CN2599323Y

CN2599323Y - Cart-wheel stepless speed variator

Info

Publication number: CN2599323Y
Application number: CNU032353588U
Authority: CN
Inventors: 伍德荣
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-01-21
Filing date: 2003-01-21
Publication date: 2004-01-14
Anticipated expiration: 2013-01-21

Abstract

The utility model relates to a roller-type stepless gearbox, which is characterized in that the roller-type stepless gearbox comprises a plurality of roller, two plane discs that are parallel to each other and are vertical to the roller, a gear transmission mechanism and a shifting mechanism; the shifting mechanism is connected with the roller through a hollow spline shaft, the diameter of the rollers is equal and the friction radius of the rollers is equal too, and the rollers are clamped between the two plane discs; the plane discs are connected with the gear transmission mechanism. The roller-type stepless gearbox increases the transmission power, enlarges the application range and can be used on the light truck and middle passenger car; the transmission efficiency reaches or closes to the gear transmission level; moreover, the utility model has simple production process and resolves the technical problem of difficult processing and production of the V-shaped metal belt.

Description

The roller type stepless speed variator

Technical field: the utility model belongs to mechanical stepless transmission, relates to a kind of roller type stepless speed variator.

Background technique: eighties of last century mid-term, Dutch VDT (Van Doorne ' s Transmission) company is developed into based on pushing-block-v-belt " stepless speed variator of (pushing block formula V band) technology.That is: commercialization realized in " Continuously VariableTransmission " abbreviation " CVT " in 1987.Compare with the hydraudynamic drive technology, " CVT " product structure is simple, cheap; And realized efficient transmission at wide speed range, consult Zhejiang University's thesis for the doctorate: " research of wet clutch metal band type stepless speed variator " CVT " control strategy " author Luo Yongge July calendar year 2001, P.4-P.10 or monograph: " mechanical stepless transmission " Zhou Youqiang chief editor China Machine Press June calendar year 2001, P.238-P.242.For new way has been opened up in the continuation development of stepless speed variator.This Lu Yikai, each main automobile production state imitates one after another, follows up, and states such as Europe, U.S., day are all developing " CVT " technology of oneself.

But, at present also there are some shortcomings in " CVT " technology: the one, and transmission power is less, and application area is restricted, and is used for slight type car more than at present; The 2nd, though transmission efficiency is higher than hydraudynamic drive, but still be lower than gear-shift transmission; The 3rd, the manufacturing difficulty of pushing block V-type metal tape is still the exclusive proprietary technology of " CVT " company so far.

Existing " CVT " technology belongs to the mechanical friction transmission, is the power (torque) that increases its transmission, requires to increase the positive pressure between the surface of contact.We can be with the method that applies external force, and (for example oil cylinder working-pressure or spring force) strengthens this positive pressure.But the component that is produced owing to the V-arrangement inclined-plane can make metal tape expand outwardly, thereby has strengthened the tension force of steel band.For keeping the pliability of steel band, the only thick about 0.2mm of " CVT " employed steel band.Though can use the multilayer steel band, can reach 10 layers at most, strengthen its tensile strength, but the mechanical strength of steel band remains the restraining factors of restriction " CVT " transmission power.

Summary of the invention: the utility model is less in order to solve " CVT " transmission power, application area is restricted and the problem of the manufacturing difficulty of pushing block V formula type metal tape, propose a kind of roller type stepless speed variator, it is characterized in that: described roller type stepless speed variator comprise a plurality of rollers, two that be parallel to each other and with perpendicular plane disc, gear drive and the gearshift of roller; Described gearshift is connected with described roller by hollow splined shaft, and described roller diameter is identical, friction radius equates, and is clamped between described two plane discs; Described plane disc is connected with gear drive.

This roller type stepless speed variator has increased transmitted power, has enlarged application area, can be used for pick up truck and middle bus; Transmission efficiency reaches or near the gear-shift transmission level; And manufacturing is simple, has exempted V-arrangement metal tape manufacturing difficult technologies difficult point.

Description of drawings: Fig. 1 is a structure principle chart of the present utility model;

Fig. 2 is the central cross-sectional view of structure principle chart of the present utility model;

Fig. 3 is a gearshift sketch of the present utility model;

Fig. 4 is an example structure schematic representation of the present utility model;

Fig. 5 is an embodiment's of the present utility model structure principle chart.

Embodiment: as shown in Figure 1, two that be parallel to each other and with the perpendicular plane disc 1 of roller, adding under the spring force effect, with several diameters identical and to disc centre distance be in the middle of driving rolls 2 that friction radius equates is clamped in.As shown in Figure 2, the driving torque of motor is distributed to four hollow splined shafts 21 that distribute by 90 degree by cone gear, roller 2 of each splined shaft 21 suit, and torque connects by spline passes to roller 2.

If: roller diameter is d;

The positive pressure of surface of contact is: Q;

Friction factor is μ

Then the friction torque of a roller is: M=Q μ d

The total frictional force square of four rolling: T=4Q μ d=Me β i ' (1)

In the formula: Me---engine torque;

β---torque reserve coefficient;

The velocity ratio of i '---cone gear.

