Oil cooling lubrication ball return pipe structure

Abstract

The invention discloses an oil cooling lubrication ball return pipe structure, a sleeve is sleeved on the outer side of a ball return pipe, the end part of the sleeve and the outer wall of the ball return pipe are sealed, a lubricating oil cavity is formed between the inner wall of the sleeve and the outer wall of the ball return pipe, and a lubrication cooling oil hole is formed in a ball return pipe section in the lubricating oil cavity. The lubricating and cooling oil hole is a through hole; and the sleeve is provided with an oil inlet hole and an oil outlet hole which are communicated with the lubricating oil cavity. According to the invention, the outer side of the ball return pipe is sleeved with the sleeve to form the sealed lubricating oil cavity, the ball return pipe is provided with the lubricating cooling oil hole, and the sleeve is provided with the oil inlet hole and the oil outlet hole, so that lubricating oil directly and uniformly lubricates each steel ball and circularly takes away heat; therefore, the problem that in the prior art, a ball screw pair cannot achieve uniform lubrication and constant temperature at the same time is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of return bead pipes, and particularly relates to an oil-cooled lubrication return bead pipe structure. BACKGROUND

[0002] With the increasing popularity of ball screw pairs in high-speed and high-load applications, the requirements for speed and load are continuously improved, resulting in increasingly serious heating problems during operation. High temperature can cause the viscosity of lubricating oil to decrease sharply, making it difficult to form an oil film with sufficient thickness, and at the same time causing the lubricating oil to oxidize, decompose and coke, generating acidic substances and particles, and aggravating the wear of components. In addition, high temperature also causes thermal stress of the ball screw, ball nut and steel ball, changes the original design clearance of the ball screw pair, and causes the pre-tightening force to surge or the local stress to concentrate. Under extreme conditions, high temperature above 150 DEG C can even cause the steel ball, ball screw raceway and ball nut raceway to over-temper, resulting in a decrease in material hardness and deterioration of microstructure, accelerating fatigue wear and seriously affecting the service life. In actual working conditions, the speed and load of the ball screw pair often change in real time, and ordinary lubrication methods cannot ensure uniform lubrication of each steel ball and cannot keep the ball screw pair operating within a constant temperature range. Therefore, the existing technology urgently needs a new lubrication method to effectively control the temperature of the lubricated ball screw pair and achieve the comprehensive effect of uniform lubrication and constant temperature. SUMMARY

[0003] The technical problem to be solved by the application is to provide an oil-cooled lubrication return bead pipe structure to solve the problem that the ball screw pair cannot simultaneously achieve uniform lubrication and constant temperature in the prior art.

[0004] To solve the above technical problems, the application adopts the technical scheme of an oil-cooled lubrication return bead pipe structure, a sleeve pipe is sleeved outside the return bead pipe, the end of the sleeve pipe and the outer wall of the return bead pipe are sealed, the inner wall of the sleeve pipe and the outer wall of the return bead pipe constitute a lubricating oil cavity, a lubricating cooling oil hole is formed in the return bead pipe segment in the lubricating oil cavity, and the lubricating cooling oil hole is a through hole; the sleeve pipe has an oil inlet hole and an oil outlet hole communicating with the lubricating oil cavity.

[0005] The oil-cooled lubrication return bead pipe structure has a plurality of lubricating cooling oil holes, and the plurality of lubricating cooling oil holes are uniformly distributed on the return bead pipe segment. The oil-cooled lubrication return bead pipe structure is integrally formed by the return bead pipe and the sleeve pipe.

[0006] In the above-mentioned oil-cooled lubrication return tube structure, the oil inlet and oil outlet are connected to an external oil cooling circulation pipeline.

