阅读说明：本技术 一种发动机曲轴数控磨床 (Engine crankshaft numerically controlled grinder ) 是由 宗轶琦 张乾坤 沈辉 李红 陶海 于 2020-12-25 设计创作，主要内容包括：一种发动机曲轴数控磨床,属于磨床技术领域。其特征是,包括床身底座、头架总成、尾架总成、砂轮架总成,所述床身底座上设有纵向进给系统总成、垫板,所述垫板布置有横向进给系统总成；所述头架总成、尾架总成相对布置,并安装于与纵向进给系统总成相连的工作台,所述砂轮架总成通过横向进给系统总成安装于垫板；所述头架总成、尾架总成共同夹持固定曲轴,并通过头架总成驱动曲轴,通过纵向进给系统总成调节头架总成、尾架总成的纵向位移,通过横向进给系统总成调节砂轮架总成的横向位移,以便对曲轴实施磨削。本发明通过控制可控电机可实现在磨削过程中曲轴作变速转动,又能保证在磨削过程中曲轴在磨削点匀速。(An engine crankshaft numerical control grinding machine belongs to the technical field of grinding machines. The grinding wheel machine tool is characterized by comprising a tool body base, a headstock assembly, a tailstock assembly and a grinding wheel frame assembly, wherein the tool body base is provided with a longitudinal feeding system assembly and a base plate, and the base plate is provided with a transverse feeding system assembly; the headstock assembly and the tailstock assembly are oppositely arranged and are arranged on a workbench connected with the longitudinal feeding system assembly, and the grinding wheel frame assembly is arranged on the base plate through the transverse feeding system assembly; the headstock assembly and the tailstock assembly clamp and fix the crankshaft together, the crankshaft is driven by the headstock assembly, the longitudinal displacement of the headstock assembly and the tailstock assembly is adjusted by the longitudinal feeding system assembly, and the transverse displacement of the grinding carriage assembly is adjusted by the transverse feeding system assembly, so that the crankshaft is ground. The invention can realize the variable-speed rotation of the crankshaft in the grinding process by controlling the controllable motor, and can ensure the uniform speed of the crankshaft at the grinding point in the grinding process.)

1. The numerical control grinding machine for the engine crankshaft is characterized by comprising a machine body base (2), a headstock assembly (65), a tailstock assembly (66) and a grinding carriage assembly (96), wherein the machine body base is provided with a longitudinal feeding system assembly (3) and a base plate (92), and the base plate is provided with a transverse feeding system assembly; the headstock assembly and the tailstock assembly are oppositely arranged and are arranged on a workbench connected with the longitudinal feeding system assembly, and the grinding wheel frame assembly is arranged on the base plate through the transverse feeding system assembly; the headstock assembly and the tailstock assembly clamp and fix the crankshaft together, the crankshaft is driven by the headstock assembly, the longitudinal displacement of the headstock assembly and the tailstock assembly is adjusted by the longitudinal feeding system assembly, and the transverse displacement of the grinding carriage assembly is adjusted by the transverse feeding system assembly, so that the crankshaft is ground.

2. The numerical control grinding machine of the engine crankshaft as claimed in claim 1, wherein the headstock assembly comprises an alternating current servo motor (92), a headstock box body (61), a large gear (8), a small gear (13), a gear shaft (7), a small belt wheel (22), a large belt wheel (20), a headstock tip (19), a belt (21), a headstock spindle (14) and a drive plate (60); the headstock main shaft and the alternating current servo motor are fixedly arranged in the headstock box body, the alternating current servo motor drives the pinion, the large gear is arranged on the gear shaft and is in meshed transmission with the pinion, and the other end of the gear shaft is in transmission connection with the large belt wheel through the small belt wheel and the belt; the large belt wheel is rotationally connected with the main shaft, the driving plate is fixedly connected with the large belt wheel, and the tip is arranged in the middle of the driving plate and used for being connected with a central hole in the end part of the crankshaft; the alternating current servo motor drives the gear shaft to rotate through the small gear and the large gear, then drives the driving plate and the tip to rotate through the small belt wheel and the large belt wheel, and finally drives the crankshaft to rotate.

3. The numerically controlled grinder for the engine crankshaft as claimed in claim 2, wherein a dial sleeve (57) is connected to the end face of the dial, and a headstock dial (56) is vertically connected to the end of the dial sleeve.

4. The numerically controlled grinder for engine crankshafts as claimed in claim 3, characterized in that said large pulley is rotationally connected to the headstock spindle through angular contact ball bearings (18).

