GB2152604A

GB2152604A - Power transmission system using two engines

Info

Publication number: GB2152604A
Application number: GB08500225A
Authority: GB
Inventors: Elio Ferraccioli
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-01-05
Filing date: 1985-01-04
Publication date: 1985-08-07
Also published as: GB8500225D0; GB2152604B; GB8400183D0

Abstract

A power transmission system which comprises two power sources connected to an output through an epicyclic gear box. One of the power sources, E1, drives the annulus E0 whilst the other, E2, drives the planet wheel carrier S of the epicyclic gear box. The output is derived from the sun wheel W. The two power sources may be internal-combustion engines or one may comprise an electric motor. Where internal-combustion engines are used one may have its speed set by a lever whilst the other is controlled by an accelerator pedal. <IMAGE>

Description

SPECIFICATION Power transmission system This invention relates to a power transmission system.

More particularly, the invention relates to a power transmission system employing a steplessly variable gear box suitable for manual, automatic or combined uses, and which includes two engines.

According to the present invention there is provided a power transmission system comprising two power sources and an epicyclic gear box, one of the power sources being connected to the annulus of the gear box, the other of the power sources being connected to the planet wheel carrier of the gear box, the output of the power transmission system being connected to the sun wheel of the epicyclic gear box.

In the case of its application to the internal combustion engine with standard functions of transport, each one of the two engines would take half the total power, although the division could be uneven as well, depending on the power at disposal and the specific performance required.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic illustration of a power transmission system made in accordance with the present invention; and Figures 2 to 7 are engine speed-power-time graphs of the power transmission system of the present invention.

Referring to the drawings, Fig. 1 shows an essential outlay of a power transmission system which includes:- (a) two engines identified by Engine 1(E1) and Engine 2(E2), each one with its own carburettor, (or pump if diesel) respectively: C1 and C2; C1 is controlled by the accelerator pedal A and C2 by a sliding lever L.

(b) the gear box is an epicyclic gear box with the following components: (1) a sun wheel W linked through a clutch to the tyre-wheels (on the road wheels) at a ratio of 1 (one).

(2) an annulus E0 linked to Engine El at a ratio of 1 (one).

(3) a cage S carrying a series of planet wheels P operated, as a whole, by Engine E2 at a ratio of 1 (one). The series of planet wheels P links the annulus EO to the sun wheel W.

All the gears must be able to rotate only in the same clockwise or anti-clockwise direction (also the individual planet wheels). The diameters of the gears can be determined depending on the performance required but, for practical purposes of demonstration, we use these diameter sizes: dW = 1 (one) dS = 1 (one) Diameter of each planet wheel.

dE0 = 3 (three) The diameter sizes mean that when annulus EG makes 1 revolution and cage S makes 3/4 revolution sun wheel W is static and that when annulus E0 makes 1 revolution and cage S makes 1 revolution sun wheel W makes 1 revolution.

Which means also that if we vary the speed V of Engine E2 from VE2 = 3/4 VE1 to VE2 = VE1 we will achieve the object of a sun wheel W capable of passing from 0 (zero) to 1 (one) ratio.

Going then to show the practical working of this power transmission system, we start with a first, manual system in which: (a) the two carburettors (or pumps) C1 and C2 regulated as to determine the possible speeds of the two engines El and E2-from minimum to maximum-as follows:- VE1 = 1200 revs (idle speed) up to 6000 revs VE2 = 900 (idle speed) up to 6000 revs and: (b) a sliding !ever L whose only function is to determine the number of revolutions of Engine E2 depending on the speed of Engine El, that is:- the position of L determines the number of revs E2 and therefore cage S at given ratios of any number of revs of engine El and therefore annulus El.The lever L is able to slide through five equidistant points P1 to P5-"Neutral": 1; 2; 3; 4 (Direct).

Keeping in mind that:-- VW = 4(VS - 3/4 VEO) In Figs. 2 to 5 we have the various ratios of VS and VW for the total range of reves of Engine E0, that is: P1:VS= 9/12 VEO:VW=O overall ratio = 0 P2:VS = 10/12 VEO:VW = 1/3 VEO 2/5 VS overall ratio = 2.75 P3 :VS = 1 1/12 VE0 :VW = 2/3 VEO overall ratio = 1.43 8/1 1VS P4 : VS = VE0 = VW overall ratio = 1 An overall ratio is determined by the equation:- VE0iVS divided divided by VW 2 The carburettors (or pumps) overriding implement could be electronic or of any nature.An eventual overdrive ratio can be built in by a permanent multiplication of W altering, in so doing, all the ratios all the way from zero to maximum.

