Ball nut with integrated self-lubricating structure
By setting an adjustment mechanism and an arc groove on the surface of the ball nut, self-lubrication and rapid heat dissipation are achieved, solving the problem of heat accumulation in the ball nut in the electric vehicle steering system, extending its service life and ensuring the stability and smoothness of the steering system.
Patent Information
- Application Number
- CN202511842515.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-02-10
AI Technical Summary
In electric vehicle steering systems, ball nuts generate heat under high-temperature conditions, leading to misalignment and shortened service life.
A ball nut with an integrated self-lubricating structure was designed. By setting an adjustment mechanism and an arc groove on the surface of the ball nut, self-lubrication and rapid heat dissipation are achieved. The combination of an adjustment plate, an arc plate, a cylinder and an annular plate increases the surface area to conduct heat and wrap the ball screw, ensuring stable delivery of lubricating oil.
This effectively avoids heat buildup, ensures stable lubricant delivery, extends the service life of the ball nuts, and guarantees smooth operation of the steering system and linear steering wheel operation.
Smart Images
Figure CN121497790A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of transmission devices, and in particular to a ball nut with an integrated self-lubricating structure. Background Technology
[0002] The steering system of an electric vehicle is a comprehensive system based on mechanical transmission, with electronic control as the core and electric power assist as the execution. Its core function is to accurately translate the driver's steering operation (or the instructions of the autonomous driving system) into wheel deflection, while providing on-demand assistance according to the vehicle's operating conditions (vehicle speed, steering effort, etc.) to ensure the smoothness, accuracy and safety of steering, and to adapt to the electrification and intelligent characteristics of electric vehicles.
[0003] The steering system of an electric vehicle includes a ball screw and a ball nut. The ball screw pair consists of a ball screw, a ball nut, and balls. The power assist motor drives the ball nut to rotate through a reduction mechanism. The balls roll in the raceway between the screw and the nut, converting the rotational motion into the linear motion of the screw (or rack, in some structures the screw and rack are integrated), which directly drives the rack to steer the wheels. In existing technology, during the driving process of electric vehicles, the steering system needs to continuously adapt to road conditions and adjust the direction. The balls roll continuously between the nut raceway and the lead screw, and at the same time, there is inevitably slight sliding friction. The ball nut body will generate heat accumulation, especially under the high temperature conditions in summer. Over time, thermal expansion will cause misfitting, which will lead to abnormal clearance between the raceway and the balls, thus affecting the service life.
[0004] Therefore, it is necessary to propose a ball nut with an integrated self-lubricating structure to solve the above problems. Summary of the Invention
[0005] The main objective of this invention is to provide a ball nut with an integrated self-lubricating structure, which can effectively solve the problems in the prior art.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A ball nut with an integrated self-lubricating structure includes a ball screw, a ball nut body sleeved on the outside of the ball screw, a pulley installed on the left side of the ball nut body, a mounting hole on the outer surface of the ball nut body, a connecting hole on the wall of the mounting hole, and a guide block installed on the wall of the mounting hole. The surface of the ball nut has an arc-shaped groove next to the two mounting holes, and the groove wall is provided with an adjustment mechanism for self-lubrication of the ball nut body. The adjustment mechanism includes an adjustment plate slidably connected to the wall of an arc-shaped groove. An arc-shaped plate is slidably connected to the edge of the adjustment plate surface. The arc-shaped plate is fixedly connected to the ball nut body. A first strip block evenly distributed in a ring is fixedly connected to the end of the adjustment plate surface away from the arc-shaped groove. A first circular groove is opened on the end face of the first strip block. A first cylinder is slidably connected to the wall of the first circular groove. A first spring is sleeved on the outside of the first cylinder. A cylinder is fitted on the surface of a plurality of first strip blocks. The cylinder is sleeved on the outside of the ball screw. An annular plate is rotatably connected to the end of the cylinder away from the adjustment plate. The annular plate is fixedly connected to the ball screw. A connecting groove is provided at the end of the arc-shaped groove wall away from the adjusting plate. A first ball is installed on the connecting groove wall. A connecting rod is fixedly connected to the surface of the first ball. A second ball is fixedly connected to the end of the connecting rod away from the first ball. The arc-shaped groove is connected to the connecting hole. A stop block is installed next to the connecting groove on the arc-shaped groove wall by a torsion spring. The stop block is installed in conjunction with the first ball.
[0007] Preferably, the arc-shaped groove wall is fixedly connected to an arc-shaped cover plate, and the arc-shaped cover plate has a liquid inlet in the middle of its surface.
