An internal circulation static pressure guide rail for a numerical control machine tool

Abstract

The application discloses an internal circulation static pressure guide rail for a numerical control machine tool and belongs to the technical field of ultra-precision machine tool transmission components, which comprises an integrated guide rail body, the top surface of the integrated guide rail body is provided with a rail body, the side wall of the rail body is provided with an array type pressure equalizing oil cavity, the inner part of the integrated guide rail body is provided with an oil supply main channel and a liquid return auxiliary channel in layers, an integrated sliding table is slidingly assembled above the integrated guide rail body, the sliding table is integrated with a micro high-pressure oil pump and a filter element bin, the bottom is provided with an L-shaped supporting block with a transfer oil channel, the transfer oil channel is slidingly connected to the oil supply main channel, after high-pressure oil is throttled through a porous graphite throttler, a lateral guiding oil film and a vertical bearing oil film are formed between the L-shaped supporting block and the side wall of the rail body and between the rail body and the top surface of the integrated sliding table, respectively, the application cancels an external hydraulic oil supply structure, adopts a sliding table integrated type follow-up internal circulation oil circuit, and solves the problems of complicated pipeline, large oil pressure loss and poor oil film stability of a traditional static pressure guide rail.

Description

Technical Field

[0001] This invention relates to the field of linear transmission components for machine tools, specifically an internal circulating hydrostatic guide rail for CNC machine tools. Background Technology

[0002] CNC machine tools such as ultra-precision grinding machines, coordinate measuring machines, and high-precision machining centers generally use hydrostatic guideways as linear motion components. They rely on high-pressure hydraulic oil to form a non-contact hydrostatic oil film to achieve low-friction and high-precision feed. Currently, hydrostatic guideways in the industry are mainly divided into imported external circulation hydrostatic guideways and domestically produced simple internal circulation hydrostatic guideways. High-precision hydrostatic guideways adapted to high-end ultra-precision machining equipment still rely on imports. Domestic products have obvious shortcomings in circulation efficiency and accuracy retention. Both types of products rely on throttles to adjust the oil pressure and control the oil film thickness, and are the core basic components of ultra-precision machining equipment.

[0003] Currently, mainstream hydrostatic guideways employ two technical solutions. The first is an imported external circulation hydrostatic guideway, which solves the oil circulation problem by configuring a separate hydraulic pump station outside the machine tool and laying independent external oil supply and return pipelines. High-pressure oil is delivered from the external pump station to the pressure equalization chamber between the guideway and the slide table. After the oil film is depressurized, it flows back to the pump station through external pipelines. This solution results in a bulky hydraulic system that occupies a large amount of machine tool installation space; there are many pipeline connection joints, and hydraulic oil leakage is prone to occur under long-term reciprocating vibration of the equipment; there is fluid flow resistance inside the long-distance pipeline, resulting in significant oil pressure loss during the delivery process; and oil film pressure fluctuations during high-speed feed of the slide table, leading to poor motion stability. The second is a domestically produced simplified internal circulation hydrostatic guideway, which eliminates the need for an external pump station and solves the problem by integrating the hydraulic system with the external pump station. The conventional guide rail has simple straight-hole oil supply and return channels inside its base, relying on the internal channels of the guide rail to complete oil circulation. However, it lacks an integrated oil supply and filtration unit on the slide table. This design suffers from several drawbacks: relying solely on the guide rail's internal channels for circulation, without a synchronously moving oil supply power source or filtration structure, results in low oil circulation efficiency; the straight-hole channels lack flow field guidance structures, making it prone to forming eddies and uneven oil film distribution, leading to slight swaying during slide table operation; furthermore, the lack of a bidirectional oil film, contact seal, and integrated temperature control structure exacerbates problems such as wear and leakage from contact rubber seals, impurity intrusion, heat accumulation, and thermal deformation, resulting in rapid accuracy degradation after long-term operation. Therefore, we propose an internal circulation hydrostatic guide rail for CNC machine tools. Summary of the Invention

