CN209130129U - A kind of two grades of pure electric vehicle speed changers - Google Patents

Abstract

The utility model discloses a kind of two grades of pure electric vehicle speed changers, including front housing, the front bearing retainer connecting with front housing, an axle assembly, two axle assemblies, case of transmission and the rear bearing cover connecting with case of transmission；One axle assembly is supported on front housing, and the both ends of two axle assemblies are respectively supported on an axle assembly inner ring and case of transmission；Two axis, one shelves gear is set on two axle assemblies, sliding sleeve is set between two axis, one shelves gear and an axle assembly, selector fork is set above sliding sleeve, speed-changer operation device is arranged in shift fork axle in selector fork empty set above selector fork；Uniformly distributed 3 jackshafts around two axle assemblies；The both ends of each jackshaft are respectively supported on front housing and case of transmission.The utility model uses the technology path of three jackshafts, reduces center away from the small in size, light-weight, compact-sized of, speed changer；Meanwhile three jackshafts use structure symmetrical once on two, both can guarantee lubrication, moreover it is possible to which reduction churning loss as far as possible improves gearbox efficiency.

Description

A kind of two grades of pure electric vehicle speed changers

Technical field

The utility model belongs to speed changer field, is related to a kind of two grades of pure electric vehicle speed changers.

Background technique

With the advance of society and the fast development of auto industry, automobile has become the highly important vehicles of people. With being increasingly stringenter for petroleum-based energy anxiety and emission reduction regulation, many countries including China have put into effect relevant policies, Encouragement taps a new source of energy automobile, pure electric automobile is small with noise, zero-emission, it is comfortable clean the advantages that become a kind of development and become Gesture and auto industry to the inexorable trend of automation and intelligent development, at present the technology path of pure electric coach gradually by Pure electricity is directly driven onto motor and EMT is added to change.

Also there are two grades of pure electric vehicle speed changers in the market, but the technology path generallyd use is single jackshaft or double jackshafts Scheme, gear shift sliding sleeve use big chamfering structure.Therefore generally existing product weight is big, and stability is insufficient, and gear shift ride comfort is poor, makes an uproar The problems such as sound is big.

Utility model content

The shortcomings that the purpose of the utility model is to overcome the above-mentioned prior arts provides a kind of two grades of pure electric vehicle speed changers.

In order to achieve the above objectives, the utility model is achieved using following technical scheme:

A kind of two grades of pure electric vehicle speed changers, including front housing, the front bearing retainer being connect with front housing, an axle assembly, two axle assemblies, Case of transmission and the rear bearing cover being connect with case of transmission；One axle assembly is supported on front housing, the both ends point of two axle assemblies It is not supported on an axle assembly inner ring and case of transmission；

Two axis, one shelves gear is set on two axle assemblies, sliding sleeve is set between two axis, one shelves gear and an axle assembly, on sliding sleeve Side sets gradually selector fork, gear shift shifting block and speed-changer operation device, and selector fork empty set is in shift fork axle, and the two of shift fork axle End is separately fixed on front housing and case of transmission；

First jackshaft is set below two axle assemblies；Second jackshaft, other side setting are set at the upper side of two axle assemblies Third jackshaft；One end of each jackshaft is both supported upon on front housing, and the other end is both supported upon on case of transmission；Each centre One shelves gear of intermediate shaft transmission gear and jackshaft, the axis being arranged on intermediate shaft transmission gear and an axle assembly are respectively provided on axis Gear often engages, and one shelves gear of jackshaft is often engaged with two axis, one shelves gear；Setting inputs the rotor that tests the speed on second jackshaft；Two Axle assembly rear end setting output flange and output are tested the speed rotor.

The utility model further improvement is that

Intermediate shaft transmission gear, one shelves gear of jackshaft, a shaft gear and two axis, one shelves gear are helical gear.

Intermediate shaft transmission gear is identical with the rotation direction of one shelves gear of jackshaft, one grade of tooth of intermediate shaft transmission gear and jackshaft Wheel is duplicate gear.

One axle assembly is supported by the first four point positioning ball bearing；Two axle assembly both ends pass through no outer ring cylindrical roller respectively Bearing and the support of the second four point positioning ball bearing；The both ends of each jackshaft pass through band clasp slot cylinder roller bearing and circle respectively Column roller bearing supports.

