EP1415088A1

EP1415088A1 - Axial piston motor

Info

Publication number: EP1415088A1
Application number: EP01969545A
Authority: EP
Inventors: Alexander Zein
Original assignee: TWE TECH WISSENSCHAFTLICHE ENT; TWE Technisch-Wissenschaftliche Entwicklungsgesellschaft mbH
Current assignee: Kilic Hasan Hayri Dr
Priority date: 2001-07-27
Filing date: 2001-07-27
Publication date: 2004-05-06
Anticipated expiration: 2021-07-27
Also published as: WO2003012289A1; EP1415088B1; DE50112612D1; ATE364133T1

Abstract

The invention relates to an axial piston motor (1) whose axial pistons (3) move periodically in an oscillating manner with the rotation of the axial piston motor (1) in the housing (2). One proven disadvantage is that conventional mechanics tends to block automatically when certain performance values are exceeded. The invention has the aim of providing an axial piston engine (1) having an enhanced operating range. According to the invention, this is achieved in that an equal number of axial pistons (3) is arranged on the opposite front faces (5) of the housing (2), said axial pistons coming out on the corresponding front faces (5) of the housing (2) and exerting forces on slanted thrust bearings (6) arranged on both front faces (5) in at least segments of the rotation of the axial piston motor (1), wherein an axial piston (3) on the opposite front face (5) is assigned to an axial piston (3) on the front face, to which it is permanently connected by means of a force transmitting element (7).

Description

axial piston

The invention relates to an axial piston machine with a housing, the axial pistons of which are arranged in parallel running bores each at the same distance from the machine axis and emerge from an end face of the housing, with a counter bearing arranged obliquely with respect to the direction of movement of the axial pistons on the end face of the housing and into which forces are exerted the axial pistons are introduced, with a working medium, by means of which the axial pistons are pressurized in the housing and, in such a driven manner, periodically move in an oscillating manner with the rotation of the axial piston machine in the housing.

Such axial piston motors or also axial piston pumps or compressors are used in many places. Wherever high torques or high pressures are required, the use of such an axial piston machine is ideal. Due to its compact design, such a machine has an enormous power density. Even at the lowest speeds, the axial piston motor usually generates high torques, which significantly reduces the design effort for any downstream gearboxes. Often there is no need for a gearbox behind such an engine.

The same applies to axial piston pumps or compressors. With preferably low volume flows, pressures of 500 bar and more can be generated.

The adjustment of the output torque, the delivery pressure or the delivery volume is particularly easy. By simply adjusting the angle of inclination of the inclined counter bearing, the output torque can be adapted to the current requirements. The same applies to the pressure ratio or the flow rate.

It is already known to adjust axial piston machines in their stroke by adjusting the angle of inclination of the counter bearing to the current operating conditions. In axial piston pumps for hydraulic fluid, the system pressure is usually regulated in this way. However, it has proven to be disadvantageous to increase the inclination of the thrust bearing and thus the stroke of the axial piston beyond certain limits, since the mechanical system in question tends to self-lock beyond these limit values. Often there is elastic deformation of the axial piston, which prevents it from being pushed back into the barrel bore. Furthermore, the stroke movement of the axial piston is usually connected to a radial relative movement of the contact surface of the axial piston on the oblique counter bearing. Therefore, from a limit angle, which depends on the surfaces of the components, between the axial piston and thrust bearing, self-locking occurs when the axial piston is pushed back.

Based on the described disadvantages of the prior art, the invention has for its object to develop an axial piston machine of the type mentioned in such a way that the angle of inclination of the counter bearing can be set higher than in previously known devices of this type without increasing it Wear or self-locking of the machine comes. Furthermore, it is an object of the invention to expand the operating range in terms of output torque, volume flow, the machine should always have a good efficiency.

According to the invention, the object is achieved in that an equal number of axial pistons is arranged on the opposite end faces of the housing, which emerge on the respective end faces of the housing and exert forces there, at least on sections of the rotation of the axial piston machine, on inclined counter bearings arranged on both end faces, wherein an axial piston on one end face is assigned an axial piston on the opposite end face, with which it is in a fixed connection via a force transmission element and to which it transmits axial forces via the force transmission element during operation.

The coupling according to the invention of two opposing axial pistons has the decisive advantage that blocking of the axial piston machine is impossible. The axial pistons do not have to be pushed back into their bore holes in the housing through the counter bearing, but rather are pulled back into the housing by the respective opposite piston via the force transmission element. The process of returning an axial piston is now driven by the working medium and, according to the invention, is not carried out by contacting the counter bearing. Advantageously, the novel return of the axial pistons makes it possible to set the angle of inclination of the thrust bearing almost arbitrarily within the geometric limits. Due to the expansion of the angle of inclination range in which the machine can be operated, the axial piston machine according to the invention can be operated with very low strokes with consistently low wear. This simultaneously increases the torques that can be generated and a particularly high power density can be achieved. The forced return of the axial pistons according to the invention also enables the machine to be operated at exceptionally high speeds.

