CN102623375A

CN102623375A - Z-axis lifting mechanism with stress state balancing function

Info

Publication number: CN102623375A
Application number: CN2012100686233A
Authority: CN
Inventors: 刘延杰; 吴明月; 荣伟彬; 孙立宁
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2012-03-15
Filing date: 2012-03-15
Publication date: 2012-08-01
Anticipated expiration: 2032-03-15
Also published as: CN102623375B; WO2013135052A1

Abstract

A Z-axis lifting mechanism with a stress state balancing function relates to the manufacturing field of semiconductor silicon wafer transmission robots, and solves the problems of a conventional Z-axis transmission lifting mechanism, such as poor structural stress state and larger micro-deformation of ball guide rails. The Z-axis lifting mechanism with the stress state balancing function adopts the structure that an upper mounting cover and a lower mounting cover are oppositely arranged up and down, a Z-axis driving device component is connected with a lower mounting seat, a pre-tightening wheel support frame is sleeved on the Z-axis driving device component and connected with the lower mounting seat, three lead screw transmission mechanisms are uniformly distributed between the upper mounting cover and the lower mounting cover along the same circumference, the center end of a synchronous gear transmission belt is sleeved on a synchronous transmission driving gear, three outer side ends of the synchronous gear transmission belt are respectively sleeved on three synchronous transmission driven gears, three ball screws are respectively in threaded connected with three turn-screws; a lower deep-groove ball bearing is mounted in a lower bearing mounting hole of the lower mounting seat, and an upper deep-groove ball bearing is mounted in an upper bearing mounting hole. The Z-axis lifting mechanism provided by the invention is used on a silicon chip transmission robot.

Description

A kind of Z axle elevating mechanism that can the force balance state

Technical field

The present invention relates to a kind of semi-conductor silicon chip transferring robot and make the field, relate in particular to the Z through-drive elevating mechanism in a kind of chip transmission robot.

Background technology

In the Z of chip transmission robot through-drive elevating mechanism, more use be column Z through-drive elevating mechanism, promptly use spherical guide as the motion benchmark that the Z axle goes up and down, spherical guide is installed on the datum level of column.But this transmission mechanism exists following shortcoming: the one, and structural stress state is bad.Column Z through-drive elevating mechanism be subjected to force direction in axis of movement direction along spherical guide, and the best of guide rail be subjected to force direction be with the vertical direction on spherical guide plane; The 2nd, because the total weight of superstructure all passes to spherical guide through support slipper with the form of cantilever beam; Spherical guide is outside the gravity that normally bears; Also additionally bear very big turning torque; Make spherical guide produce bigger microdeformation; Gently then motion-affecting flexibility, heavy then shorten useful life of spherical guide; The 3rd because between the installed surface and lateral register face of spherical guide, between the face of installing and locating up and down of column, all exist the shaped position tolerance relation of complicacy between the reference for installation of spherical guide installed surface and ball-screw; Therefore the column processing technology is complicated, rate of finished products is lower, and processing cost is high; The 4th, because the weight of column generally all at tens kilograms, is installed in the side direction in the cabinet, inevitably cause crank, be prone to make main frame to produce and topple; The 5th, because contact area is very big between the last lower installation board of the installed surface up and down of column and main frame, make it when assembling, be difficult for adjustment, waste time and energy.

Summary of the invention

The objective of the invention is for the Z through-drive elevating mechanism that solves existing chip transmission robot exist the useful life that structural stress state is bad, spherical guide produces bigger microdeformation, spherical guide short, the column processing technology is complicated, rate of finished products is lower, crank, main frame are prone to produce and topple, be difficult for when assemble the problem adjusted, and a kind of Z axle elevating mechanism that can the force balance state is provided.