Three annular grooves self-locking for selector fork are set in shift fork axle；Inside selector fork setting compressed spring and Self-locking steel ball；Self-locking steel ball one end is placed in annular groove, and the other end is contacted with compressed spring.

Front limit pad and rear limit pad of the setting for selector fork limit in shift fork axle.

Shifting block groove is arranged in selector fork front and rear sides, and one end of gear shift shifting block U-shaped structure is stuck in shifting block groove.

Two axis, one shelves gear empty set is on two axle assemblies, the front/rear end of two axis, one shelves gear and the end face contacted Upper setting oil-way.

Several oil ducts for lubrication are respectively provided on front housing, front bearing retainer, case of transmission and rear bearing cover.

Speed-changer operation device is single-shaft shifting mechanism；Front housing, front bearing retainer, case of transmission and rear bearing cover are aluminium Alloy material；Case of transmission is pre-large post-small, at 5 ° of angular rear closing ins.

Compared with prior art, the utility model has the following beneficial effects:

The utility model is by one axle assembly of setting and two axle assemblies of axle assembly right end connection and under two axle assemblies The first jackshaft of side's setting；Second jackshaft is set at the upper side of two axle assemblies, and third jackshaft is arranged in the other side；In three Between axis technology path, center is away from for 90mm, and center is away from small by 39% compared with other technology paths of same torque section, entirely Speed changer it is small in size, light-weight, compact-sized, chassis version applicatory is more, and the arrangement on vehicle chassis is also more convenient； Meanwhile three jackshafts are in addition to the shaft head structure of the second jackshaft, identical, structure symmetrical once in use two, Both lubrication had been can guarantee, moreover it is possible to which reduction churning loss as far as possible improves gearbox efficiency.Speed changer front and back bearings lid respectively needs to push down The end face of four bearings, using bearing cap integral design, intensity is good, and part is few；Speed changer monnolithic case using up big and down small, Wineglass formula shape-designing, casing rigidity are good.Setting inputs the rotor that tests the speed, the setting output of two axle assembly rear ends on the second jackshaft Test the speed rotor, exports the revolving speed with input by velocity sensor induction speed variator, facilitates matching gear shift.Meanwhile two axle assembly Upper setting two axis, one shelves gear is arranged sliding sleeve, selector fork is arranged above sliding sleeve, changes between two axis, one shelves gear and an axle assembly Shelves shift fork empty set is in shift fork axle, and setting speed-changer operation device is mentioned using the gear changing mode of sliding sleeve gear shift above selector fork The high ride comfort of gear shift, selector fork empty set can slide back and forth realization and hang shelves in shift fork axle；Meanwhile sliding sleeve gear shift Structure is simple, part is few, failure rate is low, improves safety while cost is reduced.

Further, intermediate shaft transmission gear, one shelves gear of jackshaft, a shaft gear and two axis, one shelves gear are all made of tiltedly Gear, helical gear work load capacity is stronger, and the noise of speed changer reduces, and can reach similar product international most advanced level.

Further, intermediate shaft transmission gear and one shelves gear of jackshaft are designed to duplicate gear, improve two on jackshaft The relative position degree of a gear reduces noise, improves bearing capacity；Simultaneously as helical teeth speed variator, there are axial force, bearing is more Use tapered roller bearing；And tapered roller bearing needs to adjust axial gap, is not easy to the assembly of assembly, if not adjusting or adjusting Whole improper, bearing is easily damaged.The rotation direction of the jackshaft gear of the utility model is identical, therefore the two pairs of gears engaged simultaneously Axial force is contrary, at the same when design gear helical angle size setting with the axial force of each shifting gear it is of substantially equal for mark Standard, two axial forces that the helical teeth engagement acted on jackshaft generates are cancelled out each other a part, and the assembling of assembly is improved Energy and reliability improve transmission efficiency simultaneously.

Further, an axle assembly and two axle assemblies are all made of the support of four point positioning ball bearing and fix, and bear helical gear The axial force generated is engaged, limit speed is high, and it is at low cost, it is easy for installation；Jackshaft rear and front end has used band clasp slot respectively Cylinder roller bearing and cylinder roller bearing support, improve assembly assembly performance and reliability at the same improve transmission imitate Rate.

