CN1110770A

CN1110770A - Gear speed variator with load

Info

Publication number: CN1110770A
Application number: CN 93119669
Authority: CN
Inventors: 郑悦
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-10-30
Filing date: 1993-10-30
Publication date: 1995-10-25
Anticipated expiration: 2013-10-30
Also published as: CN1051605C

Abstract

The speed variator for gears with load features that speed variation is realized by applying power to different gears in brake mode for planetary gear speed variator or friction contact mode for fixed-axle gear one and the engaged object of each gear is not changed, so avoiding collision between gears on speed varying. Its advantages are high drive efficiency and on-load speed variation.

Description

Gear speed variator with load

This is that the invention of energy gear graduation belongs to mechanical transmission fields about not cutting off load.

This is the target that the mechanical transmission fields people chase always.The infinite variable speed efficient electric power formula, hydraulic type and friction type that can the on-load speed change is lower usually.Though and gear type speed change efficient height, it is difficult being used for the on-load speed change.The present invention is intended to bring up a kind of gear-shift transmission, and it can not cut off load and automatically or manually change velocity ratio in the power transmission.

Basic inventive concept is, all gears and gear pair all are in and determine constant engagement, when the conversion velocity ratio, do not change its engagement, promptly before the speed change with whose engagement, after the speed change still with whose engagement.In other words, speed changer is speed change in any case, and each gear is all determined unchangeably and the gear engagement that originally is meshed with it.Speed change just feeds different gears with power.And existing speed-changing gear box generally all comes speed change by changing some gear meshing object, and therefore gear has engaging-in when speed change and nibble out, for avoiding the tooth collision, and have to use clutch, synchronizer, make mechanism become complicated, and be difficult to accomplish the on-load speed change.Therefore the exchange of gear when the present invention has avoided speed change has been avoided the engaging-in of gear and has been nibbled out, is easy to accomplish simply the on-load speed change.

First kind of way of realization of the present invention is at planet transmission " brake type speed change ".Planetary transmission always has at least one gear not rotate with respect to casing, claims that here it is a fixed gear.Make planetary transmission that a plurality of fixed gears be arranged, each fixed gear is all keeping meshing with one or several gear definitely, thereby is representing a corresponding velocity ratio of speed changer.Under general situation, except that a fixed gear, all the other fixed gears are all rotating relative to casing, so just transmitted power of unique fixed gear that does not rotate, the velocity ratio of its representative becomes speed changer work velocity ratio at this moment.If release out this fixed gear, make it free to rotate, prevent the rotation of another fixed gear simultaneously, a then back fixed gear enters work, and the velocity ratio of speed changer just is transformed on the velocity ratio of a back fixed gear representative.This speed change is to be undertaken by the braking to certain gear, therefore can be called " brake type speed change ".Brake available break or various stop mechanism is finished.When all fixed gears were all released out and rotated, speed changer was positioned at neutral gear.

An embodiment of brake type speed change sees transmission sketch Fig. 1.Have off-centre on the input shaft 1, two ends are supported on housing 4 and output shaft 5 through bearing 2,3 respectively.Output shaft 5 is supported on housing 4 through bearing 7,8, and output gear 6 coaxially is being connected on it.On the eccentric segment of input shaft 1, supporting 11,12, the 13 and 14 tetrad planetary pinions of forming through planetary bearing 9,10, wherein planetary pinion 14 keeps engagement with output inner gear 6, and

planetary pinion

11,12,13 keeps engagement with fixed gear (internal gear) 15,16,17 respectively.Fixed

gear

15,16,17 all can rotate in housing, their outer neck face is equipped with

break

18,19,20, can brake fixed

gear

15,16,17 respectively, when which fixed gear was braked, speed changer was just with the velocity ratio work of which fixed gear representative.