5. The numerically controlled grinder for the engine crankshaft as claimed in claim 2, wherein the tailstock assembly comprises a tailstock center (38), a sleeve (33), a tailstock base (96) and a piston (34), the sleeve is in sliding fit with the tailstock base, the tailstock center is mounted at the end of the sleeve, the piston is mounted at the bottom of the sleeve, and the piston is driven to drive the sleeve and the tailstock center to longitudinally displace so that the tailstock center is matched with the end of the crankshaft.

6. The numerical control grinding machine for the engine crankshaft is characterized in that a rack is arranged at the tail part of the piston, a gear sleeve (5) is connected to the rack in a meshed mode, a tailstock deflector rod (6) is fixedly connected to the gear sleeve, and a handle rod (95) is fixedly connected to the end part of the tailstock deflector rod; the tail frame deflector rod drives the gear sleeve to rotate by rotating the handle rod, so that the piston is driven, and finally the sleeve and the tail frame tip are driven to longitudinally move; or the piston is pushed by the pressure oil, so that the sleeve drives the tailstock center to move longitudinally.

7. The numerical control grinding machine for the engine crankshaft is characterized in that the tailstock assembly further comprises a grinding motor (94), a tailstock belt wheel (39) and a diamond roller (37), the diamond roller is sleeved outside the tailstock center, the grinding motor drives the tailstock belt wheel, and the tailstock belt wheel is in transmission connection with the diamond roller so as to grind a grinding wheel (71) of the grinding wheel assembly.

8. The numerical control grinding machine for the engine crankshaft as recited in claim 7, characterized in that a spring (35) and a tailstock lead screw (32) are arranged in an inner cavity of the sleeve (33), the spring is arranged in the inner cavity of the sleeve, one end of the tailstock lead screw extends into the inner cavity of the sleeve and is fixed with the spring, the middle part of the tailstock lead screw is fixed on the sleeve through a lead screw nut (30) at the tail part of the sleeve, and the other end of the tailstock lead screw is connected with a tailstock base through a thrust ball bearing (29).

9. The numerically controlled grinder for the engine crankshaft as claimed in claim 8, wherein the grinding carriage assembly comprises a grinding wheel (71), a power motor (97), and the grinding wheel is driven by the power motor to grind the crankshaft; the transverse feeding system assembly drives a transverse ball screw (951) through a motor to drive the grinding wheel to transversely displace along the corresponding guide rail.

10. The numerically controlled grinder for the engine crankshaft as claimed in claim 9, wherein the longitudinal feeding system assembly drives a longitudinal ball screw (47) through a motor to drive a lower table (44) to move transversely along a corresponding guide rail, the lower table is connected with an upper table (45), and the upper table is provided with a headstock assembly and a tailstock assembly respectively.

Technical Field

The invention relates to a numerical control grinding machine for an engine crankshaft, and belongs to the technical field of grinding machines.

Background

The crankshaft is one of key parts of the engine, and has the advantages of complex part structure, large production batch and high precision requirement. The crankshaft is still generally processed by a grinding process, and a high requirement is provided for a crankshaft grinding machine in order to meet the increasing processing requirement of the crankshaft. When the crankshaft rotates, the transverse feeding speed of the grinding wheel is controlled to be always tangent to the connecting rod neck, and the crankshaft rotates for a circle, so that the connecting rod neck is ground. However, in the case of a constant speed rotation of the crankshaft, certain problems arise during grinding: the actual grinding depth at each tangent point (grinding point) of the connecting rod neck is different. Therefore, the grinding time of the grinding wheel at each tangent point (grinding point) on the connecting rod neck is different; the relative grinding speeds at various tangent points (grinding points) on the connecting rod neck are different; when the crankshafts are positioned at different rotating angles, the speeds and directions of grinding points are different, so that the grinding forces are different; the above-described problems cause the actual cut-in of each tangent point to be different, and thus have a certain influence on the machining accuracy, surface roughness, waviness, and other machining surface qualities of the crankshaft.

Disclosure of Invention

The invention aims to provide a numerical control grinding machine for an engine crankshaft, aiming at the defects of the prior art.