The present invention includes down mount pad; Z axial brake device assembly; Pretension wheel supporting mechanism; Synchronous tooth driving-belt; The screw transmission mechanism; Last mounting cover; Two connecting plates; Three lead-screw drive mechanisms; Z axial brake device assembly comprises Z spindle motor seat; The encoder positioning pipe; Encoder; Z axle servomotor; The friction type brake; Synchronous Transmission driving gear and connecting plate; The upper end of said Z axle servo motor shaft is an output shaft; The lower end is a motor shaft; Said Z axle servomotor is installed in the Z spindle motor seat; And the output shaft of Z axle servomotor is positioned at the outside of Z spindle motor seat; The upper end of output shaft is provided with the transmission external tooth; Said the friction type brake and Synchronous Transmission driving gear are installed on the output shaft of Z axle servomotor from the bottom to top successively; And the center internal tooth of Synchronous Transmission driving gear and the engagement of transmission external tooth; Connecting plate is installed on the end face of Synchronous Transmission driving gear; Said encoder is arranged in the Z spindle motor seat; And encoder is installed on the motor shaft on the Z axle servomotor; The encoder positioning pipe is arranged on Z spindle motor seat outside; And the encoder positioning pipe is arranged between the flange of elasticity spacer and Z spindle motor seat lower end on the encoder; Pretension wheel supporting mechanism comprises the pretension wheeling supporting frame; Pretension wheeling supporting frame loam cake; Three pretension wheel slip frame mechanisms; Pretension wheeling supporting frame loam cake is installed on the upper surface of pretension wheeling supporting frame; Three pretension wheel slip frame mechanisms are uniformly distributed with on the upper surface that is arranged on pretension wheeling supporting frame loam cake; And each pretension wheel slip frame mechanism is installed on the pretension wheeling supporting frame and covers; Each pretension wheel slip frame mechanism comprises pretension wheel locating piece outside plate; Pretension wheel locating piece; Pretension wheel positioning sliding block; Pretension wheel rotating turret back shaft; Pretension wheel rotating turret; Two thrust jackscrews; Two locking nuts and two pretension wheel mechanisms; The upper surface of pretension wheel locating piece is provided with T-slot; The lower end of pretension wheel positioning sliding block is provided with the T shape head that matches with T-slot; T shape head cooperates installation with T-slot; Pretension wheel locating piece outside plate is installed on the outside end face of pretension wheel locating piece; Two thrust jackscrews are threaded through the screw on locking nut and the pretension wheel locating piece outside plate; The end face of screw and T shape head over against; Be provided with the rotating turret mounting groove towards the side at Z axle center on the pretension wheel positioning sliding block; The pretension wheel positioning sliding block of rotating turret mounting groove upside is provided with the rotating shaft unthreaded hole; The pretension wheel positioning sliding block of rotating turret mounting groove downside is provided with the rotating shaft screwed hole; Pretension wheel rotating turret is arranged in the rotating turret mounting groove; Pretension wheel rotating turret back shaft passes the rotating shaft unthreaded hole and pretension wheel rotating turret is threaded with the rotating shaft screwed hole; Be separately installed with the pretension wheel mechanism in the dome portion of two symmetries on the pretension wheel rotating turret; And the pretension wheel shaft on the pretension wheel mechanism is installed in the shrinkage pool on the pretension wheel rotating turret corresponding with it; Each lead-screw drive mechanism comprises the lower bearing baffle ring; The lower shaft circlip; Following deep groove ball bearing; Thrust shaft block; Thrust bearing; The thrust bearing flap; The Synchronous Transmission driven gear; The turn-screw axle; The upper bearing (metal) baffle ring; Last deep groove ball bearing; Last circlip for shaft; The top of said turn-screw axle is turn-screw; The bottom of said turn-screw axle is an optical axis; The Synchronous Transmission driven gear is installed on the optical axis; The upper bearing (metal) baffle ring; Last deep groove ball bearing and last circlip for shaft are installed in the upper end of turn-screw axle from the bottom to top successively; The thrust bearing flap; Thrust bearing; Thrust shaft block; Following deep groove ball bearing; Lower shaft is installed in the lower end of turn-screw axle from top to bottom successively with circlip and lower bearing baffle ring; Said screw transmission mechanism comprises Z axle Movable bracket and three ball screws; Z axle Movable bracket is by spider and three screw carriages; Three screw carriages are uniformly distributed with setting along the outer surface of spider; The outside end face of each screw carriage is provided with the screw installing hole; A ball screw is housed in each screw installing hole; The place, axle center of each ball screw is provided with the spiral shell that cooperates with turn-screw and buckles; Last mounting cover and following mount pad are up and down over against setting; The place of keeping to the side is provided with three lower bearing installing holes along same circumference uniform distribution on the end face of following mount pad; The same circumference uniform distribution in end face upper edge of last mounting cover is provided with three upper bearing (metal) installing holes; And three upper bearing (metal) installing holes and three lower bearing installing holes one by one over against; Z axial brake device assembly; Pretension wheel supporting mechanism; Synchronous tooth driving-belt; The screw transmission mechanism; Two connecting plates and three lead-screw drive mechanisms all are arranged between mounting cover and the following mount pad; Z spindle motor seat is connected with following mount pad; The pretension wheeling supporting frame is sleeved on the Z axial brake device assembly; And the pretension wheeling supporting frame is connected with following mount pad; Three lead-screw drive mechanisms are arranged between mounting cover and the following mount pad along same circumference uniform distribution; The center-side of tooth driving-belt is sleeved on the Synchronous Transmission driving gear synchronously; Three outboard ends of tooth driving-belt are set on three Synchronous Transmission driven gears synchronously; Six pretension wheel mechanisms on the pretension wheel supporting mechanism paste on the flank of tooth of Synchronous Transmission driving gear; Z axle Movable bracket is arranged on the top of pretension wheel supporting mechanism; And three ball wire mother stocks on the pretension wheel supporting mechanism are not threaded with three turn-screws; Following deep groove ball bearing on each lead-screw drive mechanism is installed in down in the corresponding lower bearing installing hole of mount pad; Last deep groove ball bearing on each lead-screw drive mechanism is installed in the corresponding upper bearing (metal) installing hole, and two connecting plates are symmetrical set with the axial line of Z axle servomotor.