[0008] Preferably, the surface of the arc-shaped plate is fixedly connected with a third strip block that is evenly distributed in a ring. The end face of the third strip block is provided with a third circular groove. The wall of the third circular groove is slidably connected with a third cylinder. A third spring is sleeved on the outside of the third cylinder.
[0009] Preferably, a sliding groove is provided at the edge of the mounting hole wall, and a rectangular groove is provided on the surface of the ball nut body next to the two sliding grooves. An adjusting column is slidably connected to the wall of the rectangular groove, and a locking block is symmetrically slidably connected to the surface of the adjusting column. The locking block is slidably connected to the sliding groove, and the locking block is installed in conjunction with the guide block.
[0010] Preferably, a slot is provided at the edge of the guide block surface, and the block engages with the slot.
[0011] Preferably, the surface of the pulley is provided with positioning holes that are evenly distributed in an annular pattern. One of the positioning holes is slidably inserted into the wall of an adjusting column, and the other two positioning holes are slidably inserted into the walls of positioning blocks. Both positioning blocks are fixedly connected to the ball nut body.
[0012] Preferably, the surface of the adjusting column is provided with a second circular groove, the wall of the second circular groove is fixedly connected to a second spring, the other end of the second spring is fixedly connected to a movable column, the end of the movable column away from the second spring is fitted with a locking block, and the surfaces of the two locking blocks near the adjusting column are provided with inclined grooves.
[0013] Preferably, the surface of the adjusting plate away from the arc-shaped plate is fixedly connected with a second strip block that is evenly distributed in a ring.
[0014] Compared with the prior art, the present invention provides a ball nut with an integrated self-lubricating structure, which has the following advantages: This ball nut with an integrated self-lubricating structure features heat-conducting adjusting plates and arc-shaped plates. Multiple second strip-shaped blocks on the surfaces of these plates increase their surface area, optimizing the heat dissipation of the ball nut body. A cylinder connects to the adjusting and arc-shaped plates via first and third strip-shaped blocks. The cylinder's surface has multiple grooves that mate with these blocks, further increasing its surface area and enabling heat conduction. This further optimizes the ball nut's heat dissipation, allowing heat to be quickly transferred to the surfaces of the arc-shaped plates, adjusting plates, and cylinder, preventing heat accumulation. The cylinder, adjusting plates, arc-shaped plates, and annular plate enclose the parts of the ball screw that mate with the ball nut body, facilitating heat dissipation while sealing the ball screw. Fine dust cannot adhere to the ball screw surface, preventing oil buildup inside the ball nut body, which would affect overall operation and extend the ball nut's service life.
[0015] This ball nut with an integrated self-lubricating structure allows the ball screw to move along its own axis as the ball nut body is adjusted and rotated along with the pulley. The annular plate moves along with the ball screw, and the third and first strip blocks move relative to the cylinder. Utilizing the friction between the multiple grooves on the cylinder surface and the first strip block, the adjusting plate is pressed into the arc-shaped groove. In other words, during the adjustment and rotation of the ball nut body, the lubricating oil stored in the arc-shaped groove can smoothly pass through the connecting hole and contact the rolling balls inside the ball nut body, thereby achieving self-lubrication of the ball nut body. This ensures stable lubricating oil delivery during the adjustment and rotation of the ball nut body, avoiding sudden changes in friction due to poor local lubrication, thus ensuring smooth, linear, and stick-free steering wheel rotation. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural diagram of the arc-shaped plate of the present invention; Figure 3 This is the invention Figure 2 Enlarged view at point A1; Figure 4 This is the invention Figure 2 Enlarged view at point A2; Figure 5This is a partial structural diagram of the cylinder and annular plate of the present invention; Figure 6 This is the invention Figure 5 Enlarged view at point B in the middle; Figure 7 This is a partial structural diagram of the arc-shaped groove of the present invention; Figure 8 This is a partial structural diagram of the arc-shaped plate of the present invention; Figure 9 This is the invention Figure 8 Enlarged view at point C1; Figure 10 This is the invention Figure 8 Enlarged view at point C2; Figure 11 This is a partial structural diagram of the positioning block and adjusting column of the present invention; Figure 12 This is a partial structural diagram of the mounting holes of the present invention; Figure 13 This is the invention Figure 12 Enlarged view of point D in the middle.