When the two engines are at idle speed and the sliding lever is in neutral (connection from sum wheel W to the clutch disengaged) it could happen that the idle speed of either annulus E0 or cage S is not what it should be, that is: V (a) VS < 3/4 VEO or (b) VS > 3/4 VEO In order to maintain the correct speed of the engines if condition (a) occurs, the result should be that either annulus E0 supplies enough energy to keep cage S at 3/4 VE0, or annulus E0 goes to a standstill. This happens because cage S is unable to rotate below the speed of 3/4 VE0. In fact, to do that, it should pass an anticlockwise rotation to sun wheel W which, in our instance, can only revolve in a clockwise sense).Then, if Engine El goes to a standstill, the inconvenience could be overcome by keeping it (through the accelerator pedal) at a speed higher than the idle, or moving the sliding lever beyond PI.

If condition (b) occurs, cage S passes a clockwise rotation to sun wheel W (which is disengaged), then one depressed the clutch and passes the sliding lever from Neutral to P1 (thus engaging sun wheel W) the, when the clutch is released, the car moves instead of keeping static as it does when VS = 3/4 VEO.

Once the car is in motion, the eventual imprecision of speeds in the two engine sections should not represent real malfunctioning since, as cage S is unable to revolve more than annulus E0, to do this. the planet wheel would revolve anticlockwise on their own axes, the malfunctioning would be limited to a "wrong" ratio either in excess or defect of that theoretically corresponding to the sliding lever position which, in any case, can be corrected by hand.

A second independant manual system could be adopted for special performance cars. The difference would be in that the planet wheels would be free to rotate on their axes in both directions and the two carburettors or pumps would act in complete independence all the way, giving therefore to Engine E2 the possibility to revolve more than Engine El.

Keeping in mind that:when E0 is static then VW = 4VS and when VS > VEO then VW = VEO + 4(VS - VE0) In Fig. 5 we have an example of the same theoretical performance of W for different combinations of Engines El and E2. This system, with or without a built in overdrive ratio, can perform up to an indefinite overdrive ratio and. only for overdriving purpose, could be applied also on the first manual system using a catch releasing command which would leave the planet wheels free to rotate in both directions on their own axes: this catch releasing command would act when L passes from P4 to an added P5.

Thus, the same output angular speed can be obtained for different torques. In Fig. 6 the overall ratio is .83 and in Fig. 7 the overall ratio is .77, this ratio being calculated using the formula given above.

An automatic system can be obtained by using the first manual system in which the sliding lever is substituted by a centrifuge, or a means of any other nature, to control the two carburettors or pumps.

A combined system could comprise the automatic system just described with the addition that the centrifuge would act on the carburettors (or pumps) and, as well, on a sliding lever which.

through a button, could be fixed at any one position or be operated by hand faster than the centrifuge would do.

This power transmission system could be developed in different ways to obtain different results for different uses changing the types of differentials and linking the various parts in different combinations. Possibly, it could be also convenient for a hybrid system in which one internal combustion engine would feed annulus EO and, through alternator and batteries, an electric engine linked to cage S, thus giving the possibility to use only the electric engine for short journeys.

Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims

1. A power transmission system comprising two power sources and an epicyclic gear box, one of the power sources being connected to the annulus of the gear box, the other of the power sources being connected to the planet wheel carrier of the gear box, the output of the power transmission system being connected to the sun wheel of the epicylic gear box.

2. A power transmission system as claimed in claim 1, wherein the engines are internal combination engines.

3. A power transmission system as claimed in either claim 1 or claim 2, wherein one of the engines is steplessly controlled via an accelerator pedal.

4. A power transmission system as claimed in any preceding claim, wherein one of the engines is controlled by a power which can take up to one of a number of preset positions.

5. A power transmission system substantially as hereinbefore described with reference to the accompanying drawings.