In this specification, with Z _xThe expression label is the number of teeth of the gear of x, and for example gear 6 numbers of teeth are Z ₆Because Fig. 1 belongs to the planetary mechanism of two interior engagements, its velocity ratio formula is that the crowd knows.Braking is not changeed if fixed gear 15 is braked device 18, and the 16, the 17th, and is free to rotate, then the ratio of input shaft 1 and the rotating speed of output shaft 5

i_{15} = \frac{1}{1 - \frac{Z_{15} Z_{14}}{Z_{11} Z_{6}}}

If relax away 15, and make break 19 that fixed gear 16 brakings are not changeed, then the work speed ratio of speed changer just is changed to

i_{16} = \frac{1}{1 - \frac{Z_{16} Z_{14}}{Z_{12} Z_{6}}}

For present embodiment, the variation slightly of the number of teeth can make speed changer that very wide slewing range is arranged.But very little velocity ratio then is difficult for accomplishing.

Another embodiment of brake type speed change sees transmission sketch Fig. 2.This is the Gear Planet Transmission pattern of using the most extensively in the industrial products, is called the NGW Gear Planet Transmission in China.Input shaft 21 is bearing on housing 42 and the output shaft 27 through bearing 25,26.Installing three

sun gears

22,23,24 on the input shaft 21, they keep engagement with

planetary pinion

30,31,32 respectively, also keep engagement with another

group gear

33,34,35 respectively.30,31,32 be contained on the planet axis 28 through bearing housing, 33,34,35 are contained on the planet axis 29 through bearing housing, and these two groups of planetary pinions are symmetrically distributed, can be around planet axis rotation separately, and also can be around axle 21 revolution.Planetary pinion 30,33 and fixed gear 36 keep engagement, and

planetary pinion

34,31 and fixed gear 37 keep engagement, and

planetary pinion

32,35 and fixed gear 38 keep engagement.Fixed

gear

36,37,38 all is an internal gear, can rotate in housing, and their outer neck face is equipped with

break

39,40,41.Planet axis 28,29 is installed on the output shaft 27, becomes pivoted arm.Arbitrary fixed gear is not changeed by the braking of its break, and speed changer is just with the speed ratio work of its representative.For example be braked device 39 braking and do not change when 36, and the 37, the 38th, free to rotate, then the speed ratio of the speed changer ratio of the rotating speed of output shaft 27 (input shaft 21 with) is

i ₃₆=1+ (Z ₃₆)/(Z ₂₂)

Unclamp 36, and with 37 brakings, the speed ratio of speed changer just is transformed to

i ₃₇=1+ (Z ₃₇)/(Z ₂₃)

The rest may be inferred, realizes the brake type speed change.

The principle that after having seen this embodiment, can more clearly conclude " brake type speed change " is as follows:

At least have fixed gear and planetary planetary transmission, if be provided with K rotating fixed gear, and the K cover planetary pinion that meshes definitely with each fixed gear, speed changer just can have K speed ratio so.Prevent certain fixed gear relative to the rotating of casing, speed changer is just with the formed speed ratio work of this fixed gear.The braking object is when a fixed gear is changed to another fixed gear, and the speed ratio of speed changer is just done corresponding conversion thereupon.

NN formula transmission shown in Figure 1, planetary pinion can be that many groups are equally distributed, and correspondingly eccentric shaft (planet axis) also should have as much individual mutually.Except that NN and NGW, WW, N, the various Gear Planet Transmission of NW, NGWN or the like that Chinese mechanical engineering circle is alleged all can utilize above-mentioned principle to make brake type on-load speed changer.

In the brake type speed changer, the fixed gear that is not braked, relatively input speed rotates extremely slowly, and therefore corresponding arrestment mechanism is easy to design, utilizes known technology not accomplish not difficultly.For example the outer neck face of fixed gear among Fig. 1 15,16,17 is also made gear shape, then the stop pin that can radially move embeds the outer neck face between cog of which fixed gear, and which fixed gear just is braked.

Second kind of way of realization of the present invention is the speed change that is mainly used in the centrifugal friction engagement type of fixed shaft type speed changer.Its embodiment sees Fig. 3.

