FR2604488A1 - HYDROSTATIC MACHINE WITH AXIAL PISTONS WITH SLIDING SKATES - Google Patents

Abstract

A. HYDROSTATIC MACHINE WITH AXIAL PISTONS WITH SLIDING PADS. B. CHARACTERIZED IN THAT IN AN AXIAL PISTON MACHINE (PUMP OR MOTOR), WITH AN INTERNALLY LOADED PRESSURE PLATE 9, THE OUTSIDE DIAMETER D OF THE WORKING SURFACE 11 OF THE SLIDING PLATE 12 IS WITHDRAWN BY A VALUE SUCH AS AN EDGE 14 DELIMING THE EXTERNAL DIAMETER D IS CROSSED BY THE SPAN SURFACE 10 OF EACH SLIDING PAD 6. C. THE INVENTION CONCERNS HYDROSTATIC MACHINES WITH AXIAL PISTONS WITH SLIDING PADS.

Description

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  Hydrostatic axial piston machine with glide pads

is lying".

  The invention relates to a hydrostatic machine

  than axial pistons, comprising a cylinder body

  including the pistons in the cylindrical bores

  are connected to sliding glides, which are

  pressed on a bearing surface of a sliding plate

  by means of a pressure plate, in order to produce a

reciprocating motion.

  It is known a device for pressing the piston sliding pads, on an inclined plate

  of an axial piston machine (DE-AS 1 269 494). Some

  hydrostatically discharged pistons are supported against the reach surface of a cradle, by

  a holding disk which is supported on a spherical projection

  cylinder drum. The axial piston machine must be particularly suitable for high speeds of rotation, as a result of axial guidance disposed in the

  plane of the holding disk. With this solution, a

  think of the reversing couple with skates

  is not possible. Pressure through the pressure plate

  sion, centrally charged by the force of an augmented

  the tendency to overturn the sliding pad.

  In addition, a device is known for 2. the axial support of the piston of axial piston machines on

  their inclined plateau (DE-AS 1 528 528). A record of

  the piston sliding pads against an intermediate disk, which is rotatably guided on an inclined plate, connected to the holding plate by

  a training cleat. It is necessary to allow a high charge

  slip shoes, with low wear, as well as an increase in the rotational speed of the axial piston machine, in each hydrostatic bearing disposed in each bearing surface of the sliding pads and

  under each sliding pad, in the bearing surface.

  A reversal of the sliding pads and thus the local wear is not preventable, with this configuration of the

  slip plate. The disposal of the hydrological discharge

  state, under the sliding plate, leads, in addition, to the formation of additional vanishing points,

  It is also known (DE-OS 2,042,106) a machine

  not hydraulic usable as pump or as engine,

  whose bearing surfaces of sliding skids possesses

  dent a recess in the bearing surfaces, to obtain

  higher speeds and pressures, which is

  at least one of the chokes between the feed hole

  to the hydrostatic discharge and the

  border of the reach surface. To get a strangle-

  In fact, it is necessary to manufacture the slip shoe very precisely, which is reduced to nothing in a very short time due to wear and no longer makes it possible to operate safely. Pumps and piston engines (German Offenlegungsschrift No. 1,703,854) are also known, whose sliding pads, shaped like bearing bushings, are deformable in the area of the bearing surface, under the action of pressure. a film of liquid. In these apparatus, the resultant piston force acting on the slip shoe and the hydrostatic discharge is in one direction

260,488

  3.- action, making that the desired compensation of the efforts

  reversal is not feasible.

  The purpose is to design the sliding shoe pressure in an axial piston machine so that the wear on the sliding shoe bearing surfaces and the bearing surface of the sliding plate are reduced to a minimum and that the performance of the axial piston machine and in so doing,

  its operational safety, be increased.

  The object of the invention is to pocket, by a compensation of the overturning torque on the sliding shoe, any overturning of the bearing surface of the sliding shoe, with the bearing surface of the sliding plate, in a hydrostatic axial piston machine, with piston sliding pads

discharged hydrostatically.