The technical scheme of the invention is as follows:

a numerical control grinding machine for an engine crankshaft is characterized by comprising a machine body base, a headstock assembly, a tailstock assembly and a grinding carriage assembly, wherein the machine body base is provided with a longitudinal feeding system assembly and a base plate, and the base plate is provided with a transverse feeding system assembly; the headstock assembly and the tailstock assembly are oppositely arranged and are arranged on a workbench connected with the longitudinal feeding system assembly, and the grinding wheel frame assembly is arranged on the base plate through the transverse feeding system assembly; the headstock assembly and the tailstock assembly clamp and fix the crankshaft together, the crankshaft is driven by the headstock assembly, the longitudinal displacement of the headstock assembly and the tailstock assembly is adjusted by the longitudinal feeding system assembly, and the transverse displacement of the grinding carriage assembly is adjusted by the transverse feeding system assembly, so that the crankshaft is ground.

Furthermore, the headstock assembly comprises an alternating-current servo motor, a headstock box body, a large gear, a small gear, a gear shaft, a small belt wheel, a large belt wheel, a headstock tip, a belt, a headstock main shaft and a drive plate; the headstock main shaft and the alternating current servo motor are fixedly arranged in the headstock box body, the alternating current servo motor drives the pinion, the large gear is arranged on the gear shaft and is in meshed transmission with the pinion, and the other end of the gear shaft is in transmission connection with the large belt wheel through the small belt wheel and the belt; the large belt wheel is rotationally connected with the main shaft, the driving plate is fixedly connected with the large belt wheel, and the tip is arranged in the middle of the driving plate and used for being connected with a central hole in the end part of the crankshaft; the alternating current servo motor drives the gear shaft to rotate through the small gear and the large gear, then drives the driving plate and the tip to rotate through the small belt wheel and the large belt wheel, and finally drives the crankshaft to rotate.

Furthermore, the end face of the driving plate is connected with a driving rod sleeve, and the end part of the driving rod sleeve is vertically connected with a headstock driving rod.

Furthermore, the large belt wheel is rotationally connected with the headstock main shaft through an angular contact ball bearing.

Furthermore, the tailstock assembly comprises a tailstock center, a sleeve, a tailstock base and a piston, the sleeve is in sliding fit with the tailstock base, the tailstock center is installed at the end of the sleeve, the piston is installed at the bottom of the sleeve, and the piston is driven to drive the sleeve and the tailstock center to longitudinally displace so that the tailstock center is matched with the end of the crankshaft.

Furthermore, a rack is arranged at the tail of the piston, the rack is meshed and connected with a gear sleeve, a tailstock deflector rod is fixedly connected onto the gear sleeve, and the end part of the tailstock deflector rod is fixedly connected with a handle rod; the tail frame deflector rod drives the gear sleeve to rotate by rotating the handle rod, so that the piston is driven, and finally the sleeve and the tail frame tip are driven to longitudinally move; or the piston is pushed by the pressure oil, so that the sleeve drives the tailstock center to move longitudinally.

Furthermore, the tailstock assembly further comprises a grinding motor, a tailstock belt wheel and a diamond roller, the diamond roller is sleeved outside the tailstock center, the grinding motor drives the tailstock belt wheel, and the tailstock belt wheel is in transmission connection with the diamond roller so as to grind a grinding wheel of the grinding wheel assembly.

Further, the sleeve inner chamber is provided with spring, tailstock lead screw, the sleeve inner chamber is arranged in to the spring, tailstock lead screw one end stretches into the sleeve inner chamber to it is fixed with the spring, and tailstock lead screw middle part is fixed in the sleeve through the lead screw nut of sleeve afterbody, and the other end of tailstock lead screw passes through thrust ball bearing and links to each other with the tailstock base.

Furthermore, the grinding carriage assembly comprises a grinding wheel and a power motor, and the power motor drives the grinding wheel to grind the crankshaft; the transverse feeding system assembly drives a transverse ball screw through a motor to drive the grinding wheel to transversely displace along the corresponding guide rail.

Furthermore, the longitudinal feeding system assembly drives a longitudinal ball screw through a motor to drive the lower workbench to transversely displace along the corresponding guide rail, the lower workbench is connected with an upper workbench, and the upper workbench is respectively provided with a headstock assembly and a tailstock assembly.