Can determine the great positive pressure of needs conversely according to the power that is transmitted in principle, as long as its contact stress does not transfinite.So:

By (1) formula Q=(Me β i ')/(4 μ d) (2)

Can find out by (2) formula, wear for guaranteeing friction, the required positive pressure Q of roller is relevant with the biography torque, and automobile is when exercising, engine load often changes, if only determine Q by maximum load, then when underrun, surface of contact still is in high-pressure state, thereby has reduced transmission efficiency and fatigue life, so the modern mechanical stepless speed variator adopts automatic pressurization device mostly, promptly on the adjacent end face circumference of certain a pair of driving and driven element, respectively make corresponding and uniform V-shaped groove, inlay steel ball in the groove, wherein Me is a driving torque, and Ml is the load resisting moment.During idle running, both sides V-shaped groove center-aligned, along with load increases, two V-shaped grooves relatively rotate, misplace.Thereby carve tight therebetween steel ball and produce end thrust.

Practical Calculation shows: select Bearing Steel for use, when surface hardness was HRC58-63, designed " RCVT " product can be complementary with the motor of pick up truck.Promptly this product can be used for the pick up truck series of certain automobile group.This is just having bigger breakthrough and raising than existing variable v-belt drive " CTV " aspect the transmission power.

As shown in Figure 1, two plane discs 1 pass to axle 6 outputs by gear 3,4 respectively with the power of being accepted, because of the sense of rotation of two disks is opposite, so after having idle pulley will turn to the furnishing unanimity between the gear 4,5, pass to axle 6 outputs again.

As shown in Figure 3, gearshift comprises leading screw 8, nut 7, steel pipe 20 and rim gear wheel driving mechanism; Steel pipe 20 and case of transmission are connected and fixed motionless, and it is positioned at hollow splined shaft 21, and is enclosed within outside the leading screw 8; Leading screw 8 is connected with driving mechanism; Nut 7 two ends penetrate steel pipe 20 and connect shift fork 22, and shift fork 22 passes the both sides that slotted eye is stuck in roller.With leading screw 8 mutually the nut 7 of downlink connection be enclosed within the interior circle of steel pipe 20, the two ends of steel pipe circumference (at a distance of 180 degree) have the thin-and-long slotted eye that its length equates with the horizontal shift motion of roller vertically.There is pin shape convex parts 23 at the nut two ends, penetrate steel pipe 20 by long and narrow hole, and are embedded in the circular groove of circle in the shift fork 22, and the fork-shaped of shift fork 22 is constructed the both sides that the thin-and-long slotted eye that passes splined shaft 21 is stuck in roller 2.During gear shift, ring gear 10 driven gears 9 and leading screw 8 rotate rapidly, cause nut 7 to slide vertically in steel pipe.By being connected of pin shape convex parts and circular trough, driving shift fork and roller and move vertically.Because each roller 2 all mates identical leading screw 8 and gear 9 are arranged.They are driven by same ring gear 10, so these leading screws rotate the identical number of turns synchronously, thereby all roller produces identical lateral displacement.When needs change velocity ratio, must make four rolling synchronous horizontal mobile phase distance together promptly keep friction radius to equate.

If change speed ratio in the opposite direction, when for example changing downshift into by upgrading, ring gear 10 backward rotation, then roller displacement in the opposite direction.

For further improving working life and transmission efficiency, can set up a direct high mechanical transmission.As Fig. 4, shown in Figure 5, be parallel with rotatingshaft 11 in one side of RVCT, engine power promptly was connected with axle 11 by

gear

12,13 before entering RVCT, and axle 11 is connected with gear 15 by gear 14, engine torque is to transmit or transmit by axle 11 by RCVT, whom the engagement cover that is decided by to be connected in series at clutch end 17 is connected with, meshes that to overlap 17 are the spline housings that can slide vertically.If it move and little gear ring 18 engagements to left, then torque is to transmit by RCVT, the clutch end gear 15 of axle 11 is not connected with axle 16 at this moment, be in unloaded state, if engagement cover 17 moves right, be connected with gear 15, then torque is by gear 12-13-axle 11-gear 14-15-17-16 output.At this moment, RCVT is in zero load, what the surface of contact of its roller only bore spring initially gives tight load, contact stress is very little, helps improving the fatigue life of material, in the direct drive process of mechanical axis, little gear ring 18 is run-in synchronism with spline housing 17 all the time, if when wanting gear shift, can make spline housing 17 and little gear ring 18 engagements very easily, just immediately mechanical transmission is reverted to the RCVT transmission.

Claims

1, a kind of roller type stepless speed variator is characterized in that: described roller type stepless speed variator comprise a plurality of rollers, two that be parallel to each other and with perpendicular plane disc, gear drive and the gearshift of roller; Described gearshift is connected with described roller by hollow splined shaft, and described roller diameter is identical, friction radius equates, and is clamped between described two plane discs; Described plane disc is connected with gear drive.

2, roller type stepless speed variator as claimed in claim 1 is characterized in that: described gearshift comprises leading screw, nut, steel pipe and rim gear wheel driving mechanism; Described steel pipe and case of transmission are connected and fixed motionless, are positioned at described hollow splined shaft, and are enclosed within outside the described leading screw, and two ends radially have the thin-and-long slotted eye that its length equates with the horizontal shift motion of roller vertically; Described leading screw is connected with described driving mechanism; Described nut is connected with described leading screw and is enclosed within circle in the described steel pipe, and two ends penetrate steel pipe and connect shift fork, and described shift fork passes the both sides that described slotted eye is stuck in roller.

3, roller type stepless speed variator as claimed in claim 1 is characterized in that: described roller type stepless speed variator is provided with the direct high mechanical transmission.