High-speed heavy-load ball screw assembly

Abstract

The invention relates to a high-speed heavy-load ball screw pair which comprises a ball screw and a ball nut matched with the ball screw, a raceway is formed between the ball screw and the ball nut, and the ball screw is driven by a driving unit to rotate to drive the ball nut to do linear motion along the ball screw; the two ends of the interior of the pipe wall of the ball nut are each provided with a ball return channel arranged in the axial direction of the ball nut. The ball nut is provided with two return grooves corresponding to each ball return channel, the return grooves are communicated with the ball return channels, return devices are arranged in the return grooves, circulation channels are defined by the two return devices, the ball return channels and the roller path, the two circulation channels are not communicated with each other and are respectively provided with a ball circulation chain, and the lead screw pair is high in bearing capacity and stable in operation. And the requirement of high-speed operation can be met.

Description

Technical Field

[0001] The invention relates to a high-speed and heavy-load ball screw pair, belonging to the technical field of ball screw pairs. Background Art

[0002] A ball screw pair is a device that drives the nut to move linearly by rotating the screw, and is commonly used in the field of transmission and positioning. With the growing demand for high-precision and high-efficiency processing in the manufacturing industry, ball screw pairs have been widely used in CNC machine tools, aerospace equipment, precision instruments and other fields. However, traditional ball screw pairs often find it difficult to simultaneously meet the requirements of high speed and large load under high-speed and heavy-load conditions, which limits the application of ball screw pairs in high-power equipment, especially in working environments that require high speed, heavy load and long life. The existing structural design and material selection are difficult to meet the requirements. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a high-speed heavy-load ball screw pair with high load-bearing capacity and stable operation.

[0004] In order to achieve the above-mentioned object, the technical solution proposed in the present invention is: a high-speed heavy-load ball screw pair, comprising a ball screw and a ball nut matched with the ball screw, a raceway is formed between the ball screw and the ball nut, the ball screw is driven to rotate by a driving unit, and drives the ball nut to make a linear motion along the ball screw; A ball return channel arranged along the axial direction of the ball nut is respectively provided at both ends of the inner wall of the ball nut; the ball nut is provided with two return grooves connected to the ball return channel corresponding to each ball return channel, and a return device is provided in the return groove, and the two return devices, the ball return channel and the raceway form a circulation channel, and the two circulation channels are not connected to each other and are respectively provided with a ball circulation chain.

[0005] A further design of the above technical solution is that the two ball circulating chains are arranged with staggered or non-staggered spacing in the axial direction.

[0006] Each ball return channel extends to a corresponding end face of the ball nut.

[0007] The ball screw is provided with a spiral groove, a large diameter portion is formed between adjacent grooves, and the axial width of the groove is 3 to 5 times the axial width of the large diameter portion.

[0008] Two screw holes are provided on the edge of the return groove, and a positioning portion extending along the direction of the ball return channel is provided on one side of the return groove corresponding to the ball return channel. The positioning portion forms an exit / entrance of the return groove, and the return groove forms an entrance / exit of the return groove corresponding to the raceway.

[0009] The return device is provided with a fixing hole corresponding to the screw hole, a return device outlet / entrance connected to the ball return channel is provided corresponding to the positioning part, and a return device inlet / outlet connected to the raceway is provided corresponding to the return groove inlet / outlet; a return channel connecting the return device outlet / entrance and the return device inlet / outlet is provided inside the return device.

[0010] The center line connecting the two fixing holes of the return device passes through the center of the return device.

[0011] A bead stopper is provided on the return device.

[0012] The two ball circulation chains are centrally symmetrically arranged.

[0013] The end surface of the ball nut is provided with a plurality of mounting holes arranged along the circumferential direction, and the tube wall of the ball nut is provided with an oil hole connecting the outer side wall and the raceway.

[0014] The beneficial effects of the present invention are: The ball screw pair of the present invention is provided with two sets of ball circulating chains, which can increase the number of load-bearing circles and thus improve the load-bearing capacity; the staggered arrangement of the two ball circulating chains can also increase the preload force of the ball screw pair.

[0015] In the present invention, the groove width of the lead screw and the nut has a larger ratio to the straight line segment, and can accommodate balls of larger specifications, further improving the load-bearing capacity.

[0016] The present invention arranges a ball return channel inside the ball nut, so that the balls circulate inside the ball nut all the time, thus simplifying the structure and reducing the required radial space.