The invention considers that when the crankshaft is ground by a tangent point tracking grinding method, the crankshaft rotates at variable speed in the grinding process, but the crankshaft is ensured to be at a constant speed at the grinding point in the grinding process, and the grinding can be realized by controlling a controllable motor. Specifically, the method comprises the following steps:

1. the purpose of controlling the rotating speed of the movement path of the machine tool is achieved by controlling the voltage and the current of the alternating current servo motor through the headstock assembly. Because the working characteristics are good when the rotating speed of the motor is high, and the rotating speed of the crankshaft is relatively low in the grinding process, a speed reducing device is adopted in the middle, and two-stage speed reduction (large and small gears and large and small belt wheels) is adopted. The transmission chain of the headstock main shaft part mainly comprises gear transmission and belt wheel transmission. The alternating current servo motor is electrified, the motor rotates, and the motor is transmitted to the belt pulley on the headstock main shaft through gear transmission. In the head stock, the spindle does not rotate, which is advantageous in improving the machining accuracy. The belt pulley is installed on angular contact ball bearing, and the driver plate passes through bolted connection on the belt pulley, can rotate along with the belt pulley, so install headstock top on the driver plate alright drive the bent axle rotatory.

2. The tail frame assembly is another main component which is matched with the head frame assembly to support and center the workpiece. The whole tailstock is fixed on the workbench through two T-shaped screws, a boss is formed on the inner side of the tailstock base and used for clamping the tailstock assembly on the workbench, and when the tailstock assembly moves on the workbench, the tailstock assembly plays a role in positioning. The front end and the rear end of the tailstock assembly are respectively provided with a T-shaped screw, when the tailstock moves to a preset position, the T-shaped screws are screwed down to abut against the workbench to play a role in clamping, so that the tailstock is fixed on the workbench, and the machining precision is improved.

3. The diamond roller is arranged at the left end of the sleeve, and can be detached when the grinding machine works at ordinary times, and the grinding wheel is trimmed at a working gap. The grinding carriage assembly is a key part for driving a grinding wheel to rotate at a high speed by a grinding machine and mainly comprises a transmission part and a main shaft bearing part. The spindle and the bearing are the key parts of the grinding carriage, the spindle of the grinding carriage has high rotating speed, and frequent speed change is not needed, so the invention adopts the hydraulic sliding bearing as the spindle bearing, and the motor transmits the spindle of the grinding carriage through the belt. The bottom of the grinding carriage adopts a ball screw to lead the grinding wheel to do reciprocating movement when grinding the crankshaft. The spindle axial thrust form of the grinding carriage assembly adopts a front shaft end bidirectional thrust support, a compression ring abuts against two ends of a spindle shoulder, and a middle adjusting distance adjusting gasket is ground to adjust an inner gap.

4. The longitudinal feeding system is driven by a lead screw nut to enable the workbench to move longitudinally, so that the headstock and the tailstock which are arranged on the workbench can perform longitudinal feeding after clamping a workpiece. And the grinding carriage assembly is characterized in that the longitudinal feeding system is arranged on the base of the grinder body, and the headstock and the tailstock assembly are arranged on a workbench on the longitudinal feeding system through T-shaped screws.

The invention has the following advantages:

1. the longitudinal feeding system assembly and the transverse feeding system assembly have good quick response, do not creep when doing low-speed feeding movement, move stably and have high sensitivity; the vibration-proof structure has enough strength and dynamic rigidity, good vibration resistance and no vibration of a transmission piece caused by friction self-vibration; the transmission adopts a ball screw pair, so that the loss of rolling friction is much smaller than that of sliding friction, and the roller has good wear resistance, good precision retention performance and long service life; the ball adopts the internal circulation mode, and ball nut external diameter is small, and the rigidity is little, difficult wearing and tearing, and transmission efficiency is high. The head frame shell is thin, and heat dissipation is facilitated.

2. The headstock assembly has simple structure and convenient use and maintenance. The motor of the headstock assembly is an alternating current servo motor, the motor is transmitted to a large belt wheel on the headstock spindle through gear transmission, the headstock spindle does not rotate, vibration is reduced, and the machining precision is improved.

3. Compared with the headstock assembly, the tailstock assembly is small in size, light in weight and more convenient to move on the workbench. The tailstock assembly is simple in structure and good in manufacturability, a boss is made on the inner side of the tailstock base and used for clamping the tailstock base on the workbench, and when the tailstock assembly moves on the workbench, the tailstock assembly plays a role in positioning. The T-shaped screws are respectively arranged at the front end and the rear end of the tailstock base, and when the tailstock moves to a preset position, the T-shaped screws are screwed to abut against the workbench to play a role in clamping, so that the tailstock is fixed on the workbench, and the processing precision is improved. The tailstock assembly is dressed by the diamond roller, when the grinding wheel is dressed, the diamond roller and the grinding wheel move relatively, the time for dressing the grinding wheel by the roller is short, and the production efficiency is improved.

