Ball screw assembly with internally cooled nut

Abstract

The utility model relates to the technical field of mechanical transmission, in particular to a ball screw pair with a nut internally cooled. A ball screw pair cooled in a nut comprises a screw shaft and a ball nut arranged on the screw shaft in a sliding mode, a spiral ball channel is formed in the inner wall of the ball nut, a tangent plane is arranged on the outer wall of the ball nut, a bent pipe communicated with the ball channel is installed on the tangent plane, a cover plate covering the tangent plane is connected to the upper portion of the bent pipe, and the cover plate is connected with the screw shaft. A cooling pipe is arranged on the inner wall of the cover plate, the cooling pipe and the bent pipe are arranged at intervals, and a cooling liquid inlet and a cooling liquid outlet which are communicated with the two ends of the cooling pipe are formed in the ball nuts at the two ends of the cover plate respectively. According to the utility model, the cover plate covers the whole section of the bent pipe, so that the bent pipe is fixed and sealed; the cooling liquid is repeatedly circulated in the cover plate, the steel ball rotating at a high speed in the ball nut can be cooled in time, heat generated by friction is reduced, the high precision of a ball screw pair is ensured, the service life is prolonged, and the working efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission technology, and in particular to a ball screw pair with internal cooling of the nut. Background Technology

[0002] With the continuous improvement of industrialization, mechanical equipment requires higher precision, faster speed, and longer service life. In ball screw assemblies, the rolling friction between the steel balls and the raceways during operation causes the system temperature to rise, thus affecting the precision of mechanical transmission, especially in high-speed and high-precision mechanical equipment. Existing technology mainly uses hollow screw shafts, directly introducing coolant into the ball screw and circulating it through internal pipes to remove heat. While this method has a certain heat dissipation effect, hollow screws are difficult to design and manufacture, the load on the hollow screw bearings is reduced, the screw shaft is more prone to bending deformation during subsequent operation, and subsequent maintenance is complex and unsuitable for high-load applications. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a ball screw pair with internal cooling of the nut in order to solve the problems existing in the prior art in the background art.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a ball screw pair with internal cooling, including a screw shaft and a ball nut slidably mounted on the screw shaft. The inner wall of the ball nut has a spiral ball groove, and the outer wall of the ball nut has a cross section. A bent tube communicating with the ball groove is installed on the cross section. A cover plate covering the cross section is connected above the bent tube. A cooling pipe is provided on the inner wall of the cover plate. The cooling pipe and the bent tube are spaced apart. The ball nuts at both ends of the cover plate are respectively provided with a coolant inlet and a coolant outlet communicating with the two ends of the cooling pipe.

[0005] Furthermore, one end of the ball nut has a flange, and a coolant inlet is provided on the peripheral wall of the flange.

[0006] Furthermore, a second coolant inlet is provided on the end face of the flange.

[0007] Furthermore, the end of the cut surface away from the flange is provided with an arc-shaped retaining edge, and a coolant outlet is provided on the peripheral wall of the arc-shaped retaining edge.

[0008] Furthermore, a second coolant outlet is provided on the end face of the arc-shaped retaining edge.

[0009] Furthermore, the cover plate is an arc-shaped plate, and the arc of the cover plate is the same as the arc of the ball nut.

[0010] Furthermore, fixing holes are provided at the four corners of the cut surface.

[0011] Furthermore, the cover plate has stepped surfaces at its four corners, and threaded holes are provided on the stepped surfaces.

[0012] Another technical solution adopted by this utility model to solve its technical problem is: a ball screw pair with internal cooling, including a screw shaft and a ball nut slidably disposed on the screw shaft. The inner wall of the ball nut has a spiral ball channel, and the outer wall of the ball nut has a cross section. A bent tube communicating with the ball channel is installed on the cross section. A cover plate covering the cross section is connected above the bent tube. The cover plate has a hollow cavity. The ball nuts at both ends of the cover plate have coolant inlets and coolant outlets communicating with the two ends of the hollow cavity, respectively.