[0017] The two ball circulation chains are symmetrically distributed in space, and the two return devices used in a single ball circulation chain are also symmetrically arranged, so that the mass center of the overall component is at the structural center of the ball nut body. The operating characteristics of the ball screw pair during forward and reverse rotation are exactly the same, avoiding adverse movement during operation and improving operational stability, thereby meeting the requirements of the high-speed and long-life working environment of the screw pair. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 for Figure 1 A quarter section view of Figure 3 for Figure 1 A cross-sectional view of Figure 4 for Figure 1 Exploded diagram of Figure 5 This is the axonometric view of the ball screw; Figure 6 This is a partial enlarged view of the ball screw; Figure 7 This is the axonometric view of the ball nut; Figure 8 This is the left view of the ball nut; Fig. 9 It is the front view of the ball nut; Fig.10 Rear view of the ball nut Fig.11 It is a cross-sectional view of the ball nut; Fig.12 This is the right view of the ball nut; Fig.13 This is the axonometric view of the return device; Fig.14 This is the front view of the return device; Fig.15 It is the side view of the return device; Fig.16 This is the rear view of the return device.

[0019] Markings in the figure: 1-ball screw, 11-large diameter part, 12-groove, 2-ball nut, 21-mounting hole, 22, 23, 24, 25-return groove, 221, 222, 231, 232, 241, 242, 251, 252-screw hole, 223, 233, 243, 253-positioning part, 224, 234, 244, 254-return groove exit / entrance, 225, 235, 245, 255-return groove entry / exit, 26, 27-ball return channel, 28-oil hole, 29-roller, 3, 4, 5, 6-returner, 31, 32-fixing hole, 33-bead stopper, 34-returner exit / entrance, 35-returner entry / exit, 7, 8-ball circulation chain. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0021] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the high-speed and heavy-load ball screw pair of this embodiment includes a ball screw 1 and a ball nut 2 that cooperates with the ball screw. A raceway is formed between the ball screw 1 and the ball nut 2. The ball screw 1 is connected to the upper drive unit and is driven to rotate, thereby driving the ball nut 2 to make a linear motion along the ball screw 1.

[0022] The tube wall of the ball nut 2 is provided with four return devices 3, 4, 5 and 6. Return devices 3 and 4 and return devices 5 and 6 respectively form a group of return devices. The two groups of return devices together with the ball screw and the ball nut respectively constitute the space where the ball circulation chains 1 and 2 are located. The ball circulation chains 7 and 8 are composed of balls and are respectively arranged in the above-mentioned spaces. The ball circulation chain 7 is not connected to the ball circulation chain 8.

[0023] The two ball circulation chains 7 and 8 are set with misaligned or non-misaligned distances in the axial direction. When misaligned, the two ball circulation chains 7 and 8 are offset by a distance, such as a few tenths of a millimeter, so that one of the two ball circulation chains 7 and 8 is just engaged with the ball screw 1, and the other is in a misaligned state. After installation, there is a preload force, but only one circulation chain is carrying. When non-misaligned, both circulation chains are engaged with the ball screw 1 and are carrying, and the number of load-bearing circles is doubled, thereby improving the load-bearing capacity.

[0024] The two ball circulation chains are arranged in a central symmetric manner, so that the mass center of the entire component is at the structural center of the ball nut 2, avoiding undesirable movement during operation and improving the operating stability.

[0025] Combination Figure 5 and Figure 6 As shown, the ball screw 1 is provided with a spiral groove 12, and between adjacent grooves 12 is a large diameter portion 11, that is, the outer circumferential surface of the screw, which serves as the base portion of the screw. The axial width of the groove is 3 to 5 times the axial width of the large diameter portion. This embodiment adopts a larger load-bearing structure, and the width of the groove 12 of the screw and nut is larger than the width of the large diameter portion 11, which can accommodate larger-sized balls and has a greater load-bearing capacity per unit axial space; for example, the maximum steel ball diameter (groove width) of a common 16-lead screw pair is 10mm, and the width of the straight section (large diameter section) is 5.8mm, while the 16-lead screw pair of this embodiment adopts a combination of 12.7mm steel balls and 3.07mm straight sections. The spiral structure on the ball nut 2 matches the ball screw 1.

[0026] Combination Figure 7 , Figure 8 , Fig. 9 , Fig.10 , Fig.11 and Fig.12 As shown, the two ends of the inner wall of the ball nut 2 are respectively provided with ball return channels 26 and 27 arranged along the axial direction of the ball nut 2. The ball return channels 26 and 27 both extend to the corresponding end faces of the ball nut 2 and can be made by punching holes from the two end faces of the ball nut 2, which has machinability and engineering feasibility.