[0007] The above-mentioned oil-cooled lubrication return ball tube structure also includes a connecting seat. The sleeve is installed on the connecting seat and provides support for the return ball tube. The connecting seat is equipped with a sensor for monitoring the temperature of the ball nut. Compared with the prior art, the present invention has the following advantages: The oil-cooled lubrication return ball tube structure of the present invention forms a lubricating oil cavity by sleeve and sealing the outside of the return ball tube. In conjunction with the lubricating cooling oil hole (through hole) located on the return ball tube section inside the lubricating oil cavity, as well as the oil inlet and oil outlet holes on the sleeve, the closed-loop circulation of lubricating oil is realized. This structure allows the lubricating oil injected into the lubricating oil cavity through the oil inlet hole to directly enter the interior of the return ball tube through the lubricating cooling oil hole, thereby uniformly and fully covering each steel ball. This solves the problem that ordinary lubrication methods in the prior art cannot uniformly lubricate the steel balls, ensuring the comprehensiveness and consistency of lubrication, and effectively preventing local wear and oil film rupture caused by uneven lubrication. Meanwhile, the circulating lubricating oil continuously carries away the heat generated during the operation of the ball screw assembly and discharges it through the oil outlet, achieving active temperature control of the ball screw assembly and keeping it within a constant range. This avoids the hazards caused by high temperatures, such as decreased lubricating oil viscosity, oxidation and coking, as well as thermal stress concentration, clearance changes, and increased preload in components. It significantly improves the heat dissipation performance and thermal stability of the ball screw assembly, extending its service life. Furthermore, this structure, through continuous oil supply and heat dissipation, suppresses the deterioration of lubricating oil performance and the risk of material over-tempering. Overall, it achieves synergistic optimization of lubrication and cooling, meeting the dual requirements of uniform lubrication and constant temperature under high-speed, high-load conditions.

[0008] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0009] Figure 1 This is a structural diagram of a ball screw assembly.

[0010] Figure 2 for Figure 1 The P-direction view.

[0011] Figure 3 Schematic diagram of the bead return tube structure Figure 1 .

[0012] Figure 4 for Figure 3 AA sectional view.

[0013] Figure 5 Schematic diagram of the bead return tube structure Figure 2 .

[0014] Explanation of reference numerals in the attached figures: Detailed Implementation

[0015] like Figures 1-5 As shown, an oil-cooled lubrication return tube structure is provided. A sleeve is fitted on the outside of the return tube 3. The end of the sleeve is sealed to the outer wall of the return tube 3. The inner wall of the sleeve and the outer wall of the return tube 3 form a lubricating oil cavity 303. A lubricating and cooling oil hole 304 is provided on the return tube 3 segment located in the lubricating oil cavity 303. The lubricating and cooling oil hole 304 is a through hole. The sleeve has an oil inlet hole 301 and an oil outlet hole 302 that communicate with the lubricating oil cavity 303.

[0016] It should be noted that in the ball screw 1 system of a CNC machine tool, the return tube 3 is used to guide the cyclic movement of the steel balls 6. The return tube 3 is mounted on the ball nut 2, which is fitted onto the ball screw 1. The return tube 3 is typically made of high-strength steel, with a sleeve fitted on its outer side. The sleeve material can be selected from copper alloy or stainless steel to ensure good thermal conductivity and corrosion resistance. The end of the sleeve is sealed to the outer wall of the return tube 3 by welding or O-ring sealing to ensure no leakage. The sleeve can also be integrally machined with the return tube 3, such as by using 3D printing technology. This sealing structure creates a closed lubricating oil cavity 303 between the inner wall of the sleeve and the outer wall of the return tube 3. The dimensions of the lubricating oil cavity 303 need to be designed according to the diameter and length of the return tube 3. For example, in typical machine tool applications, the gap width of the oil cavity is approximately 2-5 mm to accommodate sufficient lubricating oil.

