FR2674484A1 - Transmission system with speed variation, in particular for electric vehicles - Google Patents

Abstract

The invention relates to a transmission system with speed variation, designed in particular for an electrically actuated vehicle. …<??>The system is actuated by a manual control which includes a power source consisting of an electric motor (1) with relative rotation, including an external stator which can turn with respect to an internal rotating rotor, so that the power leaving the external stator or the central rotor can be transmitted respectively to a front differential mechanism (1D) and to a rear differential mechanism (2D), of the vehicle; the transmission shafts (21, 22) respectively provided between the electric motor (1) and the front and rear differentials (1D, 2D) can be selectively locked so that the power supplied by the motor (1) can be selectively altered when it is applied to the differentials, in order to correspondingly alter the speeds of the wheels of the motor vehicle. …<??>Application to remote-control electric motor vehicles. … …

Description

The present invention relates to a transmission system with change

speed, mainly suitable for an electrically powered automobile; in particular, the application is made to a remote-controlled electric automobile.

speed in 3 modes.

Remote-controlled electric automobiles have been designed in recent years with a standard

of satisfactory quality as a result of

made in radio technology However, the mechanical transmission adopted in this field has

not yet modified to take into account the perfection-

developments in radio technology The conventional electric automobile uses a direct current electric motor and a simple transmission system

which is composed of a simplified differential device.

By changing the transmission ratio of the transmission device, it is possible to select a

correct torque to satisfy the transmission imperative

energy zion.

However, the general type of electric automobile

remote control is not equipped with a

efficient gear shifting to enable the auto-

ordered bile to function better in response to

training condition.

The inventor devoted a long period of time to the study of the transmission system in an electric automobile and it finally came to

to a manual operated gear change system

is lying. The main object of the present invention is to provide a manual gear shifting system mainly suitable for a powered automobile.

electrically, where a specially designed motor is used

ment, which comprises a rotating stator consisting of its

carcass and a rotor The rotating stator is movable relative to the rotor and the motor serves as a power source for the automobile Two differentials made up of 5 gears having different gearing ratios are used to control the operation of the wheels .

Thus, by means of a selective locking of the transmission shafts of the automobile, it is possible to vary the speed of the wheels in correspondence. According to a characteristic of the transmission device according to the invention, the latter comprises in the essential: an electric motor with relative rotation, serving

power source for the electric powered vehicle

ment and comprising two output shafts; a circular forward fin member in association with one of said output shafts of said relatively rotating electric motor; a circular rear fin member in association with the other output shaft of said relatively rotating electric motor; two centrifugal clutches disposed in juxtaposition respectively to said front fin element and to said rear fin element; two transmission shafts connected at a respective end with said centrifugal clutches; two differential mechanisms front and rear connected

at the respective other end of said transmission shafts

sion correspondents; _ a control lever comprising a fork in the form

of C, provided with two branches which can be selective-

ment brought into contact with said circular front fin element or said circular rear fin element so as to block one of said circular finned elements so that it does not rotate flush when said control lever is moved by pivoting on either side of a neutral position of this lever, thus making it possible to block one of said output shafts so that it

does not turn.

According to another characteristic of the transmission system according to the invention, the relatively rotating electric motor involved in this system essentially comprises: a stator formed by the outer casing of the motor and which is provided with a shaft. output unitarily linked to said carcass and projecting from the motor, this output shaft being rotatably supported by a bearing so that said stator can rotate freely; a rotor disposed inside said stator and rotatably supported by bearings located respectively at

each end of said carcass, said rotor comprising

both a shaft projecting outwardly as for a common electric motor, said rotor having the same magnetic poles and the same windings as a common electric motor; two copper rings are provided on the outer surface of said outer stator which are in constant contact with two carbon brushes so as to allow the transmission of electrical energy from a battery to said relatively rotating electric motor; said relatively rotating electric motor being further characterized in that said outer stator is rotatable in a direction opposite to that of the rotor so that energy can be transmitted to the rotor.

output by means of the two output shafts.

According to yet another characteristic of the transmission system according to the invention, the centrifugal clutches are replaced by two locking mechanisms of the lag wrench type which are set according to three options so that the locking mechanisms can only be rotated. clockwise or

in the opposite direction or without restraint.

Other characteristics and advantages of the invention will be demonstrated in the following section.

the description, given by way of non-limiting example,

with reference to the accompanying drawings in which: FIG. 1 is a perspective view of a conventional transmission device; Figure 2 is a perspective and sectional view of the relative rotation motor involved in the transmission system of the present invention; Fig. 3 is a diagram showing the 3-mode speed change transmission device; Figure 4 is a plan view of Figure 3; Fig. 5 is a schematic view showing the centrifugal clutch of the present invention;

Figure 6 is a diagram showing a locking mechanism

lug wrench type thread, which can be operated

selectively.

