A fixed beam numerical control milling machine feeding system

Abstract

The present application relates to the technical field of feeding system, especially to a fixed beam numerical control milling machine feeding system, which comprises a connecting arm, a ball nut, a ball screw, an oil shell, a lower filter cartridge, an upper filter cartridge, a pump shell and a motor, the ball screw is rotatably installed in the oil shell, the ball nut is sleeved on the outer side of the ball screw, the lower filter cartridge and the upper filter cartridge are arranged below the oil shell, a flow guide hopper is arranged at the lower end of the oil shell, the pump shell is arranged at one side of the lower end of the pump shell, the pump shaft is rotatably installed in the pump shell, the impeller is sleeved on the outer wall of the pump shaft, the filter element is arranged in the upper filter cartridge and the lower filter cartridge, and the motor is arranged at one side of the oil shell. The lubricating oil circulation filtering system and the oil shell for soaking lubricating oil in the lower end of the ball nut can solve the problems of long downtime, short maintenance period and inconvenient injection of lubricant during the maintenance process, and can avoid reducing the service life of the ball nut due to the grinding paste effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feeding system, and particularly relates to a fixed beam numerical control milling machine feeding system. BACKGROUND

[0002] The fixed beam numerical control milling machine belongs to a kind of numerical control machine tool, and is opposite to dynamic beam type, and its cross beam is fixed, and worktable moves in the machining process. This structure is suitable for processing large or heavy workpieces, because the fixed beam structure is more stable, and the rigidity is better, and it is suitable for high-precision machining. The fixed beam numerical control milling machine includes bed, cross beam, worktable, spindle system, numerical control system, feeding system and the like. The bed is a basic support, the cross beam is fixed, the worktable moves on the bed, the spindle is responsible for cutting movement, and the numerical control system controls the movement and processing parameters of each shaft.

[0003] The feeding system is the core of the numerical control milling machine to realize accurate movement. The numerical control system generates X / Y / Z axis movement instructions according to the program. The servo motor receives the numerical control system instructions. The servo motor receives the pulse signal. The ball screw is driven to rotate. The ball screw cooperates with the ball nut to convert the rotary motion into linear motion, and pushes the worktable or spindle to move along the guide rail.

[0004] In the process of using ball screw and ball nut together, the ball screw realizes movement by rolling steel balls between the screw and the nut. In this way, the friction is small, the efficiency is high, and the internal structural parts include screw, nut, steel ball, return pipe and the like. There is a necessary gap between the ball screw and the nut. Dust or foreign matter can enter the raceway. The traditional solution is to set a rubber or polyurethane sealing ring at the opening of the ball nut to directly adhere to the surface of the screw, block large particles of pollutants, and regularly inject lubricating grease or lubricating oil through the oil injection hole to reduce the friction between the steel ball and the raceway and reduce the temperature rise. Ball screw and ball nut are used in the feeding system of the fixed beam numerical control milling machine. In the high-frequency and heavy-load processing environment, at least 1 lubrication maintenance is required every month. The dusty environment will shorten the maintenance period. During the maintenance process, the ball nut is exposed to the outside world by disassembling the equipment structure. The lubricant is injected through the oil injection hole, which consumes time and is inconvenient to operate, prolongs the downtime, and during the use of the feeding system, dust adsorbs the lubricating grease, forms a grinding paste effect, accelerates wear and tear, and reduces the service life of the ball nut. Therefore, the skilled person in the art provides a fixed beam numerical control milling machine feeding system to solve the problems raised in the background art. SUMMARY

[0005] The purpose of the present application is to solve the problem of the service life of the ball nut in the background art, that is, the dust adsorbs the lubricating grease, forms a grinding paste effect, accelerates wear and tear, and reduces the service life of the ball nut.

