CN1104731A

CN1104731A - Stepless speed change with centrigual friction

Info

Publication number: CN1104731A
Application number: CN 93115309
Authority: CN
Inventors: 郑悦
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-30
Filing date: 1993-12-30
Publication date: 1995-07-05

Abstract

The stepless speed variator uses centrifugal force as positive pressure that acts directly on internal friction wheel, not bearing, to increase drive efficiency. It is suitable for car or motor with full-load starter.

Description

Stepless speed change with centrigual friction

The invention belongs to mechanical transmission fields, be based on No. the 90104953rd, Chinese patent literature and american documentation literature 07-735, on No. 330 and further make.

It is the transmission of friction positive pressure that above-mentioned patent documentation has proposed with centrifugal force, but fails to solve the stepless change problem.Other prior art document has a large amount of introductions about friction stepless gearbox, but fails to solve the friction positive pressure in bearing and low this two large problems of transmission efficiency, and this is two hang-ups that perplex the stepless transmission artificer of friction in decades.

Among schematic representation Fig. 1 of the present invention, pivoted arm 7 is housed on the input shaft 5, suit planetary bearing 8,8 supporting epicyclic friction gear 1a and 1b in the

slide block

9,9 is housed symmetrically, in the breach of pivoted arm 7 as pivoted arm such as n ₁Direction is rotated, and when changeing very soon, centrifugal action makes planet wheel 1a and 1b be adjacent to interior friction wheel 2, and the automatic direction of planet wheel is shown in arrow among the figure, with n ₁On the contrary, thus mechanism can make retarder and use.Little spring 10 makes 8,9,1a, 2b outwards strut, the impact when contacting with interior friction wheel to eliminate planet wheel.

Among Fig. 2, in the breach of the pivoted arm 6,7 that is connected on the input shaft 5 slide block 9 is housed slidably, suit planetary bearing 8 in it.The epicyclic friction gear 1,3 that the coaxial line one is connected, in planetary bearing 8, jack shaft passes through the perforate of pivoted arm 12 with the two end axles end bearing, and 1 other also has the be connected reverse gear planet wheel 11 of coaxial line of an one.1,3 respectively with the loop contacts in the protruding cross section of

interior friction wheel

2,4, the radius of 1,3 contacting points is respectively R1, R3.The 2nd, be placed in through feather key 18 and can slide vertically within the casing 16 but rotatable, 4 outputting powers, it is set within 16, rotatablely also can slide vertically, and be connected with axial interlock with 2 through thrust-bearing 17.4 output terminal does not have spiral internal gear 13, and interior cover has between the

output shaft

14,14 and 4 of spiral external gear and is set with spring 15.

The input shaft rotating speed is n ₁, be supported on casing 16 through bearing 25 and 24 _aWith in the output within the

friction wheel

4,5 drive planet wheels 1,3 revolution through pivoted arm 6,7 and slide block 9,

planetary bearing

8, and 1,3 is that the friction positive pressure is adjacent to 2,4 and rotations with centrifugal force, and the contact radius when 2,4 is respectively R ₂, R ₄The time, velocity ratio

I=(input speed n ₁)/(output speed n ₄)=

\frac{1}{1 - \frac{R_{2} R_{3}}{R_{1} R_{4}}}

When 2,4 one were slided vertically, in Fig. 2, a left side is sliding then 1,3 to be depressed, and rightly slidingly then 1,3 can follow to rise under centrifugal action and was adjacent to, and breach in the pivoted arm 6,7 and slide block 9 make 1,3 footpath become possibility up and down.2, during 4 axial slips, 1,3 contact radius R ₁And R ₃Change, velocity ratio i changes thereupon, becomes stepless change thereupon.1,3 axis remain and 5,2,4 three parallel axes.

Among Fig. 2, bar 21 is sold 20 and is connected with 2, can push away, draw 2,4 to move vertically, and 19 is guide runner, be 20 do axially directed.The output gear that inside and outside

spiral gear

13,14 constitutes is paid, and when transmitting than high pulling torque, can produce bigger axial engaging force, and this axial force can be used to push away or draws 4,2 to move vertically, changes velocity ratio automatically.For example being designed to input shaft 5 is permanent torques, and when then 4,13 gear pair load torques strengthened, axially

engaging force promotion

4,2 was moved to the directions that velocity ratio i increases, and the increase of i remains unchanged input torque, and vice versa.Return spring 15 is used for making 2,4 returns, when axially engaging force weakens, make 2,4 under the spring force effect return.

