CN205618642U - Electric motor car is with automatic energy -conserving drive assembly of square that increases of split type self -adaptation - Google Patents

Abstract

The utility model discloses an electric motor car is with automatic energy -conserving drive assembly of square that increases of split type self -adaptation, including box, main shaft, power input gear, gear shaft, clutch assembly, pinion stand, one -level gear, drive unit, single gear wheel and one -way spacing spiral cam. The utility model discloses a components of a whole that can function independently multi -sheet clutch assembly transmission moment of torsion has simple structure, and the assembly is swift, and easily processing can unlimited increases friction area, and the faying face is good, and the separation is fast, does not strike, and torsional forces value is the advantage such as stably. Through adjusting outer tooth friction plate and the quantity of internal tooth welt and/or the demand that adjusting button square adjusting nut adapts to different moments of torsion, promote the spacing spiral cam of thrust through one -way spacing spiral cam in addition for outer tooth friction plate and internal tooth welt loosen each other, have restricted the unlimited pressure boost of axial, guarantee that main shaft axial pressure is less than 5000N, has avoided main shaft bearing's damage. The utility model discloses reduce axial pressure, had the conversion of driving climbing machinery steadily, advantages such as sensitivity height.

Description

A kind of electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation

Technical field

This utility model relates to driving device for electric vehicle field, particularly relate to a kind of electric motor car with split type oneself Adapt to automatically increase the energy-conservation drive assembly of square.

Background technology

At present, automobile, motorcycle, electric bicycle are essentially all by speed adjusting lever or accelerator pedal Directly control air throttle or electric current controls speed, or use hand-control mechanical automatic automatic transmission mode to realize becoming Speed.The operation of handle or accelerator pedal depends entirely on the operation of human pilot, usually can cause operation with Garage's situation is not mated, and causes motor fluctuation of service, stall phenomenon occurs.Motor vehicles is by rider In the case of being unaware of running resistance, the speed change gear controlled according only to experiential operating, unavoidable exist with Lower problem: 1, increase due to running resistance when startup, upward slope and heavy load, force motor speed to decline In the work of inefficient district.2, owing to not having mechanical transmission to adjust moment of torsion and speed, can only be in plains region Promote the use of, it is impossible to meet and use under mountain area, hills and heavy load conditions, reduce range.3、 At driving wheel, installing space is little, after being mounted with electromotor or motor be difficult to accommodate again automatic transmission and other New technique.4, do not possesses adaptive function, it is impossible to automatically detect, revise and get rid of the operation of driver Mistake.5, when speed change is unexpected, power of motor is necessarily caused to be difficult to mate with running resistance.6、 Continue apart from short, climbing capacity is poor, subject range is little.

As Chinese Patent Application No. 201510565642.0 discloses a kind of battery-operated motor cycle inner rotor motor spiral shell Rotating tapered sleeve transmission self-adapting automatic gear shift drive assembly, it includes that internal rotor drives motor, casing, biography Moving axis, slow gear drive mechanism and mechanical intelligent adaptive rate assembly, slow gear drive mechanism includes surmounting Clutch inner ring is coated at the inner circle of a driving sleeve and inner ring and is provided with the spiral for coordinating with driving sleeve Cam.This patent has following defects that

1, the rubbing surface in this patent uses taper transferring structure, and friction area is limited, and faying face is poor, and Being difficult to, relying on increases disc spring quantity and increases torsional forces, torque value at 70-80N.m, in conjunction with time axle To pressure at more than 15000N, and the axial compressive force after clutch assembly separates reaches as high as 25000N, The diameter of axle only has the main shaft of 20mm under long high pressure stress, and axial all relevant bearings cannot hold Being subject to, easily cause main shaft bending, moment of torsion is unstable, and driving climbing machinery switching instant has impact phenomenon, machine Tool unstable properties, the defects such as market maintenance rate is high, it is impossible to batch production.

2, in this patent, the kind of drive of original main shaft and external conical sleeve is to use lead of screw groove, and centre is deposited The steel ball of a diameter of 6mm realizes, and reference for assembling is poor, and main shaft processes pole with external conical sleeve lead of screw groove It is complicated so that the manufacturing cost of product is high.The most above-mentioned patent complicated in mechanical structure, product parts is relatively Many, poor practicability.