[0006] In order to achieve the above object, the present application provides the following technical scheme: A fixed beam numerical control milling machine feeding system, comprising a connecting arm, a ball nut, a ball screw, an oil shell, a lower filter cylinder, an upper filter cylinder, a pump shell and a motor, the ball screw is rotatably installed in the oil shell, the ball nut is sleeved on the outer side of the ball screw, the lower filter cylinder and the upper filter cylinder are arranged below the oil shell and are in butt joint with each other, a flow guide hopper is arranged at the lower end of the oil shell, a pump shell is arranged at one side of the lower end of the pump shell, a pump shaft is rotatably installed in the pump shell, an impeller rotatably installed in the pump shell is sleeved on the outer wall of the pump shaft, filter elements are arranged in the upper filter cylinder and the lower filter cylinder, a suction pipe is in communication between the suction end of the pump shell and the lower filter cylinder, a connecting pipe is in communication between the upper filter cylinder and the flow guide hopper, a conveying pipe is arranged at the output end of the pump shell and located in one end of the oil shell, the motor is arranged at one side of the oil shell, a drive gear is arranged at the output end of the motor, a driven gear one engaged with the drive gear is arranged at one end of the ball screw, and a driven gear two engaged with the drive gear is sleeved on the outer wall of the pump shaft.

[0007] Preferably, the number of teeth of the drive gear is the same as that of the driven gear one, and the number of teeth of the driven gear two is less than that of the drive gear. When the drive gear rotates, the driven gear one and the driven gear two are pushed, driving the rotation of the ball screw and the pump shaft, and the pump shaft is accelerated.

[0008] Preferably, the inner wall of the lower end of the oil shell is provided with oppositely distributed flow guide chutes, and the height of the flow guide chute gradually decreases from the two sides to the center. The flow guide chute makes the lubricating oil in the oil shell flow to the center of the oil shell, facilitating the collection of lubricating oil into the flow guide hopper.

[0009] Preferably, one end of the conveying pipe is open and the output direction is backward and horizontally distributed. The conveying pipe outputs the filtered lubricating oil, which pushes the lubricating oil in the oil shell, facilitating the flow of the lubricating oil in the oil shell, and the lubricating oil in the ball nut flows easily, thereby carrying out the dust or foreign matter that may enter.

[0010] Preferably, the side cross-sectional view of the filter element is in a serpentine distribution, and the shape of the filter element is in a tubular shape with two groups of sleeves connected to each other. The surface area of the filter element is increased, thereby improving the filtering effect of the lubricating oil.

[0011] Preferably, a spiral rolling groove in a spiral distribution is formed in the inner part of the ball nut, a ball return pipe in communication with the spiral rolling groove is embedded and installed in the inner part of the upper end of the ball nut, and a steel ball is rotatably installed in the inner part of the ball return pipe and the spiral rolling groove. The spiral rolling groove is matched with the ball screw, facilitating the flow of the steel ball, and the steel ball in the ball nut circulates and rolls through the ball return pipe.

[0012] Preferably, the upper end of the ball nut is internally provided with a pressing groove communicated with the ball return pipe, the pressing groove is internally provided with a gland, screw holes are formed in the gland and the ball nut, screws are installed in the screw holes, and dustproof rings are arranged on both ends of the ball nut and slidably sleeved with the outer wall of the ball screw. The gland is used for replacing the steel balls in the spiral groove, the gland is used for closing the pressing groove, the screw thread is installed in the gland and the ball nut, the gland is fixed, and the dustproof ring is used for intercepting large metal debris or foreign matters.

[0013] Preferably, the outer wall of the ball nut is provided with symmetrically distributed connecting arms, the upper ends of the connecting arms are provided with oppositely distributed supports, and the supports are internally provided with mounting holes. The supports are connected with the moving frame or the moving platform in the feeding system of the numerical control milling machine, and the mounting holes are used for mounting parts.

[0014] Preferably, the lower end of the connecting arm is provided with a sliding block, the outer side of the sliding block is sleeved with a guide rail, the inner sides of both ends of the lower end of the sliding block are internally provided with straight-line rolling grooves, and the lower end and the inner sides of both ends of the guide rail are internally and rotatably provided with rolling balls which are equidistantly distributed and rollingly installed in the straight-line rolling grooves. The sliding block is slidingly installed through the guide rail, the rolling balls roll in the straight-line rolling grooves, the sliding property of the sliding block is improved, and the abrasion of the sliding part during movement is reduced.

