second balls 26a, so as to prevent the second balls 26a from falling off during the actual operation of the ball screw device 2 .

In this embodiment, each holding portion 241 is a C-shaped notch as an example, and the angle at which each C-shaped notch covers each second ball 26a is preferably greater than 180 degrees, and more preferably, please refer to FIG. 2D, which is 200 degrees. Degree to 270 degrees, the second ball 26a is positioned and operated. The wall thickness of the ball retainer 24 shown in FIG. 2D can be increased by 20-50% compared with the thickness of the ball retainer 24 shown in FIG. 2C , making it more resistant to wear and increasing its service life.

In addition, in another embodiment, each C-shaped notch of the ball cage 24 further has a crowned top 2411 and a bottom 2412 . It can be seen from the figure that the radial thickness of the crowned top 2411 is greater than the radial thickness of the bottom 2412 . In this embodiment, the thickness of the crown top is increased, which can increase the covering area and structural strength of the first ball 26b, and increase the stability during operation. In addition, the C-shaped notch can also have a larger covering angle (200-270 degrees) to cover the first ball 26b, so that the positioning and operation of the second ball 26a can be smoother.

The lamination manufacturing method adopted by the ball cage 24 can be one of the following methods: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), ink jet printing (Ink jet printing, IJP), or melt extrusion molding (Fused deposition modeling, FDM). The material of the ball cage 14 can be nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastics, carbon nanotube reinforced plastics, glass fiber reinforced plastics, polyvinyl fluoride ( PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), or polyimide (PI), or any combination of the above materials.

In addition, in order to improve the wear resistance and lubricity of the ball cage 24 to increase its service life, it can be made of composite materials, that is, ceramic powder (such as: zirconia powder, alumina powder, etc.) powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes) or lubricating materials such as graphite powder, carbon powder, and solid lubricant. In addition, in order to enhance the structural strength of the ball cage 24 , glass fibers, carbon fibers, silicon carbide fibers, or whiskers fibers may also be added.

And if the ball cage 24 is made of nylon as an example, during the selective laser sintering (Selective laser sintering, SLS) process in the laminated manufacturing method, because nylon itself has a certain self-lubricating property, and the selective laser sintering Laser sintering technology uses laser light to sinter nylon powder into shape, so the inside of the finished product will contain tiny holes and make the surface appear tiny depressions, both of which have the function of storing oil, so the ball cage 24 with this design structure will It has good lubricity, reduces the friction generated by rotation, and can increase the service life of the bearing. The toughness and lubricity of the nylon material enable the second ball 26 a to run smoothly in the second ball channel P2 and the holding portion 241 . In addition, the retaining portion 241 of the ball retainer 24 of this embodiment has a non-closed hole, so the contact surface with the second ball 26a is relatively small, so the friction is also small, and the ball retainer 24 has a simple structure. , light weight and easy processing and manufacturing.

Compared with the injection molding method, because the ball cage 24 has a ring-shaped thin-walled body, regardless of whether the mold is injected with a single-point or multi-point injection port, a joint line will be generated after cooling, resulting in stress concentration and easy deformation of the shape. Reduced strength, shortened service life and other disadvantages. In this embodiment, the additive manufacturing method is used for manufacturing, so there is no need to make complicated injection molds, which can save mold costs and reduce costs. In addition, compared with the metal ball cage made by traditional CNC milling machine and wire-cut electric discharge machining, the manufacturing procedures of traditional CNC milling machine and wire-cut electric discharge machining are more complicated, and the metal ball cage produced has poor corrosion resistance , the manufacturing cost is higher.