The present invention compared with prior art has following beneficial effect: one, compare with column Z shaft transmission; The present invention is with the lead-screw drive mechanism 4 and 61 transmissions of ball screw that rotatablely move and be 120 ° of layouts by three of 15 outputs of Z axle servomotor; Z axle servomotor 15 rotatablely moving of output are converted into the rectilinear motion of ball screw 61; Realize that Z axle Movable bracket 59 is along Z-direction rectilinear motion up or down; Transmission principle of the present invention has very high transmission accuracy; And the weight that the present invention only bears upper mechanism equably; And can not produce extra turning torque because of unbalance stress; Improved stress greatly, made the Z shaft transmission more reasonable.Two, because Z axial brake device assembly 2 of the present invention is design placed in the middle; Three are 120 ° of lead-screw drive mechanisms that are uniformly distributed with 4 and make the load capacity of whole system have bigger lifting; Therefore Z axle elevating mechanism load capacity of the present invention is strong, is applicable to the article that transmission weight is heavier, volume is bigger.Three, because the present invention has cancelled the heavier column of weight, and load is equally distributed along circumference, corrected column and has been prone to the crank problem that produces, makes the main frame steadily of centre of gravity.Four, because the key mounting holes of Z axle elevating mechanism of the present invention has stipulated all that accordingly with the station processing request, therefore in assembling, adjustment process is simple relatively.

Description of drawings

Fig. 1 is the overall structure stereogram of Z axle elevating mechanism of the present invention; Fig. 2 is the three-dimensional exploded view of Z axle elevating mechanism of the present invention; Fig. 3 is the structural perspective of Z axial brake device assembly 2; Fig. 4 is the three-dimensional exploded view of Z axial brake device assembly 2; Fig. 5 is the structural perspective of pretension wheel supporting mechanism 3; Fig. 6 is the three-dimensional exploded view of No. 27 parts of pretension wheel slip frame mechanism; Fig. 7 is the three-dimensional exploded view of lead-screw drive mechanism 4; Fig. 8 is the three-dimensional exploded view of screw transmission mechanism 8.

