Rotary driving mechanism for Z-axis gear transmission nut of gantry machining center

Abstract

The utility model discloses a gantry machining center Z-axis gear transmission nut rotation driving mechanism which is characterized in that a left Z-axis driving device is connected with a left lead screw in a matched mode, a right Z-axis driving device is connected with a right lead screw in a matched mode, and the left lead screw and the right lead screw are connected with the two sides of a spindle box respectively. Driving rotating shaft systems of the left Z-axis driving device and the right Z-axis driving device are installed in main bearing holes of the gear box body, middle rotating shaft systems are installed in middle bearing holes of the gear box body, driven rotating shaft systems are installed in driven bearing holes of the gear box body, and the driving rotating shaft systems are meshed with the middle rotating shaft systems. The middle rotating shaft system is meshed with the driven rotating shaft system, the power output end of the servo motor is installed in an inner hole in one end of the coupler, an inner hole in the other end of the coupler is connected with the driving rotating shaft system, the driven rotating shaft system is bonded with the Z-axis driving assembly, and a lead screw nut of the Z-axis driving assembly is in threaded connection with the left-side lead screw or the right-side lead screw.

Description

Technical Field

[0001] The utility model belongs to the technical field of driving equipment, and in particular relates to a Z-axis gear transmission nut rotation driving mechanism of a gantry machining center. Background Art

[0002] The existing gantry machining center Z-axis drive generally adopts a servo motor, a coupling and a lead screw pair connection. The rotational motion of the motor is transmitted to the lead screw through the coupling, and the lead screw drives the nut thereon and the spindle box (46) (Z-axis) to perform linear motion. This Z-axis drive mode has the advantages of simplicity and relatively low cost, and can meet the drive requirements of the Z-axis stroke and load under normal circumstances; if the load requirements of the Z-axis are increased, dual servo motors, synchronous drive and dual lead screw nut pair transmission can also be used to increase the load; however, for applications where the Z-axis has a long stroke and a large load at the same time, the above two transmission forms seem to be somewhat inadequate. This transmission mode will have problems such as poor stability and insufficient transmission torque. Therefore, it is very promising to study a Z-axis drive mechanism for long strokes and large loads. Utility Model Content

[0003] The utility model aims to solve the problems of the prior art and provides a Z-axis gear transmission nut rotation drive mechanism for a gantry machining center.

[0004] In order to solve the technical problem, the technical solution of the utility model is: a Z-axis gear transmission nut rotation drive mechanism of a gantry machining center, including a spindle box, a left-side screw, a right-side screw, a left-side Z-axis drive device and a right-side Z-axis drive device, the left-side Z-axis drive device is matched and connected with the left-side screw, the right-side Z-axis drive device is matched and connected with the right-side screw, the left-side screw and the right-side screw are respectively connected to the two sides of the spindle box, the left-side Z-axis drive device and the right-side Z-axis drive device both include a servo motor, a coupling, a gear box body, a Z-axis drive assembly, an active rotating shaft system, an intermediate rotating shaft system and a driven rotating shaft system, The active rotating shaft system is installed in the main bearing hole of the gear box body, the intermediate rotating shaft system is installed in the middle bearing hole of the gear box body, the driven rotating shaft system is installed in the driven bearing hole of the gear box body, the active rotating shaft system is meshed with the intermediate rotating shaft system, the intermediate rotating shaft system is meshed with the driven rotating shaft system, the power output end of the servo motor is installed in the inner hole at one end of the coupling, the inner hole at the other end of the coupling is connected to the active rotating shaft system, the driven rotating shaft system is keyed to the Z-axis driving assembly, the screw nut of the Z-axis driving assembly is threadedly connected to the left screw or the right screw, driving the main shaft box connected to the left screw and the right screw to do linear reciprocating motion.