[0004] The purpose of this invention is to provide an internal circulating hydrostatic guide rail for CNC machine tools to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an internal circulation hydrostatic guide rail for CNC machine tools, comprising an integrated guide rail body, a rail body fixed on the top surface of the integrated guide rail body, and an array of pressure equalizing oil chambers on the outer side wall of the rail body; the integrated guide rail body is provided with upper and lower arranged main oil supply channels and secondary return channels in layers; an integrated slide table is slidably mounted on the top of the integrated guide rail body, and a micro high-pressure oil pump mounting chamber and a matching filter element compartment are respectively provided at both ends of the bottom side of the integrated slide table; an oil injection port communicating with the filter element compartment is opened on the side wall of the slide table; and L-shaped pressure oil chambers that slide against the outer wall of the rail body are fixed on both sides of the bottom of the integrated slide table. The integrated slide block has a built-in transfer oil channel for the main oil supply channel, which can be slidably connected to the main oil supply channel. The main oil supply channel is connected to the equalizing oil chamber through a throttling orifice with a porous graphite throttling device. The main oil supply channel also branches upward to connect to the top surface of the track body. The high-pressure oil output by the micro high-pressure oil pump is sent to the transfer oil channel through the built-in oil supply channel of the slide. One path sprays out from the equalizing oil chamber, forming a lateral guiding oil film in the gap between the L-shaped pressure oil chamber and the side wall of the track body. The other path is sent into the transverse flow field guide groove on the bottom surface of the slide, forming a bearing static pressure oil film in the gap between the slide and the top surface of the track body. The top surface of the integrated slide is provided with a discharge hole that connects to the transverse flow field guide groove. The depressurized low-pressure oil is collected along the transverse flow field guide groove, the discharge hole, and the gap between the side wall of the L-shaped slide block. It flows into the return liquid auxiliary channel through the bottom drainage hole of the equalizing oil chamber, and then flows upward to the filter chamber for filtration through the return docking hole before being resupplying to the oil pump, forming a closed self-circulating static pressure oil circuit.

[0006] Preferably, a mover with a permanent magnet inside is installed in the middle of the bottom of the integrated slide table. A linear motor cable is connected to the mover. A stator is installed on the integrated guide rail. A coil is embedded inside the stator. After the driver inputs a variable frequency AC power, it generates a continuously moving alternating magnetic field along the length direction. The alternating magnetic field of the moving stator interacts with the permanent magnet magnetic field of the mover to generate a continuous linear traction force along the integrated guide rail.

[0007] Preferably, the integrated slide table is provided with an annular air cavity, and the side wall of the integrated slide table is provided with multiple sets of micro-slit air film channels communicating with the annular air cavity. The micro-slit air film channels are connected to an external high-pressure air source through high-pressure air nozzles. The external high-pressure air source is introduced into the annular air cavity through the high-pressure air nozzles and then sprayed out evenly through the micro-slit air film channels. At the same time, a double-layer annular non-contact sealing air curtain is formed at the outer gap of the vertically bearing oil film and the laterally guiding oil film.

[0008] Preferably, multiple micro-slit air film channels form continuous wave crests on the integrated slide.

[0009] Preferably, flow regulating valves are distributed within the micro-slit air film channels, and the flow regulating valves are used to independently regulate the sealed compressed air intake flow rate of the corresponding air film channels.

[0010] Preferably, the integrated slide table is provided with a low-temperature coolant chamber, which stores low-temperature coolant. A cooling tank is provided outside the pressure equalizing oil chamber. The cooling tank is connected to the low-temperature coolant chamber through a heat exchange tube. A miniature temperature control valve is installed at the connection between the low-temperature coolant chamber and the heat exchange tube to control the coolant flow rate. The coolant circulates in the heat exchange tube, exchanges heat with the track body, and absorbs the heat generated by the static pressure oil circulation and oil film shear. The miniature temperature control valve adjusts the coolant flow rate according to the real-time temperature of the track body to achieve precise temperature control.

[0011] Preferably, the low-temperature coolant cavity, the annular gas cavity, and the transverse flow field guide groove are distributed sequentially from top to bottom on the integrated slide.

[0012] Preferably, the integrated slide is provided with multiple through holes, which are used to assemble temperature detection probes and discharge gas trapped inside the oil passage and gas chamber, respectively.

[0013] Preferably, the integrated guide rail body has protective plates on both sides, and the two ends of the integrated guide rail body are closed.