Embodiment

Specifically first embodiment: FIG 1 to 8 with the embodiment described, the present embodiment includes a lower mount 1, Z-axis drive unit assembly 2, tightening wheel support mechanism 3, the synchronous toothed belt 7, the screw nut drive mechanism 8, installed on the cover 9, the two plates 6, and three screw gear mechanism 4, see Figure 3 and Figure 4: Z-axis drive unit assembly 2 comprises a Z-axis motor base 10, the encoder positioning tube 12, an encoder 14, Z axis servo motor 15, the friction brake 17, synchronous drive pinion 19 and the connection plate 20, the Z-axis servo motor 15 is the upper end of the output shaft axis 15-1, 15-2 lower end of the motor shaft, the Z-axis servo motor 15 is mounted by screws 16 in the Z-axis motor base 10, the Z-axis servo motor 15 and the output shaft 15-1 is located in the Z axis motor base 10 outside of the upper end of the output shaft 15-1 15-1 with external gear drive -1, and the friction brake 17 and the synchronous drive the driving gear 19 are in turn mounted on the Z-axis servo motor 15 on the output shaft 15-1, and the synchronous drive the driving gear 19 within the center of the outer tooth 15 and the drive gear - 1-1 engagement, the friction brake 17 by a screw 18 and the Z-axis servo motor 15 is fixedly connected to the upper end of the chassis plane, the connecting plate 20 by means of mounting screw 21 is mounted on the driving gear 19 simultaneously drives the end surface 22 through the connector mounting screws the center hole plate 20 and the output shaft to the center of the end face 15-1 screw threaded connection, the role of the web 20 will be synchronized with the drive pinion gear 19 in the Z-axis servo motor 15 is fixed on the motor axial direction; said encoder 14 Setting the Z-axis motor base 10, and the encoder 14 is mounted on the Z-axis servo motor 15 on the motor shaft 15-2, the encoder 14 to the top wire clamp comes encoder positioning tube 12 is provided in the Z-axis motor outside the base 10 and the tube 12 is provided encoder position encoder 14 in the resilient positioning pieces 14-1 and the Z-axis motor base 10 between the bottom of the flange, radial positioning of the encoder 14 is followed by a mounting screw 13 passes through the Flexible positioning piece positioning holes 14-1, the encoder positioning tube 12 to the center hole, Z-axis motor base 10 and the mounting hole, and then fastening the mount; friction brake 17 is the role of the system when sudden blackout able to respond quickly, due to the inertia continues to rotate in the Z-axis servo motor 15 for braking, preventing the action of gravity due to the system of the upper bodies themselves reduced, resulting in equipment accidents; Figure 5: preload wheel support mechanism 3 includes pretensioners wheel support frame 24, preload wheel bracket cover 25, three preload mechanism 27 movable shelf skating, preload wheel bracket cover 25 through the mounting screw tightening wheel support frame 26 mounted on the upper surface 24, three a tightening roller mechanism 27 movable shelf disposed uniform tightening wheel support frame upper end surface of cover 25, and each movable frame roller mechanism 27 is preloaded by tightening the mounting screws 32 are mounted on the wheel cover 25 of the support frame ; Figure 6: Each preload mechanism 27 includes a movable shelf skating round positioning block preload outer plate 31, preload wheel positioning block 33, the slider 34 preload wheel positioning, preload round turret support shaft 35, preload wheel rotation frame 37, two thrust top wire 28, two 29 and two preload nut wheel mechanism 38, preload wheel positioning block 33 with the upper surface of the T-shaped slot 33-1, preload wheel positioning the lower end of the slider 34 is provided with a T-shaped groove matching the T-shaped head 33-1 34-1, T-shaped head of the T-slot 33-1 and 34-1 with the installation, and the preload ring 34 may be positioned along the slider Slide the T-shaped slot 33-1, preload wheel positioning block outer plate 31 by mounting screws 30 mounted on the pretension wheel positioning the outer end face of the block 33, two thrust top wire 28 through the lock nut 29 and tightening wheel positioning block screw on the outer plate 31 3-1 threaded connection holes 3-1 and 34-1 T-shaped head end is right, clockwise thrust the top wire 28, with the top wire 28 screwed thrust preload wheel positioning block outer plate 31 can be positioned round the slider 34 along preload preload wheel support frame 24 in the radial direction ejection; said locking nut 29 is the role of the top wire 28 will be thrust into the position of spin lock ; preload wheel-Z-axis slider 34 toward the center of the turret mounted on the side of a groove 34-2, 34-2 on the turret side of the mounting groove preload wheel-slide 34 is provided with a rotation shaft aperture 34-3, 34-2 turret mounting slots positioned lower preload wheel rotation axis slider 34 is provided with a threaded hole 34-4, preload wheel rotation frame 37 provided in the turret mounting groove 34-2, the pre- tight round turret support shaft 35 passes through the rotating shaft of light holes 34-3 and preload wheel rotation frame 37 and the rotary shaft threaded hole 34-4 threaded connection, two tight jacking wire 36 positioned symmetrically disposed in the slider preload Wheel 34 on both sides, and with the tightening of wheel rotation axis 35 perpendicular to the direction of the support frame to preload the turret wheel support shaft 35 locked tight jacking wire 36 is to prevent the tightening wheel support shaft 35 and the turret preload wheel-slip