4. The main shaft of the grinding wheel frame assembly adopts the hydraulic bearing, so that the rotating precision of the main shaft of the grinding wheel is obviously improved. The belt pulley for driving the grinding wheel is not directly arranged on the main shaft, but arranged on a separate bracket, and the main shaft is driven to rotate by the spline, so that the deformation of the main shaft and the stress of a bearing are reduced.

Drawings

FIG. 1 is a schematic front view of a numerically controlled crankshaft grinding machine according to the present invention;

FIG. 2 is a cross-sectional view of a crankshaft numerically controlled grinder head frame assembly in accordance with the present invention;

FIG. 3 is a side partial schematic view of FIG. 2;

FIG. 4 is a front view of a tailstock assembly of the numerically controlled grinding machine for crankshafts according to the present invention;

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a schematic front view of a grinding carriage assembly of the numerically controlled crankshaft grinding machine according to the present invention;

FIG. 7 is a schematic front view of the longitudinal feed system assembly of the present invention;

in fig. 1:

2-a bed base; 3-a longitudinal feed system assembly; 65-head frame assembly; 66-a tailstock assembly; 92-a backing plate; 951-transverse ball screw; 96-a wheel carriage assembly; 97-a power motor;

in fig. 2:

7-gear shaft; 8-a bull gear; 9-bond 1; 10-a sleeve; 11-cover sealing; 12-bond 2; 13-pinion gear; 14-a head spindle; 15-screws; 16-flange 1; 17-the sleeve 2; 18-angular contact ball bearings; 19-headstock finials; 20-large belt wheel; 21-a belt; 22-a small pulley; the 23-linkage 3; 24-a felt ring; 25-flange 2; 26-screw 2; 92-ac servo motor;

in fig. 3:

56-headstock deflector rod; 57-a poker sleeve; 58-bolt; 60-a dial; 61-headstock box;

in fig. 4:

4-screw 1; 5-gear sleeve; 6-tail frame deflector rod; 27-tailstock end cover; a 28-bond; 29-thrust ball bearing; 30-lead screw nut; 32-tailstock screw; 33-a sleeve; 34-a piston; 35-a spring; 36-spacer bush; 37-diamond rollers; 38-tailstock centre; 39-tail frame belt wheel; 93-bond 2; 94-grinding the motor;

in fig. 5:

62-bolt; 63-spring washer; 95-a handle bar; 96-tailstock base;

in fig. 6:

67-a stop; 68-a compression ring; 69-flange plate; 70-grinding wheel cover; 71-a grinding wheel; 72-left end cap; 73-spacing adjustment shims; 74-a housing; 75-left hydraulic bearing; 76-a front bearing sleeve; 77-round nut; 78-main shaft; 79-right fluid bearing; 80-rear bearing sleeve; 81-the bearing compresses the inner ring; 82, pressing the outer ring by the bearing; 83-bearing retainer ring; 84-a coupling cap; 85-right flange plate; 86-right adjustment pad; 87-radial ball bearings; 88-a pulley; 89-belt wheel flange; 90-an unloading cover; 91-upper cover;

in fig. 7:

40-angular contact ball bearings; 42-end cap 1; 43-bearing seat 1; 44-lower table; 45-upper working table; 46-nut sleeves; 47-longitudinal ball screw; 48-end cap 2; 49-a coupling; 50-a power motor; 51-bolt; 53-bearing seat 2; 54-thrust ball bearing; 55-lead screw nut.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

The invention consists of five parts, including a lathe bed base 2, a longitudinal feeding system assembly 3, a headstock assembly 65, a tailstock assembly 66 and a grinding wheel frame assembly 1. As shown in figure 1: the bed body base 2 is provided with a longitudinal feeding system 3 and a backing plate 92. The bed body base 2 is connected with the longitudinal feeding system 3 through a longitudinal ball screw 47, the grinding carriage assembly 1 is connected on the base plate 92 (arranged with the transverse feeding system assembly), and the headstock assembly 65 and the tailstock assembly 66 are connected on the upper workbench guide rail.