[0013] Furthermore, the inner wall of the cover plate is provided with a groove that mates with the bent pipe.

[0014] The beneficial effects of this utility model are:

[0015] The cover plate of this utility model covers the entire cross-section of the installed bend, which serves to fix and seal the bend.

[0016] The coolant is repeatedly circulated inside the cover plate to cool the high-speed rotating steel balls inside the ball nut in a timely manner, reduce the heat generated by friction, ensure the high precision of the ball screw pair, and improve service life and working efficiency.

[0017] This invention can also cool down lubricating grease, reduce system oil deterioration, and play an auxiliary lubrication role;

[0018] This invention allows for the installation of coolant inlets and outlets at different locations as needed, providing more options and increasing the product's versatility. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present invention.

[0021] Figure 2 yes Figure 1 A schematic diagram of the structure of a ball nut.

[0022] Figure 3 yes Figure 2 Top view.

[0023] Figure 4 yes Figure 2 Side view.

[0024] Figure 5 yes Figure 4 Sectional view along the AA direction.

[0025] Figure 6 This is a cross-sectional view of Embodiment 2 of this utility model.

[0026] In the diagram: 1. Lead screw shaft; 2. Ball nut; 21. Cross-section; 22. Flange; 221. Coolant inlet 1; 222. Coolant inlet 2; 23. Arc-shaped flange; 231. Coolant outlet 1; 232. Coolant outlet 2; 3. Bend; 4. Cover plate; 41. Cooling pipe; 41'. Hollow cavity; 42. Stepped surface. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0028] Example 1

[0029] like Figures 1-5 As shown, a ball screw assembly with internal cooling includes a screw shaft 1 and a ball nut 2 slidably mounted on the screw shaft 1. The inner wall of the ball nut 2 has a helical ball channel (not shown in the figure), and the outer wall of the ball nut 2 has a cross section 21. A bent tube 3 communicating with the ball channel is installed on the cross section 21. A cover plate 4 covering the cross section 21 is connected above the bent tube 3. A cooling pipe 41 is provided on the inner wall of the cover plate 4. The cooling pipe 41 is spaced apart from the bent tube 3. The ball nuts 2 at both ends of the cover plate 4 have coolant inlets and coolant outlets communicating with the two ends of the cooling pipe 41, respectively.

[0030] Specifically, one end of the ball nut 2 has a flange 22. A coolant inlet 221 is provided on the peripheral wall of the flange 22, and a second coolant inlet 222 is provided on the end face of the flange 22. The end of the cross-section 21 away from the flange 22 has an arc-shaped flange 23. A coolant outlet 231 is provided on the peripheral wall of the arc-shaped flange 23, and a second coolant outlet 232 is provided on the end face of the arc-shaped flange 23. Thus, coolant can enter the cover plate 4 in two ways. The inlet method can be changed according to the customer's installation requirements. If the coolant enters from the second coolant inlet 222, the coolant inlet 221 can be sealed with a copper plug. The same applies to the coolant outlet. This inlet and outlet design provides customers with more options.

[0031] The cover plate 4 is an arc-shaped plate, and the arc of the cover plate 4 is the same as that of the ball nut 2, ensuring that the cover plate 4 covers the entire cross-section 21 of the installed bend 3. On the one hand, it serves to fix the bend 3; on the other hand, the coolant circulating repeatedly in the cooling pipe 41 can cool down the high-speed rotating steel balls in the ball nut 2 in time, ensuring the high precision of the entire ball screw pair and improving its service life and working efficiency.

[0032] The ball nut 2 has fixing holes at the four corners of its cross-section 21, and the cover plate 4 has stepped surfaces 42 at the four corners. Threaded holes are opened on the stepped surfaces 42. The cover plate 4 and the ball nut 2 are fixed together with screws. Coolant enters the cooling pipe 41 inside the cover plate 4 through the coolant inlet 221. After cooling the steel balls inside the ball nut 2, the coolant flows from the coolant outlet 231 to the cooling system center of the external workbench.