[0014] Preferably, one side of the integrated slide table is provided with multiple circular holes for installing diaphragm feedback throttling devices. High-pressure oil enters the circular holes, and after being throttled and stabilized by the diaphragm, it is individually delivered to the pressure equalization oil chamber corresponding to the track body.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. This invention integrates a miniature high-pressure oil pump and filter element into an integrated slide, eliminating the need for a traditional external hydraulic pump station and long-distance external pipelines, significantly reducing the space occupied by the equipment and eliminating problems such as leakage at pipeline joints and oil pressure loss in long pipelines. Relying on the layered arrangement of the main oil supply channel and the secondary return channel within the integrated guide rail, it achieves local return flow, resulting in a short oil circulation path and stable oil film pressure under high-speed feed conditions. The internal circulation hydrostatic guide rail designed in this structure is a leading technology internationally, replacing imported machine tool technology.

[0017] 2. This invention features a bidirectional hydrostatic support structure with a top-mounted oil film and an L-shaped support block for lateral oil film guidance. Combined with a transverse flow field guide groove, it optimizes the oil flow field, preventing turbulent oil eddies and ensuring a uniform oil film thickness. This allows the slide to withstand both vertical loads and lateral cutting forces simultaneously, resulting in smooth slide operation without slight wobbling and significantly improved straightness accuracy. The integrated slide incorporates an annular air chamber and a wave-shaped micro-slit air film channel, forming a non-contact annular sealing air curtain that replaces traditional contact rubber seals. This eliminates friction and wear, preventing hydrostatic oil leakage and blocking external chips and dust from entering the oil chamber and throttling structure, thus extending the service life of the guide rails and throttling elements.

[0018] 3. The integrated, independently layered low-temperature coolant chamber is equipped with a micro temperature control valve to adjust the coolant flow in real time, actively absorbing the heat generated by oil film shearing and oil circuit circulation, and suppressing the thermal deformation of the track body; the three-layer medium chamber is solidly separated, and the cooling, gas sealing and oil circuit do not interfere with each other, which greatly reduces the accuracy decay under long-term ultra-precision working conditions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure after partial cross-section of the present invention;

[0021] Figure 3 This is a schematic diagram of the integrated slide table from below.

[0022] Figure 4 This is a schematic diagram of the side structure of the integrated slide table;

[0023] Figure 5 A schematic diagram of the integrated guide rail structure;

[0024] Figure 6 This is a schematic diagram of the structure after partial cross-section of the integrated guide rail body;

[0025] Figure 7 A schematic diagram of the structure at the transverse flow field guide groove in the integrated slide table;

[0026] Figure 8 This is a schematic diagram of the structure of the annular air cavity in the integrated slide table;

[0027] Figure 9 This is a schematic diagram of the structure of the low-temperature coolant cavity in the integrated slide.

[0028] In the diagram: 1. Integrated guide rail body; 2. Pressure equalizing oil chamber; 3. Rail body; 4. Main oil supply channel; 5. Secondary return channel; 6. Integrated slide table; 7. Mover; 8. Stator; 9. Circular hole; 11. Protective plate; 21. Drain hole; 22. Docking hole; 23. Cooling tank; 31. L-shaped support block; 61. Installation chamber; 62. Filter cartridge compartment; 63. Oil inlet; 64. Throttling orifice; 65. Transverse flow field guide groove; 66. Discharge hole; 67. Annular air chamber; 68. Micro-slit air film channel; 69. Low temperature coolant chamber. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a technical solution: an internal circulation hydrostatic guide rail for CNC machine tools. By integrating a miniature high-pressure oil pump and filter element into an integrated slide table 6, the traditional external circulation guide rail's external hydraulic pump station and long-distance external pipeline are eliminated, significantly reducing the equipment's space occupation and eliminating problems such as pipeline joint leakage and oil pressure loss in long pipelines. Relying on the layered arrangement of the main oil supply channel 4 and the secondary return channel 5 within the integrated guide rail body 1, local return is achieved, resulting in a short oil circulation path and stable oil film pressure under high-speed feed conditions. Compared with the hydrostatic guide rails currently used internationally, imported external circulation hydrostatic guide rails require independent external pump stations and return pipelines, resulting in a large overall system volume, high requirements for equipment installation space, and numerous pipeline connection points, which are prone to media leakage. At the same time, pipeline resistance leads to hydrostatic oil pressure loss, affecting oil film stability. This structure is a leading technology that replaces imported machine tool technology.

[0031] It includes an integrated guide rail body 1, which is the basic load-bearing component. It is made of ductile iron QT700 through integrated forging and artificial aging treatment, and has a long strip-shaped integral structure. A rail body 3 is fixed on the top surface of the integrated guide rail body 1. An array of pressure equalizing oil chambers 2 are provided on the outer wall protrusion of the rail body 3.