In this embodiment, the ball screw device 2 further includes two dust-proof components 28 , which can be sleeved on both ends of the nut 22 and located outside the return component 27 . The dust-proof assembly 28 includes a dust-proof part 281 and a fixing part 282, and the dust-proof part 281 has a wiper part 2811. After the assembly is completed, the wiper part 2811 will contact the outer surface of the screw rod 21 to prevent water vapor, dust or foreign matter from entering The interior of the ball screw device 2 enables it to function normally and even prolongs the service life of the entire device. The fixing part 282 is fastened to two ends of the nut 22 and is disposed on the outside of the dustproof part 281 so that the dustproof part 281 is not easy to drop when the ball screw device 2 moves linearly. The quantity of the above components (return component 27 , return channel 271 , dustproof component 28 , reinforcing member 29 ) is just an example, and the present invention is not limited to the above, and can be adjusted according to actual applications.

Based on the above, the ball screw device and its bearing sleeve assembly of the present invention, because the ball retainer has a ring-shaped thin-walled body and is made by an additive manufacturing method, compared with the traditional use of CNC milling machines and wire-cut electric discharge machining And other processing methods, the pass rate is higher. At the same time, because the circumference of the plurality of holding parts provided on the ring-shaped thin-walled body is not less than half of the circumference of the largest section of each ball accommodated therein, it has an inverted draft configuration, if Using traditional tools or injection molding for processing requires the design of special tools or an additional slider for radial movement, which is expensive. However, the present invention adopts the method of additive manufacturing (3D printing), so that the ball retainer with reverse draft configuration can be directly manufactured, so the cost is lower.

In addition, since the ball cage of the present invention can be made of plastic resin, it has the advantages of light weight, low noise, and good lubricity.

The above description is only illustrative, not limiting. Any equivalent modifications or changes made without departing from the spirit and scope of the present invention shall be included in the scope of the appended claims.

Claims (20)

