A novel structure of a drive screw

Abstract

This utility model relates to a novel structure for a transmission lead screw. The utility model includes a lead screw raceway axially arranged on the outer periphery of the lead screw. The lead screw raceway includes multiple raised units, with a first groove unit formed between adjacent raised units. The cross-section of each raised unit includes a first arc segment and a second arc segment joined together to form a double arc profile. The inner periphery of the nut forms a threaded raceway that mates with the lead screw raceway. The threaded raceway includes multiple second groove units, each of which has a triangular cross-section with a 90° apex angle. The two sides of the second groove unit respectively contact the first arc segment and the second arc segment of the corresponding raised unit to form a line contact transmission pair. This utility model can improve transmission efficiency while increasing axial load capacity and reducing backlash, thus improving transmission efficiency.

Description

Technical Field

[0001] This utility model relates to the field of lead screw technology, and in particular to a novel structure of a transmission lead screw. Background Technology

[0002] Currently, commonly used lead screw types mainly include trapezoidal lead screws, ball screws, and planetary roller screws. Trapezoidal lead screws transmit force through surface contact on the threaded side, featuring a simple structure, mature manufacturing process, and low cost, making them widely used in general mechanical equipment. However, due to their surface contact friction pair, they experience high frictional resistance, low transmission efficiency, and significant heat generation and wear, making them unsuitable for achieving high-efficiency, high-precision linear transmission.

[0003] Ball screws achieve near-point or line contact transmission by rolling balls between the screw and nut, significantly reducing friction, improving transmission efficiency, and offering high positioning and repeatability accuracy. Therefore, they are widely used in CNC machine tools, semiconductor equipment, and high-end automated equipment. However, the raceway cross-section in ball screw structures often employs complex Gothic arcs or other special curved surfaces. High precision machining is required for the raceways of the screw and nut, and strict control over the dimensions and form tolerances of the mating balls leads to complex manufacturing processes and high production costs. This is especially true in the field of miniature ball screws, where the smaller screw diameter and limited pitch make raceway dimensions even more difficult to control, and the limited space for ball assembly makes stable mass production of miniature ball screws challenging.

[0004] Planetary roller screws utilize multiple rollers moving in a planetary motion between the screw and nut, achieving similarly high load-bearing capacity and transmission efficiency. However, planetary roller screws have a more complex structure, requiring not only high-precision machining of the screw and nut raceways but also the machining of multiple rollers and their guiding structures. The overall assembly process is complex, and machining and assembly errors significantly impact performance, leading to high manufacturing costs and limiting their widespread application. In the field of micro-transmissions, due to further reductions in part size and limitations in machining tools and fixtures, the machining difficulty of planetary roller screw raceways and rollers is even greater, making it difficult to meet the demands of mass production at low cost.

[0005] Therefore, there is an urgent need to provide a transmission screw that simultaneously achieves low cost and high transmission efficiency. Summary of the Invention

[0006] Therefore, this utility model provides a novel transmission screw structure that can improve transmission efficiency while increasing axial load capacity and reducing axial clearance, thereby improving transmission efficiency.

[0007] To solve the above-mentioned technical problems, this utility model provides a novel transmission screw structure, including a screw and a nut that is threadedly engaged with the screw. The screw has a screw raceway arranged axially on its outer periphery. The screw raceway includes multiple protruding units. A first groove unit is formed between two adjacent protruding units. The cross section of the protruding unit includes a first arc segment and a second arc segment that are spliced ​​together to form a double arc profile. The inner circumference of the nut forms a threaded raceway that mates with the lead screw raceway. The threaded raceway includes a plurality of second groove units. The cross-section of each second groove unit is a triangular surface with a vertices of 90°. The two sides of the second groove unit respectively contact the first arc segment and the second arc segment of the corresponding protrusion unit to form a line contact transmission pair.

[0008] In one embodiment of this utility model, the material of the lead screw is 20CrMo, GCr15 or 50CrMo4 treated by carburizing heat treatment process.

[0009] In one embodiment of this utility model, the hardness of the contact position between the lead screw and the nut is HRC58~62.

[0010] In one embodiment of this utility model, the nut is made of 20CrMo or GCr15 that has undergone carburizing heat treatment.

[0011] In one embodiment of this utility model, the surface hardness of the nut is HRC58-62.

[0012] In one embodiment of this utility model, the lead screw raceway of the lead screw and the thread raceway of the nut are both formed by grinding.

[0013] In one embodiment of this utility model, the precision grade of the lead screw and the nut is not lower than C5.

[0014] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art: This invention discloses a novel transmission screw structure that converts rotational motion into linear motion by forming a line contact transmission pair extending along the helical direction between the screw and the nut. Based on traditional trapezoidal and planetary screw structures, the structure optimizes the surface contact transmission of the original trapezoidal screw into a line contact transmission by improving the raceway cross-section of the nut and screw. The thread raceway cross-section of the nut is optimized from the original trapezoidal thread to a triangular surface with a 90° apex angle, allowing it to form a line contact engagement with the screw's double-arc groove. While maintaining high transmission efficiency, this structure can form stable support in the meshing area, improving the axial load-bearing capacity of the screw pair; simultaneously, the line contact form helps reduce backlash, thereby improving overall transmission accuracy and operational stability.

[0015] This structure can significantly improve transmission efficiency without the need for a complex rolling element circulation structure, thereby effectively reducing the difficulty of parts processing and the requirements for assembly precision, and achieving a reduction in overall production costs. Attached Figure Description

[0016] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 This is a cross-sectional schematic diagram of the structure of the transmission lead screw of this utility model.

[0018] Figure 2 This is a schematic diagram of the overall structure of the transmission lead screw of this utility model.

