WO1990015231A1

WO1990015231A1 - Starter motor for an engine with a free floating stepped piston

Info

Publication number: WO1990015231A1
Application number: PCT/EP1990/000867
Authority: WO
Inventors: Frank Stelzer
Original assignee: Frank Stelzer
Priority date: 1989-06-08
Filing date: 1990-05-31
Publication date: 1990-12-13
Also published as: DE4090967A1; DE3918786A1; DE4090967D2; AU5670590A

Abstract

In a starter motor for an axial-piston engine with a stepped piston (14), two variable-length belt elements (98, 100) pass around an exentric element (92, 94, 96). The belt elements are connected directly or indirectly to interspaced points (114, 116) on the stepped piston.

Description

description

Starter for a motor with a free-flying stepped piston.

The invention relates to a starter for a motor having a free-flying stepped piston, comprising a rotatable about an axis

Eccentric element, via which a translational movement can be transmitted to the step piston.

A motor with a free-floating stepped piston can be found in DE-A-30 29 287. This motor, known as the "Stelzer" motor, has a simple design and consists of only a few individual parts. Therefore, a universal application is possible, whereby the force gained during the combustion can be directly implemented in work by the piston stages. The stepped piston can be axially pierced to allow e.g. to pump a liquid.

In order to set the step piston in vibration, that is to say to start the engine, it is known that a pin engages in a recess provided laterally in a region of the step piston, the pin itself starting from an eccentric disk. The starter and the stepped piston consequently form an essentially rigid unit, which means that there is a risk of the pin tearing off (see e.g. DE-A-38 20 240).

The object of the present invention is to provide a starter as described in the introduction

Art in such a way that it is ensured with a simple structure that the

Step piston can be set to the desired frequency without the risk of damage or tearing of interlocking parts. Also supposed to be easy decoupling of starter and stepped piston may be possible.

The object is essentially achieved in that the eccentric element has at least two transmission elements which can be changed in length to the required extent and which are connected on opposite sides of the axis either to a slide element which can be moved back and forth along the stepped piston, which in turn indirectly or directly with is connected to the step piston, or bypassing the slide element, act on sections of the step piston to impress a reciprocating movement.

10

In this case, the transmission element is an element which yields to a degree, by means of which the change in distance which occurs as a function of the position of the eccentric element can be compensated for between the connection points of the transmission element on the eccentric element and the sliding element or stepped piston sections. 15 The transmission element is preferably a belt such as steel-reinforced belts.

According to the invention, the e.g. Transfer elements designed as belt elements transmit a rotational movement transmitted by an eccentric element such as an eccentric disk or 20 disks to a slide which can only be moved back and forth along the step piston. This can be done in that the slide is fixed by means of bearing blocks running parallel to the longitudinal axis of the stepped piston and can therefore only be moved back and forth along this. -25

The eccentric disc can be arranged on a shaft which in turn starts eccentrically from a disc which can be set in rotation by means of, for example, a V-belt or by means of a positive connection by means of, for example, an electric starter. The disc which is rotated by the starter with the shaft emanating from it, from which in turn the discs guiding the transmission elements originate, can therefore be referred to as a crank mechanism in order to convert the rotational movement into a translational movement by means of the slide which can only be moved axially along the stepped piston which in turn is transferable to the stepped piston. The transmission elements such as belts have, for example, elasticity due to elasticity, so that despite the eccentric movement of the shaft having the disks and the resulting change in distance to the points of the slide, in which the transmission elements effectively engage the slide, destruction does not occur .

In this connection, it should be mentioned that the disks do not essentially rotate, but only move back and forth slightly depending on the position of the eccentric element.

If the transmission elements are preferably steel-reinforced belts, ropes or similar elements can also be used.