[0005] Preferably, the active rotating shaft system includes an active sealing retaining ring, an active radial oil seal, an upper bearing pressure cover, an active shaft bearing, an active shaft, a sealing gasket, a cover plate, a main helical gear, a main bearing pressure cover and a main transmission key. The inner hole at the other end of the coupling is connected to the active shaft. The active shaft is sleeved with a main helical gear, and the active shaft and the main helical gear are bonded by the main transmission key. The upper end of the active shaft is sleeved with an upper bearing pressure cover, and an active sealing retaining ring and an active radial oil seal are arranged between the upper bearing pressure cover and the active shaft. The active shaft is also sleeved with an active shaft bearing. There are two active shaft bearings, which are respectively sleeved on the active shaft on both sides of the main helical gear. The lower end of the active shaft is sleeved with a main bearing pressure cover, and an active sealing retaining ring and an active radial oil seal are arranged between the main bearing pressure cover and the active shaft. The sealing gasket and cover plate of the active rotating shaft system are installed in the main bearing hole of the gear box body by screws.

[0006] Preferably, a brake is installed at the upper end of the driving shaft to control the start and stop of the rotational movement of the driving shaft.

[0007] Preferably, the intermediate rotating shaft system includes an intermediate gear shaft retaining ring, an intermediate rotating shaft, an intermediate bearing retaining ring, an intermediate helical gear, an intermediate bearing pressure cover, an intermediate shaft bearing and an intermediate transmission key. The intermediate rotating shaft is equipped with an intermediate shaft bearing, an intermediate helical gear and an intermediate bearing retaining ring. The intermediate rotating shaft and the intermediate helical gear are bonded by the intermediate transmission key. The intermediate helical gear is meshed with the main helical gear. The intermediate shaft bearing is fitted in the middle bearing hole of the gear box body. The upper end of the intermediate rotating shaft is positioned between the middle bearing hole by the intermediate gear shaft retaining ring. The intermediate shaft bearing at the lower end of the intermediate rotating shaft is axially positioned by the intermediate bearing pressure cover.

[0008] Preferably, the Z-axis drive assembly includes a screw nut, a sealing end cover, an elastic retaining ring for a hole, a bearing seat, an oil retaining ring, a transmission radial oil seal, an outer spacer ring, a locking nut, an O-ring, a transmission bearing cover, a transmission shaft, a transmission bearing and an inner spacer ring. The screw nut is connected to the transmission shaft with a key, and a transmission bearing, an inner spacer ring, an outer spacer ring, an oil retaining ring and a transmission radial oil seal are installed on the transmission shaft. The inner spacer ring and the outer spacer ring are arranged opposite to each other, and the oil retaining ring and the transmission radial oil seal are arranged near one end of the screw nut. The left end of the transmission shaft is locked by a locking nut to form a transmission shaft system, and the transmission shaft system is installed in the inner hole of the bearing seat. One end of the transmission shaft system is limited by an elastic retaining ring for a hole, and one end of the bearing seat is pressed against the outer ring of the transmission bearing by a transmission bearing cover and an O-ring for axial positioning, and a sealing end cover is installed at the other end of the bearing seat.

[0009] Preferably, the driven rotating shaft system includes a driven sealing retainer ring III, a driven radial oil seal, a driven sealing retainer ring II, a lower flange ring, a driven helical gear, a driven transmission key, an upper flange ring, a driven bearing cover, a driven sealing retainer ring I and a driven shaft bearing. The driven helical gear is mounted on the lead screw nut, the driven helical gear and the lead screw nut are bonded to each other through the driven transmission key, the driven helical gear is meshed with the intermediate helical gear, the lead screw nuts on both sides of the driven helical gear are respectively mounted with an upper flange ring and a lower flange ring, the lead screw nut on the upper side of the upper flange ring is mounted with a driven shaft bearing, and the lead screw nut on the lower side of the lower flange ring is also mounted with a driven shaft bearing, a driven sealing retainer ring II, a driven radial oil seal and a driven sealing retainer ring III are sequentially arranged between the lead screw nut and the driven bearing hole of the gear box body, and the top of the lead screw nut is sealed and connected to the driven bearing hole of the gear box body through a driven bearing cover and a driven sealing retainer ring I and axially positioned.

[0010] Preferably, the reduction ratio between the main helical gear and the intermediate helical gear is 1:1, and the reduction ratio between the intermediate helical gear and the driven helical gear is 1:2.