3, directly being driven power transmission shaft by slowspeed machine, motor cost is big, and moment of torsion is little, and electric current is big, during climbing It is easily generated big electric current, have impact on the traveling distance that storage battery once charges, shorten the service life of storage battery.

4, battery-operated motor cycle electromechanical, vehicle is single, and operation strategies is little.

Utility model content

For overcoming the problems referred to above, this utility model provides a kind of electric motor car and automatically increases by split type self adaptation The energy-conservation drive assembly of square, which solves traditional product structure complicated, and manufacturing cost is high, and mechanical performance is unstable Fixed, and the problem that market maintenance rate is high.

This utility model solves its technical problem and be the technical scheme is that a kind of electric motor car is with split type Self adaptation increases the energy-conservation drive assembly of square automatically, including casing, coordinates with body pivot and outputs power Main shaft, also includes power input gear, gear shaft, clutch assembly, pinion stand, one-stage gear, biography Moving cell, ratchet and unidirectional spacing spiral cam.

Wherein, power input gear coordinates with external motor-driven, and is meshed with gear shaft.

Gear shaft and pinion stand fix formation one chamber, and clutch assembly is installed in the chamber.

Described clutch assembly has the spline assembly seat and the spacing spiral cam of thrust being set on main shaft； Alternately stacked in the outside of spline assembly seat it is configured with several external tooth friction plates and internal tooth liner plate；Thrust limits One end of position spiral cam is connected with spline assembly seat, and the other end is provided with and unidirectional spacing spiral cam phase The cam coordinated；It is provided with for by spline away from the side of the spacing spiral cam of thrust at spline assembly seat External tooth friction plate on assembly seat and the disc spring of internal tooth liner plate compression, the outer end of this disc spring is additionally provided with for adjusting The moment of torsion adjusting nut of joint disc spring pressing power.Further, described spline assembly seat contacts with main shaft Offer spline on medial surface, on main shaft, be correspondingly arranged on one group of keyway matched with spline accordingly. Further, between disc spring and main shaft, it is additionally provided with the disc spring seat being set on main shaft.

One-stage gear is arranged on pinion stand, and is turned round by the gear unit realization that matches with ratchet The conversion of square.Preferably, one-stage gear and pinion stand are integrated.

Unidirectional spacing spiral cam is provided with the groove matched with cam, unidirectional spacing spiral prominence wheel case It is contained on main shaft, and can axially compress the spacing spiral cam of thrust under the drive of ratchet so that from External tooth friction plate and the internal tooth liner plate of clutch assembly mutually unclamp.

As this utility model one detailed description of the invention, above-mentioned gear unit includes countershaft, on this countershaft There is the first gear being meshed with one-stage gear, and the second gear being meshed with ratchet, should First gear and the second gear are coaxially disposed, and the diameter of one-stage gear is less than the diameter of the first gear. Owing to one-stage gear is delivered between ratchet use the lever ratchet speed ratio design big by small band Principle, adds torque effect pushing clutch assembly moment open, and moment reduces electric current simultaneously so that The climbing efficiency of vehicle is greatly enhanced.Certainly, the concrete structure of gear unit is not limited to tool described above Body embodiment, i.e. uses multiple sets of teeth wheels can also realize good transmission effect as increased the quantity of countershaft Really, do not repeat them here.

The over-travel of internal tooth liner plate during for preventing clutch assembly from unclamping, as of the present utility model enter one Step is improved, and on main shaft, the location arrangements of corresponding disc spring has collar flange.Described disc spring seat is total towards spline Become a side end face of seat at collar flange outwardly and compress spline assembly seat, this spline assembly seat Internal diameter is less than the internal diameter of disc spring seat.When unidirectional spacing spiral cam axially compresses the spacing spiral cam of thrust, Spline assembly seat overcomes under the effect of disc spring to left movement until moving at the collar flange of main shaft so that External tooth friction plate and the internal tooth liner plate of clutch assembly mutually unclamp.Serve spacing at above-mentioned collar flange Effect.The axial distance of above-mentioned cam is less than or equal to the axle between spline assembly seat to collar flange To distance；The diameter of cam is less than the internal diameter of unidirectional spacing spiral cam upper groove.