In a particularly noteworthy inventive design, it is provided that the interaction between the slide element and the stepped piston takes place via pistons, preferably pressurized with pressure medium, which start from the slide element and which, for example, Transfer the translational movement of the slide element via elements starting from the step piston. The pistons preferably assume a common pressure space, which e.g. can be acted upon with hydraulic oil. As a result, the pistons are moved outwards in the direction of the elements extending from the stepped piston in order to abut against them.

In order to shift the stepped piston to the desired position in relation to the slide element, in a further refinement, the ones starting from the slide have

Piston stroke limits open. These are caused by existing in the piston

Longitudinal slots and stop elements formed in these from the carriage.

In order to enable the starter piston to be decoupled from the stepped piston, the pistons extending from the slide element are retractable. So that the decoupling takes place as quickly as possible, the surrounding coil springs can act on the pistons. Further details, advantages and features of the invention result not only from the claims, the features to be extracted from them - individually and / or in combination - but also from the following description of preferred embodiments to be taken from the drawing.

Show it:

1 shows a sectional illustration of a free-flight piston engine with a first embodiment of a starter,

2 is a plan view of the starter of FIG. 1,

3 shows a sectional illustration through a free-flight piston engine with a further embodiment of a starter,

Fig. 4 is a perspective view of a preferred embodiment of a starter and

5 is a perspective view, partly in section, of essential elements of the starter according to FIG. 4.

In the figures, in which the same elements are provided with the same reference numerals, a free-flight piston engine is shown, as can be found in DE-A-30 29 287. In this regard, reference is made to the disclosure in this regard. The motor (10) has a stepped piston (14) arranged in a motor housing (12) with outer piston steps (16) and (18) and an inner step (20). The inner step (20) can be moved within a pre-compression chamber (22), from which the pre-compressed fuel mixture flows via channels (24) and (26) in combustion chambers (28) and (30). Pre-compressor rooms (22) and combustion chambers (28) and (30) could of course be replaced. The piston center pieces (30) and (32) extending in the channels (24) and (26) also have the function of a valve. In order to start a corresponding engine (10), the invention provides that sections (36) and (38) extend from the outer piston stages (16) and (18), which are connected via transmission elements (40) and (42) with a pin ( 44) are connected, which is eccentrically and rotatably mounted in its own rotatably mounted shafts, which can be designed as cylinder sections (46) and (48). The pin (44) with the cylinder sections (46) and (48) consequently represents a type of crank drive, which in turn can be set in rotation by a starter motor, not shown. The transmission elements (40) and (42) are connected to the sections (36) and (38) via cylindrical elements (50) and (52) extending from them. If the crank mechanism (44), (46), (48) is now set in rotation, this movement is converted into a translational movement, as a result of which the stepped piston (14) is set in vibration. The translational movement is of course only transmitted from the transmission element (40) or (42) to the stepped piston (14), to which a tensile force acts by means of the pin (44).

In order to accommodate the change in length of the transmission elements (40) and (42) to the sections (50) and (52) depending on the position of the pin (44), the former are designed to a certain extent to be elastic. Therefore, steel reinforced belts are particularly suitable. Ropes or the like are of course also possible. Of course, the transmission elements (40) and (42) can also be rigid. In this case, the sections (50) and (52) or the sections (36) and (38) extending directly from the outer piston stages (16) and (18) must be elastic to a certain extent. The latter can preferably be spring bars.

3 shows an embodiment of the invention that is particularly noteworthy. Thus, the crank mechanism consisting of the pin (44) and the cylinder sections (46), (48) sets a carriage (54) in translational motion, which carries hydraulically or pneumatically actuated cylinders (56) and (58), their pistons (60) and (62) interact with the sections (36) and (38) of the outer piston stages (16) and (18). In the exemplary embodiment, the pistons (60) and (62) are extended, ie they rest on the inner surfaces of the sections (36) and (38). If the crank mechanism (44), (46) and (48) is now set in rotation, the slide (54) is set in a back and forth movement parallel to the longitudinal axis of the stepped piston (14), which moves on the stepped piston (14) is transmitted itself. This will start the engine. The starter can then be decoupled by pulling back the pistons (60) and (62) so that the stepped piston (14) is exposed.