[0017] In the diagram: 1. Ball screw; 11. Ball nut body; 12. Pulley; 121. Positioning hole; 122. Positioning block; 13. Mounting hole; 131. Slide groove; 132. Rectangular groove; 133. Adjusting column; 1331. Second circular groove; 1332. Second spring; 1333. Movable column; 134. Locking block; 14. Connecting hole; 15. Guide block; 2. Arc-shaped groove; 21. Arc-shaped cover plate; 22. 3. Liquid inlet; 4. Adjustment mechanism; 5. Adjustment plate; 6. Arc plate; 7. Third strip block; 8. Third circular groove; 9. Third cylinder; 10. Third spring; 11. First strip block; 12. First circular groove; 13. First cylinder; 14. First spring; 15. Cylinder; 16. Annular plate; 17. Connecting groove; 18. First sphere; 19. Connecting rod; 20. Second sphere; 21. Stop block. Detailed Implementation
[0018] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.
[0019] Please see Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 12 and Figure 13A ball nut with an integrated self-lubricating structure includes a ball screw 1, a ball nut body 11 sleeved on the outside of the ball screw 1, a pulley 12 installed on the left side of the ball nut body 11, a mounting hole 13 on the outer surface of the ball nut body 11, a connecting hole 14 on the wall of the mounting hole 13, and a guide block 15 installed on the wall of the mounting hole 13. An arc-shaped groove 2 is provided on the surface of the ball nut next to the two mounting holes 13, and an adjustment mechanism 3 for self-lubrication of the ball nut body 11 is provided on the groove wall of the arc-shaped groove 2. The adjustment mechanism 3 includes an adjustment plate 31 that is slidably connected to the wall of the arc groove 2. An arc plate 32 is slidably connected to the edge of the surface of the adjustment plate 31. The arc plate 32 is fixedly connected to the ball nut body 11. A first strip block 33 that is evenly distributed in a ring is fixedly connected to the end of the surface of the adjustment plate 31 away from the arc groove 2. A first circular groove 34 is opened on the end face of the first strip block 33. A first cylinder 35 is slidably connected to the wall of the first circular groove 34. A first spring 36 is sleeved on the outside of the first cylinder 35. A cylinder 37 is fitted on the surface of the multiple first strip blocks 33. The cylinder 37 is sleeved on the outside of the ball screw 1. An annular plate 38 is rotatably connected to the end of the cylinder 37 away from the adjustment plate 31. The annular plate 38 is fixedly connected to the ball screw 1. A connecting groove 4 is provided at the end of the arc-shaped groove 2 away from the adjusting plate 31. A first ball 5 is installed on the wall of the connecting groove 4. A connecting rod 6 is fixedly connected to the surface of the first ball 5. A second ball 7 is fixedly connected to the end of the connecting rod 6 away from the first ball 5. The arc-shaped groove 2 is connected to the connecting hole 14. A stop block 8 is installed next to the connecting groove 4 on the wall of the arc-shaped groove 2 by a torsion spring. The stop block 8 is installed in conjunction with the first ball 5. It should be noted that during the adjustment and rotation of the ball nut body 11, both the adjusting plate 31 and the arc-shaped plate 32 can conduct heat. The arrangement of multiple second strip blocks increases the surface area of the arc-shaped plate 32 and the adjusting plate 31, optimizing the heat dissipation performance of the ball nut body 11. The cylinder 37 is connected to the adjusting plate 31 and the arc-shaped plate 32 through the first strip block 33 and the third strip block 321. The surface of the cylinder 37 is provided with multiple grooves that fit the first strip block 33 and the third strip block 321, which also increases the surface area of the cylinder 37. The cylinder 37 can also conduct heat, further optimizing the ball nut body 11. The ball screw 1 has excellent heat dissipation performance, allowing heat to be quickly transferred to the surfaces of the arc plate 32, the adjusting plate 31, and the cylinder 37, thus achieving rapid heat dissipation and avoiding heat accumulation. Furthermore, the arrangement of the cylinder 37, the adjusting plate 31, the arc plate 32, and the annular plate 38 can cover the part of the ball screw 1 that can mate with the ball nut body 11, which facilitates heat dissipation of the ball nut body 11 while sealing the ball screw 1. Fine dust will not adhere to the surface of the ball screw 1, preventing the formation of grease on the inside of the ball nut body 11, which would affect the overall operation and extend the service life of the ball nut body 11. It should be noted that during the adjustment and rotation of the ball nut body 11, the ball contacts the surface of the second ball 7 and moves relative to it, causing the second ball 7 to move. Due to the connecting action of the connecting rod 6, the first ball 5 moves together with the second ball 7. Due to the elastic force of the torsion spring, the stop block 8 is in close contact with the surface of the first ball 5. The first ball 5 is adjusted and moved, and the connecting groove 4 is no longer closed. Under the pressure of the adjusting plate 31, the lubricating oil is placed in the connecting hole 14 through the connecting groove 4. After the ball separates from the second ball 7, the first ball 5 is adjusted and moved, so that the end of the connecting groove 4 near the arc groove 2 is closed again. This cycle continues, ensuring stable lubricating oil delivery while the ball nut body 11 is adjusted and rotated, avoiding sudden changes in friction due to poor local lubrication, thus ensuring smooth and linear steering wheel rotation without any sticking, and still achieving self-lubrication, ensuring stable operation of the electric vehicle steering system.