loosening the threaded block 34, tightening wheel rotation frame 37 can preload the turret wheel rotates freely on the support shaft 35, tightening wheel rotation frame 37 of the two symmetrical convex portion mounted on each wheel mechanism 38 with preload and preload preload on the wheel mechanism 38 mounted on shaft 39 and its corresponding preload wheel rotation frame 37 on the concave hole 37-1; pretension wheel support mechanism three effects: first, to preload wheel mechanism 38 providing the correct positioning of the height direction, the second drive mechanism 38 for tightening the radial direction of the adjustment provided, to ensure tightening wheel mechanism 38 via toothed belt 7 synchronized tooth surfaces tightly bonded to the synchronous drive teeth of the pinion gear 19 surface; Figure 7: Each screw gear mechanism 4 includes a lower bearing retaining ring 44, the lower shaft circlip 45, under the deep groove ball bearing 46, thrust bearing 47, thrust bearing 49, thrust bearing seat cover 50, synchronous transmission driven gear 53, the drive screw shaft 54, the bearing retaining ring 56, the deep groove ball bearings 57, the upper shaft circlip 58, said drive screw shaft 54 of the upper part of the drive screw 54-1, the lower portion of the drive shaft 54 of the screw axis 54-2, synchronous transmission driven gear 53 is mounted on the optical axis 54-2 and synchronous transmission driven gear 53 via mounting screws 52 and drive screw shaft 54 a flange fixed connection, the upper bearing retaining ring 56, the deep groove ball bearing 57 and the shaft 58 by a circlip which are in turn mounted on the upper end of the drive screw shaft 54, a thrust bearing cap 50, thrust bearing 49, thrust bearing 47, the next deep groove ball bearings 46, the lower shaft circlip 45 and lower bearing retaining ring 44 from top to bottom in turn drive screw shaft 54 mounted on the lower end of the thrust bearing cap 50 By mounting screws 51 and thrust bearing 47 is fixedly connected; under deep groove ball bearings 46 and 57 on the role of deep groove ball bearing is to drive the rotation of the screw shaft 54 to provide precise positioning; thrust bearing 49 is to assume the role of movable carriage 59 from the Z-axis systems are hosted on weight, resulting in lower weight to prevent deep groove ball bearing 46 damage; Figure 8: said nut Z axis drive mechanism 8 includes a movable carriage 59 and three ball nut 61, Z-axis movable carriage 59 by a central plate bracket nut 59-1 and 59-2 three, three wire mother disc tray 59-2 59-1 along the center of the outer surface of the fabric are set, each wire 59-2 female bracket nut outer end surface of the mounting hole 59-2-1, 59-2-1 each nut mounting hole in the ball screw nut 61 is provided with a, each axis of the ball screw nut 61 is provided with a drive screw at the center of the spiral with the buckle 61-1 54-1, the ball screw nut 61 by mounting bracket 60 and the nut 59-2 is fixedly connected; see Figure 1 and Figure 2: the cover plate 9 and the lower mount an up and down is on the set, the lower mount an end surface near the edge along the same circumference were emplaced three lower bearing mounting holes 1-1, mounted on the end face of the cover 9 are laid along the same circumference with three upper bearing Mounting holes 9-1, and the three upper bearing mounting holes 9-1 with three mounting holes 1-1 eleven lower bearing is on, Z-axis drive assembly 2, preload wheel support mechanism 3, synchronous toothed belt 7, nut drive mechanism 8, the two plates 6, and three screw gear mechanism 4 are disposed on the cover plate 9 and the lower mount between 1, Z-axis drive unit assembly 2 in the Z-axis motor base 10 by means of mounting screws 11 with the lower mount a connection, pretension wheel support mechanism 3 wheel support frame 24 on the preload set the Z-axis drive assembly 2 and pretension wheel support frame 24 by mounting screws 23 and the lower mount a connection, three screw drive mechanism 4 are along the same circumference cloth cover 9 disposed on the upper and lower mounting mount one between synchronous toothed belt 7 Set in the center of the end of the 7-1 synchronous drive pinion gear 19, the synchronous toothed belt 7 7-2 are three packages, the outer end of the three synchronous drive the driven gear 53, on the wheel support mechanism 3 preload force of the preload, tightening wheel support mechanism 3 of the six preload tight wheel mechanism 38 paste the cover tight in synchronous drive pinion gear 19 tooth surface, in order to achieve synchronous toothed belt 7 and the synchronous drive pinion 19 synchronous transmission; Z-axis movable carriage 59 is set in the pretension wheel support mechanism 3 above, and the pre- Tight wheel support mechanism 3 on three ball nut 61, respectively, with three drive screw 54-1 threaded connection, each screw drive mechanism 4 on the next deep groove ball bearing 46 mounted on the lower mount a corresponding lower bearing mounting holes 1-1, the lower bearing retaining ring 44 by mounting screws 43 and the lower mount 1 is fixedly connected, each of the screw gear mechanism 4 on the deep groove ball bearing 57 mounted on the respective bearing mounting hole 9-1 , the upper bearing retaining ring 56 by mounting screws 55 and the cover plate 9 is fixedly connected on the thrust bearing 47 by mounting screws 48 and the lower mount 1 is fixedly connected, two plates 6 Z-axis servo motor 15 to the axis line symmetrically arranged, and the ends of each plate 6 by means of mounting screws 5, and its corresponding lower mount 1 and the upper cover plate 9 is fixed connection.