[0015] Preferably, the inner walls of the upper filter cartridge and the lower filter cartridge are provided with support rings abutting the upper and lower ends of the filter element, the outer walls of the upper filter cartridge and the lower filter cartridge are provided with abutting annular abutting rings, and the abutting rings are fixed through bolts. The support rings are used for pressing the upper and lower ends of the filter element in the upper filter cartridge and the lower filter cartridge after abutting, so that the lubricating oil in the upper filter cartridge does not directly enter the lower filter cartridge through the filter element, and the upper filter cartridge and the lower filter cartridge are fixed together through the rotation of the bolts in the abutting rings after abutting.

[0016] Compared with the prior art, the ball nut has the following beneficial effects:

[0017] The two ends of the ball nut are slidingly arranged in the guide rail through the sliding blocks, straight-line sliding guidance is achieved, the rotating force of the ball screw is converted into the rolling of the steel balls, the ball nut moves linearly, the feeding system of the numerical control milling machine is used, the lower end of the ball nut is immersed in the liquid lubricating oil in the oil shell, the steel balls are lubricated when contacting the lubricating oil, and the abrasion is reduced.

[0018] Meanwhile, when the screw rod rotates, the lubricating oil inside the oil shell circulates in the filter assembly and the inside of the oil shell through the linkage structure, the lubricating oil passing through the filter assembly is filtered, the internal dust and other foreign matters are stripped, the discharge of the dust and foreign matters inside the power-assisted ball nut is assisted during the flow of the lubricating oil, and the discharge is intercepted through the filter element, the use of the ball screw automatically drives the use of the lubricating oil circulation filtering system, the short-term maintenance of the fixed beam numerical control milling machine feeding system is avoided, the fixed beam numerical control milling machine feeding system maintenance cycle is measured by years, and only the hydraulic oil needs to be replaced, without disassembling the ball nut, the use convenience is significantly improved, and the service life of the ball nut is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a top view stereoscopic structure schematic diagram of the application;

[0020] Figure 2 It is a bottom view stereoscopic structure schematic diagram of the application;

[0021] Figure 3 It is a side view stereoscopic structure schematic diagram of the oil shell of the application;

[0022] Figure 4 It is a side view stereoscopic structure schematic diagram of the upper filter cartridge and the lower filter cartridge of the application;

[0023] Figure 5 It is a top view stereoscopic structure schematic diagram of the oil shell of the application;

[0024] Figure 6 It is a side view stereoscopic structure schematic diagram of the driving gear of the application;

[0025] Figure 7 It is a side view stereoscopic structure schematic diagram of the impeller of the application;

[0026] Figure 8 It is a side view stereoscopic structure schematic diagram of the pump shell of the application;

[0027] Figure 9 It is a main sectional view stereoscopic structure schematic diagram of the upper filter cartridge and the lower filter cartridge of the application;

[0028] Figure 10 It is a main view stereoscopic structure schematic diagram of the ball nut of the application;

[0029] Figure 11 It is a main sectional view stereoscopic structure schematic diagram of the ball return pipe of the application;

[0030] Figure 12 It is a bottom view stereoscopic structure schematic diagram of the sliding block of the application;

[0031] Figure 13 It is a main sectional view stereoscopic structure schematic diagram of the filter element of the application;

[0032] Figure 14 This is a side-view perspective three-dimensional structural diagram showing the distribution of steel balls inside the ball nut according to the present invention;

[0033] Figure 15 This is a side-view three-dimensional structural diagram of the rolling trajectory of the steel ball inside the ball nut according to the present invention.

