Self-lubricating ball spline

Abstract

The utility model relates to a kind of self-lubricating ball spline in the ball spline field, including spline barrel, spline shaft and ball return device, ball return device is set to the both ends of spline barrel, spline shaft passes through spline barrel, the surface of spline shaft is provided with guide groove, the ball return device is provided with lubricating assembly, lubricating assembly includes oil storage cavity, filling port, pressurizing port and infiltration hole, filling port, pressurizing port and infiltration hole are all communicated with oil storage cavity, filling port and pressurizing port extend to the side wall and end face of ball return device, infiltration hole extends to the inner wall of ball return device, the end of infiltration hole close to the inner wall of spline barrel is provided with necking, necking place is provided with the oiling ball that can roll, oiling ball and guide groove roll contact, realize the circulation track of ball, especially the long-acting, uniform, active lubrication of key guide groove and ball return device area, significantly improve the service life, working stability and maintenance-free of product.

Description

Technical Field

[0001] This utility model relates to the field of ball splines, and in particular to a self-lubricating ball spline. Background Technology

[0002] A ball spline is a precision mechanical transmission component widely used in applications requiring high precision, high rigidity, and low friction for linear or rotary motion, such as automated equipment, CNC machine tools, robot joints, and precision measuring instruments. Its basic structure typically includes a spline cylinder, a spline shaft, and a ball circulation track inside the spline cylinder, consisting of guide grooves on the spline shaft, ball grooves within the spline cylinder, and ball return channels in returners at both ends. The balls roll within the circulation track, enabling smooth, low-resistance linear movement of the spline shaft relative to the spline cylinder and torque transmission. The core advantages of a ball spline lie in its high transmission accuracy, high load-bearing capacity, and low coefficient of friction.

[0003] Traditional ball splines present significant challenges in lubrication maintenance during long-term operation. Manual lubrication or initial filling often fails to ensure lubricant is evenly distributed across the entire ball circulation path, typically lacking continuous oil supply. This is particularly problematic as it struggles to reach the deep guide grooves and return ball channels, making it difficult to distribute lubricant evenly across all friction surfaces. This can easily create lubrication blind spots, where some areas have insufficient oil film while others accumulate excessive grease. The lubrication condition in these areas deteriorates more easily, impacting the overall lifespan and reliability of the spline. Utility Model Content

[0004] In order to overcome the shortcomings of existing technical solutions, this utility model provides a self-lubricating ball spline, which can effectively solve the technical problem of uneven lubrication.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A self-lubricating ball spline includes a spline cylinder, a spline shaft, and a ball return device. The ball return device is located at both ends of the spline cylinder. The spline shaft passes through the spline cylinder and has a guide groove on its surface. The spline cylinder has a first ball groove and a second ball groove. The ball return device has a ball return channel. The first ball groove and the second ball groove are connected through the ball return channel. The first ball groove, the second ball groove, and the ball return channel together form a ball circulation track. The ball return device has a lubrication assembly, which includes an oil reservoir, a filling port, a pressurizing port, and a permeation hole. The filling port, the pressurizing port, and the permeation hole are all connected to the oil reservoir. The filling port and the pressurizing port extend to the side wall and end face of the ball return device. The permeation hole extends to the inner wall of the ball return device. The end of the permeation hole near the inner wall of the spline cylinder has a constriction, and a rollable oil ball is provided at the constriction. The oil ball rolls in contact with the guide groove.

[0007] Furthermore, the inner wall of the ball returner is provided with a dustproof block, the cross-sectional shape of which corresponds to the cross-sectional shape of the guide groove, and the dustproof block is located on the side of the lubrication assembly away from the spline cylinder.

[0008] Furthermore, an oil scraper is provided at one end of the dust block near the lubrication assembly.

[0009] Furthermore, the guide groove is parallel to the axis of the spline shaft, and there are three or more sets of guide grooves arranged around the axis of the spline shaft, with the number of ball circulation tracks corresponding to the number of guide grooves.

[0010] Furthermore, the end face of the spline cylinder is provided with a positioning hole, and the end of the ball returner near the spline cylinder is provided with a matching positioning protrusion.

[0011] Furthermore, the side wall of the splined cylinder is provided with a mounting ring groove, and a positioning plane is provided inside the mounting ring groove.