Increasing the angle of inclination of a counter bearing always results in a radial displacement of the axial pistons relative to the counter bearings. So that the angle of inclination of the thrust bearing can be easily adjusted, particularly during operation, without great effort, it is expedient to design the axial piston to be radially displaceable relative to the thrust bearing.

So that the counter bearings do not have to rotate with the housing and thus contribute to increasing any imbalances, in particular due to their inclination to the axis of rotation, it is expedient to make the axial pistons displaceable in the circumferential direction relative to the counter bearings. In this way, the rotating masses of the axial piston machine according to the invention are considerably reduced and an otherwise costly, complex balancing of the machine is considerably simplified. An advantageous development of the invention provides that the axial pistons only bear axially on the counter bearings and are not in any fixed connection with them, which would enable the transmission of tensile forces from the axial pistons to the counter bearings and therefore only transmit compressive forces from the axial pistons to the counter bearings become. On the one hand, mechanical overdetermination of the axial piston machine according to the invention is avoided constructively from the outset, as a result of which it is no longer necessary to maintain closely coordinated manufacturing tolerances of the components involved in the axial direction. On the other hand, the number of structural components required is reduced.

In order to reduce the operational wear of the axial piston motor, it is particularly expedient if the counter bearing is movably mounted in its circumferential direction. At high speeds, there are high peripheral speeds of the axial pistons relative to the counter bearings, which results in great wear. To extend the service life, it is therefore advisable to provide the thrust bearing with a component which is movable in the circumferential direction and which rotates with the axial piston.

So that the design of the axial piston machine according to the invention is particularly compact, it is expedient if the counter bearings are designed to be stationary and the housing rotates together with the axial pistons.

An expedient embodiment of the axial piston machine according to the invention provides that the housing is mounted on a central standing shaft on at least one side. Such storage is simple to construct and always proves to be robust.

It is of particular advantage to feed the working fluid through holes in the central shaft to the axial piston machine and then to discharge it again. The central shaft is therefore particularly well suited for supplying the working medium because, because of the rest position, no hollow rotary coupling or the like is required to supply the working medium to the axial piston machine. An advantageous development of the invention provides that a distributor device is attached to the central shaft with channels running in the radial direction, via which the working medium is supplied to the displacements of the axial pistons in the housing depending on the respective phase angle or the working medium is discharged again from the displacements , Such a distribution device ensures through appropriate windows to the channels of the housing that the correct amount of working medium is always available or discharged in the correct phase of rotation. In this way, the direction of rotation of the axial piston motor is also structurally fixed, which is why the machine can generate high torques from a standstill and does not require any starting device.

In order to be able to always adapt the output torque to the current operating conditions, it is expedient that the angle of inclination of the counter bearing can be adjusted. The special design of the axial piston motor according to the invention enables a particularly wide adjustment range of the angle of inclination and problem-free adjustment even during operation.

A particularly inexpensive and simple sealing of the axial pistons in the housing is obtained if the displacements of the axial pistons are sealed off from the environment by means of piston rings in the running surface of the housing of the axial pistons. Such a seal has already proven itself in numerous technical applications and the corresponding components are inexpensive to obtain.

A particularly high degree of flexibility results when several axial piston motors according to the invention are connected in series. In this way, almost any performance is possible and the effort for the storage of spare parts is significantly reduced. The availability of the entire system can be significantly increased by a single reserve axial piston machine.

An advantageous development of the invention provides that a central output shaft emerges from an end face of the housing. This central The output shaft is used both for the output of the torque of an axial piston motor according to the invention and for the mounting of the rotating housing.

In order to compensate for any axial expansion of an axial piston motor according to the invention, it is expedient if the output shaft is axially displaceably mounted in the housing and an elastically prestressed component ensures a defined axial position of the housing in relation to the output shaft. The temperature fields in the axial piston motor resulting from the exposure to the working medium and from frictional processes result in an axial expansion, which in this way does not influence the surrounding components.

To minimize the wear of the axial piston machine according to the invention, it is particularly advantageous if the axial pistons have a component which is elastically preloaded in the axial direction and which deforms as a function of the axial force exerted by the thrust bearing on the thrust piston, and thus any shocks between the axial piston and thrust bearing cushions. On the one hand, the smooth running of the machine increases, on the other hand, the load on all components involved due to shocks and vibrations is significantly reduced.

So that the counter bearing does not always have to be laboriously compared in terms of its angle of inclination, it makes sense to connect the two counter bearings to one another via mechanical components such that the angle of inclination of the two counter bearings is always identical. Such a mechanical connection always works reliably and is inexpensive to manufacture.

An exemplary embodiment of an axial piston motor according to the invention is described in more detail to illustrate the invention with reference to a drawing. It shows:

Fig. 1: A longitudinal section through an axial piston motor according to the invention. In Figure 1, an axial piston engine 1 according to the invention is shown cut in the longitudinal direction. In the housing 2, the axial pistons 3 are movably mounted in the longitudinal direction in the bore 4. The axial pistons 1 emerge from the two end faces 5 of the housing 2 and extend as far as the counter bearings 6, which are each located opposite the end faces 5. Two opposing axial pistons 3 are connected via a force transmission element 7. The axial pistons 3 are supported in the running bores 4 via linear bearings 8.

