WO1995005551A1

WO1995005551A1 - Slider-crank driving mechanism for the transformation of a reciprocating motion into rotation or vice versa

Info

Publication number: WO1995005551A1
Application number: PCT/EP1993/002190
Authority: WO
Inventors: Anton Schad
Original assignee: Anton Schad
Priority date: 1993-08-17
Filing date: 1993-08-17
Publication date: 1995-02-23
Also published as: EP0639729A1

Abstract

Slider-crank driving mechanism for the transformation of a reciprocating motion into rotation or vice versa so as to obtain higher efficiency, by using at least two or more plates (6) which alternately move towards one another in opposite directions, and each of which features a guiding slot (5) which is angular to the dead-centre line (S) and in a curve terminates in one long and one short end, with both ends being rectangular to the dead-centre line (S), and by using a crankshaft, the journal of which (3) gears in the guiding slot (5).

Description

Slider-crank driving mechanism for the transformation of a reciprocating motion into rotation or vice versa.

DESCRIPTION

BACKGROUND AND SUMMARY

The present invention relates to a slider-crank driving mechanism as defined in the characterizing clause of Claim 1.

For the transformation of a reciprocating motion into rotation, pistons connected to either joints or bearings with connecting rod and crankshaft are frequently used. Yet such slider-crank mechanisms only obtain relatively low efficiency, since during each rotation two dead centres have to be run through. If the wrist pin articulated to one end to the connecting rod and the crank pin articulated to the other end of the connecting rod as well as the bottom-bracket-bearing neck are at an angle of 180° to one another, thus forming a straight line, the so-called dead centre or slack point is reached. Starting out from this constellation in the initial position and in the cylinder, ignition takes place, after which the energy thus released is absorbed by the cylinder walls, the piston and via the piston within the connecting rod and the crankshaft, just like the energy released by a hammer blow onto an anvil is absorbed within the anvil; in this version, efficiency was virtually nil, since the dead centres can only be passed when the initial movement stems from rotation.

Generically speaking, Scotch-yoke mechanisms in which the crank journal gears in rectangular or oblique-angled guiding slots also are crank mechanisms for reciprocating internal combustion engines, cf. e.g US 39 06 908.

A consequential benefit of the present invention is that a mechanism is created with which the efficiency obtained when transforming a reciprocating motion into rotation is as high as possible.

This task is fulfilled by the characteristic features as defined in Claims 1 and 2.

Oblique-angled and bent slider cranks are disclosed in German Patent Nos. DE-PS 71 83 16 and DE-PS 58 40 82, but all the ends of the guiding slots have the same length.

SUBSTITUTESHEET According to the present invention there is provided high efficiency of the initial movement due to the unequal length of the ends of the guiding slots (5), which are angular to the dead- centre line (S) .

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to preferred embodiments and with the aid of the accompanying drawings in which

Figure I is a side view or sectional view B-B of Figure II showing the slider-crank driving mechanism with two plates (T)(6), (G)(6), which both feature a guiding slot (5), which is obliquely- angled to the dead-centre line (S), and has one short and one long end each, at the beginning of the downward or forward movement of the upper plate (T)(6) and the upward or back movement of the lower plate (G)(6);

Figure II is a side view or sectional view A-A of Figure I; Figure III is a side view of the slider-crank driving mechanism at maximum transmission of energy; and

Figure IV is a side view of the slider-crank driving mechanism with the crank journals (3) being shown in the straight line of the dead-centre line (S) .

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 1 and 2 (sectional view of Figure 1) show a slider- crank driving mechanism with two plates moving in opposite directions with (T)(6) being the driven plate and (G)(6) the driving plate. Towards their respective ends, the angular guiding slots (5) in both plates are not bent straight but in a curve so that the change in direction causes the ends to be rectangular, i.e. at angle of 90°, to the dead-centre line (S) . The end of the guiding slot (5) for the initial downward or forward movement is longer than the end in the angular guiding slot (5) for the final movement of the driven plate (G)(6). Thus, a good effect is obtained during the final stage of the downward or forward movement to the stop point.

For this effect to work, at least two plates (6) moving in opposite directions and featuring the guiding slots (5) as described above and a crankshaft with the bottom-bracket-bearing necks (1) and the crank journals (3) articulated at an angle of 180° to the crank webs (2), thus forming a straight line, are necessary. As in the case of an ordinary crankshaft, the bottom- bracket-bearing necks (1) will rotate around their own axes. But the crank journals (3) which rotate around the bottom-bracket- bearing necks (1) and are linked by the crank webs (2) do not run on the bearings of the connecting rods articulated to the pistons; rather they gear in the guiding slots (5) in the plates (6) and, during the reciprocating motion, slide along within these slots, which are angular to the dead-centre line (S) .