Input shaft 43 is bearing on left casing 77 and the output shaft 47 through bearing 44,46.47 are supported on the right shell body 78 through bearing 45 and supporting 59, and the 75, the 76th, oil sealing is installing output gear 60 on 47.Gear 56 is supported in the supporting 57 that is packed on the right shell body 78, and gear 54 is supported on the flange of gear 56 and is packed within the supporting 55 of right shell body.Gear 58 is supported on another flange of gear 56 and is packed within the supporting 59 of right shell body.Gear 54,56,58,60 respectively with gear 64,65,66,67 engagement, back 4 gears are installed on the axle 61, axle 61 is supported on the left and right casing through bearing 62,63.Crouch slippingly in the keyway of axle 43 in the stage casing of C shape key 48, its right-hand member that erects is held by axle sleeve 49 and plate washer 79, thereby can stir axle sleeve 49 and rotate with axle 43, also can 49 slippages vertically of pulling shaft cover.Be fixed with pin 50 and 51 on the axle sleeve 49, stretch into centrifugal 52 respectively, in 53 the endoporus, when axle 43 through key 48, axle sleeve 49, pin 50,51 drive centrifugal 52, during 53 rotations, action of centrifugal force makes centrifugal 52,53 outer neck cylndrical surface be adjacent to the interior neck cylndrical surface of Fig. 3 middle gear 58, driven gear 58 rotations by the effect of frictional force.Since gear 54,56,58 and 60 interior neck cylndrical surface be coaxial, with internal diameter and arrange, so C type key 48 can spur centrifugal 52,53 slippage vertically, move to the interior neck cylndrical surface of which gear, just which gear is the frictional force that is produced by centrifugal force drive and rotate together.Move in the gear 54,54 rotations also drive the output shafts rotation through gear 64, axle 61, gear 67, gear 60, and this moment, the speed ratio ratio of the rotating speed of output shaft 47 (input shaft 43 with) of speed changer equaled

i ₅₄= (Z64)/(Z54) · (Z60)/(Z67)

Centrifugal moves in the gear 56, then the speed ratio of speed changer

i ₅₆= (Z ₆₅)/(Z ₅₆) · (Z ₆₀)/(Z ₆₇)

Centrifugal in gear 58 (position among Fig. 3), speed ratio is

i ₅₈= (Z ₆₆)/(Z ₅₈) · (Z ₆₀)/(Z ₆₇)

Centrifugal speed ratio is centrifugal and moves within the gear 60 in gear 58 (position among Fig. 3), and input shaft directly drives output shaft rotation, the speed ratio of speed changer through centrifugal frictional force

i ₆₀＝1

Because centrifugal is smoothly moved on the neck face in gear, is frictionally with engaging of gear, thus speed changer can on-load level and smooth and easily speed change.

If put a slip ring free to rotate abreast with gear (for example 54), then centrifugal just drives slip ring idle running when moving within this slip ring, breaks away from other gear, is equivalent to speed changer and is placed on " neutral gear ".Can be with reference to 92 among the figure 4.

The left end of C type key erects and is held by axle sleeve 70, shelves ring 71, and bearing 72 inner rings are loaded on the axle sleeve 70, and the outer ring is loaded in the axle sleeve 73, and by 70,71,73 axial restraints.A upright arm of axle sleeve 73 is packed in the right-hand member of speed change lever 74, speed change lever 74 stretches out through left casing 77 and connects speed Control mechanism (summary), therefore, speed change lever is when Zola or the right side push away vertically, just, carry out speed-change and gearshift through 73,72,70,48,49,50,51 drives centrifugal 52,53 axial slips.