According to the invention, the cranks (46) and (48) could of course be used to tap the work obtained by the combustion. In other words, this translates into a rotational movement of the stepped piston (14).

4 and 5 show a particularly noteworthy embodiment of a starter designed according to the invention for a free-flight piston engine, which can likewise have a basic structure like the Stelzer engine. Bearing blocks (70) and (72) are arranged on sections (66) and (68) of the motor and parallel to the indicated step piston (14), along which a carriage (74) can be moved back and forth.

The slide has a cylindrical base or base body (76), from which the bearing blocks (70) and (72) surround bearing eyes (78) and (80). In the exemplary embodiment above and with respect to the carriage (74), a drive unit (82) is arranged that cannot be moved, by means of which a rotational movement is converted into a linear movement to be carried out by the carriage (74), which in turn is transmitted to the stepped piston (14).

The drive unit (82) also starts from an engine block section (84) and is penetrated by the bearing blocks (70) and (72). The drive unit (82) has a disk (88) which can be rotated by means of an electric starter (84) via a V-belt (86) and which can be rotated about an axis (90). Eccentrically to this ends a shaft (92) which carries disc elements (94) and (96), of which transmission elements in the form of preferably flexible steel-reinforced belts (98) and (100) run out, which are guided around disc elements (102) and (104). The disk elements (102) and (104) start from sections (106) and (108) of the carriage (74). The disk elements (102) and (104) practically wobble as a function of the position of the eccentric element (92), (94) and (96). The flexible connecting elements (98) and (100) do not rotate. They are guided by the disk elements (94) and (104) or (96) and (102). The disk elements (94), (96) can be rotated with respect to the stub shaft (92), ie the stub shaft rotates with respect to the disk elements (94) and (96) so that they remain in their position.

In other words, the disk elements (94) and (96) which are mounted eccentrically with respect to the disk element (88) can be displaced relative to the deflection disks (102) and (104), the distance from the position of the disk element (88) being variable. This change in length is compensated for by the transmission elements (98) and (100) themselves. For this purpose, they are designed to be elastic to such an extent that the change in distance can be compensated for without the risk of destruction.

By mounting the carriage (74) on the bearing blocks (70) and (72) running along the stepped piston (14), the rotary movement of the disk (88) is consequently converted into a translational movement, that is to say a reciprocating movement of the carriage (74) and always by tensile stress on one of the transmission elements (98) or (100).

This movement is in turn over in the cuboid base body (76) of the

Transfer pistons (110) and (112), which are mounted on a slide, to elements (114) and (116) starting from the stepped piston (14).

For this purpose, the pistons (110) and (112) can be displaced outward from the base body (76) in the direction of the sections (114) and (116). This is made possible by the fact that the pistons (110) and (112) start from a pressure chamber (118) which can be acted upon by a pressure medium such as hydraulic oil via a line (120). In order to ensure that even with an uneven stroke movement of the pistons (110) and (112) the stepped piston assumes the desired position in relation to the slide, stroke limits are provided which are slit through the lengthways extending in the pistons (110) and (112) or longitudinal channels (122) are formed, into which bolts or screws (124) extending from the slide (74), preferably from the base body (76), engage. As a result, both pistons (110) and (112) reach the desired extended end position, the stepped piston (14) being displaced into the desired position simultaneously by interacting with the sections (114) and (116).

In order to be able to decouple the starter, i.e. retract the pistons (110) and (112) as quickly as possible, the pistons (110) and (112) are surrounded by spring elements such as coil springs (126) and (128), which act as a force produce against the force caused by the pressure medium. As a result, the pressure medium can be pressed out of the pressure chamber (118) accelerated, provided that the pressure medium itself is no longer pressurized. This in turn leads to a rapid retraction of the pistons (110) and (112).