[0020] Please see Figure 1 The arc-shaped groove 2 has an arc-shaped cover plate 21 fixedly connected to its wall, and an inlet 22 is provided in the middle of the surface of the arc-shaped cover plate 21. It should be noted that the inlet 22 facilitates the replenishment of lubricating oil in the arc-shaped groove 2, and the arc-shaped cover plate 21 and the arc-shaped groove 2 form an oil tank for holding lubricating oil.
[0021] Please see Figure 4 and Figure 10 The surface of the arc plate 32 is fixedly connected with a third strip block 321 that is evenly distributed in a ring. The end face of the third strip block 321 is provided with a third circular groove 322. The wall of the third circular groove 322 is slidably connected with a third cylinder 323. A third spring 324 is sleeved on the outside of the third cylinder 323. During the adjustment and movement of the ball screw 1, relative movement occurs between the third circular groove 322 and the third cylinder 323, and the third spring 324 is compressed. By utilizing the elastic force of multiple third springs 324, the cylinder 37 can be easily restored to its initial state.
[0022] Please see Figure 1 , Figure 3 and Figure 11A sliding groove 131 is provided at the edge of the mounting hole 13. A rectangular groove 132 is provided on the surface of the ball nut body 11 next to the two sliding grooves 131. An adjusting column 133 is slidably connected to the wall of the rectangular groove 132. A locking block 134 is symmetrically slidably connected to the surface of the adjusting column 133. The locking block 134 is slidably connected to the sliding groove 131 and is installed in conjunction with the guide block 15. A locking groove is provided at the edge of the surface of the guide block 15, and the locking block 134 is engaged with the locking groove. A ring of evenly distributed positioning holes 121 is provided on the surface of the pulley 12. The wall of one positioning hole 121 is slidably inserted into the adjusting column 133, and the walls of the other two positioning holes 121 are slidably inserted into positioning blocks 122. Both positioning blocks 122 are fixedly connected to the ball nut body 11. It should be noted that the positioning block 122, the positioning hole 121, and the adjusting column 133 are designed to ensure that the pulley 12 rotates stably and drives the ball nut body 11 to rotate, thus ensuring stable transmission.
[0023] Please see Figure 3 The surface of the adjusting column 133 is provided with a second circular groove 1331. A second spring 1332 is fixedly connected to the groove wall of the second circular groove 1331. The other end of the second spring 1332 is fixedly connected to a movable column 1333. The end of the movable column 1333 away from the second spring 1332 is fitted with a locking block 134. The surfaces of the two locking blocks 134 near the adjusting column 133 are provided with inclined grooves. It should be noted that, in actual use, after positioning the adjusting column 133 through the positioning hole 121, its other end is inserted into the rectangular groove 132. The movable column 1333 contacts the inclined groove and moves relative to it. The locking block 134 moves relative to the sliding groove 131, and the movable column 1333 moves relative to the second circular groove 1331. The second spring 1332 is compressed, so that the locking block 134 engages with the locking groove, thereby limiting the installation of the guide block 15. The installation of the guide block 15 is limited when the pulley 12 and the ball nut body 11 are installed together, which facilitates the disassembly and assembly of the ball nut body 11.
[0024] Please see Figure 1 , Figure 2 , Figure 5 , Figure 7 , Figure 8 and Figure 12 The surface of the adjusting plate 31 away from the arc plate 32 is fixedly connected with second strip blocks that are evenly distributed in a ring. It should be noted that the arrangement of multiple second strip blocks can increase the surface area of the arc plate 32 and the adjusting plate 31, ensuring the heat dissipation effect of the ball nut body 11.