[0032] The integrated guide rail body 1 has a layered arrangement of an upper and lower oil supply main channel 4 and a lower return channel 5. An integrated slide table 6 is slidably mounted on top of the integrated guide rail body 1. The oil supply main channel 4 and the lower return channel 5 are independent of each other and arranged in an upper and lower layered layout inside the integrated guide rail body 1. The pressure equalization oil chambers 2 are evenly distributed on the mating surfaces of the integrated guide rail body 1 and the integrated slide table 6. Each pressure equalization oil chamber 2 is connected to the oil supply main channel 4 through a throttling orifice. The material and aging treatment of the integrated guide rail body 1 ensure its high rigidity and low deformation characteristics. The bottom two ends of the integrated slide table 6 are respectively provided with a miniature high-pressure oil pump mounting chamber 61 and a matching filter element compartment 62. The filter element compartment 62 is detachably equipped with a filter element. The oil pump suction port is connected to the filter element compartment 62 through an internal channel. An oil filling port 63 is opened on the side wall of the slide table to connect to the filter element compartment 62. The internal threads are machined and fitted with sealing plugs to achieve sealing. When the equipment is first assembled or when the oil is changed later, hydraulic oil can be directly added to the filter chamber 62 and the entire closed oil circuit through the oil filling port 63. After the filling is completed, the sealing plug is tightened to seal the entire oil circuit, forming a completely closed inner cavity and preventing external impurities from entering and oil from leaking out.

[0033] The integrated slide table 6 has L-shaped pressure oil chambers 31 fixed on both sides of its bottom, which slide against the outer wall of the track body 3. The L-shaped support block 31 has a built-in transfer oil channel that can slide and connect to the main oil supply channel 4. The transfer oil channel slides and connects to the opening of the main oil supply channel 4 on the side wall of the integrated guide rail body 1 as the integrated slide table 6 moves back and forth, realizing dynamic follow-up oil supply connection. The main oil supply channel 4 is connected to the pressure equalization oil chamber 2 through the throttling hole 64 with a porous graphite throttling device. The integrated slide table 6 has multiple circular holes 9 for installing thin film feedback throttling devices on one side. High pressure oil enters the circular holes 9, and after being throttled and stabilized by the thin film, it is individually delivered to the pressure equalization oil chamber 2 corresponding to the track body 3.

[0034] The porous graphite throttling device is a conventional hydrostatic throttling element with the characteristics of uniform pressure stabilization, microporous oil seepage, and stable pressure. It is used for primary pressure stabilization and throttling of high-pressure oil. The integrated slide 6 has a pre-reserved circular hole 9 on its side wall. The circular hole 9 can be selectively equipped with a thin-film feedback throttling device. The thin-film feedback throttling device is an existing high-precision adaptive throttling device that can adaptively adjust the oil outlet pressure according to load changes. This invention can select either single porous graphite throttling oil supply or single thin-film feedback throttling oil supply according to the processing conditions, forming a dual-throttling selective adaptation structure, which is suitable for light-load precision machining and heavy-load cutting machining scenarios respectively.

[0035] The main oil supply channel 4 also branches upwards to connect to the top surface of the track body 3; the high-pressure oil output by the micro high-pressure oil pump is sent to the transfer oil channel through the built-in oil channel of the integrated slide table 6. One path sprays out from the pressure equalization oil chamber 2, forming a lateral guiding oil film in the gap between the L-shaped pressure oil chamber 31 and the side wall of the track body 3; the other path is sent into the transverse flow field guide groove 65 on the bottom surface of the integrated slide table 6, forming a bearing static pressure oil film in the gap between the integrated slide table 6 and the top surface of the track body 3; the top surface of the integrated slide table 6 is provided with a discharge hole 66 that connects to the transverse flow field guide groove 65; the depressurized low-pressure oil is collected along the transverse flow field guide groove 65, the discharge hole 66, and the gap between the side wall of the L-shaped support block 31, and flows into the return liquid auxiliary channel 5 through the bottom drainage hole 21 of the pressure equalization oil chamber 2. Then, it flows upwards through the return docking hole 22 back to the filter chamber 62 for filtration and is then resupplyed to the oil pump, forming a closed self-circulating static pressure oil circuit.