[0034] Reference numerals: 1. Bracket; 2. Connecting arm; 3. Ball nut; 4. Ball screw; 5. Oil tank; 6. Guide rail; 7. Lower filter cartridge; 8. Upper filter cartridge; 9. Guide hopper; 10. Pump casing; 11. Suction pipe; 12. Connecting pipe; 13. Conveying pipe; 14. Guide chute; 15. Motor; 16. Drive gear; 17. Driven gear one; 18. Driven gear two; 19. Pump shaft; 20. Impeller; 21. Slider; 22. Linear groove; 23. Ball; 24. Connecting ring; 25. Filter element; 26. Support ring; 27. Pressure cap; 28. Return ball tube; 29. ​​Dustproof ring; 30. Pressure groove; 31. Screw hole; 32. Steel ball; 33. Spiral groove. Detailed Implementation

[0035] 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.

[0036] Please see Figures 1 to 15 The present invention provides three embodiments:

[0037] Example 1:

[0038] A feed system for a fixed-beam CNC milling machine includes a connecting arm 2, a ball nut 3, a ball screw 4, an oil tank 5, a lower filter cylinder 7, an upper filter cylinder 8, a pump housing 10, and a motor 15. The ball screw 4 is rotatably mounted inside the oil tank 5, and the ball nut 3 is sleeved on the outside of the ball screw 4. The lower filter cylinder 7 and the upper filter cylinder 8 are arranged below the oil tank 5 and are connected to each other. A guide bucket 9 is arranged at the lower end of the oil tank 5. The motor 15 is arranged on one side of the oil tank 5. A drive gear 16 is arranged at the output end of the motor 15. A driven gear 17 that meshes with the drive gear 16 is arranged at one end of the ball screw 4.

[0039] The number of teeth on the drive gear 16 and the driven gear 17 is the same.

[0040] The ball nut 3 has a spiral groove 33 distributed in a spiral pattern inside. The upper end of the ball nut 3 is embedded with a return ball tube 28 that communicates with the spiral groove 33. Steel balls 32 are rolled inside the return ball tube 28 and the spiral groove 33.

[0041] The upper end of the ball nut 3 is internally provided with a pressing groove 30 communicated with the ball returning pipe 28, the pressing groove 30 is internally provided with a pressing cover 27, the pressing cover 27 and the ball nut 3 are internally provided with screw holes 31, the screw holes 31 are internally provided with screws, the two ends of the ball nut 3 are provided with dustproof rings 29 slidably sleeved on the outer wall of the ball screw 4;

[0042] The outer wall of the ball nut 3 is provided with symmetrically distributed connecting arms 2, the upper ends of the connecting arms 2 are provided with oppositely distributed supports 1, the supports 1 are internally provided with mounting holes;

[0043] The lower end of the connecting arm 2 is provided with a sliding block 21, the outer side of the sliding block 21 is sleeved with a guide rail 6, the inner sides of the two ends of the lower end of the sliding block 21 are internally provided with straight line rolling grooves 22, the inner sides of the two ends of the lower end of the guide rail 6 are internally and rotatably provided with rolling balls 23 equidistantly distributed and rollingly installed in the straight line rolling grooves 22;

[0044] The motor 15 drives the driving gear 16, drives the ball screw 4 to rotate through the same number of driven gears 17, when the screw rotates, the steel ball 32 rolls in the spiral groove of the ball screw 4 and the spiral rolling groove 33, drives the nut to move along the screw axis, the steel ball 32 returns to the starting point from one end of the spiral rolling groove 33 through the ball returning pipe 28, forms a closed circulation path, ensures continuous movement, the ball nut 3 drives the connecting arm 2 to move, the connecting arm 2 slides in the guide rail 6 through the sliding block 21, the sliding block 21 at the lower end of the connecting arm 2 cooperates with the guide rail 6 through the rolling ball 23, reduces the friction coefficient, ensures the straight line motion precision, the moving frame or the moving platform of the fixed beam numerical control milling machine feeding system is installed on the support 1, realizes the effective use of the fixed beam numerical control milling machine feeding system, the guide rail 6 is installed on the rack of the fixed beam numerical control milling machine, guarantees the levelness of the guide rail 6, the fixed beam numerical control milling machine feeding system needs to reserve the installation space of the oil tank 5, the dustproof ring 29 used in the fixed beam numerical control milling machine intercepts large-sized foreign matters, the lower end of the ball nut 3 moves in the oil tank 5, is soaked in lubricating oil, the outer wall of the steel ball 32 carries lubricating oil into the spiral path of the spiral rolling groove 33 and the ball screw 4, lubricates the ball nut 3 through soaking, prolongs the maintenance period, avoids the abrasion effect to accelerate the wear of the raceway, and the positioning precision decreases year by year.