[0017] Lubricating and cooling oil holes 304 need to be provided on the return bead tube 3 section located within the lubricating oil chamber 303. These oil holes are through holes, and their diameter is designed according to the oil flow requirements, for example, 1-2 mm in diameter. The through holes allow lubricating oil to directly penetrate from the oil chamber into the interior of the return bead tube 3. Simultaneously, an oil inlet hole 301 and an oil outlet hole 302 are machined on the sleeve. The oil inlet hole 301 is located at one end of the sleeve for connecting to an external oil pump, while the oil outlet hole 302 is located at the other end for oil return. The diameters of the oil inlet hole 301 and the oil outlet hole 302 are typically matched to the oil pipe, for example, using a standard M10 threaded interface.

[0018] In practical application, when the ball screw 1 is running, an external oil pump injects lubricating oil into the lubrication chamber 303 through the oil inlet 301. The lubricating oil flows within the chamber and enters the return ball tube 3 through the lubrication and cooling oil hole 304, directly contacting the steel balls 6 and the steel ball channel 305. During its flow, the lubricating oil absorbs the heat generated by friction and lubricates the steel balls 6, reducing wear. Then, the heated lubricating oil is discharged from the oil outlet 302, returning to the external cooling system for cooling and filtration, achieving recycling. This design utilizes the fluidity and specific heat capacity of the oil to achieve continuous cooling and lubrication of the return ball tube 3.

[0019] For example, in the X-axis transmission of a CNC machine tool, the ball return tube 3 is installed below the ball nut 2. ISO VG32 hydraulic oil is used for lubrication and is injected at a constant flow rate through the oil inlet 301. The oil is evenly distributed within the oil chamber and penetrates into the steel ball channel 305 of the ball return tube 3 via the lubrication and cooling oil hole 304. In high-speed motion scenarios, the heat generated by the steel ball 6 is rapidly carried away by the oil, and the oil temperature at the oil outlet 302 is significantly reduced. This oil-cooled lubricated ball return tube 3 structure achieves effective temperature control and friction reduction for the ball screw 1, thereby improving transmission accuracy and component lifespan.

[0020] The design of the sealed oil chamber and through-hole enables active cooling and uniform lubrication of the return bead tube 3, avoiding localized overheating and dry friction problems. Simultaneously, the circulating oil circuit achieves efficient energy utilization and reduced maintenance costs.

[0021] In one embodiment, there are multiple lubrication and cooling oil holes 304, which are evenly distributed on the return bead tube 3 segment. To achieve this feature, precision machining is first required on the lubrication chamber 303 covering segment of the return ball tube 3. For example, multiple through holes can be evenly arranged circumferentially and axially on the wall of the return ball tube 3 using a CNC drilling machine or laser drilling machine, or holes can be directly formed using 3D printing technology. The number and spacing of the holes need to be designed according to the size of the return ball tube 3 and lubrication requirements. For example, in typical applications, multiple rows of holes may be opened on the return ball tube 3 segment, evenly arranged circumferentially, with each row containing 8-12 holes and equal spacing to ensure uniform oil distribution. The evenly distributed oil holes allow lubricating oil to simultaneously penetrate from the lubrication chamber 303 to multiple points inside the steel ball channel 305 of the return ball tube 3, thereby achieving complete coverage of the steel ball 6 and the raceway. In the ball screw system of a CNC machine tool, after lubricating oil is injected through the oil inlet 301, the oil flows into the return ball tube 3 through multiple uniformly distributed oil holes. For example, during high-speed motion, the steel balls 6 can obtain timely lubrication and cooling as they pass through each oil hole area. This uniformly distributed design achieves balanced cooling and lubrication, avoiding local overheating or oil stagnation, thereby improving transmission smoothness and component life.

[0022] In one embodiment, the return tube 3 and the sleeve are integrally formed.