[0036] Currently, all hydrostatic guideways and hydrostatic spindles in China use a 0.2mm capillary structure to balance hydrostatic pressure, and have extremely high requirements for oil quality, temperature control, and filtration, which often leads to problems. Ours uses 32# hydraulic oil, and the oil circuits have 5mm channels, which greatly reduces the failure rate and requirements.

[0037] This invention adopts an integrated slide table 6 with a follow-up integrated internal circulation oil circuit, completely abandoning the traditional external circulation guide rail external pump station and external pipeline structure. All oil supply, pressure stabilization, filtration, and return circulation functions are integrated inside the integrated slide table 6 and the integrated guide rail body 1, realizing a closed-loop autonomous circulation without external pipelines.

[0038] In the initial state of the equipment, the operator opens the oil inlet 63 plug and adds hydraulic oil into the filter chamber 62. The hydraulic oil fills the filter chamber 62, the inner cavity of the micro high-pressure oil pump, the oil supply channel built into the slide, the transfer oil channel of the L-shaped support block 31, the main oil supply channel 4 of the integrated guide rail body 1, the pressure equalization oil chamber 2, and the return secondary channel 5. After the filling is completed, the oil inlet 63 is sealed to completely close the entire oil circuit.

[0039] When the equipment starts working, the miniature high-pressure oil pump continuously draws clean hydraulic oil from the filter chamber 62 after high-precision filtration by the filter element. The high-pressure oil is delivered to the transfer oil channel of the L-shaped support blocks 31 on both sides through the fixed oil delivery channel inside the integrated slide table 6. During the reciprocating motion of the integrated slide table 6, the L-shaped support blocks 31 always slide against the outer wall of the track body 3, and the transfer oil channel always slides and seals with the opening of the main oil supply channel 4, realizing dynamic and uninterrupted oil supply input.

[0040] After the high-pressure oil enters the main oil supply channel 4, it is divided into two independent pressure-stabilized oil supply paths: the first path is a lateral guide oil supply branch. After the high-pressure oil is stabilized and reduced in pressure by the porous graphite throttling device inside the throttling orifice 64, it is evenly delivered to the array-type pressure equalization oil chamber 2 on the side wall of the track body 3. After the high-pressure oil is sprayed out from the pressure equalization oil chamber 2, it is evenly filled in the tiny fit gap between the inner side wall of the L-shaped support block 31 and the outer side wall of the track body 3, forming a continuous and uniform lateral static pressure guide oil film. This film supports the lateral non-contact sliding of the slide table throughout the entire process, counteracts the horizontal lateral force generated by the machine tool cutting process, and eliminates the lateral offset and slight vibration of the slide table.

[0041] The second path is a vertical bearing oil supply branch. The main oil supply channel 4 branches upward to supply oil. The high-pressure oil enters the transverse flow field guide groove 65 opened on the bottom surface of the integrated slide table 6. The transverse flow field guide groove 65 can divert, equalize, and guide the high-pressure oil, avoiding local eddies and pressure concentration of the oil. This allows the high-pressure oil to be evenly spread between the bottom surface of the integrated slide table 6 and the top surface of the track body 3, forming a highly stable vertical bearing static pressure oil film, which stably bears the vertical load of the slide table, worktable, and workpiece.

[0042] After the two high-pressure oils complete their contactless support and guidance functions, they are depressurized to form low-pressure oil. The low-pressure oil is collected and returned through multiple paths: part of the low-pressure oil is collected laterally along the transverse flow field guide groove 65, and some residual oil and gas in the cavity can be discharged and merged through the discharge hole 66 on the top surface of the integrated slide table 6 to ensure that there is no air blockage in the oil circuit and the flow field is stable; another part of the low-pressure oil flows down naturally along the gap between the L-shaped support block 31 and the side wall of the track body 3.

[0043] All the collected low-pressure oil flows vertically downwards through the drainage hole 21 at the bottom of the equalizing oil chamber 2 into the return channel 5 inside the integrated guide rail body 1. The return channel 5 is arranged along the length of the guide rail, which can collect the pressure relief oil in the working area of ​​the slide table nearby. It does not need to flow to both ends of the guide rail. After the low-pressure oil flows a short distance within the coverage area of ​​the slide table, it flows vertically upwards through the return docking hole 22 back to the filter element chamber 62. After secondary filtration and purification by the filter element, it re-enters the oil suction end of the micro high-pressure oil pump and continues to circulate, forming a completely closed, autonomous, and non-external static pressure oil circuit internal circulation system.