[0011] Compared with the prior art, the advantages of the utility model are:

[0012] (1) Aiming at the large load and long stroke requirements of the Z-axis drive of the gantry machining center, the utility model designs a driving mechanism, which changes the conventional Z-axis driving form of rotating the screw to transmit the nut and the spindle box to perform linear motion, and adopts a dual servo motor, a gear box body and a screw nut sub-mechanism. The servo motor drives the main helical gear of the gear box body, which is transmitted to the driven helical gear and the connected screw nut to perform rotational motion through the intermediate helical gear, thereby driving the screw and the spindle box to perform linear reciprocating motion in the Z-axis direction;

[0013] (2) The utility model uses dual servo motors, a gear box and a screw nut pair mechanism to directly apply the high torque rotational motion of the gear box to the screw nut, and transmits it to the screw and the spindle box to make linear motion along the Z axis. For the Z axis drive of the gantry machining center with a long stroke and a large load, it has the characteristics of stable transmission, large load, short transmission chain, and sensitive dynamic response. It also has the advantages of being able to effectively reduce the length of the Z axis transmission mechanism, thereby reducing the overall height of the gantry machine tool, which is convenient for transportation.

[0014] (3) Compared with the high-speed rotational motion of a long screw, the high-speed rotational motion of the screw nut of the utility model has the advantages of smaller rotational inertia and avoiding the deflection error caused by the high-speed rotation of the screw, which can effectively improve the transmission accuracy and movement speed;

[0015] (4) Since the servo motor of the utility model is installed in the middle and upper part of the entire Z-axis, it occupies less height space, can reduce the length of the Z-axis transmission mechanism, thereby reducing the overall height of the gantry machine tool, and facilitating transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 , a schematic diagram of the structure of a Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to the utility model;

[0017] Figure 2 , a schematic cross-sectional view of the left Z-axis driving device or the right Z-axis driving device of the utility model;

[0018] Figure 3 、The utility model Figure 2 BB section view;

[0019] Figure 4 , a schematic cross-sectional structural diagram of the Z-axis drive assembly of the utility model.

[0020] Description of reference numerals:

[0021] 1. Servo motor, 2. Brake, 3. Coupling, 4. Intermediate gear shaft retaining ring, 5. Active sealing retaining ring, 6. Active radial oil seal, 7. Upper bearing cover, 8. Active shaft bearing, 9. Intermediate shaft, 10. Active shaft, 11. Sealing gasket, 12. Cover plate, 13. Gear box, 14. Main helical gear, 15. Main bearing cover, 16. Intermediate bearing retaining ring, 17. Intermediate helical gear, 18. Intermediate bearing cover, 19. Intermediate shaft bearing, 20. Z-axis drive assembly, 21. Driven sealing retaining ring III, 22. Driven radial oil seal, 23. Driven sealing retaining ring II, 24. Lower flange ring, 25. Driven helical gear , 26, driven transmission key, 27, upper flange ring, 28, driven bearing cover, 29, driven sealing ring Ⅰ, 30, driven shaft bearing, 31, intermediate transmission key, 32, main transmission key, 33, screw nut, 34, sealing end cover, 35, elastic retaining ring for hole, 36, bearing seat, 37, oil retaining ring, 38, transmission radial oil seal, 39, outer spacer, 40, locking nut, 41, O-ring, 42, transmission bearing cover, 43, transmission shaft, 44, transmission bearing, 45, inner spacer, 46, spindle box, 47, left side screw, 48, right side screw, 49, left side Z-axis drive device, 50, right side Z-axis drive device. DETAILED DESCRIPTION

[0022] The following describes the specific implementation of the utility model in conjunction with embodiments:

[0023] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0024] Example 1

[0025] like Figures 1 to 3 As shown, the utility model discloses a Z-axis gear transmission nut rotation drive mechanism of a gantry machining center, including a spindle box 46, a left side lead screw 47, a right side lead screw 48, a left side Z-axis drive device 49 and a right side Z-axis drive device 50, the left side Z-axis drive device 49 is matched and connected with the left side lead screw 47, the right side Z-axis drive device 50 is matched and connected with the right side lead screw 48, the left side lead screw 47 and the right side lead screw 48 are respectively connected to the two sides of the spindle box 46, the left side Z-axis drive device 49 and the right side Z-axis drive device 50 both include a servo motor 1, a coupling 3, a gear box body 13, a Z-axis drive assembly 20, an active rotating shaft system, an intermediate rotating shaft system and a driven rotating shaft system, The active rotating shaft system is installed in the main bearing hole of the gear box body 13, the intermediate rotating shaft system is installed in the middle bearing hole of the gear box body 13, and the driven rotating shaft system is installed in the driven bearing hole of the gear box body 13. The active rotating shaft system is meshed with the intermediate rotating shaft system, and the intermediate rotating shaft system is meshed with the driven rotating shaft system. The power output end of the servo motor 1 is installed in the inner hole at one end of the coupling 3, and the inner hole at the other end of the coupling 3 is connected to the active rotating shaft system. The driven rotating shaft system is bonded to the Z-axis driving assembly 20, and the screw nut 33 of the Z-axis driving assembly 20 is threadedly connected to the left screw 47 or the right screw 48, driving the main shaft box 46 connected to the left screw 47 and the right screw 48 to do linear reciprocating motion.

[0026] Example 2

[0027] like Figure 2As shown, preferably, the active rotating shaft system includes an active sealing ring 5, an active radial oil seal 6, an upper bearing cover 7, an active shaft bearing 8, an active shaft 10, a sealing gasket 11, a cover plate 12, a main helical gear 14, a main bearing cover 15 and a main transmission key 32. The inner hole at the other end of the coupling 3 is connected to the active shaft 10. The active shaft 10 is sleeved with a main helical gear 14. The active shaft 10 and the main helical gear 14 are bonded by the main transmission key 32. The upper end of the active shaft 10 is sleeved with an upper bearing cover 7. The upper bearing cover An active sealing retainer ring 5 and an active radial oil seal 6 are arranged between 7 and the driving shaft 10. The driving shaft 10 is also provided with an active shaft bearing 8. There are two active shaft bearings 8, which are respectively provided on the driving shaft 10 on both sides of the main helical gear 14. A main bearing gland 15 is provided at the lower end of the driving shaft 10. An active sealing retainer ring 5 and an active radial oil seal 6 are arranged between the main bearing gland 15 and the driving shaft 10. The sealing gasket 11 and the cover plate 12 of the active rotating shaft system are installed in the main bearing hole of the gear box body 13 by screws.

[0028] like Figure 2 As shown, preferably, a brake 2 is installed at the upper end of the driving shaft 10 to control the start and stop of the rotational movement of the driving shaft 10.

[0029] The flange of the servo motor 1 is installed on the gear box body 13, and the lower part of the output shaft of the servo motor 1 is installed on the inner hole of one end of the coupling 3. The inner hole of the other end of the coupling 3 is connected to the driving shaft 10. The driving shaft 10 is equipped with an active radial oil seal 6, an active shaft bearing 8, a main helical gear 14 and a main transmission key 32 to form a main transmission shaft system. The main transmission shaft system is matched in the bearing hole of the gear box body 13, and the two ends are axially positioned by the upper bearing cover 7, the active sealing retaining ring 5 and the main bearing cover 15 respectively. This series of combinations forms an active rotating shaft system, and the start and stop of its rotational motion can be controlled by the brake 2 installed on the upper end of the driving shaft 10.

[0030] Example 3

[0031] like Figure 2 As shown, preferably, the intermediate rotating shaft system includes an intermediate gear shaft retaining ring 4, an intermediate rotating shaft 9, an intermediate bearing retaining ring 16, an intermediate helical gear 17, an intermediate bearing pressure cover 18, an intermediate shaft bearing 19 and an intermediate transmission key 31. The intermediate rotating shaft 9 is provided with an intermediate shaft bearing 19, an intermediate helical gear 17 and an intermediate bearing retaining ring 16. The intermediate rotating shaft 9 and the intermediate helical gear 17 are bonded by the intermediate transmission key 31. The intermediate helical gear 17 is meshed with the main helical gear 14. The intermediate shaft bearing 19 is fitted in the middle bearing hole of the gear box body 13. The upper end of the intermediate rotating shaft 9 is positioned between the middle bearing hole by the intermediate gear shaft retaining ring 4. The intermediate shaft bearing 19 at the lower end of the intermediate rotating shaft 9 is axially positioned by the intermediate bearing pressure cover 18.