[0045] Example two:

[0046] The lower end of the pump shell 10 is provided with a pump shell 10, the pump shaft 19 is rotatably installed in the pump shell 10, the impeller 20 is rotatably installed in the pump shell 10, the filter element 25 is arranged in the upper filter cylinder 8 and the lower filter cylinder 7, the suction pipe 11 is communicated between the suction end of the pump shell 10 and the lower filter cylinder 7, the connecting pipe 12 is communicated between the upper filter cylinder 8 and the flow guide hopper 9, the delivery pipe 13 is arranged in one end of the oil tank 5, the pump shaft 19 is sleeved with the driven gear two 18 engaged with the driving gear 16;

[0047] The number of teeth of the driven gear two 18 is less than that of the driving gear 16;

[0048] The upper filter cartridge 8 and the inner wall of the lower filter cartridge 7 are provided with a support ring 26 which is attached to the upper and lower ends of the filter core 25. The outer walls of the upper filter cartridge 8 and the lower filter cartridge 7 are provided with a ring-shaped butt joint ring 24 which is attached to each other and is annular. The butt joint ring 24 is fixed by bolts;

[0049] The driving gear 16 simultaneously drives the driven gear two 18 with fewer teeth to increase the speed transmission, and the pump shaft 19 rotates at high speed, and the impeller 20 generates negative pressure suction force. Through the suction end of the pump shell 10, it enters the suction pipe 11, the lower filter cartridge 7, the upper filter cartridge 8, the connecting pipe 12, and finally acts on the flow guide hopper 9. The lubricating oil in the oil tank 5 enters the lower filter cartridge 7 and the upper filter cartridge 8, and is intercepted by the serpentine sleeve type filter core 25 with increased surface area. The inclined groove on the inner wall of the oil tank 5 guides the pollutants to the center to avoid deposition on the movement path of the ball nut 3. The pump shell 10 extracts clean lubricating oil from the lower filter cartridge 7 through the suction pipe 11, and injects it into the oil tank 5 through the delivery pipe 13, forming a circulating flow. The process of circulating flow realizes the filtration of suction lubricating oil:

[0050] It is worth mentioning that the opening of the delivery pipe 13 is provided with a one-way valve. The movement of the ball screw 4 is bidirectional, and the movement direction of the ball nut 3 is realized by forward rotation and reverse rotation. The impeller 20 will only generate suction force when it rotates forward, so the reverse rotation of the ball screw 4 will not drive the pump shaft 19 to generate suction force. At this time, the one-way valve prevents the filtered lubricating oil in the shell from entering the inside of the suction pipe 11, thereby protecting the pipeline system. At the same time, the one-way valve will be effectively opened under the action of the delivery oil pressure.

[0051] Example three:

[0052] The inner wall of the lower end of the oil tank 5 is provided with oppositely distributed flow guide inclined grooves 14, and the height of the flow guide inclined grooves 14 gradually decreases from the two sides to the center;

[0053] One end of the delivery pipe 13 is horizontally distributed and outputs backward;

[0054] The side cross-sectional view of the filter core 25 is in a serpentine shape. The filter core 25 has a tubular shape with two groups of sleeves connected to each other;