Embodiment two: combine Fig. 6 that this execution mode is described; Each pretension wheel mechanism 38 of this execution mode comprises pretension wheel shaft 39, pretension wheel 41, circlip for shaft 42 and two pretension wheel bearings 40; Said on the inner chamber of pretension wheel 41 recessed edge place a pretension wheel bearing 40 respectively is installed; Pretension wheel 41 is installed on the pretension wheel shaft 39; Circlip for shaft 42 is installed on the outer pretension that is exposed at and takes turns in the groove of pretension wheel shaft 39 upper ends of 41 upper surfaces, and circlip for shaft 42 is in order to the fixing relative position of pretension wheel bearing 40.Other composition and annexation are identical with embodiment one.

Operation principle of the present invention is: during 15 runnings of Z axle servomotor, the encoder 14 that is installed on the Z axle servomotor 15 lower end motor shaft 15-2 is started working, to the operating state of host computer feedback data with control Z axle servomotor 15; Because the internal tooth of Synchronous Transmission driving gear 19 and the engagement of the transmission external tooth 15-1-1 on the Z axle servomotor 15; Therefore; The output shaft 15-1 run-in synchronism of Synchronous Transmission driving gear 19 and Z axle servomotor 15; And drive synchronous tooth driving-belt 7; Synchronous Transmission driven gear 53; Three turn-screw axles 54 carry out run-in synchronism; Because the turn-screw 54-1 on the turn-screw axle 54 buckles 61-1 with the spiral shell on the ball screw 61 and cooperates; Therefore; Z axle Movable bracket 59 moves up and down along turn-screw axle 54; Be that Z axle servomotor 15 rotatablely moving of output are converted into the rectilinear motion of ball screw 61, realize that Z axle Movable bracket 59 is along Z-direction rectilinear motion up or down.