Spring 68,69 is intended to alleviate starting-impact, or increases some positive pressures to centrifugal.For transmission for vehicles, such spring can be very weak or not, then during low engine speed centrifugal can't set up positive pressure (centrifugal force), speed changer is in neutral state automatically, and the motor raising speed will make vehicle mildly start to walk.The speed changer of this centrifugal friction engagement type of Fig. 3, owing to be outer gearing between gear, centrifugal mechanism needs bigger radial dimension, thereby the radial dimension of speed changer can be bigger.Certainly, can use a plurality of 52,53 such centrifugal, evenly distribute, cause bigger friction positive pressure, but weight can increase also.

In Fig. 3, supporting 55,57 and 59 all is the bearing support that is installed in the casing 78, but interior corresponding rolling bearing of suit of these bearing supports or sliding bearing, remove to support corresponding gear 54,56,58,60 through these bearings again, but, the ins and outs that these crowds know are not given among Fig. 3 and being drawn.

Another embodiment of centrifugal friction engagement type speed change is that interior engaging tooth changes speed, and what its radial dimension can be than outer gearing formula is little.Principle sees also Fig. 4, Fig. 5 and Fig. 6.

Among Fig. 4, gear the 83, the 85th, the turriform gear, all be by the less external gear of an internal gear and diameter coaxially one link to each other and constitute.86,87,88 all is middle ring gear, on the outer neck face of their ring an external gear is arranged, and an internal gear is then arranged on the inner cylindrical surface.The inside and outside engagement of turriform gear and middle ring gear is characteristics of this type speed changer.Outer tooth ring 84 is supported on the internal gear engagement of

housing

96,84 and middle ring gear 86 through ring-shaped bearing 96a; Middle ring gear 86 is supported on the internal gear engagement of the external gear and the turriform gear 83 of

housing

96,86 through semi-circular supporting 89; Turriform gear 83 is supported on housing, the internal gear engagement of its external gear and middle ring gear 87; Middle ring gear 87 is supported on housing through semi-circular supporting 90, the internal gear engagement of its external gear and turriform gear 85; Turriform gear 85 is supported on housing, the internal gear engagement of its external gear and middle ring gear 88; Middle ring gear 88 is supported on housing through semi-circular supporting 91, and its external gear connects internal gear 82 with output shaft and is meshed.Output shaft 82 left sides that have internal gear directly are supported on housing, and the right then is supported on housing through bearing 95a.95b is an oil sealing.

The structure of semi-circular supporting 89,90,91 above-mentioned can further show with their left side views.Fig. 5 is 91 a left view among Fig. 4, the both shoulders position of ring gear 88 external gear both sides in the middle of the inside radius of semi-ring is partly supporting, and the outer radius part of semi-ring then is supported on housing, and 91a analyses and observe and to be installed in the screw that housing is used.91b then is a Sliding bush, and the supporting and the friction factor of center tooth interannular are reduced.P+ is the sensing of the gear mesh force of speed changer when just changeing, and the sensing when P-is counter-rotating is because these point to all in the semi-ring radian, so semi-ring has when being bearing in loaded-up and the same stability of traditional ring-shaped bearing (as bearing).And speed changer is when zero load idle running, and the gravity tester of gear points to the semi-ring middle part, thereby has stability equally to vertically downward.In other words, this semi-circular supporting for the working condition of supporting force sensing in the semi-ring scope, all is effective.Semi-circular supporting can make designs simplification, and assembling is saved the useful space easily, and the supporting for inside engaged gear has meaning especially.

The transmission principle of Fig. 4 mechanism is identical with Fig. 3 mechanism.In imaginary line profile 94 presentation graphs 3 centrifugal 52, the centrifugal mechanism axle sleeve 49 in 93 presentation graphs 3 of imaginary line profile.Have among Fig. 3 48 in Fig. 4 mechanism equally, 49,50,51,52,53,68,69,79,70,71,72,73, the centrifugal mechanism that 74 grades constitute, can there be equally distributed a plurality of centrifugal equally, 83,84,85, the interior neck cylndrical surface of 82 gears is same diameter equally, coaxial line is arranged side by side, the neck cylndrical surface is moved to the left to 85 successively in centrifugal from 82,83, in the time of in 84, the speed ratio of the speed changer ratio of the rotating speed of output shaft 82 (input shaft 80 with) echelon strengthens, turriform gear-middle ring gear group is many more to the step of reduction that forms, the speed ratio shelves number that speed changer has is many more, slowest ratio (in this example be centrifugal in 84 time) is also big more, because the slowest ratio of engagement centrifugal friction joined speed variator is the product of each grade speed ratio in this.Because the facewidth of the front and back stages gear engagement of gear is overlaid in the axial direction, therefore allow in certain axial length, the shelves number of the step of reduction-speed ratio of speed changer is more.