If the axial pistons 3 located in the housing 2 are acted upon by working medium, the housing 2 rotates. The housing 2 is supported on one side on a central standing shaft 9. On the other side of the housing 2 there is a central output shaft 10 which rotates with the housing 2 and is mounted in an external bearing 11.

The working medium is fed into the axial piston motor 1 via bores 12 in the central, standing shaft 9 and also discharged again. On the central, standing shaft 9 there is a distributor device 13 with radially extending channels 14, via which the displacements 15 are filled and emptied with working medium, depending on the respective angle of rotation of the axial piston 3.

The gap between the axially movable axial pistons 3 and the running bores 4 in the housing 2 is sealed off from the environment by means of piston rings 16. The counter bearing 6 has a circumferentially movable contact disk 17, which rotates with the axial piston 3.

To compensate for axial expansions, the output shaft 10 is mounted in an axially movable manner in the housing 2 and is pressed against the corresponding end face 5 from the inside by means of an elastically prestressed component 18.

The counter bearings 6 are connected to one another via a lever 19 such that the same angle of inclination always results.

Claims

claims

1. axial piston machine (1) with a housing (2), the axial pistons (3) are arranged in parallel bore holes (4) at the same distance from the machine axis and emerge from an end face (5) of the housing (2) with an obliquely opposite the direction of movement of the axial pistons (3) on the end face (5) of the housing (2) counter bearing (6), into which forces from the axial pistons (3) are introduced, with a working medium by means of which the axial pistons (3) in the housing (2) are pressurized and in such a manner drive periodically with the rotation of the axial piston machine oscillating in the housing (2), characterized in that on the opposite end faces (5) of the housing (2) an equal number of axial pistons (3) is arranged, which emerge on the respective end faces (5) of the housing (2) and there at least on sections of the circulation of the axial piston machine (1) forces on b Exercise oblique counter bearings (6) arranged on both end faces (5), an axial piston (3) on one end face (5) being assigned an axial piston (3) on the opposite end face (5), with which it is connected via a force transmission element (7 ) is in a fixed connection and to which it transmits axial forces via the force transmission element (7) during operation.

2. Axial piston machine (1) according to claim 1, characterized in that the axial pistons (3) are radially displaceable relative to the counter bearings (6).

3. axial piston machine (1) according to claim 1, characterized in that the axial pistons (3) relative to the counter bearings (6) are displaceable in the circumferential direction.

4. Axial piston machine (1) according to claim 1, characterized in that the axial pistons (3) against the counter bearings (6) only bear axially and are not in any fixed connection with these, which transmit the tensile forces from the axial pistons (3) to the Counter bearing (6) would enable and therefore only compressive forces are transmitted from the axial piston (3) to the counter bearing (6).

5. Axial piston machine (1) according to claim 1, characterized in that the counter bearing (6) is movably mounted in the circumferential direction.

6. Axial piston machine (1) according to claim 1, characterized in that the axial pistons (3) by means of linear bearings (8) in the housing (2) are mounted.

7. axial piston machine (1) according to claim 1, characterized in that the counter bearing (6) are designed to be stationary and the housing (2) rotates together with the axial piston (3).

8. axial piston machine (1) according to claim 1, characterized in that the housing (2) is mounted on at least one side on a central standing shaft (9).

9. Axial piston machine (1) according to claim 8, characterized in that through working holes (12) in the central shaft (8) the working medium is fed to the axial piston machine (1) and discharged again.

10. axial piston machine (1) according to claim 8 and 9, characterized in that on the central shaft (9) a distributor device (13) is attached with channels running in the radial direction, which feeds working medium to the displacements (15) of the axial pistons (3) in the housing (2) depending on the respective phase angle or removes working medium from the displacements (15).

11. Axial piston machine (1) according to claim 1, characterized in that the angle of inclination of the counter bearing (6) can be adjusted.

12. Axial piston machine (1) according to claim 1, characterized in that the displacements (15) of the axial piston (3) by means of piston rings (16) in the running surfaces of the axial piston (3) are sealed from the environment.

13. Axial piston machine (1) according to claim 1, characterized in that several axial piston machines (1) according to the invention are connected in series.

14. Axial piston motor according to claim 1, characterized in that a central output shaft (10) emerges from an end face (5) of the housing (2).

15. Axial piston motor according to claim 14, characterized in that the output shaft (10) in the housing (2) is axially displaceably mounted and an elastically biased component (18) ensures a defined axial position of the housing (2) to the output shaft (10).

16. An axial piston machine according to claim 1, characterized in that the axial pistons (3) have a component which is elastically preloaded in the axial direction and which, depending on the axial force which the counter bearing (6) exerts on the axial piston (3), deforms and so any bumps between Axial piston (3) and counter bearings (6) cushioned.

17. Axial piston machine (1) according to claim 1, characterized in that the two counter bearings are connected to one another via mechanical components, in particular a lever (19), such that the angle of inclination of the two counter bearings (6) is always identical.