[0012] Compared with the prior art, the beneficial effects of this utility model are: the built-in self-lubricating mechanism, through the synergistic effect of the oil storage chamber, controllable permeation holes and rolling oil beads, achieves long-term, uniform and active lubrication of the ball circulation track, especially the key guide groove and return ball area, effectively overcoming the inherent defects of the traditional ball spline lubrication method, and significantly improving the product's service life, working stability and maintenance-free nature. Attached Figure Description

[0013] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of this utility model;

[0015] Figure 3 This is a schematic diagram of the ball bearing circulation track in this utility model;

[0016] The numbers in the diagram are: 1-Splined cylinder, 2-Splined shaft, 3-Ball return device, 4-Guide groove, 5-First ball groove, 6-Second ball groove, 7-Ball return channel, 8-Oil storage chamber, 9-Filling port, 10-Pressure port, 11-Permeation hole, 12-Oil bead, 13-Dustproof block, 14-Oil scraper. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] The following is combined with Figures 1-3 A detailed description of a self-lubricating ball spline of this utility model is provided below:

[0019] A self-lubricating ball spline includes a spline cylinder 1, a spline shaft 2, and a ball return device 3. The ball return device 3 is disposed at both ends of the spline cylinder 1. The spline shaft 2 passes through the spline cylinder 1, and a guide groove 4 is provided on the surface of the spline shaft 2. A first ball groove 5 and a second ball groove 6 are provided inside the spline cylinder 1. A ball return channel 7 is provided inside the ball return device 3. The first ball groove 5 and the second ball groove 6 are connected through the ball return channel 7. The first ball groove 5, the second ball groove 6, and the ball return channel 7 combine to form a ball circulation track. The ball return device 3 is equipped with a lubrication assembly, which includes an oil storage chamber 8, a filling port 9, a pressurizing port 10, and a permeation hole 11. The filling port 9, the pressurizing port 10, and the permeation hole 11 are all connected to the oil storage chamber 8. The filling port 9 and the pressurizing port 10 extend to the side wall of the ball return device 3, and the permeation hole 11 extends to the inner wall of the ball return device 3. The end of the permeation hole 11 near the inner wall of the spline cylinder 1 is provided with a narrowing, and a rollable oil bead 12 is provided at the narrowing. The oil bead 12 rolls in contact with the guide groove 4.

[0020] The oil reservoir 8 in the lubrication assembly can store sufficient lubricating oil. Lubricant can be easily replenished to the reservoir 8 through the filling port 9, and pressure can be applied to the reservoir 8 through the pressurization port 10. Under pressure or capillary action, the lubricating oil slowly and continuously seeps out through the permeation holes 11. The oil beads 12 themselves directly roll in contact with the guide groove 4 of the spline shaft 2. When the spline shaft 2 moves, the oil beads 12 roll accordingly, actively and evenly applying lubricating oil to the surface of the guide groove 4 they contact. The lubricating oil applied to the guide groove 4 is carried by the movement of the balls in the circulation track to the first ball groove 5, the second ball groove 6, and the return ball channel 7 within the spline cylinder 1, thereby effectively diffusing the lubricant to all friction surfaces of the entire ball circulation track. This solves the problem of uneven lubrication caused by traditional methods. The lubricating oil starts from the guide groove 4 and spreads outwards and from point to surface, ensuring that the area in contact with the oil beads 12 is preferentially and fully lubricated, and the lubricant is carried to other parts of the track by the movement of the balls.

[0021] The built-in self-lubricating mechanism, through the synergistic effect of the oil storage chamber 8, the controllable permeation hole 11 and the rolling oil-coating beads 12, achieves long-term, uniform and active lubrication of the ball circulation track, especially the key guide groove 4 and the ball returner 3 area. It effectively overcomes the inherent defects of the traditional ball spline lubrication method and significantly improves the product's service life, working stability and maintenance-free operation.

[0022] The inner wall of the ball returner 3 is provided with a dustproof block 13. The cross-sectional shape of the dustproof block 13 corresponds to the cross-sectional shape of the guide groove 4. The dustproof block 13 is located on the side of the lubrication assembly away from the spline cylinder 1. The cross-sectional shape of the dustproof block 13 and the guide groove 4 are closely matched, effectively preventing external dust and debris from entering the ball circulation track. Its layout on the outside of the lubrication assembly forms a physical barrier, protecting the oil beads 12 and the penetration holes 11 from contamination, and preventing the lubricating oil from being diluted or deteriorated by contaminants, significantly improving the long-term reliability of the lubrication system.