For Fig. 3, centrifugal friction engagement type speed change shown in Figure 4, for increasing frictional force producing enough transmitting torques, answer tool certain mass, available metal material for centrifugal 52,53,94 etc., and the friction surface at centrifugal top, the nonmetallic material that then can adhere to one deck high coefficient of friction.

By the way understand the setting of above-mentioned neutral gear among Fig. 4.Slip ring 92 is enclosed within 84 free to rotate, moves on within 92 when centrifugal, drives 92 idle running, and power can't be exported, and speed changer places neutral gear.Neutral position usually should be adjacent with the slowest ratio gear, and speed changer is than the needs of descending continuous transformation when starting to walk to meet on-load (as vehicle).

The right-hand member of input shaft 80 is supported on output shaft 82 through bearing 81, its left end, and the left end of whole speed changer comprises that centrifugal block axis to control mechanism that moves or the like, all is described at Fig. 3, also is that principle is identical to Fig. 4 mechanism, thereby omits and do not draw.

Transmission sketch Fig. 6 has done open-and-shut explanation to Fig. 4 driving mechanism.The external gear 83 of left side turriform gear meshes with the internal gear of middle ring gear 86a, the external gear of 86a then with the internal gear 85a of inter-chamber tower generating gear engagement, the external gear 85b of inter-chamber tower generating gear then with the engagement of the internal gear of middle ring gear 88a, the external gear of 88a is meshed with output gear (output shaft) 82a, the facewidth of the inside and outside gear of middle ring gear is overlapping in the axial direction, can make the axial dimension of mechanism less.The 97th, input is consulted and gear, is meshed with the internal gear 83a of left side turriform gear.Each turriform gear support is in casing, and ring gear is supported on casing (omit among Fig. 6 and do not draw) through Fig. 5 and 89,90,91 such semi-circular supportings shown in Figure 4 in the middle of each.Fig. 6 illustrates the basic pattern of this transmission except cooperating Fig. 4, the inside engaged gear retarder of Gou Chenging like this, the less and bigger output torque of permission of size, internal gear does not need tooth surface heat treatment usually, cost is lower, compares with outer gearing fixed axis gear retarder, and certain advantage is arranged.The neck cylndrical surface needs not to be with internal diameter in this moment each gear.

The supporting of mentioning in this specification everywhere though direct supporting is shown on the drawing, all can be used rolling bearing (except that semi-circular supporting), rolling element, sliding bearing, supports.Be posted by the supporting in the housing, because size is bigger, sliding bearing, the lining that might allow to use the engineering plastics of low coefficient of friction to make.

The present invention's design does not change gear meshing object gear when being speed change, just power being fed corresponding gear, is to change the object that power feeds during speed change, makes the gear that is passed into power, become the driving gear of corresponding speed ratio, or transmit the fixed gear of reaction force.Aforementioned all embodiments are to have explained the distinct methods that feeds power.The brake type speed change of Fig. 1, Fig. 2 is with mode of braking power to be fed respective gears; The centrifugal friction engagement type speed change of Fig. 3, Fig. 4 is in the mode that centrifugal force produces friction power to be fed corresponding gear, for example Fig. 7, shown in Figure 8 feed the mode of power with the friction circle conical surface, be the third way of realization of the present invention.