As further improvement of the utility model, the end of main shaft is additionally provided with one or two flanges.More enter One step, this utility model also includes casing fixed plate, and casing has left box body and right case, left box body Being fixed in casing fixed plate, the left side endoporus at gear shaft is provided with the first main shaft bearing, this first master The internal diameter of axle bearing is installed on main shaft；The second master that internal diameter is set on main shaft it is additionally provided with on right case Axle bearing, the right side of this second main shaft bearing is provided with the nut being set on main shaft, the outside of this nut It is additionally provided with the right cover plate preventing axial runout.

This utility model compared with prior art, has an advantage in that:

1, this utility model uses split multidisc clutch assembly transfer of torque, on the one hand can be by regulation External tooth friction plate adapts to the needs of the different moment of torsion of various with the quantity of internal tooth liner plate, on the other hand can Compressing disc spring by regulation moment of torsion adjusting nut makes it promote disc spring seat and then reach to demarcate torque demand.This Utility model uses split multidisc clutch assembly to have simple in construction, and assembling is quick, it is easy to processing, The advantages such as torsional forces value stabilization, after moment of torsion exceedes the calibration value of clutch assembly, unidirectional spacing spiral prominence Wheel promotes the spacing spiral cam of thrust so that external tooth friction plate and internal tooth liner plate mutually unclamp, and effectively limit The most unlimited supercharging, main shaft axial compressive force is less than 5000N, it is to avoid the damage of main shaft upper bearing (metal).

2, this utility model uses the side that the spacing spiral cam of thrust cooperates with unidirectional spacing spiral cam Formula, and the structure of cam, groove is optimized, the axial distance of concrete cam is less than or equal to Spline assembly seat unclamps gap to the axial distance between collar flange, i.e. clutch assembly；Cam Diameter, less than the internal diameter of unidirectional spacing spiral cam upper groove, effectively reduces axial compressive force, limits axle To unlimited supercharging.

3, gear unit of the present utility model uses mechanical lever-type ratchet speed ratio design principle, in conjunction with The advantage of aforementioned multidisc clutch assembly so that travelling climbing torque greatly, electric current is little, and electric efficiency is high, Extend the service life of storage battery.

4, this utility model uses dynamo-electric split-type design, is used as power by external motor, adjusts speed ratio, Vehicle uses wide, low cost, and for various vehicles, as long as appropriately adjusting in mechanical strength, I.e. can operate with and two take turns, make driving means on three-wheel, four-wheel storage battery motorcycle and four-wheel battery automobile.

5, it is optimized on mechanism transmission design, simplifies traditional structure, optimize processing technique, Decrease part, reduce cost.

To sum up, this utility model has can infinitely increase friction area, and faying face is good, separates fast, does not rushes Hit, the advantage of torsional forces value stabilization.It is noted that this utility model decreases axial compressive force, make Climbing mechanical switch of must driving a vehicle is steady, and sensitivity is higher.

Below with reference to drawings and Examples, this utility model is described in detail.

Accompanying drawing explanation

Fig. 1 is sectional view of the present utility model.

Fig. 2 is the sectional view of multidisc clutch assembly.

Fig. 3 is the partial enlarged drawing of Fig. 2.

Fig. 4 is the fundamental diagram of multidisc clutch assembly in this utility model.

Wherein, 1, main shaft；2, adpting flange；3, jump ring I；4, power input gear；5, gear Axle；6, jump ring II；7, oil sealing I；8, clutch shaft bearing；9, pad is adjusted；10, moment of torsion adjusts spiral shell Female；11, disc spring；12, disc spring seat；13, casing fixed plate；14, the first counter shaft bearing；15, one Level gear；16, right case；17, the second counter shaft bearing；18, countershaft；19, ratchet；20、 Unidirectional spacing spiral cam；21, nut；22, right gland；23, oil sealing II；24, right gland screw； 25, the second main shaft bearing；26, plane bearing I；27, the 3rd bearing；28, ball；29, gland； 30, plane bearing II；31, pinion stand；32, the spacing spiral cam of thrust；33, the second bearing；34、 Screw；35, screw；37, internal tooth liner plate；38, external tooth friction plate；39, spline assembly seat；40、 First main shaft bearing；41, oil sealing III；42, left box body；43, collar flange；44, spline；12a、 The bottom face of disc spring seat；39a, the end face outside of spline assembly seat；101, cam；102, groove.