[0023] The dustproof block 13 is equipped with an oil scraper 14 at one end near the lubrication assembly. The oil scraper 14 can scrape off excess lubricating oil remaining on the surface of the spline shaft 2 and guide it back to the ball circulation track or the area near the oil reservoir 8, reducing lubricant waste. At the same time, this design prevents lubricating oil from leaking outward along the spline shaft 2, avoiding contamination of surrounding equipment, and combining environmental protection with maintenance cost advantages.

[0024] The guide groove 4 is parallel to the axis of the spline shaft 2, and there are three or more sets of guide grooves 4 arranged around the axis of the spline shaft 2. The number of ball bearing circulation tracks corresponds to the number of guide grooves 4. The multiple sets of parallel guide grooves 4 and corresponding ball bearing circulation tracks ensure that the load is evenly distributed in the circumferential direction of the spline shaft 2, which greatly improves the axial torque bearing capacity and anti-eccentric load performance. The synchronous rolling of multiple tracks further reduces vibration and noise, ensuring accuracy and stability under high-speed movement.

[0025] The splined cylinder 1 has a positioning hole on its end face, and the ball returner 3 has a matching positioning protrusion at the end near the splined cylinder 1. The matching structure of the positioning hole and the protrusion ensures zero deviation in the installation position of the ball returner 3 and the splined cylinder 1. This avoids poor contact between the oil bead 12 and the guide groove 4 or misalignment of the penetration hole 11 due to misalignment, fundamentally ensuring the working effectiveness of the lubrication assembly, while simplifying the assembly process.

[0026] The side wall of the spline cylinder 1 is provided with an installation ring groove, and a positioning plane is provided in the installation ring groove. The installation ring groove provides a standardized mechanical interface, which facilitates the quick alignment and locking of the spline cylinder 1 with the equipment frame, while the positioning plane completely eliminates the risk of circumferential rotation.

[0027] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A self-lubricating ball spline, comprising a spline cylinder, a spline shaft, and a ball return device, wherein the ball return device is disposed at both ends of the spline cylinder, the spline shaft passes through the spline cylinder, a guide groove is provided on the surface of the spline shaft, a first ball groove and a second ball groove are provided inside the spline cylinder, a ball return channel is provided inside the ball return device, the first ball groove and the second ball groove are connected through the ball return channel, and the first ball groove, the second ball groove, and the ball return channel combine to form a ball circulation track, characterized in that: The ball return device is equipped with a lubrication assembly, which includes an oil storage chamber, a filling port, a pressurizing port, and a permeation hole. The filling port, pressurizing port, and permeation hole are all connected to the oil storage chamber. The filling port and pressurizing port extend to the side wall and end face of the ball return device, and the permeation hole extends to the inner wall of the ball return device. The end of the permeation hole near the inner wall of the spline cylinder is provided with a narrowing, and a rollable oil bead is provided at the narrowing. The oil bead rolls in contact with the guide groove.

2. The self-lubricating ball spline according to claim 1, characterized in that: The inner wall of the ball returner is provided with a dustproof block, the cross-sectional shape of which corresponds to the cross-sectional shape of the guide groove, and the dustproof block is located on the side of the lubrication assembly away from the spline cylinder.

3. The self-lubricating ball spline according to claim 2, characterized in that: The dustproof block is equipped with an oil scraper at one end near the lubrication component.

4. A self-lubricating ball spline according to any one of claims 1-3, characterized in that: The guide groove is parallel to the axis of the spline shaft, and there are three or more sets of guide grooves arranged around the axis of the spline shaft. The number of ball bearing circulation tracks corresponds to the number of guide grooves.

5. A self-lubricating ball spline according to any one of claims 1-3, characterized in that: The end face of the spline cylinder is provided with a positioning hole, and the end of the ball returner near the spline cylinder is provided with a matching positioning protrusion.

6. A self-lubricating ball spline according to any one of claims 1-3, characterized in that: The side wall of the splined cylinder is provided with an mounting ring groove, and a positioning plane is provided inside the mounting ring groove.

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