[0044] The integrated slide table 6 has a mover 7 with a permanent magnet inside installed in the middle of its bottom. The stator 8 is installed on the integrated guide rail 1. The stator 8 has a coil embedded inside. After the driver inputs the frequency conversion AC power, it generates a continuously moving alternating magnetic field along the length direction. The moving alternating magnetic field of the stator 8 interacts with the permanent magnet magnetic field of the mover 7 to generate a continuous linear traction force along the direction of the integrated guide rail 1. The integrated guide rail 1 has guard plates 11 on both sides, and the two ends of the integrated guide rail 1 are closed.

[0045] The linear motor mover 7, stator 8, and matching frequency conversion drive module are all existing mature drive devices. This invention mainly protects their integrated matching structure. The mover 7 with built-in permanent magnet is fixedly installed at the bottom center of the integrated slide table 6. The stator 8 with an embedded excitation coil is fixedly installed in the middle of the integrated guide rail body 1. When the equipment is feeding, the external driver supplies frequency conversion AC power to the stator 8 coil. After the stator 8 is energized, it generates a continuously moving traveling wave alternating magnetic field along the length of the guide rail.

[0046] The alternating magnetic field of the stator 8 and the permanent magnetic field of the permanent magnet inside the mover 7 are coupled to generate a continuous and stable linear traction force, which directly drives the integrated slide table 6 to perform high-precision reciprocating linear motion along the track body 3. There are no intermediate transmission gaps such as lead screws and gears. Combined with the bidirectional hydrostatic frictionless oil film support and air curtain sealing structure, the straightness and stability of the guide rail operation are further improved.

[0047] In addition, the integrated guide rail body 1 is equipped with protective plates 11 on both sides and sealed end caps at both ends, making the overall structure highly dustproof, liquidproof, and impurity-proof. The probe holes and exhaust holes reserved in the slide table can monitor the temperature in real time and promptly discharge the gas trapped in the cavity, ensuring the long-term smooth and stable oil and gas circuits.

[0048] The integrated slide table 6 is provided with an annular air cavity 67. The side wall of the integrated slide table 6 is provided with multiple sets of micro-slit air film channels 68 that communicate with the annular air cavity 67. The micro-slit air film channels 68 are connected to an external high-pressure air source through high-pressure air nozzles. The external high-pressure air source is introduced into the annular air cavity 67 through the high-pressure air nozzles and then sprayed out evenly through the micro-slit air film channels 68. At the same time, a double-layer annular non-contact sealing air curtain is formed at the outer gap of the vertically bearing oil film and the laterally guiding oil film.

[0049] Multiple micro-slit air film channels 68 form continuous wave peaks on the integrated slide 6.

[0050] The micro-slit air film channel 68 is equipped with flow regulating valves, which are used to independently regulate the sealed compressed air intake flow rate of the corresponding air film channel.

[0051] This invention abandons the traditional contact-type rubber sealing strip structure and adopts a full-circumference micro-slit air curtain non-contact sealing, which completely eliminates defects such as seal wear, oil leakage, and chip ingress.

[0052] The integrated slide table 6 has an annular air chamber 67 inside as a pressure-stabilizing air storage chamber. Multiple high-pressure air nozzles are installed on the side wall of the integrated slide table 6. The high-pressure air nozzles are connected to a factory standard high-pressure air source. The high-pressure air source is an existing general-purpose air supply equipment. The high-pressure gas enters the annular air chamber 67 through the high-pressure air nozzles to stabilize and store pressure, so that the air pressure inside the air chamber is uniform and stable.

[0053] The integrated slide table 6 and the track body 3 have continuous wavy micro-slit air film channels 68 evenly opened on the top surface and the four sides of the side oil film. Each micro-slit air film channel 68 is independently equipped with a flow regulating valve at the air inlet end. The flow regulating valve is an existing precision pressure regulating device, which can adjust the air flow and air pressure of a single air slit individually to achieve uniform air pressure distribution throughout the circumference.

[0054] The high-pressure gas, after being stabilized, is evenly and smoothly ejected through the micro-slit air film channels 68, simultaneously forming a continuous, surrounding, and non-contact double-layer annular air curtain barrier on both the outer side of the top-mounted oil film and the outer side of the lateral guide oil film. This air curtain isolates metal chips, dust, and oil contaminants generated during machine tool processing, preventing impurities from entering the oil film gaps and throttling orifices, thus preventing throttling blockage and oil contamination. Simultaneously, it forms a positive pressure air seal inward, preventing the slight leakage of the internal static pressure oil film, completely solving the problems of oil leakage, seal wear, and rapid lifespan degradation inherent in traditional guideways. The air curtain operates without any contact friction or wear, ensuring a long-term stable and reliable sealing effect.