[0032] An intermediate shaft bearing 19, an intermediate helical gear 17, an intermediate transmission key 31 and an intermediate bearing retaining ring 16 are installed on the intermediate rotating shaft 9. The intermediate shaft bearing 19 is installed in the bearing hole in the middle of the gear box body 13. The upper end of the intermediate rotating shaft 9 is positioned with the bearing hole by the intermediate gear shaft retaining ring 4. The outer ring of the intermediate shaft bearing 19 at the lower end is axially positioned by the intermediate bearing cover 18, forming an intermediate rotating shaft system.

[0033] Example 4

[0034] like Figure 4 As shown, preferably, the Z-axis drive assembly 20 includes a screw nut 33, a sealing end cover 34, an elastic retaining ring 35 for a hole, a bearing seat 36, an oil retaining ring 37, a transmission radial oil seal 38, an outer spacer ring 39, a locking nut 40, an O-ring 41, a transmission bearing cover 42, a transmission shaft 43, a transmission bearing 44 and an inner spacer ring 45. The screw nut 33 is connected with the transmission shaft 43 by a key, and the transmission shaft 43 is equipped with a transmission bearing 44, an inner spacer ring 45, an outer spacer ring 39, an oil retaining ring 37 and a transmission radial oil seal 38. The oil seal 38, the inner spacer ring 45 and the outer spacer ring 39 are arranged opposite to each other, the oil retaining ring 37 and the transmission radial oil seal 38 are arranged near one end of the screw nut 33, and the left end of the transmission shaft 43 is locked by the locking nut 40 to form a transmission shaft system, and the transmission shaft system is installed in the inner hole of the bearing seat 36. One end of the transmission shaft system is limited by the elastic retaining ring 35 with a hole, and one end of the bearing seat 36 is pressed against the outer ring of the transmission bearing 44 by the transmission bearing cover 42 and the O-ring 41 for axial positioning, and the sealing end cover 34 is installed at the other end of the bearing seat 36.

[0035] like Figure 4 As shown, preferably, the screw nut 33 is coupled with the transmission shaft 43, and a transmission bearing 44, an inner spacer ring 45 / an outer spacer ring 39, an oil retaining ring 37 and a transmission radial oil seal 38 are installed on the transmission shaft 43, which is locked with a locking nut 40 to form a transmission shaft system, and the transmission shaft system is mounted in the inner hole of the bearing seat 36, the right end is limited by a hole elastic retaining ring 35, and the left end is pressed with a transmission bearing cover 42 to axially position the outer ring of the transmission bearing 44, and a sealing end cover 34 is installed on the right end of the bearing seat 36. This series of combinations constitutes a Z-axis drive assembly 20.

[0036] Example 5

[0037] like Figure 1As shown, preferably, the driven rotating shaft system includes a driven sealing retainer ring III 21, a driven radial oil seal 22, a driven sealing retainer ring II 23, a lower flange ring 24, a driven helical gear 25, a driven transmission key 26, an upper flange ring 27, a driven bearing gland 28, a driven sealing retainer ring I 29 and a driven shaft bearing 30, the driven helical gear 25 is sleeved on the lead screw nut 33, the driven helical gear 25 is bonded to the lead screw nut 33 through the driven transmission key 26, the driven helical gear 25 is meshed with the intermediate helical gear 17, and the lead screws on both sides of the driven helical gear 25 are engaged with the intermediate helical gear 17. The nut 33 is respectively provided with an upper flange ring 27 and a lower flange ring 24, a driven shaft bearing 30 is provided on the lead screw nut 33 on the upper side of the upper flange ring 27, and a driven shaft bearing 30 is also provided on the lead screw nut 33 on the lower side of the lower flange ring 24. A driven sealing retainer ring II 23, a driven radial oil seal 22 and a driven sealing retainer ring III 21 are sequentially arranged between the lead screw nut 33 and the driven bearing hole of the gear box body 13, and the top of the lead screw nut 33 is sealed and connected to the driven bearing hole of the gear box body 13 through a driven bearing gland 28 and a driven sealing retainer ring I 29 and axially positioned.