[0033] The internal cooling structure of the nut in this utility model can also cool the lubricating grease. When the ball screw pair is in a high-speed and high-load working environment for a long time, if it is not cooled in time, the lubricating grease in the groove will also be affected by the temperature, resulting in oil deterioration, which will accelerate the aging of the ball screw pair. Adding a cooling system at the ball circulation path can assist in lubrication, reduce oil deterioration, and thus extend the service life.

[0034] Example 2

[0035] like Figure 6 As shown, the difference from Embodiment 1 is that the cover plate 4 has a hollow cavity 41', and the ball nuts 2 at both ends of the cover plate 4 are respectively provided with coolant inlets and coolant outlets communicating with the two ends of the hollow cavity 41'. Compared with Embodiment 1, the hollow cavity 41' of the cover plate 4 omits the circulation pipe 41, directly introducing coolant into the hollow cavity 41', resulting in a larger contact area and better cooling effect. The inner wall of the cover plate 4 is provided with a groove that mates with the bent pipe 3. In this way, the cover plate 4 can better cover the insertion hole of the bent pipe 3, reduce the entry of external debris into the groove, ensure the smooth and high-speed operation of the entire lead screw pair, improve working efficiency, and extend service life.

[0036] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A ball screw assembly with internal cooling, comprising a screw shaft (1) and a ball nut (2) slidably disposed on the screw shaft (1), wherein the inner wall of the ball nut (2) is provided with a helical ball groove, characterized in that: The outer wall of the ball nut (2) has a cut surface (21), and a bent tube (3) communicating with the ball groove is installed on the cut surface (21). A cover plate (4) covering the cut surface (21) is connected above the bent tube (3). A cooling pipe (41) is provided on the inner wall of the cover plate (4). The cooling pipe (41) and the bent tube (3) are spaced apart. The ball nuts (2) at both ends of the cover plate (4) are respectively provided with a coolant inlet and a coolant outlet communicating with the two ends of the cooling pipe (41).

2. The ball screw assembly with internal cooling in the nut according to claim 1, characterized in that: One end of the ball nut (2) has a flange (22), and a coolant inlet (221) is provided on the peripheral wall of the flange (22).

3. The ball screw assembly with internal cooling in the nut according to claim 2, characterized in that: The flange (22) is provided with a coolant inlet (222) on its end face.

4. The ball screw assembly with internal cooling in the nut according to claim 2, characterized in that: The end of the cut surface (21) away from the flange (22) is provided with an arc-shaped flange (23), and a coolant outlet (231) is provided on the peripheral wall of the arc-shaped flange (23).

5. The ball screw assembly with internal cooling in the nut according to claim 4, characterized in that: A coolant outlet (232) is provided on the end face of the arc-shaped baffle (23).

6. The ball screw assembly with internal cooling in the nut according to claim 1, characterized in that: The cover plate (4) is an arc-shaped plate, and the arc of the cover plate (4) is the same as the arc of the ball nut (2).

7. The ball screw assembly with internal cooling in the nut according to claim 1, characterized in that: Fixing holes are provided at the four corners of the cut surface (21).

8. The ball screw assembly with internal cooling in the nut according to claim 7, characterized in that: The cover plate (4) has stepped surfaces (42) at its four corners, and threaded holes are provided on the stepped surfaces (42).

9. A ball screw assembly with internal cooling, comprising a screw shaft (1) and a ball nut (2) slidably disposed on the screw shaft (1), wherein the inner wall of the ball nut (2) is provided with a helical ball groove, characterized in that: The outer wall of the ball nut (2) has a cut surface (21), and a bent tube (3) communicating with the ball groove is installed on the cut surface (21). A cover plate (4) covering the cut surface (21) is connected above the bent tube (3). The cover plate (4) has a hollow cavity (41'). The ball nuts (2) at both ends of the cover plate (4) are respectively provided with coolant inlets and coolant outlets communicating with the two ends of the hollow cavity (41').

10. The ball screw assembly with internal cooling in the nut according to claim 9, characterized in that: The inner wall of the cover plate (4) is provided with a groove that mates with the bent pipe (3).

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