Claims

A method to balance the stress state of the Z axis, characterized in that: the Z-axis lift mechanism includes a lower mount (1), Z-axis drive unit assembly (2), tightening wheel support mechanism (3) , synchronous toothed belt (7) and nut drive mechanism (8), on the cover plate (9), two plates (6), three screw drive mechanism (4), Z-axis drive unit assembly (2) including Z-axis motor base (10), the encoder positioning tube (12), the encoder (14), Z-axis servo motor (15), the friction brake (17), synchronous drive pinion gear (19) and the plate (20) , the Z-axis servo motor (15) the upper end of the output shaft axis (15-1), the bottom of the motor shaft (15-2), the Z-axis servo motor (15) mounted on the Z-axis motor base (10) inside, and Z axis servo motor (15) of the output shaft (15-1) in the Z-axis motor base (10) outside of an output shaft (15-1) of the upper end of the outer gear teeth (15-1-1) said friction brake (17) and synchronous drive pinion gear (19) which are in turn mounted on the Z-axis servo motor (15) of the output shaft (15-1), the driving gear and the synchronous drive (19) to the center of internal teeth and external gear drive (15-1-1) engaging plate (20) is mounted on synchronous drive pinion (19) of the end face, said encoder (14) disposed on the Z-axis motor base (10) and the encoder (14) mounted on the Z-axis servo motor (15) on the motor shaft (15-2), the encoder positioning tube (12) is set in the Z-axis motor base (10) out of the encoder positioning tube ( 12) is set in the encoder (14) of the elastic positioning piece (14-1) and the Z-axis motor base (10) between the lower end of the flange; tightening wheel supporting means (3) comprises tightening wheel support frame (24 ), preload wheel supporting frame cover (25), three roller movable shelf preload mechanism (27), tightening wheel supporting frame cover (25) mounted on the pretension wheel support bracket (24) of the upper end face, three tightening roller movable shelf mechanism (27) disposed in uniform tightening wheel supporting frame cover (25) of the upper end face, and each movable shelf tightening roller mechanism (27) mounted on the wheel support frame pretension cover (25), each moving frame bodies pretension Skating (27) including preload wheel positioning block outer plate (31), preload wheel positioning block (33), preload wheel positioning the slider (34), preload round turret support shaft (35), preload round turret (37), two thrust the top wire (28), two lock nuts (29) and two preload wheel mechanism (38), preload wheel positioning block (33) of the upper end face of a T-slot (33-1), preload wheel-slide (34) is provided with a T-shaped lower end of the slot (33-1) mating T-shaped head (34 - 1), T-shaped head (34-1) with the T-shaped groove (33-1) with the installation, preload wheel positioning block outer plate (31) mounted on the tightening wheel positioning block (33) of the outer end surface, two Thrust top wire (28) through the lock nut (29) with pretensioners wheel positioning block outer plate (31) on the screw (3-1) threaded connections, screw (3-1) with the T-shaped head (34 - 1) is on the end face, preload wheel-slide (34) on the side toward the center of the Z-axis is provided with a turret mounting groove (34-2), the turret mounting groove (34-2) side preload wheel positioning the slider (34) is provided with a rotation shaft aperture (34-3), the turret mounting groove (34-2) preload the lower wheel-slide (34) is provided with a rotation shaft threaded hole (34 - 4), tightening wheel rotation frame (37) provided in the turret mounting groove (34-2), the preload turret wheel support shaft (35) through the rotating shaft aperture (34-3) and preload wheel rotation frame (37) and the rotary shaft threaded holes (34-4) threaded connection, tightening wheel turret (37) on two symmetrically mounted on each convex portion has pretension wheel mechanism (38), and the tightening wheel means (38) on the axle preload (39) mounted on its corresponding preload wheel turret (37) on the concave hole (37-1) and; each of the screw drive mechanism (4) includes a lower bearing retaining ring (44), the lower shaft circlip (45), under the