Detailed description of the invention

Embodiment,

Referring to Fig. 1 to 4, a kind of electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation, bag Include casing fixed plate 13, left box body 42, right case 16, and be rotatably assorted with right case and by power Output main shaft 1, also include power input gear 4, gear shaft 5, clutch assembly, pinion stand 31, One-stage gear 15, gear unit, ratchet 19 and unidirectional spacing spiral cam 20.

Left box body 42 is fixed on the left side of casing fixed plate 13, and right case 16 is fixed on casing fixed plate 13 Right side, main shaft 1 extends to right case 16 direction from left box body 42, and runs through casing fixed plate 13. It is separately installed with adpting flange 2 at the two ends, left and right of main shaft 1.

Power input gear 4 is arranged on the outside of left box body 42, and coordinates with external motor-driven, dynamic The outside of power input gear 4 is additionally provided with jump ring I 3.Under the drive of external motor, power input gear 4 The gear shaft 5 engaged can be driven to rotate together.

It is internal that gear shaft 5 is arranged on left box body 42, and it is connected shape with pinion stand 31 by screw 35 is fixing Becoming a chamber, clutch assembly is installed in the chamber, also installs between above-mentioned chamber and left box body 42 Having clutch shaft bearing 8, the outside of this clutch shaft bearing 8 is additionally provided with jump ring II 6 and oil sealing I 7.At gear shaft 5 Left side endoporus the first main shaft bearing 40 is installed, the internal diameter of this first main shaft bearing 40 is installed in main shaft 1 On, it is arranged with oil sealing III 41 on the left of it.

Described clutch assembly has disc spring seat 12, spline assembly seat 39 and the thrust limit being set on main shaft Position spiral cam 32；Alternately stacked in the outside of spline assembly seat 39 it is configured with several external tooth friction plates 38 and internal tooth liner plate 37, the external tooth alignment bosses of external tooth friction plate 38 is contained in the mounting groove of pinion stand 31, The internal tooth alignment of internal tooth liner plate 37 is arranged in the mounting groove of spline assembly seat 39.External tooth friction plate 38 He The number of combinations of internal tooth liner plate 37 to carry out group according to the vehicle torque demand of various battery-operated motor cycles, electric locomotive Closing and use, external tooth friction plate 38 and internal tooth liner plate 37 are respectively no less than two panels.The spacing spiral cam of thrust One end of 32 is connected with spline assembly seat 39 cross, and the other end is provided with and unidirectional spacing spiral cam 20 phase The cam 101 coordinated；Disc spring seat 12 is arranged with for by the external tooth friction plate on spline assembly seat 39 38 and internal tooth liner plate 37 compress disc spring 11, the outside of this disc spring 11 is additionally provided with for regulation disc spring pressing The moment of torsion adjusting nut 10 of power.

Rectangular spline 44 is offered, accordingly on the medial surface that above-mentioned spline assembly seat 39 contacts with main shaft 1 On main shaft 1, be correspondingly arranged on one group of keyway matched with spline.

On main shaft 1, the location arrangements of corresponding disc spring seat 12 has the collar flange being close to the setting of above-mentioned keyway 43, described disc spring seat 12 towards a side end face of spline assembly seat 39 at collar flange 43 outwardly And compressing spline assembly seat 39, the internal diameter of this spline assembly seat 39 is less than the internal diameter of disc spring seat 12.Work as list When spacing spiral cam 20 axially compresses thrust spacing spiral cam 32, spline assembly seat 39 overcomes dish To left movement until moving at the collar flange 43 of main shaft under the effect of spring 11 so that clutch assembly External tooth friction plate 38 and internal tooth liner plate 37 mutually unclamp.

Main shaft 1 is additionally provided with for adjusting between the first main shaft bearing 40 and moment of torsion adjusting nut 10 Bearing is to the adjustment pad 9 of position of bearings.