[0055] By disassembling the gland 27 screw, the steel ball 32 in the ball tube 28 can be quickly replaced, the lubricating oil circulation filter design can remove pollutants without disassembly, prolong the service life of the lubricant, the delivery pipe 13 horizontal injection to push the oil flow, the small flushing force inside the ball nut 3, prevent debris accumulation, single motor 15 drive ball screw 4 and oil pump, compact structure and energy optimization, reduce the additional power requirements, driven gear two 18 gear number is less, driven gear three, pump shaft 19 speed, the number of driving gear 16 is to enhance the oil circulation efficiency, dusty environment needs to be maintained every month, each downtime 2~4 hours, filter core 25 can intercept 5um above particles, the maintenance cycle is extended to 1~2 years, only need to replace the filter core 25 and lubricating oil, without disassembly ball nut 3, ball nut 3 oil immersion design to ensure the raceway lubrication, temperature rise, reduce the thermal deformation, dustproof ring 29 oil liquid barrier makes the amount of foreign matter invasion reduces, the service life of the ball screw 4 and the ball nut 3 is improved, the feeding system through the lubrication, transmission, filter integrated design, overcome the traditional ball screw 4 maintenance frequency, easy to pollution industry problems.

[0056] Working principle: motor 15 drive driving gear 16, through the same number of driven gear one 17 driven ball screw 4 rotation, ensure 1:1 speed transmission, avoid the torque loss caused by speed difference, ball screw 4 rotation, steel ball 32 in the spiral groove 33 and screw raceway rolling between, push ball nut 3 along the screw axial movement, form accurate linear motion, steel ball 32 through the ball tube 28 form closed circulation path, the connecting arm 2 of the outer wall of the ball nut 3 through the slide block 21 and guide rail 6 cooperation, the slide block 21 inside straight line rolling groove 22 and guide rail 6 inside rolling ball 23 form rolling friction, ball nut 3 lower half immersed in the lubricating oil of oil tank 5, steel ball 32 rolling oil into the raceway, form oil film lubrication, reduce the wear and temperature rise;

[0057] Oil tank 5 inner wall of the chute guide contains debris oil to the center, ball nut 3 both ends of the dustproof ring 29 block large particle foreign matter invasion raceway, delivery pipe 13 horizontal injection oil produces micro flushing force, push ball nut 3 inside debris with oil flow into the filter circuit, driving gear 16 synchronous drive gear two 18 with less gear number, speed ratio 3:1, drive pump shaft 19 high speed rotating impeller 20 generate negative pressure, through the suction pipe 11 will oil tank 5 bottom lubricating oil through the guide chute 9, connecting pipe 12 into the upper filter cartridge 8, lubricating oil flow through the serpentine sleeve filter core 25 intercept ≥5um particle pollutants, clean oil into the lower filter cartridge 7, by pump shell 10 through the delivery pipe 13 horizontal injection back to the oil tank 5, form a closed loop circulation.

[0058] The above specific embodiments are only several preferred embodiments of the present application, based on the technical scheme of the present application and the related inspiration of the above embodiments, those skilled in the art can make various alternative improvements and combinations on the above specific embodiments.

[0059] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference herein to any prior art is to be taken as an admission that the present application is not entitled to antedate such prior art by virtue of prior application. No reference to an item of prior art in any claim is to be construed as an admission that the present application is not entitled to priority to such prior art by virtue of prior application. No reference in the specification to an item of prior art is to be construed as an admission that the present application is not entitled to priority to such prior art by virtue of prior application. No reference in the specification to an item of prior art is to be construed as an admission that the present application is not entitled to priority to such prior art by virtue of prior application. No reference in the specification to an item of prior art is to be construed as an admission that the present application is not entitled to priority to such prior art by virtue of prior application. No reference in the specification to an item of prior art is to be construed as an admission