Further, three annular grooves self-locking for selector fork are set in shift fork axle；It is set inside selector fork It sets compressed spring and self-locking steel ball constitutes self-locking mechanism, self-locking mechanism is located on selector fork, and gearbox shape is simple, and structure is tight It gathers.

Further, front limit pad is set in shift fork axle and rear limit pad passes through when selector fork is moved forward and backward gear shift Limit in shift fork axle pads existing gear shift stroke limit, accurately and reliably.

Further, shifting block groove is arranged in front and rear sides on selector fork, and one end of gear shift shifting block U-shaped structure is stuck in In shifting block groove, since shifting block groove is in the front and rear sides of center on selector fork, gear shift shifting block does not have shift fork There is torque reaction, does not need additional locking device.

Further, two axis, one shelves gear empty set eliminates the needle bearing being easily damaged, to mention on two axle assemblies The high reliability of speed changer；Oil-way is set on the front/rear end of two axis, one shelves gear or the end face contacted, is guaranteed Lubrication between two axis, one shelves gear and two axle assemblies；Meanwhile on front housing, front bearing retainer, case of transmission and rear bearing cover Be respectively provided with it is several for lubricate the second jackshaft, the jackshaft on third jackshaft and the second jackshaft and third jackshaft is driven One shelves gear of gear and jackshaft.

Further, speed-changer operation device is single-shaft shifting mechanism, without gear selecting, need to only realize former and later two gears With three positions of neutral gear；Case of transmission uses pre-large post-small shape-designing, at 5 ° of angular rear closing ins, makes full use of gear pair Front and back arrangement, pre-large post-small structure space is handsome in appearance, and casting manufacturability is good；Front housing, front bearing retainer, case of transmission and Rear bearing cover is aluminum alloy material, and in conjunction with advantage small in size, the weight of speed changer further mitigates, and economic sexual clorminance is prominent Out.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the utility model；

Fig. 2 is two sections of cylindrical shell schematic diagrames of the utility model；

Fig. 3 is second jackshaft of the utility model and the explosive view for inputting the rotor that tests the speed；

Fig. 4 is the self-locking explosive view with caging system of the fork of the utility model.

Wherein: 1- front housing；2- four point positioning ball bearing；3- front bearing retainer；Mono- axle assembly of 4-；5- is without outer ring cylindrical roller axis It holds；Bis- axle assembly of 6-；7- band clasp slot cylinder roller bearing；8- jackshaft；9- case of transmission；10- cylinder roller bearing；1- Rear bearing cover；Bis- axis of 12-, one shelves gear；13- four point positioning ball bearing；14- ring flange；15- exports the rotor that tests the speed；16- shift fork Axis；Pad is limited after 17-；18- selector fork；19- manipulates assembly；20- sliding sleeve；21- front limit pad；22- inputs the rotor that tests the speed； 23- gear shift shifting block；24- compressed spring；The self-locking steel ball of 25-.

Specific embodiment

In order to make those skilled in the art better understand the scheme of the utility model, below in conjunction with the utility model reality The attached drawing in example is applied, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that described Embodiment is only the embodiment of the utility model a part, instead of all the embodiments.Based on the reality in the utility model Example is applied, every other embodiment obtained by those of ordinary skill in the art without making creative efforts is all answered When the range for belonging to the utility model protection.

It should be noted that the specification and claims of the utility model and term " first " in above-mentioned attached drawing, " second " etc. is to be used to distinguish similar objects, without being used to describe a particular order or precedence order.It should be understood that in this way The data used are interchangeable under appropriate circumstances, so that the embodiments of the present invention described herein can be in addition at this In illustrate or description those of other than sequence implement.In addition, term " includes " and " having " and their any deformation, meaning Figure be to cover it is non-exclusive include, for example, containing the process, method, system, product or equipment of a series of steps or units Those of be not necessarily limited to be clearly listed step or unit, but may include be not clearly listed or for these processes, The intrinsic other step or units of method, product or equipment.