[0038] like Figure 1 As shown, preferably, a driven transmission key 26, an upper flange ring 27, a driven helical gear 25, a lower flange ring 24, a driven shaft bearing 30, a driven sealing retaining ring II 23, a driven radial oil seal 22 and a driven sealing retaining ring III 21 are respectively installed on the screw nut 33 of the Z-axis drive assembly 20. This series of combinations forms a driven rotating shaft system, which is installed in the driven bearing hole of the gear box body 13, and the hole opening is axially positioned by a driven bearing cover 28 and a driven sealing retaining ring I 29.

[0039] like Figure 3 As shown, preferably, the reduction ratio between the main helical gear 14 and the intermediate helical gear 17 is 1:1, and the reduction ratio between the intermediate helical gear 17 and the driven helical gear 25 is 1:2.

[0040] The working principle of the utility model is as follows:

[0041] like Figures 1 to 4As shown, the utility model discloses a Z-axis gear transmission nut rotation drive mechanism for a gantry machining center, including a spindle box 46, a left lead screw 47, a right lead screw 48, a left Z-axis drive device 49 and a right Z-axis drive device 50, wherein the left Z-axis drive device 49 and the right Z-axis drive device 50 both include a servo motor 1, a coupling 3, a gear box body 13, a Z-axis drive assembly 20, an active rotating shaft system, an intermediate rotating shaft system and a driven rotating shaft system, and the active rotating shaft system, the intermediate rotating shaft system and the driven rotating shaft system are mutually meshed and driven through a main helical gear 14, an intermediate helical gear 17 and a driven helical gear 25. The servo motor 1 outputs a rotational motion, which is transmitted to the active rotating shaft system. Through the meshing transmission of the main helical gear 14 and the intermediate helical gear 17, the intermediate rotating shaft system forms a reverse and same-speed rotational motion. This rotational motion is then transmitted through the meshing transmission between the intermediate helical gear 17 and the driven helical gear 25 (reduction ratio 1:2), and the output is a low-speed, high-torque rotational motion of the active rotating shaft system, which acts on the screw nut 33. Finally, under the action of the screw nut pair, the rotational motion of the screw nut 33 is converted into a linear motion of the left screw 47 and the right screw 48, thereby driving the spindle box 46 connected to the screw to perform a linear reciprocating motion.

[0042] During the entire movement process, the meshing transmission of the main helical gear 14, the intermediate helical gear 17 and the driven helical gear 25 greatly improves the movement smoothness, and under the action of the secondary gear box 13, the high speed and small torque of the servo motor are converted into low speed and large torque to act on the screw nut 33, so as to drive the heavy-load gantry machining center spindle box 46 to operate reliably; at the same time, the high-speed rotational movement of the screw nut 33 has the advantages of smaller moment of inertia and avoidance of deflection error caused by high-speed rotation of the screw compared to the high-speed rotational movement of the long screw, which can effectively improve the transmission accuracy and movement speed; and because the servo motor is installed in the middle and upper part of the entire Z-axis, it occupies less height space, which can reduce the length of the Z-axis transmission mechanism, thereby reducing the overall height of the gantry machine tool for easy transportation.

[0043] The utility model adopts a mechanism in which the helical gear meshing transmission directly drives the lead screw nut to rotate, converts the high speed and small torque of the servo motor into a low speed and large torque to directly act on the lead screw nut. The transmission chain is short and the dynamic response is sensitive. The spindle box of the gantry machining center with a large load is driven to operate reliably, and the installation space can be saved for convenient transportation.

[0044] The utility model discloses a Z-axis driving mechanism which directly transmits the rotation synchronous drive of the lead screw nut through the meshing transmission of double-sided helical gears and is applied to a large gantry machining center, which can greatly increase the load, reduce the rotational inertia of the Z-axis rotating mechanism, and improve the motion accuracy and speed of the Z-axis of the gantry machining center.

[0045] The utility model designs a driving mechanism for the large load and long stroke requirements of the Z-axis drive of a gantry machining center, changes the conventional Z-axis driving form in which a nut and a spindle box are rotated by a lead screw to perform linear motion, adopts a double servo motor, a gear box body and a lead screw nut sub-mechanism, drives the main helical gear of the gear box body through a servo motor, transmits the rotational motion to the driven helical gear and the connected lead screw nut through an intermediate helical gear, thereby driving the lead screw and the spindle box to perform linear reciprocating motion in the Z-axis direction.