Claims

1. A fixed beam CNC milling machine feed system comprising a connecting arm (2), a ball nut (3), a ball screw (4), an oil casing (5), a lower filter cartridge (7), an upper filter cartridge (8), a pump casing (10) and a motor (15), characterized in that: The oil shell (5) is internally rotatably installed with a ball screw (4), the outer side of the ball screw (4) is sleeved with a ball nut (3), the lower side of the oil shell (5) is provided with a lower filter cylinder (7) and an upper filter cylinder (8) which are in abutment with each other, the lower end of the oil shell (5) is provided with a flow guide hopper (9), the lower end of the pump shell (10) is provided with a pump shell (10) on one side, the pump shell (10) is internally rotatably installed with a pump shaft (19), the outer wall of the pump shaft (19) is sleeved with an impeller (20) which is rotatably installed in the pump shell (10), the upper filter cylinder (8) and the lower filter cylinder (7) are internally provided with filter cores (25), the suction end of the pump shell (10) and the lower filter cylinder (7) are communicated with a suction pipe (11), the upper filter cylinder (8) and the flow guide hopper (9) are communicated with a connecting pipe (12), the output end of the pump shell (10) is provided with a conveying pipe (13) which is located in the inner side of one end of the oil shell (5), one side of the oil shell (5) is provided with a motor (15), the output end of the motor (15) is provided with a driving gear (16), one end of the ball screw (4) is provided with a driven gear one (17) which is engaged with the driving gear (16), the outer wall of the pump shaft (19) is sleeved with a driven gear two (18) which is engaged with the driving gear (16), the lower end of the ball nut (3) is immersed in the liquid lubricating oil in the inner side of the oil shell (5), when the ball screw (4) rotates, the lubricating oil in the inner side of the oil shell (5) circulates and flows in the filter assembly and the inner side of the oil shell (5).

2. The feed system of a fixed beam NC milling machine according to claim 1, wherein: The driving gear (16) and the driven gear one (17) have the same number of teeth, and the number of teeth of the driven gear two (18) is less than that of the driving gear (16).

3. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The inner wall of the lower end of the oil shell (5) is provided with oppositely distributed flow guide chutes (14) which gradually decrease in height from the two sides to the center.

4. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The conveying pipe (13) is open on one end and outputs horizontally rearward.

5. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The filter core (25) is in the shape of a snake in the side cross-sectional view, and the filter core (25) is in the shape of two groups of sleeved cylinders which are connected to each other.

6. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The inner side of the ball nut (3) is provided with a spiral rolling groove (33) which is in the shape of a spiral, the upper end of the ball nut (3) is embeddedly installed with a ball returning pipe (28) which is communicated with the spiral rolling groove (33), and the inner sides of the ball returning pipe (28) and the spiral rolling groove (33) are rotatably installed with steel balls (32).

7. The feed system for a fixed beam NC milling machine according to claim 6, wherein: The inner side of the upper end of the ball nut (3) is provided with a pressing groove (30) which is communicated with the ball returning pipe (28), the inner side of the pressing groove (30) is provided with a pressing cover (27), the inner sides of the pressing cover (27) and the ball nut (3) are provided with screw holes (31), and the inner sides of the screw holes (31) are screwingly installed with screws, and the two ends of the ball nut (3) are provided with dustproof rings (29) which are slidably sleeved on the outer wall of the ball screw (4).

8. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The outer wall of the ball nut (3) is provided with symmetrically distributed connecting arms (2), the upper ends of the connecting arms (2) are provided with oppositely distributed supports (1), and the inner sides of the supports (1) are provided with mounting holes.

9. The feed system for a fixed beam NC milling machine according to claim 8, wherein: The lower end of the connecting arm (2) is provided with a sliding block (21), the outer side of the sliding block (21) is sleeved with a guide rail (6), the inner side of the lower end of the sliding block (21) is provided with linear rolling grooves (22) at both ends, and the guide rail (6) is rotationally installed with equidistantly distributed rolling balls (23) in the linear rolling grooves (22).

10. The feed system for a fixed beam CNC milling machine according to claim 1, wherein: The inner walls of the upper filter cylinder (8) and the lower filter cylinder (7) are provided with support rings (26) which are attached to the upper and lower ends of the filter core (25), the outer walls of the upper filter cylinder (8) and the lower filter cylinder (7) are provided with mutually attached annular butt rings (24), and the butt rings (24) are fixed by bolts.

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