One-stage gear 15 is arranged on pinion stand 31 and is positioned on the right side of casing fixed plate 13, and by pair Axle 18 matches with ratchet 19 and realizes the conversion of moment of torsion.Have and one-stage gear 15 on this countershaft 18 The first gear being positioned on the left of countershaft being meshed, and be meshed with ratchet 19 to be positioned at countershaft right Second gear of side, this first gear and the second gear are coaxially disposed, and the diameter of one-stage gear 15 is little Diameter in the first gear.

Unidirectional spacing spiral cam 20 is provided with the groove 102 matched with cam 101, unidirectional spacing Spiral cam 20 is sleeved on main shaft 1, and can axially compress thrust limit under the drive of ratchet 19 Position spiral cam 11 so that external tooth friction plate 6 and internal tooth liner plate 7 mutually unclamp.Ratchet 19 He It is provided with two the 3rd bearings 27 between unidirectional spacing spiral cam 20, is equiped with between two the 3rd bearings 27 Ball 28 and gland 29, the internal tooth of the 3rd bearing 27 fixes with unidirectional spacing spiral cam 20.

The bottom face 12a of above-mentioned disc spring seat is close to end face outside 39a of spline assembly seat, additionally spline assembly End face outside 39a of seat to the axial distance of collar flange 43 end face be exactly clutch unclamp gap X, This X is in the range of 0.5～1mm.The axial distance Y of above-mentioned cam 101 is total less than or equal to spline Become the axial distance between seat 39 to collar flange 43, i.e. clutch unclamps gap X；Cam 101 Diameter D1 less than the internal diameter D2 of unidirectional spacing spiral cam 20 upper groove 102.

Left box body 42 is fixed in casing fixed plate 13 by screw 34, and this casing fixed plate 13 sets Be equipped with the second bearing 33 that internal diameter is connected with pinion stand 10, and internal diameter be connected with countershaft 18 first Counter shaft bearing 14.

The second main shaft bearing 25 that internal diameter is set on main shaft 1 it is provided with on described right case 16, and interior Footpath and the second counter shaft bearing 17 being connected on the right side of countershaft.Above-mentioned second main shaft bearing 25 and unidirectional spacing spiral shell Being provided with plane bearing I 26 between rotation cam 20, the right side of the second main shaft bearing 25 is provided with and is set in master Nut 21 on axle 1, the outside of this nut 21 is additionally provided with the right gland 22 preventing axial runout, described Right gland 22 is fixed on right case 16 by right gland screw 24, at right gland 22 and main shaft 1 Contact site is provided with oil sealing II 23.

In the present embodiment, also set between unidirectional spacing spiral cam 20 and the spacing spiral cam of thrust 32 There is plane bearing II 30.

Operation principle of the present utility model is as follows:

1, external motor is inputted to power input gear 4 by gear or Timing Belt, thus driven gear axle 5, pinion stand 31 and multidisc clutch assembly operate and produce moment of torsion, when the moment of torsion produced is in demarcation Time in the range of value, clutch assembly drives main shaft 1 power to be exported, and is passed to back wheels of vehicle by adpting flange. Now, the spacing spiral cam of thrust cooperates with the helicoid on unidirectional spacing spiral cam, Liang Zhe Rotate together under the effect of pinion stand.

2, the one-level tooth after multidisc clutch assembly torque resistance reaches calibration value, on pinion stand 31 Take turns 15 power and be transmitted to the first gear on the left of countershaft 18, then be transmitted to ratchet by second gear on right side 19, drive unidirectional spacing spiral cam 20, the unidirectional spacing spiral cam 20 spacing spiral cam of band dynamicthrust 32, promote the spline assembly seat 39 in clutch assembly to the left so that external tooth friction plate 38 and internal tooth liner plate 37 unclamp.Owing to one-stage gear 15 is delivered between ratchet 19 use the lever list big by small band To gear ratio design principle, add torque effect pushing clutch assembly moment open, moment fall simultaneously Low electric current, makes vehicle add climbing efficiency.This utility model is applicable to two to take turns, three-wheel, four-wheel electricity Bottle motorcycle and four-wheel battery automobile.

The above is only the preferred embodiment to utility model, not limits the scope of utility model Fixed, therefore on the premise of without departing from this utility model design spirit, those of ordinary skill in the art are to this reality The equivalence change done by novel described structure, feature and principle or decoration, all should fall into this practicality new In the protection domain of type.