The utility model is described in further detail with reference to the accompanying drawing:

Referring to Fig. 1 and 2, two grades of pure electric vehicle speed changers of the utility model, including front housing 1, the front bearing retainer being connect with front housing 1 3, an axle assembly 4, two axle assemblies 6, case of transmission 9 and the rear bearing cover 11 being connect with case of transmission 9；One axle assembly 4 Support is on front housing 1, and 4 right end of an axle assembly connects two axle assemblies 6, and the both ends of two axle assemblies 6 are respectively supported at 4 inner ring of an axle assembly On case of transmission 9；One axle assembly, 4 right end connects two axle assemblies 6, and two axle assemblies 6 pass through no outer ring cylindrical roller axis respectively Hold 5 and four point positioning ball bearing 13 be supported on 4 inner ring of an axle assembly and case of transmission 9；Two axis are provided on two axle assemblies 6 One shelves gear 12 is provided with sliding sleeve 20 between two axis, one shelves gear 12 and an axle assembly 4；Selector fork is set above sliding sleeve 20 18, in shift fork axle 16, shift fork axle 16 supports and is fixed on the front housing 1 and case of transmission 9 of speed changer 18 empty set of selector fork In shift fork axis hole；Speed-changer operation device 19 is set above selector fork 18；It is provided in shift fork axle 16 for selector fork 18 The front limit pad 21 of limit limits pad 17, uniformly distributed three jackshafts 8 around two axle assemblies 6, the front and back end of every jackshaft with rear It is supported on case of transmission 9 by band clasp slot cylinder roller bearing 7 and cylinder roller bearing 10 respectively.On every jackshaft It is respectively provided with one shelves gear of intermediate shaft transmission gear and jackshaft, the axis tooth being arranged on intermediate shaft transmission gear and an axle assembly 4 Wheel often engagement, one shelves gear of jackshaft are often engaged with corresponding two axis, one shelves gear 12.Two axle assemblies, 6 rear end is provided with output and surveys Fast rotor 15 and output flange 14.

Referring to Fig. 3, the input for detecting speed changer is arranged in the rear end positioned at upper left second jackshaft of two axle assembly 6 The input of revolving speed is tested the speed rotor 22.

Referring to fig. 4, shift fork is self-locking and caging system, including shift fork axle 16, rear limit pad 17, selector fork 18, front limit Pad 21, gear shift shifting block 23, compressed spring 24 and self-locking steel ball 25；One end of gear shift shifting block 23 is U-shaped structure, is stuck in selector fork In the shifting block groove that front and rear sides are arranged on 18, shifting block groove is in the front and rear sides of center on selector fork 18, front and back It stirs selector fork 18 and realizes gear shift.Setting is there are three annular groove in shift fork axle 16, the self-locking hole being arranged on selector fork 18 In compressed spring 24 and self-locking steel ball 25 are set, self-locking steel ball 25 is squeezed by compressed spring 24, makes self-locking steel ball 25 and shift fork Annular groove contact on axis 16, is realized self-locking.

The design principle of the utility model and specific work process are described further with reference to the accompanying drawing:

The utility model uses the technology path of three jackshafts, and center is away from other technologies for 90mm, with same torque section Route compared to center away from small by 39%, it is small in size, light-weight, compact-sized；Applicable more chassis version floor compartments can With lower, the arrangement on vehicle chassis is also more convenient.Three jackshafts use structure symmetrical once on two, both can guarantee Lubrication, moreover it is possible to which reduction churning loss as far as possible improves gearbox efficiency；Intermediate shaft transmission gear and centre on each jackshaft One shelves gear of axis is all duplicate gear, improves the relative position degree of two gears on jackshaft, reduces noise, improves carrying energy Power；Two axis, one shelves gear, 12 empty set eliminates the needle bearing being easily damaged, to improve reliability on two axle assemblies 6.Two Oil-way is set on the front/rear end of one shelves gear 12 of axis or the end face contacted, for guaranteeing two axis, one shelves gear 12 With the lubrication between two axle assemblies 6；It is respectively provided on the front housing 1 of speed changer, front bearing retainer 3, case of transmission 9 and rear bearing cover 11 Have several oil ducts, for lubricate intermediate shaft transmission gear on the first jackshaft and the second jackshaft and one shelves gear of jackshaft with And the band clasp slot cylinder roller bearing 7 and cylinder roller bearing 10 of jackshaft front and back end；One shaft gear is in conjunction with an axis gear shift Gear ring is by being welded together；The left and right sides is provided with shifting block groove on selector fork 18, and gear shift shifting block 23 rides over shifting block In groove, shifting block groove is in shift fork axle hole center two sides, and gear shift shifting block 23 does not have torque reaction to selector fork 18.It dials front and back Dynamic selector fork 18 realizes gear shift, saves the parts such as gear shift guide block, the fixed pin of traditional gearbox, and structure is simple, reliability It is high, at low cost；When selector fork 18 is moved forward and backward gear shift, gear shift stroke limit is realized by the limited block being arranged in shift fork axle 16 Position, accurately and reliably；Self-locking mechanism is located on selector fork, and gearbox shape is simple, compact-sized；Transmission control is electricity Dynamic single-shaft shifting mechanism need to only realize three positions of former and later two gears and neutral gear without gear selecting；It is provided in shift fork axle 16 Three annular grooves are arranged compressed spring 24 and self-locking steel ball 25 in the self-locking hole opened up on selector fork 18, pass through compression bullet Spring 24 squeezes self-locking steel ball 25, contacts self-locking steel ball 25 with the annular groove in shift fork axle 16, realizes one grade, two grades and neutral gear It is self-locking；It is respectively set that rotor is tested the speed in output and input is tested the speed rotor on two axle assemblies, 6 rear end and the second jackshaft, passes through survey The revolving speed of fast sensor sensing speed changer output and input, facilitates matching gear shift；One grade of intermediate shaft transmission gear, jackshaft tooth Wheel, two axis, one shelves gear 12 and a shaft gear are all helical gear design, and helical gear work load capacity is stronger, and speed changer is made an uproar Sound is low；The front bearing retainer 3 and rear bearing cover 11 of speed changer respectively need to push down the end face of four bearings, are all made of bearing cap monoblock type Design, intensity is good, and part is few；One axle assembly 4 and two axle assemblies 6 are all made of the support of four point positioning ball bearing, bear helical gear and nibble The axial force generated is closed, limit speed is high, and it is at low cost, it is easy for installation.The rotation of one shelves gear of intermediate shaft transmission gear and jackshaft To identical all using dextrorotation, therefore when the contrary engagement of two pairs of gear axial forces engaging simultaneously, intermediate shaft transmission gear For driven gear, one shelves gear of jackshaft is driving gear, though therefore the identical axial force of rotation direction it is contrary, while designing tooth The setting of helical angle size is of substantially equal for standard with the axial force of each shifting gear when wheel, thus acts on jackshaft Two axial forces generating of helical teeth engagement cancel out each other a part；Jackshaft rear and front end has used band clasp slot cylindrical roller Bearing 7 and cylinder roller bearing 10 improve the assembly performance of assembly and reliability while improving transmission efficiency；1 He of front housing Speed change shell 9 uses aluminum alloy material, and in conjunction with advantage small in size, the weight of speed changer further mitigates.The shell of speed changer Arrangement before and after gear pair is made full use of, pre-large post-small structure is empty at 5 ° of angular rear closing ins using pre-large post-small shape-designing Between；Speed changer monnolithic case uses up big and down small, wineglass formula shape-designing, and casing rigidity is good；Referring to Fig. 1, the shell of speed changer For two sections of core structures, main box is cylindrical in shape, without upper cover.

Specific work process:

The power of motor is combined by spline and is transmitted to the shaft gear being arranged on an axle assembly 4 of speed changer, a shaft gear It is often engaged with intermediate shaft transmission gear, driving jackshaft 8 rotates, and one shifting gear of jackshaft is often nibbled with two axis, one shifting gear 12 It closes, two axis, one shelves gear, 12 empty set on two axle assemblies 6 is provided with outer flower on two axle assemblies 6, and in two axis, one shelves gear 12 Key.Toothholder is coupled with two axle assemblies 6 by spline, when sliding sleeve 20 is moved together with selector fork 18, the conjunction gear of sliding sleeve 20 In conjunction with the external splines of two axis, one shelves gear 12, two axle assemblies 6 and two axis, one shelves gear 12 are integrally formed and by certain speed ratio It rotates and transmits power.

For one grade, the sliding sleeve 20 of operation transmission puts in first gear side, and power passes through one after an axle assembly 4 input The meshing relation of shaft gear and intermediate shaft transmission gear, driving jackshaft 8 rotate, one shelves gear of jackshaft and two axis, one shelves gear 12 also rotate with, and drive and gear ring, toothholder is combined to rotate, toothholder is connect with two axle assemblies 6 by spline, and then power is just by tooth Seat is handed to two axle assemblies 6, and then is exported by ring flange 14.