[0019] Figure 3 This is a schematic diagram of the lead screw of this utility model.

[0020] Figure 4 This is a schematic diagram of the structure of the nut of this utility model.

[0021] Explanation of reference numerals on the accompanying drawings: 1. Lead screw; 11. Lead screw raceway; 12. Raised unit; 121. Double circular arc profile; 121a. First circular arc segment; 121b. Second circular arc segment; 13. First channel unit; 2. Nut; 21. Thread raceway; 211. Second raceway unit; 212. Triangular surface. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0023] In this utility model, when directions (up, down, left, right, front, and back) are described, it is only for the convenience of describing the technical solution of this utility model, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0024] In this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number; "above," "below," "within," etc. are understood to include the stated number. In the description of this utility model, if "first" or "second" is used, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0025] In this utility model, unless otherwise explicitly defined, terms such as "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model based on the specific content of the technical solution.

[0026] Reference Figures 1 to 4 As shown, the structure of a novel transmission lead screw of this utility model includes a lead screw 1 and a nut 2 that is threadedly engaged with the lead screw 1. The lead screw 1 has a lead screw raceway 11 arranged axially on its outer periphery. The lead screw raceway 11 includes a plurality of protruding units 12. A first channel unit 13 is formed between two adjacent protruding units 12. The cross section of the protruding unit 12 includes a first arc segment 121a and a second arc segment 121b that are spliced ​​together to form a double arc profile 121. The inner circumference of the nut 2 forms a threaded raceway 21 that mates with the lead screw raceway 11. The threaded raceway 21 includes a plurality of second groove units 211. The cross-section of each second groove unit 211 is a triangular surface 212 with a vertex angle of 90°. The two sides of the second groove unit 211 respectively contact the first arc segment 121a and the second arc segment 121b of the corresponding protrusion unit 12 to form a line contact transmission pair (adopting a Gothic contact).

[0027] The thread raceway 21 of nut 2 is optimized from the original trapezoidal thread to a triangular surface 212 with a 90° apex angle, allowing it to form line contact engagement with the double-arc groove of lead screw 1. While maintaining high transmission efficiency, this structure can form stable support in the meshing area, improving the axial load-bearing capacity of the lead screw pair; at the same time, the line contact form helps to reduce backlash, thereby improving overall transmission accuracy and operational stability.

[0028] In one embodiment, the material of the lead screw 1 is 20CrMo or GCr15 treated by carburizing heat treatment or 50CrMo4 quenched by medium frequency, which improves its service life.

[0029] In one embodiment, the hardness of the contact point between the lead screw 1 and the nut 2 is HRC58-62, which improves the service life.

[0030] In one embodiment, the nut 2 is made of 20CrMo or GCr15 that has undergone carburizing heat treatment, and its hardness is improved by salt furnace treatment, thereby increasing its service life.

[0031] In one embodiment, the surface hardness of the nut 2 is HRC58-62, which improves its service life.

[0032] In one embodiment, the lead screw raceway 11 of the lead screw 1 and the thread raceway 21 of the nut 2 are both formed by grinding, which improves their service life.

[0033] In one embodiment, the precision grade of the lead screw 1 and the nut 2 is not lower than C5.

[0034] By forming a line contact transmission pair extending in the helical direction between the lead screw 1 and the nut 2, rotational motion is converted into linear motion. Based on the traditional trapezoidal lead screw and planetary roller lead screw structures, the raceway cross-sectional profiles of the nut 2 and lead screw 1 are improved, optimizing the original surface contact transmission form of the trapezoidal lead screw 1 into a line contact transmission form. This structure significantly improves transmission efficiency and eliminates the need for a complex rolling element circulation structure, thereby effectively reducing the difficulty of parts processing and assembly accuracy requirements, and achieving a reduction in overall production costs.

[0035] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although this utility model has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A novel transmission lead screw structure, comprising a lead screw (1) and a nut (2) threadedly engaged with the lead screw (1), characterized in that, The lead screw (1) has a lead screw raceway (11) arranged axially on its outer periphery. The lead screw raceway (11) includes multiple protruding units (12). A first channel unit (13) is formed between two adjacent protruding units (12). The cross section of the protruding unit (12) includes a first arc segment (121a) and a second arc segment (121b) that are spliced ​​together to form a double arc profile (121). The inner circumference of the nut (2) forms a threaded raceway (21) that mates with the lead screw raceway (11). The threaded raceway (21) includes a plurality of second groove units (211). The cross section of each second groove unit (211) is a triangular surface (212) with a vertex angle of 90°. The two sides of the second groove unit (211) respectively contact the first arc segment (121a) and the second arc segment (121b) of the corresponding protrusion unit (12) to form a line contact transmission pair.

2. The structure of the novel transmission lead screw according to claim 1, characterized in that, The material of the lead screw (1) is 20CrMo, GCr15 or 50CrMo4 treated by carburizing heat treatment process.

3. The structure of the novel transmission lead screw according to claim 1, characterized in that, The hardness of the contact position between the lead screw (1) and the nut (2) is HRC58~62.

4. The structure of the novel transmission lead screw according to claim 1, characterized in that, The nut (2) is made of 20CrMo or GCr15 that has undergone carburizing heat treatment.

5. The structure of a novel transmission lead screw according to claim 1, characterized in that, The surface hardness of the nut (2) is HRC58~62.

6. The structure of a novel transmission lead screw according to claim 1, characterized in that, The lead screw raceway (11) of the lead screw (1) and the thread raceway (21) of the nut (2) are both formed by grinding.

7. The structure of a novel transmission lead screw according to claim 1, characterized in that, The precision grade of the lead screw (1) and the nut (2) shall not be lower than C5 grade.

Images