Claims (10)

1. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation, including casing, with case The main shaft (1) that body is rotatably assorted and outputs power, it is characterised in that: also include power input gear (4), Gear shaft (5), clutch assembly, pinion stand (31), one-stage gear (15), gear unit, list To gear (19) and unidirectional spacing spiral cam (20)；

Wherein, described power input gear (4) coordinates with external motor-driven, and with gear shaft (5) It is meshed；Gear shaft (5) and pinion stand (31) fix formation one chamber, and clutch assembly is arranged on In this chamber；

Described clutch assembly has spline assembly seat (39) being set on main shaft (1) and thrust is spacing Spiral cam (32)；In the outside of spline assembly seat (39), alternately stacked several external tooths that are configured with rub Pad (38) and internal tooth liner plate (37)；One end of the spacing spiral cam of thrust (32) and spline assembly Seat (39) is connected, and the other end is provided with the cam (101) matched with unidirectional spacing spiral cam (20)； It is provided with for by spline away from the side of the spacing spiral cam of thrust (32) at spline assembly seat (39) The disc spring (11) that external tooth friction plate (38) on assembly seat (39) and internal tooth liner plate (37) compress, The outer end of this disc spring (11) is additionally provided with the moment of torsion adjusting nut (10) for regulation disc spring pressing power；

Described one-stage gear (15) is arranged on pinion stand (31), and by gear unit with unidirectional Gear (19) matches and realizes the conversion of moment of torsion；Unidirectional spacing spiral cam (20) is provided with convex The groove (102) that wheel (101) matches, unidirectional spacing spiral cam (20) is sleeved on main shaft, And can axially compress the spacing spiral cam of thrust (32) under the drive of ratchet (19) so that from External tooth friction plate (38) and the internal tooth liner plate (37) of clutch assembly mutually unclamp.

2. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: on the medial surface that described spline assembly seat (39) contacts with main shaft (1), offer spline (44), on main shaft (1), one group of keyway matched with spline (44) it is correspondingly arranged on accordingly.

3. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: between described ratchet (19) and unidirectional spacing spiral cam (20), be additionally provided with two Three bearings (27), are positioned at the ball (28) between two the 3rd bearings (27), and are used for fixing The gland (29) of three bearings (27).

4. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: between described disc spring (11) and main shaft (1), be additionally provided with the disc spring seat (12) being set on main shaft.

5. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: the position of described main shaft (1) the most corresponding upper disc spring (11) is additionally provided with collar flange (43).

6. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 5, its It is characterised by: the axial distance of described cam (101) is less than or equal to spline assembly seat (39) to ring Axial distance between shape flange (43)；The diameter of cam (101) is less than unidirectional spacing spiral cam (20) The internal diameter of upper groove (102).

7. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: described pinion stand (31) and one-stage gear (15) are integrated.

8. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 1, its It is characterised by: the end of described main shaft (1) is additionally provided with one or two flanges.

9. electric motor car as described in any one of claim 1 to 8 increases automatically by split type self adaptation that square is energy-conservation to be driven Dynamic assembly, it is characterised in that: described gear unit includes that countershaft (18), this countershaft have on (18) The first gear being meshed with one-stage gear (15), and second be meshed with ratchet (19) Gear, this first gear and the second gear be coaxially disposed, and the diameter of one-stage gear (15) is less than the The diameter of one gear.

10. electric motor car increases the energy-conservation drive assembly of square automatically by split type self adaptation as claimed in claim 9, It is characterized in that: also include casing fixed plate (13), described casing has left box body (42) and right case Body (16), left box body (42) is fixed in casing fixed plate (13), in the left side of gear shaft (5) Endoporus is provided with the first main shaft bearing (40), and the internal diameter of this first main shaft bearing (40) is installed in main shaft (1) on；The second main shaft that internal diameter is set on main shaft (1) it is additionally provided with on described right case (16) Bearing (25), the right side of this second main shaft bearing (25) is provided with the nut being set on main shaft (1) (21), the outside of this nut (21) is additionally provided with the right cover plate (22) preventing axial runout.