[0055] The integrated slide 6 is equipped with a low-temperature coolant chamber 69, which stores low-temperature coolant. The outside of the equalizing oil chamber 2 is equipped with a cooling tank 23, which is connected to the low-temperature coolant chamber 69 through a heat exchange tube. A miniature temperature control valve is installed at the connection between the low-temperature coolant chamber 69 and the heat exchange tube to control the coolant flow rate. The coolant circulates in the heat exchange tube and exchanges heat with the track body 3, absorbing the heat generated by the static pressure oil circulation and oil film shear. The miniature temperature control valve adjusts the coolant flow rate according to the real-time temperature of the track body 3 to achieve precise temperature control.

[0056] The cryogenic coolant chamber 69, the annular gas chamber 67, and the transverse flow field guide groove 65 are distributed sequentially from top to bottom on the integrated slide table 6.

[0057] The cooling channel is completely isolated from the oil and air channels, and is specifically designed to absorb heat generated by oil circulation resistance and high-speed shear friction of the oil film, thus solving the problems of heat accumulation and excessive thermal deformation in traditional guide rails.

[0058] The integrated slide 6 has three independently enclosed cavities arranged from top to bottom: a low-temperature coolant cavity 69, an annular gas cavity 67, and a transverse flow field guide groove 65. The three cavities are completely isolated by solid partitions, and the media do not cross-flow or interfere with each other, ensuring that the cooling system, sealing gas system, and static pressure oil circuit system work independently and stably.

[0059] The cryogenic coolant chamber 69 stores cryogenic coolant. The cryogenic coolant chamber 69 is connected to the cooling tank 23 in a closed loop through an external heat exchange pipeline. A miniature temperature control valve is installed at the port of the heat exchange pipeline. The miniature temperature control valve and the temperature detection probe are both existing mature temperature control devices. During operation, the temperature detection probe collects the real-time temperature signal of the track body 3 and feeds the temperature signal back to the miniature temperature control valve.

[0060] When the track body 3 experiences a temperature rise due to oil film shearing and oil circuit circulation, the micro temperature control valve automatically adjusts the coolant circulation flow rate according to the real-time temperature difference: the higher the temperature, the larger the coolant flow opening and the faster the circulation speed, resulting in higher heat exchange efficiency; when the temperature is stable, a small constant flow rate is maintained for heat preservation, and the low-temperature coolant continuously circulates in a closed loop between the low-temperature coolant chamber 69, the heat exchange pipeline, and the cooling tank 23. When the coolant flows through the cooling tank 23, it fully contacts and exchanges heat with the high-temperature track body 3, quickly removing the heat accumulated in the track body 3. After the heat exchange and temperature rise, the coolant flows back to the low-temperature coolant chamber 69 to cool down and store cold again. This continuous circulation achieves constant temperature control of the track body throughout the process, significantly suppressing the thermal deformation of the guide rail and ensuring long-term stability of linear accuracy under ultra-precision machining conditions.

