Axial-piston machine of the swashplate or oblique-axis type of construction

Abstract

In an axial-piston machine of the swashplate or oblique-axis type of construction, a contact face of the cylinder head (1) is pressed against a stationary sealing face. The contact face has located in it transition orifices (15a) for the exchange of hydraulic fluid between the cylinder head (1) and the stationary part. The transition orifices (15a) are located on a raised annular collar (13) of the end face (11) of the cylinder head (1). Microgrooves (21) are recessed in the annular collar (13) between the individual transition orifices (15a), so that, of the supporting face, only two edge webs (13a, 13b) remain. The depth of the microgrooves (21) is only a few hundredths of a millimeter. This design prevents a hydrodynamic carrying effect between the cylinder head and the stationary part.

Description

BACKGROUND OF THE INVENTION [0001] The invention relates to an axial-piston machine of the swashplate or oblique-axis type of construction, with a rotating cylinder block, with displacer spaces which are arranged in the form of a ring in the cylinder block and run parallel to the axis of rotation of the cylinder block and in which pistons are received slideably, with transition orifices of the displacer spaces, the said transition orifices issuing into an end contact face of the cylinder block, and with a stationary supporting face for the end contact face of the cylinder block, the supporting face having provided in it orifices which are connected alternately to the transition orifices of the cylinder block during the rotation of the latter, and the contact faces of the cylinder block and the supporting face being pressed against one another in a sealed-off manner. [0002] Axial-piston machines of this type are generally known. As a rule, kidney-shaped orifices of the stationary sup...

AI Technical Summary

Benefits of technology

[0009] The design according to the invention seems at first sight to be absurd, since, of course, because of this there is no longer the full extent of sealing action between the adjacent displacer spaces. It has been shown, however, that the advantage achieved thereby, to be precise the substantial reduction in a hydrodynamic carrying pressure in the sealing face between the cylinder block and the stationary supporting face, carries far more weight. The disadvantage is naturally some leakage flow through the microgroove, although this flow remains very low. To be precise, a leakage gap of this order of magnitude constitutes considerable flow resistance, so that internal leakage will remain very low.

[0011] By virtue of the configuration according to the invention, the already known measures for the reduction of pressure pulsations and noises may readily be combined. Thus, for example, the individual displacer spaces of the cylinder block may merge in the form of a block kidney into their transition orifice, the individual transition orifices being in the form of annular segments in the shape of an arc of a circle. The annular segments of the transition orifices and of the microgrooves then alternate with one another in the contact face of the cylinder block.

[0013] The advantage of the last-mentioned combination is, above all, that the reversal notches can then be made smaller, thus making further structural free spaces available. The leakage streams possibly occurring due to the microgrooves can as it were be partly avoided again by using the reversal notches.

Problems solved by technology

The disadvantage is naturally some leakage flow through the microgroove, although this flow remains very low.

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