Referring to Figure 1, a conventional differential mechanism is connected to the engine via a universal joint Dl and a rotary shaft D 2 The end of the rotary shaft D 2 is connected to a helical pinion D 3 which is in engagement with the ring gear D 4 of the differential mechanism Two planet gears are in engagement with the rotary ring D 4 so that the energy of the motor can be transmitted respectively to a left drive shaft D 61 and to a right-hand drive shaft D 62 As is well known, when one of the drive shafts D 61 or D 62 is blocked so as not to rotate, the other drive shaft D 62 or D 61 will receive all the energy coming from the motor This

idea constitutes the central idea of the present invention.

As shown in Fig. 2, an electric motor 1 of special design, which is called a relative rotation motor, is used as the power source of the electric automobile of the present invention. a rotating outer casing serving as a stator 11 for the motor, as well as an inner rotor 12, the stator and the rotor rotating in opposite directions

when the electric motor is running.

As a result, the energy produced by the relatively rotating electric motor 1 can be transmitted to the output

in both ways.

To allow the outer stator 11 to rotate freely, the electric current is introduced into the electric motor via two copper rings 141, 142 which are arranged on its outer stator. The electric current supplied by

a battery can be applied to engine 1 through the inter-

medial of two corresponding carbon brushes 13 so that the outer stator 11 can rotate

without obstruction.

At each end of the stator 11, there is provided a bearing 15 which is intended to support the rotor 12 to allow it to rotate uniformly The shaft 121 of the rotor 12, which projects outwards, is identical to that of a conventional electric motor 1 and serves as an energy output shaft Another energy output shaft 111 is individually arranged at the other end of the outer stator 11, projecting therefrom and being supported by a bearing 16 so as to allow the transmission of energy

of the motor The internal magnetic poles and windings

elements of the electric motor are identical to those of a conventional motor The electric motor can be carefully designed so that the rotational inertias of the outer stator 11 and the inner rotor 12 are identical Accordingly, the output elements of the electric motor 1 , i.e. the outer stator

11 and the inner rotor 12, can provide respective-

ing half of the output energy. When the output shaft 111 of the stator 11 is blocked so as not to rotate, all the energy of the electric motor 1 is transmitted to the shaft 121 of the rotor 12, and vice versa.

the specially designed relative rotation electric motor

ment as described above can perform the same function

that a differential mechanism to balance the trans-

energy mission.

In order to clearly explain the modes of operation of the manual gearshift transmission system of the present invention, a gearshift process will be described in the following.

in 3 modes.

Referring to Figures 3 and 4, the electric motor 1 with relative rotation serves as a source of energy and it consists of the outer stator 11 and the inner rotor 12 The energy generated by the electric motor 1 is transmitted, via from a front fin element 51 and a rear fin element 52 and also via the centrifugal clutches 41, 42, to the transmission shafts 21, 22 and finally to the front and rear differential mechanisms 1 D, 2 D. In In addition, four rotating shafts 31, 32, 33 and 34 are used to transmit the energy produced by the

engine with respective tires 81, 82, 83, 84.

A control lever 7, provided at one end with a C-shaped fork 71, is pivotally mounted

on a pivot 72, as indicated by the dotted lines

lengths in Figure 4 The fork 71 has two branches 711, 712 When the control lever 7 is placed in a neutral position, the two branches 711, 712 are spaced from the surfaces of the finned elements 51, 52 so that the energy produced by the stator 11 and the rotor 12 of the electric motor can be transmitted to the output Once the control lever 7 is pivotally brought into a position where the leg 711 is in contact with the fin member 51, the stator 11 is blocked without being able to turn and consequently

the energy produced by the electric motor 1 is transmitted

completely to the rotor 12 Likewise, once the control lever 7 has been brought into a position where the branch 712 is applied against the rear fin element 52, the energy produced by the electric motor 1 is transmitted via the stator

exterior 11 The centrifugal clutches 41, 42 allow

tempt the transmission shafts 21, 22 to rotate freely

ment even when the front and rear fin elements 51, 52 are blocked so that there is no

braking condition.

The description given above shows that it

There are three different modes of speed adjustment which are produced by the manual shift system

speed described.

If the front differential mechanism l D has

a crown D 4 which is meshed with the helical pinion

dal D 3 disposed at the end of the transmission shaft 21, establishing the transmission ratio 3: 1,

with reference to figure 1, and if the transmission report

sion between the crown wheel D 4 of the rear differential mechanism 2 D and the helical gear D 3 attached to the end of the transmission shaft 22 is 3: 2, and also if the rotational speed of the electric motor 1 is 9000 rpm, the following conditions can be produced: 1 When the drive shafts 21, 22 can rotate freely, the rotor of the electric motor can transmit a speed of 6000 rpm to the drive shaft 21 and the drive shafts. front wheel drive can rotate at a speed of 6000 xI / 3 = 2000 rpm In addition, the outer stator of the electric motor can transmit a speed of 3000 rpm to the transmission shaft 22 and the shafts of the rear wheels can reach a speed of 3000 x 2/3 = 2000 rpm When all four wheels are driven at the same speed, the automobile

can move over a uniform surface.