[0027] Taking the ball return channel 26 as an example, the ball nut 2 is provided with two return grooves 22 and 23 connected with the ball return channel 26 corresponding to the ball return channel 26, forming a space for accommodating a return device, and return devices 3 and 4 are respectively provided in the return grooves 22 and 23; the two return devices 3 and 4, the ball return channel 26 and the corresponding section of the raceway 29 form a circulation channel, and a ball circulation chain 7 is arranged in the circulation channel.

[0028] Similarly, the ball nut 2 is provided with two return grooves 24 and 25 connected to the ball return channel 27 corresponding to the ball return channel 27, and the return grooves 24 and 25 are respectively provided with return devices 5 and 6; the two return devices 5 and 6, the ball return channel 27 and the corresponding section of the raceway 29 form a circulation channel, and a ball circulation chain 8 is arranged in the circulation channel.

[0029] Taking the return groove 22 as an example, two screw holes 221 and 222 are provided at the edge of the return groove 22 for fixing the return device 3. A positioning portion 223 extending along the direction of the ball return channel is provided on one side of the return groove 22 corresponding to the ball return channel 26 for providing guidance when the return device is installed. A return groove inlet / outlet 224 is formed at the positioning portion 223, and a return groove inlet / outlet 225 is formed at the return groove corresponding to the raceway. When the ball nut 2 moves to one end, the ball enters the return device 3 from the raceway 29 through the return groove inlet / outlet 225, and enters the ball return channel 26 from the return device 3 through the return groove inlet / outlet 224. When the ball nut 2 moves to the other end, the ball enters the return device 3 from the ball return channel 26 through the return groove inlet / outlet 224, and enters the raceway 29 through the return groove inlet / outlet 225.

[0030] Similarly, two screw holes 231 and 232 are provided at the edge of the return groove 23 for fixing the return device 4. A positioning portion 233 extending along the direction in which the return ball channel is set is provided at one side of the return groove 23 corresponding to the ball return channel 26. A return groove inlet / outlet 234 is formed at the positioning portion 233. A return groove inlet / outlet 235 is formed at the return groove corresponding to the raceway. When the ball nut 2 moves to one end, the ball enters the return device 4 from the ball return channel 26 through the return groove inlet / outlet 234, and enters the raceway 29 through the return groove inlet / outlet 235; when the ball nut moves to the other end, the ball enters the return device 4 from the raceway 29 through the return groove inlet / outlet 235, and enters the ball return channel 26 from the return device 4 through the return groove inlet / outlet 234.

[0031] Two screw holes 241 and 242 are provided at the edge of the return groove 24 for fixing the return device 5. A positioning portion 243 extending along the direction of the ball return channel is provided at one side of the return groove 24 corresponding to the ball return channel 27. A return groove inlet / outlet 244 is formed at the positioning portion 243. A return groove inlet / outlet 245 is formed at the return groove corresponding to the raceway. When the ball nut 2 moves to one end, the ball enters the return device 5 from the raceway 29 through the return groove inlet / outlet 245, and enters the ball return channel 26 from the return device 5 through the return groove inlet / outlet 244; when the ball nut moves to the other end, the ball enters the return device 5 from the ball return channel 27 through the return groove inlet / outlet 244, and enters the raceway 29 through the return groove inlet / outlet 255.

[0032] Two screw holes 251 and 252 are provided at the edge of the return groove 25 for fixing the return device 6. A positioning portion 253 extending along the direction in which the ball return channel is set is provided at one side of the return groove 25 corresponding to the ball return channel 27. A return groove inlet / outlet 254 is formed at the positioning portion 253. A return groove inlet / outlet 255 is formed at the return groove corresponding to the raceway. When the ball nut 2 moves to one end, the ball enters the return device 6 from the ball return channel 27 through the return groove inlet / outlet 254, and enters the raceway 29 through the return groove inlet / outlet 255; when the ball nut moves to the other end, the ball enters the return device 6 from the raceway 29 through the return groove inlet / outlet 255, and enters the ball return channel 27 from the return device 6 through the return groove inlet / outlet 254.

[0033] The end face of the ball nut 2 is provided with a plurality of mounting holes 21 evenly arranged along the circumferential direction for fixing with the upper structure. The tube wall of the ball nut 2 is provided with an oil hole 28 connecting the outer wall and the raceway 29 for external lubricating oil to enter the interior for providing lubrication.

[0034] The return grooves 22, 23, 24 and 25 are all the same in size and structure. The return grooves 22 and 23 of the same group are symmetrically arranged, and the return grooves 24 and 25 are also symmetrically arranged. The size and structure of the return device match the return groove. Therefore, the return device used in a single ball circulating chain is exactly the same, ensuring that the operating characteristics of the ball screw pair during forward and reverse rotation are exactly the same, further improving the operating stability.