In order to be able to adjust the tension of the transmission elements (98) and (100), i.e. the belt, the sections (106) and (106) of the carriage (74) receiving the deflection disks (102) and (104) are e.g. Allen screws (130) can be moved.

Finally, it should be pointed out that the outer end faces of the pistons (110) and (112) interacting with the sections (114) and (116) of the stepped piston (14) can be provided with shock-absorbing elements such as rubber dampers (132) and (134) .

If the sections (114) and (116) transmitting the translational movement of the carriage (74) to the stepped piston (14) preferably originate from the end faces of the outer steps of the stepped piston (14), it is of course possible to use the pistons (110) and ( 112) interacting sections also start from side surfaces of the stepped piston (14). Other types of linear motion transmission from the carriage (74) to the stepped piston (14) are also conceivable.

It should also be mentioned that the transmission elements do not necessarily have to be belts, which, however, lead to an almost noiseless mode of operation, but can also be other flat elements.

Claims

Starter for a motor with a free-floating stepped piston.

1. Starter for a motor with a free-flying stepped piston (14), comprising an eccentric element (92, 94, 96) which can be rotated about an axis (90) and via which a translational movement can be transmitted to the stepped piston, characterized in that the eccentric element ( 92, 94, 96) at least two transmission elements (98, 100) which can be changed in length to the required extent and which interact directly or indirectly with the stepped piston on both sides of the axis (90).

2. Starter according to claim 1, dadu rch gekennze ichnet that the transmission elements with a along the step piston (14) reciprocable carriage (74) are connected, which in turn interacts directly or indirectly with the step piston (14).

3. Starter according to claim 1 or 2, characterized in that the transmission element (98, 100) is a resilient element by which the depending on the position of the Exzenterele¬ elementes (92, 94, 96) distance change between the connection points of the transmission element on the eccentric element or the slide element ment (74) can be compensated.

4. Starter according to claim 3, characterized in that the transmission element (98, 100) is a belt such as steel-reinforced belt.

5. Starter according to at least claim 2, characterized I et et that the slide element (74) along the step piston (14) extending pistons (110, 112) are received, which act directly or indirectly on the step piston to transmit the translation movement .

6. Starter according to claim 5, dadu rch characterized in that the pistons (110, 112) for interacting with the stepped piston (14) or from this outgoing sections (114, 116) are pressurized.

7. Starter according to claim 6, characterized in that the pistons (110, 112) emanate from a common pressure chamber (118).

8. Starter according to at least claim 6, d marked by that the pistons (110, 112) are spring-loaded against the pressure medium.

9. Starter according to at least claim 6, characterized in that each piston (110, 112) has a stroke limiter which extends through a longitudinal slot or channel (122) in the piston (V

engaging stop element (124) starting from the slide element (74) is formed like a bolt.

10. Starter according to at least one of the preceding claims, characterized in that the transmission elements (98, 100) on disc elements (94, 96, 102, 104) are guided, of which the arranged on the slide element (74) for tensioning the transmission elements adjustable are trained.

11. Starter according to at least claim 6, characterized in that the pistons (110, 112) for uncoupling the starter in engagement with the

Step piston or the sections (114, 116) extending from it.

12. Starter according to at least claim 1, characterized in that the transmission elements are apparently extendable in that the outgoing sections for transmitting the translational movement of the stepped piston (14) (36, 38) are elastic and / or resilient to the required extent.

13. Starter according to at least claim 1, characterized in that the transmission elements (98, 100) around disc elements (94, 96, 102,

104) are guided, which are arranged essentially non-rotatably.

14. Starter according to claim 13, characterized in that the eccentric element has at least one of the transmission elements (98, 100) leading disc element (94, 96) to which an eccentrically mounted shaft (92) is rotatable. ß

15. Starter according to preferably at least claim 1, characterized in that the step piston (14) impressed by the starter linear movement can only be caused by alternating tensile stress on the flexible transmission elements (98, 100).