As can be seen from Figure I, the distance of the crank journal (3) which rotates around the bottom-bracket-bearing neck (1) at the beginning of the downward or forward movement in the rectangular long end of the guiding slot (5) of the driving plate (T)(6) is approx. 0.65 of the maximum distance between crank journal (3) and dead-centre line (S) . This means that during the linear initial downward or forward movement approx. 65% are transformed into rotation rather than zero percent as is the case with conventional crankshaft-and-connecting-rod mechanisms. At the same time as the crank journal (3) slides along within the guiding slot (5) during the linear downward or forward movement of the driving plate (T)(6), the crank journal (3) moves in a circle and thus, the desired rotation of the bottom-bracket-bearing neck (1) is given rise to with higher efficiency. At the same time, the crank journal (3) of the driven plate (G)(6) which is turned by 180°, acts as a driver, and also moves in a circle, moves this plate upward or back, with the crank journal sliding along within the short end of the guiding slot (5) . In Figure III, the crank journals (3) which rotate around the bottom-bracket-bearing neck (1) are shown in a rectangular position relative to the dead-centre line (S) . In this position, the transmission of energy by the driving plate (T)(6), which moves downward or forward, into the motion of rotation is greatest.

In Figure IV, the crank journal (3) of both the driving plate (T)(6) and the driven plate (G)(6) are shown in the straight line of the dead-centre line (S) . If we assume that the driving plate (T)(6) continues its downward or forward movement, the crank journal (3) will continue to slide along within the guiding slot (5), which is obliquely-angled to the dead-centre line (S), with the rotation movement of the crank journal (3) going on as well, since it has already passed the dead-centre line (S) . Given that, during the final stage of the downward or forward movement of this plate to the stop point, the driving plate (T)(6) maintained the bias of the guiding slot (5), which is obliquely-angled to the

SUBSTITUTESHEET dead-centre line (S), the crank journal (3) during this final stage also slid along within the guiding slot (5), which is obliquely-angled to the dead-centre line (S), while the rotation movement of the crank journal (3) continued. During this movement, the opposing driven plate (G) (6) was moved upward or back with the crank journal (3) of this plate, however, sliding along within the rectangular long end of the guiding slot (5), which is obliquely- angled to the dead-centre line (S) . This even caused the crank journal (3), which moves in a circle and slides along within the long end of the guiding slot (5), which lies rectangular to the dead-centre line (S) , not only to bring the driven plate (G)(6) to the stop point in the final stage, but it also caused it to synchronously and for a short distance and time move this plate into the opposite downward or forward direction, into which the driving plate (T) (6) moved during the final stage. Thus, the driven plate (G)(6), which was responsible for the change from the upward or back movement to the downward or forward movement and which thus assumed the function of the driving plate (T)(6), already began the downward or forward movement at a point when the opposing plate (T)(6) still had to cover a short distance.

Thus, when transforming a reciprocating motion into rotation, the use of at least two or more plates (6) which alternately move towards one another in opposite directions, results in higher efficiency without ever reaching a dead centre.

Reference list;

(1) = bottom-bracket-bearing neck

(2) = crank web

(3) = crank journal

(4) = connecting rod (5) = guiding slot

(6) = plate

(5) = dead-centre line (aka. zero line)

(T) = driving plate (6) (G) = driven plate (6)

SUBSTITUTESHEET

Claims

1. Slider-crank driving mechanism for the transformation of a reciprocating motion into rotation or vice versa, by using 5 at least two or more sliding-crank slot-guidance plates (6), which are rigidly mounted onto one or two opposing connecting rods (4) with these rod again being fixed to a piston and a crankshaft, the journal of which (3) gears in the guiding slot (5) wherein the guiding slot (5), which is obliquely- 10 angled to the dead-centre line (S), in a curve terminates in one long and one short end, both of which are rectangular to the dead-centre line (S) .

152. Slider-crank driving mechanism in accordance with Claim 1 wherein the guiding slot (5), which is obliquely-angled to the dead-centre line (S), has only one end.

203. Slider-crank driving mechanism in accordance with Claim 1 wherein the length of both the long and the short end of the guiding slot (5) as well as the curve leading from the bias of this slot to the respective ends have been chosen and designed according to individual stresses and requirements.

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4. Slider-crank driving mechanism in accordance with Claim 1 to

2 and 3 wherein the construction and the mechanism of the appliance described herein can be used both with internal-

30 combustion engines and with those devices driven with muscular power such as bicycles or pedal boats.

35

4 Drawing Figures

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SUBSTITUTESHEET