[0035] Combination Fig.13 , Fig.14 , Fig.15 and Fig.16 As shown, the return device 3 is provided with fixing holes 31 and 32 corresponding to the screw holes 221 and 222. The return device can be connected to the ball nut by screws. The fixing holes 31 and 32 are designed with countersunk heads, so that after the return device is embedded in the return groove and fixed with screws, the outermost edge of the return device and the outermost edge of the ball nut are on the same cylindrical surface, neither protruding nor recessed, which is convenient for installation and use by superior users. The center line of the two fixing holes 31 and 32 passes through the structural center of the return device 3, which enhances the installation stability.

[0036] The returner 3 is provided with a returner inlet / outlet 34 connected to the ball return channel 26 and with a smooth transition at the positioning portion 223, and a returner inlet / outlet 35 connected to the raceway 29 and with a smooth transition at the return groove inlet / outlet; the returner 3 is provided with a return channel connected to the returner inlet / outlet 34 and the returner inlet / outlet 35 and with a smooth transition, so that the internal curves are completely tangent, ensuring the running stability during high-speed operation. The returner 3 is provided with a ball stopper 33, which is used to limit the flow position of the ball and prevent the ball from running out of the ball circulation chain.

[0037] When the ball nut 2 moves to one end, the ball enters the return device 3 from the raceway 29 through the return device inlet / outlet 35, and enters the ball return channel 26 from the return device 3 through the return channel and the return device inlet / outlet 34. When the ball nut 2 moves to the other end, the ball enters the return device 3 from the ball return channel 26 through the return device inlet / outlet 34, and enters the raceway 29 through the return channel and the return device inlet / outlet 35. The return devices 4, 5 and 6 are similar to the return device 3 in structure and working process, and are not described here one by one.

[0038] The technical solutions of the present invention are not limited to the above-mentioned embodiments, and any technical solutions obtained by equivalent replacement methods fall within the scope of protection required by the present invention.

Claims

1. A high-speed and heavy-load ball screw pair, comprising a ball screw and a ball nut matched with the ball screw, a raceway is formed between the ball screw and the ball nut, the ball screw is driven to rotate by a driving unit, and drives the ball nut to move linearly along the ball screw; characterized in that: A ball return channel arranged along the axial direction of the ball nut is respectively provided at both ends of the inner wall of the ball nut; the ball nut is provided with two return grooves connected to the ball return channel corresponding to each ball return channel, and a return device is provided in the return groove, and the two return devices, the ball return channel and the raceway form a circulation channel, and the two circulation channels are not connected to each other and are respectively provided with a ball circulation chain.

2. The high-speed and heavy-load ball screw pair according to claim 1, characterized in that: The two ball circulating chains are arranged with staggered or non-staggered spacing in the axial direction.

3. The high-speed and heavy-load ball screw pair according to claim 2 is characterized in that: Each ball return channel extends to a corresponding end surface of the ball nut.

4. The high-speed and heavy-load ball screw pair according to claim 3 is characterized in that: The ball screw is provided with a spiral groove, a large diameter portion is formed between adjacent grooves, and the axial width of the groove is 3 to 5 times the axial width of the large diameter portion.

5. The high-speed and heavy-load ball screw pair according to any one of claims 1 to 4, characterized in that: Two screw holes are provided on the edge of the return groove, and a positioning portion extending along the direction of the ball return channel is provided on one side of the return groove corresponding to the ball return channel. The positioning portion forms an exit / entrance of the return groove, and the return groove forms an entrance / exit of the return groove corresponding to the raceway.

6. The high-speed and heavy-load ball screw pair according to claim 5, characterized in that: The return device is provided with a fixing hole corresponding to the screw hole, a return device outlet / entrance connected to the ball return channel is provided corresponding to the positioning part, and a return device inlet / outlet connected to the raceway is provided corresponding to the return groove inlet / outlet; a return channel connecting the return device outlet / entrance and the return device inlet / outlet is provided inside the return device.

7. The high-speed and heavy-load ball screw pair according to claim 6, characterized in that: The center line connecting the two fixing holes of the return device passes through the center of the return device.

8. The high-speed and heavy-load ball screw pair according to claim 7, characterized in that: A bead stopper is provided on the return device.

9. The high-speed and heavy-load ball screw pair according to claim 1, characterized in that: The two ball circulation chains are centrally symmetrically arranged.

10. The high-speed and heavy-load ball screw pair according to claim 1, characterized in that: The end surface of the ball nut is provided with a plurality of mounting holes arranged along the circumferential direction, and the tube wall of the ball nut is provided with an oil hole connecting the outer side wall and the raceway.

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