1. A bearing sleeve assembly of a ball screw device, which is sleeved on a nut, comprising: The two bearing sleeves respectively have inner positioning grooves and inner ball grooves, and the inner ball grooves are set corresponding to the plurality of outer ball grooves of the nut, so that each inner ball groove and each outer ball groove form a a ball channel; An annular positioning component is sandwiched between the two bearing sleeves, and the annular positioning component is accommodated in the inner positioning groove; At least one ball retainer, the ball retainer has an annular thin-walled body and is made by a laminated manufacturing method and is sleeved between the nut and the bearing sleeves, and the annular thin-walled body is provided with a plurality of holding parts; a plurality of balls accommodated in the holding portions and the ball channel, and the circumference of each holding portion is not less than half of the circumference of the largest section of each ball accommodated therein, and The preload adjusting component is sandwiched between the two bearing sleeves. 2. The bearing sleeve assembly according to claim 1, wherein each holding portion has a concave conical surface on a radial cross-section. 3 . The bearing sleeve assembly according to claim 1 , wherein each holding portion has a C-shaped notch, and an angle at which each C-shaped notch wraps each ball is greater than 180 degrees. 4 . The bearing sleeve assembly according to claim 3 , wherein an angle at which each C-shaped notch covers each ball is 200° to 270°. 5. The bearing sleeve assembly of claim 4, wherein each C-shaped notch has a crowned top and a bottom, the crowned top having a greater radial thickness than the bottom. 6. The bearing sleeve assembly according to claim 1, wherein the laminated manufacturing method is selected from one of the group consisting of the following methods: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), ink jet printing (Ink jet printing, IJP), and melt extrusion molding (Fused deposition modeling, FDM). 7. The bearing sleeve assembly according to claim 1, wherein the material of the ball cage is selected from the group consisting of nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastic, carbon nanotube reinforced Plastic, glass fiber reinforced plastic, polyvinyl fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and polyimide (PI) group. 8. The bearing sleeve assembly according to claim 7, wherein the ball cage is further added with zirconia powder, alumina powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes , carbon powder, glass fiber, carbon fiber, silicon carbide fiber, or whiskers (whiskers) fiber. 9. A ball screw device comprising: screw; A nut is sheathed on the screw, and there is a first ball channel between the nut and the screw, and the outer surface of the nut has a plurality of outer ball grooves; a plurality of first balls accommodated in the first ball channel; and Bearing housing assembly, including: The two bearing sleeves respectively have inner positioning grooves and inner ball grooves, and the inner ball grooves are set corresponding to the outer ball grooves of the nut, so that each inner ball groove and each outer ball groove form a second Two ball channel; An annular positioning component is sandwiched between the two bearing sleeves, and the annular positioning component is accommodated in the inner positioning groove; At least one ball retainer, the ball retainer has an annular thin-walled body and is made by a laminated manufacturing method and is sleeved between the nut and the bearing sleeves, and the annular thin-walled body is provided with a plurality of holding parts; a plurality of second balls accommodated in the holding portions and the second ball channel, and the circumference of each holding portion is not less than half of the circumference of the largest cross section of each second ball accommodated therein, and The preload adjusting component is sandwiched between the two bearing sleeves. 10. The ball screw device according to claim 9, wherein each holding portion has a concave conical surface on a radial section. 11. The ball screw device according to claim 9, wherein the layered manufacturing method is selected from one of the group consisting of: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), ink jet printing (Ink jet printing, IJP), and melt extrusion molding (Fused deposition modeling, FDM). 12. The ball screw device according to claim 9, wherein the material of the ball cage is selected from nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastic, carbon nanotube reinforced Plastic, glass fiber reinforced plastic, polyvinyl fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and polyimide (PI) group. 13. The ball screw device according to claim 12, wherein the ball cage is further added with zirconia powder, alumina powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes , carbon powder, glass fiber, carbon fiber, silicon carbide fiber, or whiskers (whiskers) fiber. 14. A ball screw device comprising: screw; A nut is sheathed on the screw, and there is a first ball channel between the nut and the screw, and the outer surface of the nut has a plurality of outer ball grooves; a plurality of first balls accommodated in the first ball passages; A bearing sleeve is sleeved on the nut, and the inner surface of the bearing sleeve is at least provided with an inner ball groove, and the inner ball groove and the corresponding outer ball groove form a second ball channel; At least one ball retainer, the ball retainer has a ring-shaped thin-walled body and is made by a laminated manufacturing method and is sleeved on the nut, and a plurality of holding parts are arranged on the ring-shaped thin-walled body; A plurality of second balls are accommodated in the holding portions and the second ball channel, and the circumference of each holding portion is not less than half of the circumference of the largest section of each second ball accommodated therein. 15 . The ball screw device according to claim 14 , wherein each holding portion has a C-shaped notch, and an angle at which each C-shaped notch covers each second ball is greater than 180 degrees. 16 . The ball screw device according to claim 15 , wherein an angle at which each C-shaped notch covers each second ball is 200° to 270°. 17. The ball screw assembly of claim 16, wherein each C-shaped notch has a crowned top and a bottom, the crowned top having a greater radial thickness than the bottom. , 18. The ball screw device according to claim 14, wherein the layered manufacturing method is selected from one of the group consisting of: selective laser sintering (Selective laser sintering, SLS), photocuring (Stereolithography apparatus, SLA), ink jet printing (Ink jet printing, IJP), and melt extrusion molding (Fused deposition modeling, FDM). 19. The ball screw device according to claim 14, wherein the material of the ball cage is selected from the group consisting of nylon (Nylon), acrylonitrile-butadiene-styrene copolymer (ABS), carbon fiber reinforced plastic, carbon nanotube reinforced Plastic, glass fiber reinforced plastic, polyvinyl fluoride (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), and polyimide (PI) group. 20. The ball screw device according to claim 14, wherein the ball cage is further added with zirconia powder, alumina powder, silicon oxide powder, aluminum nitride powder, silicon nitride powder, silicon carbide powder, carbon nanotubes , carbon powder, glass fiber, carbon fiber, silicon carbide fiber, or whiskers (whiskers) fiber.