Among schematic representation Fig. 7,

external gear

100 and 102 all meshes with internal gear 103.External gear 99,101 is coaxial with external gear 100,102 respectively, all meshes with external gear 98 again.98 coaxial with internal gear 103.Between the

gear

99 and 100, between 101 and 102, between 98 and 103 the coaxial friction circle conical surface is housed, as shown in Figure 8.The gear 102 that has outer conical surface is installed in axle 107 through key 108.Be equipped with through feather key 104 on the axle 107 gear 101 is housed on the sliding shaft sleeve 105,105 rotationally, gear 101 one are connected with internal conical surface, and can be with 105 at feather key 104 guiding lower edge axial slips.If 101 along direction of arrow slippage to the right, its inner conical surface engages with 102 male cone (strobilus masculinus), relies on the frictional force between the inside and outside conical surface, gear 101,102 rotation that will be bonded together, and power is promptly passed over.If 101 to moving to left, the then inside and outside conical surface breaks away from, and two gears separate, and transmission of power is cut off.The joint that keeps cone of friction needs certain axial push-tight power to transmit enough moments of torsion, and this available spring or alternate manner are accomplished, belong to prior art, do not narrate here.In order to increase this axial push-tight power, design of gears can be become spiral gear, make it when transmission is meshed to produce axial force, and the direction that is designed to this axial force is the push-tight cone of friction, as the direction of arrow among Fig. 8.Among Fig. 7, as if serving as to import gear with 98,103 is output gear, and when 3 cones of friction all separated, power can't transmit, and speed changer is in neutral gear; Only 101 when 102 the conical surface engages, and the speed ratio of speed changer (ratio of 98 and 103 rotating speed) is:

i= (Z101)/(Z98) · (Z103)/(Z102)

If only 99 engage with 100 the conical surface, then speed ratio is

i= (Z ₉₉)/(Z ₉₈) · (Z ₁₀₃)/(Z ₁₀₀)

If only 98 engage with 103 the conical surface, speed ratio is i=1.If simultaneously 2 or more conical surface combinations are arranged, then speed changer is in braking state, becomes break.Owing to can arrange gear on different axial positions, therefore the gear of different speed ratios can be placed on the different axial sections, makes speed changer that many speed ratio shelves numbers can be arranged.The speed changer of this cone of friction engagement type can have multiple pattern and structure, and essential features in common is that speed change does not rely on and changes gear meshing object gear, and relies on the joint of cone of friction between control gear and separately.

The speed changer that the present invention narrated can be provided with reverse gear (input and output counterrotating) easily, and this belongs to prior art.What deserves to be mentioned is that the described brake type speed changer of Fig. 1, Fig. 2 is obtained reverse gear easily,, make the number of teeth of fixed gear be less than the number of teeth of output gear 6, promptly constitute reverse gear for example for the structure of Fig. 1.

The present invention is easy to constitute automatic transmission.Speed change lever (as 74 among Fig. 3) can automatically be controlled by certain mechanism, for example output shaft is paid engagement output through spiral gear, if the axial thrust load of the engaging force that this spiral gear is paid is through certain mechanism urges speed change lever (74), push away (drawing) speed change lever (74) when for example axial force is big left, be converted into than big speed ratio, axial force hour then (because of spring force) pushes away speed change lever (74) to the right, be converted into than close steps, then the speed ratio of speed changer keeps being directly proportional with output torque (load) size automatically, forms the constant permanent power automatic transmission of input torque.The method of formation automatic transmission has multiple, and available substantially prior art cooperates facility provided by the invention to be solved, and does not narrate here.

Principle of the present invention can make gear-shift transmission on-load speed change easily, the gear teeth collision in the time of can not gear shift occurring.Owing to be gear transmission, efficient is higher.Can in smaller size smaller, have more speed change gear, and easily automatic speed changing, constitute high efficiency " accurate stepless gear-shift transmission ", be applicable to vehicle, engineering machinery and industry equipment.