  According to the invention, the problem is solved in that, in an axial piston machine (pump or motor)

  with a pressure plate loaded internally, that is,

  say a pressure plate that the sliding shoe internally loads on its peripheral band, which is set back from the outer diameter of the bearing surface of the sliding plate, a value such that an edge limiting this outside diameter is traveled by each sliding shoe bearing surface, it being specified that the annular surface located under the bearing surface

  sliding shoe between outer diameter and hollow

  is used for hydrostatic discharge. Each sliding glide surface has, during the course

  of the edge of the sliding plate on it, a

  positive cover, such that between the recess in the sliding shoe bearing surface and the inner housing space, no shorting can occur. The invention will be described below using 4-

  of an exemplary embodiment, with the aid of the figures

  both: FIG. 1, a partial section through a hydrostatic machine with axial pistons; FIG. 2, a sectional section according to FIG. 1, with the representation of the stresses exerted

on a slip pad.

  In a casing 1 of a hydrostatic axial piston machine, not shown in detail, a cylinder body 2 is provided with pistons 3 whose spheres 4 are surrounded by a picture 5 of a sliding shoe 6,

  partially mechanically adjusted in order to

to make an articulated connection.

  A pressure plate 9, subjected to the effort

  a pressure element 8 of spherical shape, under the ac-

  tion of a spring 7, presses the sliding shoe 6 on its bearing surface 10 of annular shape, against the bearing surface 11 of a sliding shoe 12, which rests on

  the housing 1, by means of an inclined disc 13.

  The outer diameter D of the bearing surface 11 of the sliding plate 12 is recessed, so that the edge 14 limiting this outer diameter D corresponds to the bearing surface 10 of each pad

  slip, 6 making, on that occasion, a short

  circuit can take place between a recess 15, for the hydrostatic discharge and the interior space 16 of the

casing 1.

  As a result of the charge of the pressure plate

  9, by the pressure element 8 of spherical shape, the pressure plate 9 bends in the direction of the sliding plate 12, which has the consequence that the sliding plate 6, as shown in FIG. 2, is loaded only internally, depending on its path, by the pressure plate 9, with the support force PA. This support force PA, which simultaneously attempts to tilt 5.- outwardly each sliding pad 6, around

  the sphere 4 of the piston 3, with the centrifugal force PF over-

  coming on the sliding pads 6, during the rotation of the cylinder body 2, will be compensated as a result of the hydrostatic discharge FH displaced by the reduction of the

  outer diameter D of the sliding plate 12,

  with the resulting piston force FKR, so that a reversal of the sliding pad 6 is no longer possible. The local wear, which was thus linked, which could lead to the failure of the axial piston machine, as soon as possible, is prevented, as well as

  as a direct source of high frequency noise. The influ

  consequent negative negative influence on suction behavior for axial piston machines

  removed with the solution according to the invention.

  The same effect is achieved in machines

  axial piston with an externally loaded pressure plate

  subsequently, by enlarging the circular central recess in the sliding plate, to obtain a positive overlap between bearing surfaces of the sliding pads and sliding plate edge, similarly to that obtained for axial piston machines

  with backing plate loaded internally.

6.-

R E V E N D I CA TI 0 N S

  1.- hydrostatic axial piston machine comprising a rotating cylinder body, whose pistons disposed in the cylinder bores are connected to sliding pads, which are pressed on a bearing surface of a sliding plate, by means of 'a plate

  in order to produce an alternative movement,

  characterized in that in an axial piston machine (pump or motor) with a pressure plate (9) loaded internally, the outer diameter (D) of the bearing surface (11) of the sliding plate (12) is in removing a value such that an edge (14) delimiting the outer diameter (D) is traversed by the bearing surface (10)

each sliding shoe (6).

  2. A hydrostatic axial piston machine according to claim 1, characterized in that in the motor, as well as in the pump, the bearing surface 410) of each sliding shoe (6) has a positive recovery during the course of the 'arete (14) from the plate

sliding (12), with this one.