4a is the interior friction ring of the direct high on 4, normally interior garden cylinder friction ring.12 outer garden face also can be an outer garden cylinder, pushes away, draws 4,2 4a is contacted with 12, and then frictional force makes 5 to drive 4 directly rotations, i=1.This moment, 4 or 4 and 2 bulge loop moved to the vacancy, with the disengagement that falls through of contacting of planet wheel.4a and 12 contact should be the line contacts, to improve transmission efficiency.Strong for the contact that makes the two, can make 4a or/and 12 garden ring surface lays the material of high coefficient of friction and tool elasticity, obtain bigger friction torque.Perhaps make 2 anchor rings make inside and outside gear, the number of teeth is identical, and the two is pushed into when engaging, inside and outside gear engagement.Also can on 2 anchor rings, establish any pin, nail obstacle, obtain enough engagement torque, or the part of 12 outer garden faces or many parts are made is slide blocks of radially slippage that centrifugal force and 4a when still leaning on high rotating speed are adjacent to the enough friction torques of generation.Here needn't enumerate one by one.It should be noted that 2,4 axial slips trends 4a is when 12 engage, velocity ratio i should trend towards 1, makes 4a when 12 engage, and relative rotation speed goes to zero, and then this joint (for example above-mentioned gear bite type) is that the nothing impact is with stably.The front was carried, and changing velocity ratio is to make R ₁, R ₃Change vertically.

Bar 23 is connected with interior friction ring 22, pushes away and 22 move to left when making it to engage with planet wheel 11 (this moment, whole planet wheel was by 4 move to left and depress) vertically, and 2 only 4 engage with 3 with 1 disengagement, and the diameter owing to 11 is less than the R of this moment ₃(bigger), and common R ₁Be greater than R ₃, therefore 22 with 11 engage, will make 4 turn to and 5 switched in opposite, become " reversing gear ", i.e. the reversing drive position.

" neutral gear " can also be arranged, for example make 1 to contact with a slip ring that can in housing, freely rotate, speed changer no-output moment of torsion then, 4 and 5 get in touch is cut off.Be equivalent to throw-out-of clutch.This mechanism is not shown in figure two.

Planet wheel can have two groups as shown in Figure 1, also can have 3 groups, 4 groups, 5 groups etc., all is that shape is identical and equally distributed, makes 4,2 and 5 stress balances.

The outer garden face of planet wheel 3,1 and the intersection of axial section can be recessed curve as shown in Figure 2, also can be the curves of Any shape, or oblique straight line (this moment, planet wheel became taper cone pulley), decide on infinite variable speed needs.The axis keeping parallelism of planet wheel axis and input shaft and interior friction wheel in the time of only must being designed to speed change, this need make equation

R ₁-R ₃＝R ₂-R ₄

Keep setting up.

The present invention is applicable to the occasion of all on-load stepless change.And be specially adapted to automative stepless speed-variation.This be because, the present invention is some contact between the inside and outside friction wheel at common state, loss is relatively large, but at direct high (4a and 12 engage) is that line contacts or gear engagement etc., loss is little, the efficient height, and automobile is normally bigger with velocity ratio when starting, climbing, very little when on flat road, running at high speed with velocity ratio, and the distance of travelling more than 90% that accounts for usually of running at high speed.Speed changer of the present invention when velocity ratio is big the efficient relative mistake some; direct high then has the peak efficiency above gear-shift transmission; therefore; the average transmission efficiency of using can be very high; meet or exceed the transmission efficiency of gear-shift transmission; can when initial starting shift, accomplish the automatic continuous stepless speed change of on-load again; present hydraulic mechanical type stepless speed variator can be better than aspect the characteristic (power character etc.); transmission efficiency is very high; volume is little; because of simple in structure; cost is very low with saving clutch for gearless, has the low noise of friction driving simultaneously, works soft and the characteristics tool protectiveness.

Another special purposes of the present invention is starting and the speed change that is used for motor.The motor band starts usually very difficult at full capacity, also causes great impact for electrical network.The starting of use fluid coupling, varying frequency starting cost costliness, volume is big, poor reliability, then effect is not very good to use △-Y, transformation, pole-changing, string resistance, inductance or capacity starting.Use the friction clutch starting can run into the uppity problem of sliding friction.