Claims

1, a kind ofly makes the method that gear graduation can the on-load speed change, it is characterized in that, all gears and gear pair in the speed changer, when speed change, all be in and determine constant engagement, promptly each gear before speed change with which gear engagement, after speed change still with original that gear engagement, speed change just feeds the corresponding gear that constitutes a certain velocity ratio with power, and when power fed different such gear, speed changer promptly had different speed ratios.

2, but a kind of gear-shift transmission of on-load speed change, at least has input shaft, different gear pairs, output shaft and casing, it is characterized in that, all gears and gear pair, when speed change, all be in and determine constant engagement, be each gear before speed change with which gear engagement, after speed change still with original that gear engagement, different gear pairs constitutes the different velocity ratio of speed changer, and speed change just feeds the corresponding gear that constitutes a certain velocity ratio with power, makes the gear that is passed into power, become the driving gear of the active force of corresponding speed ratio, or become the fixed gear that transmits reaction force from casing, when the reaction force of power or casing fed different such gear, speed changer promptly had different speed ratios.

3, the described speed changer of claim 2, it is characterized in that, it is a kind of planetary transmission, at least has input shaft, output shaft, planet axis or eccentric shaft, be no less than 2 planetary pinions and be no less than 2 fixed gears, and has arrestment mechanism, each fixed gear all constitutes a speed ratio of speed changer with corresponding planetary pinion, these fixed gears all can rotate with respect to casing, if certain fixed gear is braked device or thereby other stop mechanism is braked and do not rotated and can transmit reaction force from casing with respect to casing, and other fixed gear rotates, speed changer is the speed ratio work that fixed gear was constituted to be braked just, brakes different fixed gear speed changers and just change into different speed ratios.

4, the described speed changer of claim 2, it is characterized in that, it is a kind of gear-shift transmission of ordinary transmission, has slip gear, power can be fed certain gear and become driving gear, speed changer is promptly with the speed ratio work that this driving gear was constituted, and slip gear feeds different gears with power, and speed changer just changes into corresponding different speed ratio.

5, the described speed changer of claim 4, it is characterized in that, its slip gear, be by the axle sleeve that rotates with power input shaft, pin, the centrifugal friction mechanism of centrifugal composition, this mechanism can slide vertically, thereby make centrifugal to engage with the interior neck cylndrical surface of different coaxial line gear, make engaged gear obtain the power that power input shaft transmits, become driving gear, speed changer is promptly with speed ratio work that this driving gear was constituted, under the frictional force action that centrifugal force produces as positive pressure, power is imported different driving gears for centrifugal, make that speed changer is corresponding to change into different speed ratios.

6, the described speed changer of claim 5 is characterized in that, the gear pair that constitutes different speed ratios is that external gear pump is paid.

7, the described speed changer of claim 5, it is characterized in that, the gear pair that constitutes different speed ratios is that inside engaged gear is paid, constitute the echelon engagement that inside engaged gear is paid by turriform gear and middle ring gear and the semi-circular supporting that can have, centrifugal engages with the interior neck cylndrical surface of which grade turriform gear, speed changer is the speed ratio work that driving gear constitutes with this turriform gear promptly, and slowest ratio is the product of each gear-stage velocity ratio.

8, the described speed changer of claim 4, it is characterized in that, slip gear is a plurality of cones of friction that are made of inside and outside conical surface, each cone of friction and respective gears constitute a speed ratio of speed changer, which cone of friction engages (other cone of friction separately), the gear coaxial with it promptly becomes driving gear, and speed changer is promptly with the speed ratio work of this cone of friction and driving gear formation thereof.

9, the described speed changer of claim 2 is characterized in that, because of the gear matched with particular design number of teeth has reverse gear, because of all fixed gears are all released out rotation, or has slip ring free to rotate and has the neutral gear of speed changer.

10, a kind of gear drive is characterized in that, constitutes the inside engaged gear gear stage by turriform gear, middle ring gear and the semi-circular supporting that can have, and the resultant gear ratio of multistage such interior engagement driving is the product of each stage gear ratio.