2 When the transmission shaft 22 associated with the external stator of the electric motor is blocked without being able to turn, the speed of 9000 rpm produced by

the electric motor will be transmitted through the

from the rotor to the transmission shaft 21, the speeds

its rotational speed of the shafts of the front wheels then being increased to 9000 x 1/3 = 3000 rpm (wheel speed), so that the speed of

the automobile is increased.

3 When the transmission shaft 22 associated with the external stator of the electric motor is released so as to rotate with the transmission shaft 21 coupled to the rotor which is then blocked, the speed of the electric motor, that is to say 9000 rpm, will be transmitted to the drive shaft 22 and the rear wheel shafts will reach a speed of 9000 x 2/3 = 6000 rpm, that is, the vehicle will move

even faster.

In the case where one of the two transmission shafts

sion 21, 22 is blocked without being able to turn, the front or rear wheels can still be driven so as to turn at the same time as the wheels associated with the transmission shaft released thanks to the use of centrifugal clutches The theoretical explanation given above to show how the wheel speeds are changed can be developed as follows. In the first application indicated above, it can be considered that the automobile is engaged in the first report which makes it possible to obtain a greater torque to produce a displacement of the stationary wheels. In the second application, the automobile is considered to be in second gear and only the front wheels are driven; the vehicle is more easily controlled to negotiate turns and it is conveniently accelerated In this condition,

the automobile is suitable for a road with bends.

In the third application, the vehicle is placed identically in the third gear and only the rear wheels are driven; in this condition, the automobile is better suited to accelerate on a straight road When the vehicle is in motion, a large driving torque is not required and the third gear is suitable

to get high speed walking.

Furthermore the centrifugal clutch can be replaced by a ratchet mechanism which can perform the same function as the centrifugal clutch However the ratchet mechanism will prevent the energy produced by the electric motor from being transmitted to the wheels when the motor is rotated in the opposite direction to cause the vehicle to move in reverse. In this condition, the electric motor

is unable to produce energy at its output.

To overcome this drawback, a latching mechanism of the lag wrench type is used, which has a neutral position as well as clockwise and counterclockwise rotation positions in order to allow the ratchet mechanism to be set according to three options o ratcheting is limited to turning only clockwise or counterclockwise or rotating without any obstruction The ratchet mechanism

of the lag wrench type can be designed in a conventional manner such as that shown in Figure 6.

he

RIYENDICATIONS

1 Variable speed transmission system,

specially adapted for an electric powered vehicle

ment and characterized in that it essentially comprises: an electric motor (1) with relative rotation, serving

power source for the electric powered vehicle

ment and comprising two output shafts (111, 121); a circular forward fin member (51) in association with one (111) of said output shafts (111, 121) of said relatively rotating electric motor;

a circular rear finned element (52) in association with

tion with the other output shaft (121) of said relatively rotating electric motor; two centrifugal clutches (41, 42) arranged in juxtaposition respectively to said front fin element (51) and to said rear fin element (52); two transmission shafts (21, 22) connected by a respective end with said centrifugal clutches

(41, 42);

two front and rear differential mechanisms (1 D, 2 D) connected to the respective other end of said corresponding transmission shafts (21, 22); a control lever (7) comprising a C-shaped fork (71) provided with two legs (711, 712) which can be selectively brought into contact with said circular front fin member (51) or said circular rear fin member (52) ) so as to block one of said circular finned elements (51, 52) so that it does not rotate when said control lever (7) is moved by pivoting on either side of a neutral position of this lever, thereby making it possible to block one of said output shafts (111, 121) in a manner

that it does not turn.

2 variable speed transmission system according to claim 1, characterized in that said electric motor (1) with relative rotation essentially comprises: a stator (11) formed by the outer casing of the motor and which is provided with an output shaft (111) unitarily linked to said frame and projecting from the motor, this output shaft (111) being rotatably supported by a bearing (1 6) so that said stator (11) can rotate freely; a rotor (12) disposed inside said stator (11) and rotatably supported by bearings (15) located respectively at each end of said carcass, said rotor (12) comprising a shaft (121) projecting from the exterior as for an electric motor

common;-

said rotor (12) having the same magnetic poles and the same windings as a common electric motor; two copper rings (141, 142) are provided on the outer surface of said outer stator (11) which are in constant contact with two carbon brushes (13) so as to allow the transmission of electrical energy from a battery said electric motor (1) with relative rotation; said relatively rotating electric motor (1) being further characterized in that said outer stator (11) is rotatable in a direction opposite to that of the rotor (12) so that energy can be transmitted to the output by means of the two output shafts (111,

121>.

3 Variable speed transmission system according to claim 1, characterized in that said centrifugal clutches (41, 42) are replaced by two locking mechanisms of the key type à'tirefonds which are set according to three options so that the latching mechanisms can only be turned clockwise

or in the opposite direction or without restraint.