Utilizing the double band full load starter of making big or middle power Wechselstrommotor of speed changer of the present invention, is fit closely on original characteristic.When motor just started, rotating speed was low, and the rotating speed that input shaft 5 is motor reel is also just very low, and planet wheel centrifugal force is little thereby friction torque is little, and load may not be rotated but induction-motor load is also minimum; Along with rotating speed raises, centrifugal force raises, friction torque increases, starting load is until full load, and like this, motor is zero at the moment load of starting just, be equivalent to starting under no load, very little to the electrical network impact, load is inserted by flexible in the rotating speed elevation process, and whole characteristic is very similar to the use fluid coupling.But, volume of the present invention is very little, can with the same housing of motor, same axle (input shaft) saves 2 block bearings, and can doublely do retarder, on-load speed changer, thereby cost has substantial degradation, and the present invention is beneficial to and is used in high rotating speed occasion, square direct ratio of centrifugal force and rotating speed, be beneficial to the weight that alleviates planetary gear train, reduced volume.Therefore, can be used for synchronous speed is 2 grades of AC motor of 3000 rev/mins.2 utmost point electrodes are lower than the little cost in light weight of volume of 4 utmost points, 6 utmost points, 8 utmost points, and efficient improves motor starter-speed changer overall efficiency.Certainly, the present invention can only not make speed changer as starter yet, then structure is simpler, " direct high " that has only an aforesaid i=1, the slide block that makes among Fig. 2 the part of 12 outer garden face make radially slippage becomes centrifugal, and input shaft directly produces friction torque by centrifugal and drives output shaft and rotate.Such centrifugal starter can be contained in the casing with motor.Double speed changer as motor starter needn't be a stepless speed variator of the present invention, also can be No. 90104953 described centrifugal friction formula planetary reducer that level is arranged of Chinese patent literature.

For the present invention, protruding cross section friction ring is placed on the outer garden of planet wheel, and the intersection that makes interior friction wheel have interior garden face and axial section is the outer garden section of the continuously changed contact radius of curve or skew lines, utilize the principle of the invention, with planet wheel centrifugal force is positive pressure, displacement to axial between inside and outside friction wheel, stepless change equally continuously.

Like this, the invention solves the positive pressure of friction type stepless speed changer in bearing and low these two difficult problems of transmission efficiency.

Claims

1, a kind of friction type stepless speed changer, has input shaft, pivoted arm, epicyclic friction gear, interior friction wheel, output shaft and casing, it is characterized in that, has the epicyclic friction gear that at least two group coaxial lines are connected, one of them epicyclic friction gear of every group engages with not rotatable interior friction wheel under centrifugal action, wherein another epicyclic friction gear under centrifugal action rotating with one in friction wheel engage, the ring in the protruding cross section of interior friction wheel is to engage with epicyclic friction gear, the intersection of outer garden contoured surface of epicyclic friction gear and axial section has at least one section to be curve or skew lines, so that the contact radius of epicyclic friction gear can change continuously, planetary gear train radially slippage in slide block can the breach at pivoted arm, the axis of planet wheel remains the axis keeping parallelism with input shaft and interior friction wheel, the centrifugal force that planetary gear train relies on revolution to produce is that friction wheel produced friction torque in the friction positive pressure was adjacent to, in, displacement to axial between external friction wheel changes the friction wheel contact radius continuously and makes the speed changer can stepless change.

2, the described stepless speed variator of claim 1 is characterized in that, also has the pivoted arm that is connected with input shaft, and its outer garden face can engage with the interior garden face of rotatable interior friction wheel, and the formation velocity ratio is 1 direct high.

3, the described stepless speed variator of claim 2, it is characterized in that, be laid with the elastic material that can increase friction factor on the face of described inside and outside garden, but or the part of the outer garden of pivoted arm face or the each several part slide block that is radial slippage, under centrifugal action, be close to interior friction wheel, make input shaft can directly drive output shaft.

4, the described stepless speed variator of claim 2 is characterized in that, described inside and outside garden face is the identical inside and outside gear of the number of teeth, can push engagement, or inside and outside garden face be provided with any pin, the nail obstacle, make input shaft that enough torque actuated output shafts be arranged.

5, the described stepless speed variator of claim 1 is characterized in that, also has the epicyclic friction gear and the interior friction wheel of special diameter, and when the two engaged, output turned to and can make speed changer have reverse gear conversely.

6, the described stepless speed variator of claim 1, it is characterized in that, the output shaft place also has a pair of inside and outside spiral gear and the return spring that is meshed, the variation of output torque makes spiral gear pay the variation of engagement axial force, push away or draw in friction wheel produce to endwisely slip and reach to stepless change, friction wheel axle was to return in return spring can make.

7, a kind of motor that has the centrifugal friction starter, have centrifugal and interior friction wheel rotating with motor reel, it is characterized in that, rotating speed edges up and centrifugal force edges up during motor starting, friction torque between centrifugal and interior friction ring is progressively raise, can make motor can be with starting at full capacity and impact very little electrical network.

8, the described motor of claim 7 is characterized in that, also having with centrifugal force is the centrifugal friction formula stepless speed variator of friction positive pressure, or has such step change transmission or retarder.

9, claim 7 and 8 described motor is characterized in that, the input shaft of motor reel and described starter, speed changer is a same axis, can save 2 block bearings like this.