deep groove ball bearings (46), thrust bearing (47), thrust bearing (49), thrust bearing cap (50), synchronous transmission passive Gear (53), the drive screw shaft (54), the upper bearing retaining ring (56), the deep groove ball bearings (57) on the shaft with an elastic ring (58), said drive screw shaft (54) upper part of the drive screw (54-1), said drive screw shaft (54) of the lower part of the optical axis (54-2), synchronous transmission driven gear (53) mounted on the optical axis (54-2), the upper bearing retaining ring (56), the deep groove ball bearings (57) and the upper shaft circlip (58) from the bottom in turn mounted on the drive screw shaft (54) of the upper end of the thrust bearing cap (50), only thrust bearing (49), thrust bearing (47), under the deep groove ball bearings (46), the lower shaft circlip (45) and the lower bearing retaining ring (44) mounted on the drive screw sequentially from top to bottom axis (54) of the lower end; said nut drive mechanism (8) including the Z-axis movable carriage (59) and three ball screw nut (61), Z-axis movable carriage (59) by a central plate (59-1 ) and three nut bracket (59-2), three nut bracket (59-2) along the central plate (59-1) set uniform outer surface of each nut bracket (59-2 ) of the outer end surface of nut mounting holes (59-2-1), each nut mounting hole (59-2-1) is provided with a ball screw nut (61), each ball nut (61 ) of the center of the shaft is provided with a drive screw (54-1) with a screw clip (61-1), on the cover plate (9) with the lower mount (1) is on the set top and bottom, the lower mount (1) the end face near the edge are laid along the same circumference of the lower bearing has three mounting holes (1-1), on the cover plate (9) along the same circumference of the end face are laid on the bearing has three mounting holes (9-1), and three on the bearing mounting hole (9-1) and three lower bearing mounting holes (1-1) A One is on, Z-axis drive unit assembly (2), tightening wheel support mechanism (3), synchronous toothed belt ( 7), the drive nut mechanism (8), two plates (6) and three screw drive mechanism (4) are provided in the upper cover plate (9) with the lower mount (1) between, Z axis motor seat (10) with the lower mount (1) connection, pretension wheel support frame (24) Set in the Z-axis drive assembly (2) on the wheel and the preload bracket (24) with the lower mount (1) connection , three screw drive mechanism (4) along the same circumference are provided in the upper cover plate cloth (9) with the lower mount (1), between synchronous toothed belt (7) of the central terminal (7-1) set in the synchronization transmission driving gear (19), the synchronous toothed belt (7) of the three outer end (7-2) were set in three synchronous transmission driven gear (53), the tightening wheel support mechanism (3) of the six preload wheel mechanism (38) affixed to the synchronous drive pinion cover (19) of the tooth surface, Z axis movable carriage (59) provided in the tightening wheel support mechanism (3) above, and the tightening wheel support mechanism ( 3) the three ball nut (61) respectively, and three drive screw (54-1) threaded connection, each of the screw gear mechanism (4) on the lower deep groove ball bearings (46) attached to the lower mount (1) corresponding to the bearing mounting hole (1-1), each screw drive mechanism (4) on the deep groove ball bearing (57) mounted on the respective bearing mounting hole (9-1), the two plates (6) in the Z-axis servo motor (15) to set the axis of symmetry.
2. according to the said a kind of Z axle elevating mechanism that can the force balance state of claim 1; It is characterized in that: each pretension wheel mechanism (38) comprises pretension wheel shaft (39), pretension wheel (41), circlip for shaft (42) and two pretension wheel bearings (40); Said on the inner chamber of pretension wheel (41) recessed edge place a pretension wheel bearing (40) respectively is installed; Pretension wheel (41) is installed on the pretension wheel shaft (39), and circlip for shaft (42) is installed in the groove of pretension wheel shaft (39) upper end that is exposed at pretension wheel (41) upper surface outward.