[0023] In practice, injection molding or 3D printing technology can be used to produce the ball return tube 3 and the sleeve as a single component. For example, using metal injection molding technology, stainless steel powder is mixed with a binder and injected into a mold, then sintered at high temperature to form a one-piece structure. During processing, the mold design must ensure precise clearance between the ball return tube 3 and the sleeve to form the lubricating oil cavity 303. Simultaneously, the end sealing portion is formed in one step through the mold, eliminating the need for additional assembly. One-piece molding eliminates interface problems in traditional assembly, utilizing material continuity to enhance structural strength and sealing performance. In CNC machine tool applications, this one-piece ball return tube 3 structure is easy to install; for example, when assembling the ball screw 1, it can be directly fixed in the designated position, avoiding the leakage risks that may arise from welding or sealing rings. Through the one-piece molding process, manufacturing efficiency is improved and leakage risks are reduced, thereby enhancing system reliability and maintenance convenience.

[0024] In one embodiment, the oil inlet 301 and the oil outlet 302 are connected to an external oil cooling circulation pipeline.

[0025] In practice, standard interfaces, such as threaded connectors or quick-connect fittings, need to be installed at the oil inlet 301 and oil outlet 302 on the sleeve, and then connected to the external oil circuit system. The oil cooling circulation pipeline typically includes an oil pump, cooler, filter, and oil reservoir. For example, a gear pump is used to pump lubricating oil from the reservoir into the oil inlet 301. After passing through the return bead tube 3, the oil returns from the oil outlet 302, flows through the plate cooler for heat dissipation, and then passes through the filter to remove impurities, completing the circulation. The circulation pipeline utilizes the flow of oil to achieve continuous cooling and purification, with oil temperature and quality controlled by external equipment. For example, during long-term operation, the oil pump supplies oil at a constant flow rate, and the cooler maintains the oil temperature below 50°C. Through the external circulation pipeline, automatic regeneration and temperature control of the lubricating oil are achieved, thereby improving energy efficiency and system stability, and reducing downtime for maintenance.

[0026] In one embodiment, a connecting seat is also included, on which the sleeve is mounted and provides support for the return ball tube 3, and a sensor 4 for monitoring the temperature of the ball nut 2 is provided on the connecting seat. In implementation, a connector, typically made of aluminum alloy or cast iron, is first designed. Its structure includes mounting holes and a support surface for fixing the sleeve and supporting the return ball tube 3. The connector is mounted on the ball nut 2 with screws 5, ensuring alignment between the return ball tube 3 and the ball nut 2. A temperature sensor 4, either a thermocouple or an infrared sensor, is embedded in the connector near the ball nut 2 and connected to the control unit via wires. For example, the sensor 4 monitors the temperature of the ball nut 2 in real time, transmitting the data to the PLC system. The connector provides mechanical stability, while the sensor 4 monitors the temperature and prevents overheating through feedback control. During operation, if the temperature exceeds a set threshold, the system automatically adjusts the lubricating oil flow or changes the movement speed. Through the integration of the connector and sensor 4, real-time early warning and proactive protection of the ball nut 2's temperature are achieved, thus avoiding overheating damage and improving safety and operational intelligence.

[0027] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A structure for an oil-cooled lubricating return bead tube, characterized in that, A sleeve is fitted around the outside of the return tube. The end of the sleeve is sealed to the outer wall of the return tube. The inner wall of the sleeve and the outer wall of the return tube form a lubricating oil cavity. A lubricating and cooling oil hole is provided on the return tube segment located in the lubricating oil cavity. The lubricating and cooling oil hole is a through hole. The sleeve has an oil inlet hole and an oil outlet hole that connect to the lubricating oil cavity.

2. The oil-cooled lubrication return ball tube structure according to claim 1, characterized in that, The lubricating and cooling oil holes are multiple and are evenly distributed on the return pipe section.

3. The oil-cooled lubrication return ball tube structure according to claim 1, characterized in that, The return tube and the sleeve are integrally formed.

4. The oil-cooled lubrication return ball tube structure according to claim 1, characterized in that, The oil inlet and outlet are connected to an external oil cooling circulation pipeline.

5. The oil-cooled lubrication return ball tube structure according to claim 1, characterized in that, It also includes a connecting seat, on which the sleeve is mounted and provides support for the return ball tube, and the connecting seat is provided with a sensor for monitoring the temperature of the ball nut.

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