[0061] Multiple through holes are provided on the integrated slide 6. These through holes are used to assemble temperature detection probes and to discharge gas trapped inside the oil passage and gas chamber.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An internal circulating hydrostatic guide rail for CNC machine tools, comprising an integral guide rail body (1), characterized in that: The top surface of the integrated guide rail body (1) is fixed with a rail body (3), and the outer side wall protrusion of the rail body (3) is provided with an array of pressure equalization oil chambers (2). The integrated guide rail body (1) is provided with an upper and lower oil supply main channel (4) and a return secondary channel (5) arranged in layers; the integrated guide rail body (1) is slidably assembled with an integrated slide table (6) on the top. The bottom two ends of the integrated slide table (6) are respectively provided with a micro high pressure oil pump installation chamber (61) and a matching filter element chamber (62). The side wall of the slide table is opened with an oil inlet (63) that connects to the filter element chamber (62). The bottom two sides of the integrated slide table (6) are fixed with L-shaped pressure oil chambers (31) that slide against the outer wall of the rail body (3). The L-shaped support block (31) has a built-in transfer oil channel that can slide and connect to the oil supply main channel (4); The main oil supply channel (4) is connected to the pressure equalization oil chamber (2) through the throttling hole (64) with a porous graphite throttling device. The main oil supply channel (4) is also branched upward to connect to the top surface of the track body (3). The high-pressure oil output by the micro high-pressure oil pump is sent to the transfer oil channel through the built-in oil channel of the slide table. One path is sprayed out from the pressure equalization oil chamber (2) and forms a lateral guiding oil film in the gap between the L-shaped pressure oil chamber (31) and the side wall of the track body (3). The other path is sent into the transverse flow field guide groove (65) on the bottom surface of the slide table and forms a bearing static pressure oil film in the gap between the slide table and the top surface of the track body (3). The top surface of the integrated slide (6) is provided with a discharge hole (66) that connects to the transverse flow field guide groove (65); the low-pressure oil is collected along the transverse flow field guide groove (65), the discharge hole (66), and the gap between the side wall of the L-shaped support block, and flows into the return liquid secondary channel (5) through the diversion hole (21) set at the bottom of the pressure equalization oil chamber (2), and then flows back upward to the filter element chamber (62) through the return docking hole (22) set on the pressure equalization oil chamber (2) for filtration and then resupply to the oil pump, forming a closed self-circulating static pressure oil circuit.

2. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 1, characterized in that: The bottom center of the integrated slide (6) is equipped with a mover (7) with a permanent magnet inside. A linear motor cable (71) is connected to the mover (7). A stator (8) is installed on the integrated guide rail (1). A coil is embedded inside the stator (8). After the driver inputs the frequency conversion AC power, it generates a continuously moving alternating magnetic field along the length direction. The moving alternating magnetic field of the stator (8) interacts with the permanent magnet magnetic field of the mover (7) to generate a continuous linear traction force along the direction of the integrated guide rail (1).

3. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 1, characterized in that: The integrated slide (6) is provided with an annular air chamber (67). The side wall of the integrated slide (6) is provided with multiple sets of micro-slit air film channels (68) that communicate with the annular air chamber (67). The micro-slit air film channels (68) are connected to an external high-pressure air source through high-pressure air nozzles. The external high-pressure air source is introduced into the annular air chamber (67) through the high-pressure air nozzles and then sprayed out evenly through the micro-slit air film channels (68). At the same time, a double-layer annular non-contact sealing air curtain is formed at the outer gap of the vertically bearing oil film and the laterally guiding oil film.

4. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 3, characterized in that: Multiple micro-slit air film channels (68) form continuous peaks on the integrated slide (6).

5. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 4, characterized in that: A flow regulating valve is distributed inside the micro-slit air film channel (68). The flow regulating valve is used to independently regulate the sealed compressed air intake flow rate of the corresponding air film channel.

6. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 4, characterized in that: The integrated slide (6) is provided with a low-temperature coolant chamber (69) which stores low-temperature coolant. The outside of the equalizing oil chamber (2) is provided with a cooling tank (23). The cooling tank (23) is connected to the low-temperature coolant chamber (69) through a heat exchange tube. A miniature temperature control valve is installed at the connection between the low-temperature coolant chamber (69) and the heat exchange tube to control the coolant flow rate. The coolant circulates in the heat exchange tube and exchanges heat with the track body (3), absorbing the heat generated by the static pressure oil circulation and oil film shear. The miniature temperature control valve adjusts the coolant flow rate according to the real-time temperature of the track body (3) to achieve precise temperature control.

7. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 6, characterized in that: The low-temperature coolant chamber (69), the annular gas chamber (67), and the transverse flow field guide groove (65) are distributed sequentially from top to bottom on the integrated slide (6).

8. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 1, characterized in that: The integrated slide (6) is provided with multiple through holes, which are used to assemble temperature detection probes and discharge oil and gas trapped inside the gas chamber.

9. The internal circulating hydrostatic guide rail for CNC machine tools according to claim 1, characterized in that: The integrated guide rail body (1) has guard plates (11) on both sides, and the two ends of the integrated guide rail body (1) are closed.

10. An internal circulating hydrostatic guide rail for CNC machine tools according to claim 1, characterized in that: The integrated slide (6) has multiple circular holes (9) on one side for installing diaphragm feedback throttling devices. High-pressure oil enters the circular holes (9), and after being throttled and stabilized by the diaphragm, it is separately delivered to the equalizing oil chamber (2) corresponding to the track body (3).

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