See fig. 2, 3: the alternating current servo motor 92 is fixed on the headstock box body 61 through a bolt, the headstock deflector rod 56 is vertical to the deflector rod sleeve 57, the deflector rod sleeve 57 is connected on the drive plate 60 through a bolt 58, the headstock tip 19 is arranged at the center of the drive plate 60, and the large belt wheel 20 is connected with the small belt wheel 22 through a belt 21. The headstock assembly 65 is powered by an alternating current servo motor 92 to enable the motor to rotate, the motor is in meshing transmission through a large gear 8 and a small gear 13 and transmits motion to a small belt wheel 22 on a gear shaft 7, and the small belt wheel 22 transmits motion to a large belt wheel 20 through belt transmission. The large belt wheel 20 is arranged on the angular contact ball bearing 18, the drive plate 60 is arranged on the large belt wheel 20 through the bolt 58, the drive plate rotates with the large belt wheel 20, and the headstock center rotating with the drive plate drives the crankshaft to rotate. Before formal grinding, the position of the crank can be manually adjusted through the deflector rod 56, and the deflector rod 56 is rotated to drive the driving plate, so that the crank shaft can be pulled to rotate manually.

See fig. 4, 5: the tail frame assembly comprises a grinding motor 94, the grinding motor 94 is connected with and drives the tail frame belt wheel 39 through a key 2, and the diamond roller 37 is arranged at the left part of the tail frame belt wheel 39 and used for grinding the grinding wheel 71. The tail frame center 38, the spring 35 and the tail frame screw rod 32 are arranged in the sleeve 33, and vibration can be reduced and displacement and errors can be reduced by arranging the tail frame screw rod and the spring. The lead screw 32 is externally provided with a lead screw nut 30 and a thrust ball bearing 29, the end part of the lead screw 32 is connected with the tailstock end cover 27 through a key 28, the lower part of the sleeve 33 is provided with a piston 34, the piston 34 is meshed with the gear sleeve 5, the tailstock deflector rod 6 is arranged inside the gear sleeve 5, the deflector rod 6 is externally connected with a handle rod 95, the belt wheel 39 is connected with the trail base 96 through a bolt 63, the end part of the piston 34 is a rack and is meshed with the gear sleeve 5 for transmission, and the movement of the sleeve 33 is realized by two methods: the first is to manually rotate the handle lever 95, so that the shift lever 6 drives the gear sleeve 5 to rotate, thereby driving the piston and causing the sleeve 33 to move longitudinally; the second is that the piston 34 is pushed by the pressure oil so that the sleeve 33 moves longitudinally. The crankshaft is driven through the headstock center and longitudinally moves through the tailstock center so as to be matched with the headstock center to jointly clamp and fix the crankshaft.

See fig. 1, 6: the grinding carriage assembly comprises a base plate 92, the lower part of the base plate 92 is connected with the lathe bed base 2, and the upper part of the base plate 92 is connected with a grinding carriage 96. The center of the backing plate 92 is provided with a transverse ball screw 951, and a power motor 97 is arranged behind the grinding carriage assembly 96 to provide power for the grinding wheel 71 to grind the crankshaft. The grinding carriage shell 74 is internally provided with a main shaft 78, a left hydraulic bearing 75, a right hydraulic bearing 79 and an oil inlet pipe. The bearing is externally provided with a front bearing sleeve 76 and a rear bearing sleeve 80, and the left hydraulic bearing 75 is connected with a spacing adjusting gasket 73. The outer circle of the flange 69 is sequentially provided with a grinding wheel 71 and a grinding wheel cover 70. The right hydraulic bearing 79 is connected to an unloading cover 90 through a bolt, a belt wheel flange 89, a radial ball bearing 87 and a bearing retainer ring 83 are arranged in the belt wheel 88, a connecting cover 84 and a right flange 85 are arranged at the right end of the main shaft, and the grinding carriage shell 74 is connected with a grinding carriage upper cover 91 in a sealing mode.

See fig. 1, 7: the longitudinal feeding system 3 comprises a power motor 50, the power motor 50 is connected to a bearing seat 53 through a bolt, and a coupler 49, an end cover 42, a thrust ball bearing 54 and a longitudinal ball screw 47 are installed inside the bearing seat 53. The middle part of the ball screw 47 is provided with a screw nut 55, the outside of the screw nut 55 is provided with a screw nut sleeve 46, and the screw nut sleeve 46 is tightly connected with the lower workbench 44. The end part of the screw rod is provided with a bearing seat 43, and an angular contact ball bearing 40 is arranged inside the bearing seat 43. The upper part of the longitudinal feeding system 3 is an upper workbench 45, and a headstock assembly 65 and a tailstock assembly 66 are respectively arranged on the upper workbench 45.