When hanging direct high, power is inputted from an axle assembly 4, successively total by a shaft gear, sliding sleeve 20, toothholder, two axis At directly being exported after 6, output flange 14.

The above content is only to illustrate the technical idea of the utility model, and the protection model of the utility model cannot be limited with this Enclose, it is all according to the utility model proposes technical idea, any changes made on the basis of the technical scheme each falls within this reality Within protection scope with novel claims.

Claims (10)

1. a kind of two grades of pure electric vehicle speed changers, which is characterized in that including front housing (1), the front bearing retainer (3) being connect with front housing (1), One axle assembly (4), two axle assemblies (6), case of transmission (9) and the rear bearing cover (11) being connect with case of transmission (9)；One axis Assembly (4) is supported on front housing (1), and the both ends of two axle assemblies (6) are respectively supported at an axle assembly (4) inner ring and case of transmission (9) on；

Two axis, one shelves gear (12) is set on two axle assemblies (6), is arranged between two axis, one shelves gear (12) and an axle assembly (4) and slides It covers (20), sliding sleeve (20) is sequentially arranged above selector fork (18), gear shift shifting block (23) and speed-changer operation device (19), gear shift For shift fork (18) empty set on shift fork axle (16), the both ends of shift fork axle (16) are separately fixed at front housing (1) and case of transmission (9) On；

The first jackshaft (8) are set below two axle assemblies (6)；Second jackshaft, the other side are set at the upper side of two axle assemblies (6) Third jackshaft is set；One end of each jackshaft is both supported upon on front housing (1), and the other end is both supported upon case of transmission (9) On；One shelves gear of intermediate shaft transmission gear and jackshaft, intermediate shaft transmission gear and an axle assembly are respectively provided on each jackshaft (4) shaft gear being arranged on often engages, and one shelves gear of jackshaft is often engaged with two axis, one shelves gear (12)；On second jackshaft Rotor (22) are tested the speed in setting input；Rotor (15) are tested the speed in two axle assemblies (6) rear end setting output flange (14) and output.

2. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that the intermediate shaft transmission gear, One shelves gear of jackshaft, a shaft gear and two axis, one shelves gear (12) are helical gear.

3. a kind of two grades of pure electric vehicle speed changers according to claim 1 or 2, which is characterized in that the jackshaft driving cog Wheel is identical with the rotation direction of one shelves gear of jackshaft, and intermediate shaft transmission gear and one shelves gear of jackshaft are duplicate gear.

4. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that an axle assembly (4) passes through The support of first four point positioning ball bearing (2)；Two axle assemblies (6) both ends pass through no outer ring cylinder roller bearing (5) and second respectively Four point positioning ball bearing (13) support；The both ends of each jackshaft pass through band clasp slot cylinder roller bearing (7) and cylinder respectively Roller bearing (10) support.

5. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that be arranged on the shift fork axle (16) Three annular grooves self-locking for selector fork (18)；Setting compressed spring (24) and self-locking steel ball inside selector fork (18) (25)；Self-locking steel ball (25) one end is placed in annular groove, and the other end is contacted with compressed spring (24).

6. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that be arranged on the shift fork axle (16) Front limit pad (21) and rear limit pad (17) for selector fork (18) limit.

7. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that before and after the selector fork (18) Shifting block groove is arranged in two sides, and one end of gear shift shifting block (23) U-shaped structure is stuck in shifting block groove.

8. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that two axis, one shelves gear (12) Lubricating oil is arranged on the front/rear end of two axis, one shelves gear (12) and the end face contacted on two axle assemblies (6) in empty set Slot.

9. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that the front housing (1), front bearing retainer (3), several oil ducts for lubrication are respectively provided on case of transmission (9) and rear bearing cover (11).

10. a kind of two grades of pure electric vehicle speed changers according to claim 1, which is characterized in that the speed-changer operation device It (19) is single-shaft shifting mechanism；Front housing (1), front bearing retainer (3), case of transmission (9) and rear bearing cover (11) are aluminium alloy Material；Case of transmission (9) is pre-large post-small, at 5 ° of angular rear closing ins.