[0046] The utility model uses dual servo motors, a gear box and a screw nut pair mechanism to directly apply the high-torque rotational motion of the gear box to the screw nut, and transmits it to the screw and the spindle box to make linear motion along the Z axis. For the Z-axis drive of a gantry machining center with a long stroke and a large load, the utility model has the characteristics of stable transmission, large load, short transmission chain, and sensitive dynamic response. It also has the advantages of being able to effectively reduce the length of the Z-axis transmission mechanism, thereby reducing the overall height of the gantry machine tool, which is convenient for transportation.

[0047] Compared with the high-speed rotational motion of a long lead screw, the high-speed rotational motion of the lead screw nut of the utility model has the advantages of smaller rotational inertia and avoiding deflection error caused by high-speed rotation of the lead screw, and can effectively improve transmission accuracy and movement speed.

[0048] Since the servo motor is installed at the middle and upper part of the entire Z axis, the utility model occupies less height space, can reduce the length of the Z axis transmission mechanism, thereby reducing the overall height of the gantry machine tool, and is convenient for transportation.

[0049] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in this field without departing from the purpose of the present invention.

[0050] Many other changes and modifications can be made without departing from the concept and scope of the utility model. It should be understood that the utility model is not limited to a specific embodiment, and the scope of the utility model is defined by the appended claims.

Claims

1. A Z-axis gear transmission nut rotation drive mechanism for a gantry machining center, characterized in that: The invention comprises a spindle box (46), a left lead screw (47), a right lead screw (48), a left Z-axis driving device (49) and a right Z-axis driving device (50), wherein the left Z-axis driving device (49) is coupled to the left lead screw (47), and the right Z-axis driving device (50) is coupled to the right lead screw (48), and the left lead screw (47) and the right lead screw (48) are respectively coupled to two sides of the spindle box (46), and the left Z-axis driving device (49) and the right Z-axis driving device (50) both comprise a servo motor (1), a coupling (3), a gear box (13), a Z-axis driving assembly (20), an active rotating shaft system, an intermediate rotating shaft system and a driven rotating shaft system, wherein the active rotating shaft system is mounted on the gear box. The intermediate rotating shaft system is installed in the main bearing hole of the gear box body (13), the intermediate rotating shaft system is installed in the middle bearing hole of the gear box body (13), the driven rotating shaft system is installed in the driven bearing hole of the gear box body (13), the active rotating shaft system is meshed with the intermediate rotating shaft system, and the intermediate rotating shaft system is meshed with the driven rotating shaft system. The power output end of the servo motor (1) is installed in the inner hole of one end of the coupling (3), and the inner hole of the other end of the coupling (3) is connected to the active rotating shaft system. The driven rotating shaft system is keyed with the Z-axis driving component (20), and the lead screw nut (33) of the Z-axis driving component (20) is threadedly connected with the left lead screw (47) or the right lead screw (48), driving the main shaft box (46) connected with the left lead screw (47) and the right lead screw (48) to perform linear reciprocating motion.

2. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 1, characterized in that: The active rotating shaft system comprises an active sealing ring (5), an active radial oil seal (6), an upper bearing cover (7), an active shaft bearing (8), an active shaft (10), a sealing gasket (11), a cover plate (12), a main helical gear (14), a main bearing cover (15) and a main transmission key (32); the inner hole at the other end of the coupling (3) is connected to the active shaft (10); the main helical gear (14) is sleeved on the active shaft (10); the active shaft (10) and the main helical gear (14) are bonded via the main transmission key (32); the upper end of the active shaft (10) is sleeved with an upper bearing cover (7); the upper bearing cover (7) An active sealing retaining ring (5) and an active radial oil seal (6) are arranged between the active shaft (10), and the active shaft (10) is also provided with an active shaft bearing (8). There are two active shaft bearings (8), which are respectively provided on the active shaft (10) on both sides of the main helical gear (14). A main bearing pressure cover (15) is provided on the lower end of the active shaft (10), and an active sealing retaining ring (5) and an active radial oil seal (6) are arranged between the main bearing pressure cover (15) and the active shaft (10). The sealing gasket (11) and the cover plate (12) of the active rotating shaft system are installed in the main bearing hole of the gear box body (13) by screws.

3. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 2, characterized in that: A brake (2) is installed at the upper end of the driving shaft (10) for controlling the start and stop of the rotational movement of the driving shaft (10).

4. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 2, characterized in that: The intermediate rotating shaft system comprises an intermediate gear shaft retaining ring (4), an intermediate rotating shaft (9), an intermediate bearing retaining ring (16), an intermediate helical gear (17), an intermediate bearing pressure cover (18), an intermediate shaft bearing (19) and an intermediate transmission key (31). The intermediate rotating shaft (9) is provided with an intermediate shaft bearing (19), an intermediate helical gear (17) and an intermediate bearing retaining ring (16). The intermediate rotating shaft (9) and the intermediate helical gear (17) are keyed via the intermediate transmission key (31). The intermediate helical gear (17) is meshed with the main helical gear (14). The intermediate shaft bearing (19) is mounted in a middle bearing hole of the gear box body (13). The upper end of the intermediate rotating shaft (9) is positioned with the middle bearing hole via the intermediate gear shaft retaining ring (4). The intermediate shaft bearing (19) at the lower end of the intermediate rotating shaft (9) is axially positioned via the intermediate bearing pressure cover (18).

5. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 4, characterized in that: The Z-axis drive assembly (20) comprises a lead screw nut (33), a sealing end cover (34), a hole elastic retaining ring (35), a bearing seat (36), an oil retaining ring (37), a transmission radial oil seal (38), an outer spacer ring (39), a locking nut (40), an O-ring (41), a transmission bearing cover (42), a transmission shaft (43), a transmission bearing (44) and an inner spacer ring (45). The lead screw nut (33) is key-connected to the transmission shaft (43), and the transmission bearing (44), the inner spacer ring (45), the outer spacer ring (39), the oil retaining ring (37) and the transmission shaft (43) are mounted on the transmission shaft (43). The dynamic radial oil seal (38), the inner spacer ring (45) and the outer spacer ring (39) are arranged opposite to each other, the oil retaining ring (37) and the transmission radial oil seal (38) are arranged near one end of the lead screw nut (33), the left end of the transmission shaft (43) is locked by a locking nut (40) to form a transmission shaft system, the transmission shaft system is installed in the inner hole of the bearing seat (36), one end of the transmission shaft system is limited by a hole elastic retaining ring (35), one end of the bearing seat (36) is pressed by a transmission bearing cover (42) and an O-ring (41) to tighten the outer ring of the transmission bearing (44) for axial positioning, and the other end of the bearing seat (36) is installed with a sealing end cover (34).

6. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 5, characterized in that: The driven rotating shaft system comprises a driven sealing retainer ring III (21), a driven radial oil seal (22), a driven sealing retainer ring II (23), a lower flange ring (24), a driven helical gear (25), a driven transmission key (26), an upper flange ring (27), a driven bearing gland (28), a driven sealing retainer ring I (29) and a driven shaft bearing (30). The driven helical gear (25) is sleeved on the lead screw nut (33). The driven helical gear (25) and the lead screw nut (33) are bonded via the driven transmission key (26). The driven helical gear (25) is meshed with the intermediate helical gear (17). The lead screw nuts (33) on both sides of the driven helical gear (25) are engaged with each other. 3) are respectively mounted with an upper flange ring (27) and a lower flange ring (24), a driven shaft bearing (30) is mounted on a lead screw nut (33) on the upper side of the upper flange ring (27), and a driven shaft bearing (30) is also mounted on a lead screw nut (33) on the lower side of the lower flange ring (24), a driven shaft bearing (30) is sequentially arranged between the lead screw nut (33) and the driven bearing hole of the gear housing (13), a driven sealing retainer ring II (23), a driven radial oil seal (22) and a driven sealing retainer ring III (21), and the top of the lead screw nut (33) is sealed and connected to the driven bearing hole of the gear housing (13) through a driven bearing gland (28) and a driven sealing retainer ring I (29) and axially positioned.

7. The Z-axis gear transmission nut rotation drive mechanism of a gantry machining center according to claim 6, characterized in that: The reduction ratio between the main helical gear (14) and the intermediate helical gear (17) is 1:1, and the reduction ratio between the intermediate helical gear (17) and the driven helical gear (25) is 1:2.

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