[0025] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A ball nut with an integrated self-lubricating structure, comprising a ball screw (1), a ball nut body (11) sleeved on the outside of the ball screw (1), a pulley (12) fitted on the left side of the ball nut body (11), a mounting hole (13) formed on the outer surface of the ball nut body (11), a connecting hole (14) formed on the wall of the mounting hole (13), and a guide block (15) fitted on the wall of the mounting hole (13), characterized in that: The ball nut surface is provided with an arc-shaped groove (2) next to the two mounting holes (13), and the groove wall of the arc-shaped groove (2) is provided with an adjustment mechanism (3) for self-lubrication of the ball nut body (11). The adjustment mechanism (3) includes an adjustment plate (31) slidably connected to the wall of the arc groove (2), an arc plate (32) slidably connected to the edge of the surface of the adjustment plate (31), the arc plate (32) being fixedly connected to the ball nut body (11), a first strip block (33) evenly distributed in a ring is fixedly connected to the end of the surface of the adjustment plate (31) away from the arc groove (2), a first circular groove (34) is opened on the end face of the first strip block (33), a first cylinder (35) is slidably connected to the wall of the first circular groove (34), a first spring (36) is sleeved on the outside of the first cylinder (35), a cylinder (37) is fitted on the surface of a plurality of first strip blocks (33), the cylinder (37) is sleeved on the outside of the ball screw (1), an annular plate (38) is rotatably connected to the end of the cylinder (37) away from the adjustment plate (31), and the annular plate (38) is fixedly connected to the ball screw (1). The arc-shaped groove (2) has a connecting groove (4) at one end away from the adjusting plate (31). A first ball (5) is installed on the wall of the connecting groove (4). A connecting rod (6) is fixedly connected to the surface of the first ball (5). A second ball (7) is fixedly connected to the end of the connecting rod (6) away from the first ball (5). The arc-shaped groove (2) is connected to the connecting hole (14). A stop block (8) is installed next to the connecting groove (4) on the wall of the arc-shaped groove (2) by a torsion spring. The stop block (8) is installed in cooperation with the first ball (5).
2. A ball nut with an integrated self-lubricating structure according to claim 1, characterized in that: The arc-shaped groove (2) has an arc-shaped cover plate (21) fixedly connected to its wall, and an inlet (22) is provided in the middle of the surface of the arc-shaped cover plate (21).
3. A ball nut with an integrated self-lubricating structure according to claim 1, characterized in that: The surface of the arc plate (32) is fixedly connected to a third strip block (321) that is evenly distributed in a ring. The end face of the third strip block (321) is provided with a third circular groove (322). The wall of the third circular groove (322) is slidably connected to a third cylinder (323). A third spring (324) is sleeved on the outside of the third cylinder (323).
4. A ball nut with an integrated self-lubricating structure according to claim 1, characterized in that: The mounting hole (13) has a groove (131) at the edge of the hole wall. The ball nut body (11) has a rectangular groove (132) on the surface next to the two grooves (131). The rectangular groove (132) is slidably connected to the groove wall. The adjusting column (133) is symmetrically connected to the surface of the adjusting column (133) and has a locking block (134). The locking block (134) is slidably connected to the groove (131) and is installed in conjunction with the guide block (15).
5. A ball nut with an integrated self-lubricating structure according to claim 4, characterized in that: The guide block (15) has a slot at the edge of its surface, and the card block (134) engages with the slot.
6. A ball nut with an integrated self-lubricating structure according to claim 4, characterized in that: The surface of the pulley (12) is provided with a ring of uniformly distributed positioning holes (121). One of the positioning holes (121) is slidably inserted into the adjusting column (133), and the other two positioning holes (121) are slidably inserted into the positioning blocks (122). Both positioning blocks (122) are fixedly connected to the ball nut body (11).
7. A ball nut with an integrated self-lubricating structure according to claim 4, characterized in that: The surface of the adjusting column (133) is provided with a second circular groove (1331), and a second spring (1332) is fixedly connected to the groove wall of the second circular groove (1331). The other end of the second spring (1332) is fixedly connected to a movable column (1333). The end of the movable column (1333) away from the second spring (1332) is fitted with a locking block (134). The surfaces of the two locking blocks (134) near the adjusting column (133) are provided with inclined grooves.
8. A ball nut with an integrated self-lubricating structure according to claim 1, characterized in that: The surface of the adjusting plate (31) away from the arc plate (32) is fixedly connected with a second strip block that is evenly distributed in a ring.