EP2104786B1 - Axial piston engine having a housing comprising a radially extended inner section - Google Patents

Abstract

The machine (1) has a housing (2) for enclosing an interior space (3) with two transverse walls (18a, 18b) and a periphery wall (2c). Swash-plates (4) supported longitudinally adjacent to a cylinder drum (5) are flexibly supported at pistons (9). The plates are adjustably supported back and forth along extending piston bores (6) in the drum. The periphery wall has a radial elevation formed in a longitudinal direction of the housing and formed by two u-shaped periphery wall sections. The sections limit a radially extended interior section.

Description

The invention relates to an axial piston machine according to the preamble of claim 1.

An axial piston machine of this type is generally state of the art, which may be of different types, e.g. Example, to a so-called swash plate machine or Schrägachsenmaschine, and which may be variable or unchangeable throughput volume each axial piston machines. An axial piston machine with the features according to the preamble of claim 1 is for example from the patent application US 2001/0042437 A1 known.

In the EP 0 450 623 A1 is z. B. an axial piston machine of the swash plate type with variable flow rate described. From the DE 100 30 147 A1 is z. B. an axial piston machine of the bent axis type with variable or fixed throughput volume.

All types of machines have in common that the cylindrical cylinder in cross-section is arranged in a housing interior whose housing peripheral wall surrounds the cylinder block with a sufficient radial distance. For functional operation, the interior is at least partially filled with the hydraulic medium, in particular hydraulic oil, the axial piston machine and that at a low pressure.

For reasons of space and material savings, it is endeavored to comply with the smallest possible cross-sectional size for the housing. Therefore, the peripheral wall of the housing surrounds the cylinder barrel with a sufficiently small radial distance. Since the cross-sectional shape of the cylinder drum is usually round, have common Housing a substantially round or hollow cylindrical cross-sectional shape. In axial piston variable flow rate, it is known elongated and z. B. arranged axially parallel adjusting devices in chambers of wall thickening of the housing, which are connected by channels to the interior.

The invention has for its object to improve an axial piston machine of the type specified above with respect to a space-saving form of their housing. In addition, an at least space-favorable hydraulic connection point of the axial piston machine to a hydraulic circuit and / or to a leak connection to be achieved. Furthermore, a space-favorable arrangement of parts of an adjusting device for changing the throughput volume of the axial piston machine is also desired.

This object is solved by the features of claim 1. Advantageous developments of the invention are described in the subclaims.

The invention is based on the finding that a radial extension of the housing of the axial piston machine offers space-favorable arrangement and / or training possibilities both inside and outside.

According to the invention, the peripheral wall has at least one radial elevation which extends longitudinally in the longitudinal direction of the drive shaft and which is formed by two angular or U-shaped circumferential wall sections which delimit a radially widened interior section. As a result, on the one hand, a radially expanded interior portion is created, which is the arrangement of additional parts of the axial piston machine available, for. B. dividing an adjusting device for reducing or increasing the flow rate of the axial piston machine, which are adjusting elements for Adjusting the throughput volume or may act to stop elements to limit an adjustment.

Furthermore, the peripheral wall sections delimiting the extended interior section in the area of the ridge of the radial elevation formed by them offer an advantageous arrangement point for fastening elements for fastening attachments of the axial piston machine, for example. B. for direct or indirect fastening of fittings for hydraulic lines. An advantage of such an arrangement point is z. Example is that the ridge of the survey is raised with respect to both sides sloping side wall sections and therefore a space-saving or large space for mounting or dismounting of the respective attachment is present.

For an attachment in the form of a line connection part, there is the advantage that the radially expanded interior section is advantageous in terms of flow, because there is a larger free interior in the region of the flow opening.

An axial piston machine is described in which a radial elevation with an angular or U-shaped cross section is arranged on the circumference of the transverse wall of the housing, in whose ridge region a hydraulic connection point with a connection opening is arranged. This embodiment leads to a raised and thus from the surrounding area of the housing transversely spaced hydraulic connection point, which ensures not only a spatially favorable arrangement but also a handling-friendly assembly and disassembly of the associated hydraulic line due to the surrounding space. This embodiment also makes it possible not only to arrange the hydraulic line radially, but also bent or angular bent form, z. B. at an acute angle of z. B. angled about 45 °.

In the context of the invention, a plurality of elevations may be arranged transversely opposite each other and / or offset on one side of the housing and / or in the circumferential direction, resulting in a polygonal or semi-circular or substantially quadrangular cross-sectional shape for the housing and correspondingly more radially expanded interior sections available are.

If in each case two, three or four elevations according to the invention are arranged offset in the circumferential direction, can be an adjusting device for adjusting and adjusting the flow rate of the axial piston machine and a limiting device of the maximum setting, z. As the pivoting limitation of a swash plate, realize in space-favorable manner.

Advantageous developments of the invention lead to further improvements of the space-favorable design of the housing and / or add-on attachments and improvements in the attachment of the axial piston on a support, whereby the assembly and disassembly of existing in the housing interior components of the axial piston machine is improved.

Fig. 1

eine erfindungsgemäße Axialkolbenmaschine in prinzipieller Darstellung im axialen Schnitt;

Fig. 2

eine Schrägscheibe der Axialkolbenmaschine in ihrer Stellung minimalen Durchsatzvolumens in perspektivischer Einzelteildarstellung;

Fig. 3

eine erfindungsgemäße Axialkolbenmaschine in perspektivischer Vorderansicht und

Fig. 4

ein hinteres Topfgehäuse der Axialkolbenmaschine nach Fig. 1 oder 3 in der Vorderansicht.

Hereinafter, advantageous embodiments of the invention will be explained in more detail with reference to a preferred embodiment and the drawing. Show it:

Fig. 1

an axial piston machine according to the invention in a schematic representation in axial section;

Fig. 2

a swash plate of the axial piston machine in its position minimum throughput volume in perspective detail view;

Fig. 3

an axial piston machine according to the invention in a perspective front view and

Fig. 4

a rear pot housing of the axial piston after Fig. 1 or 3 in the front view.

In the Fig. 1 illustrated, exemplified and designated in its entirety by 1 axial piston machine has a housing 2, in whose interior 3 a swash plate 4 and a cylinder drum 5 are arranged axially adjacent to each other. In the cylinder drum 5 with a round cross-sectional shape piston holes 6 are arranged distributed on a circumference, the z. B. extend parallel to the central axis 7 of the cylinder block 5 and the axial piston machine 1 and open at the side facing the swash plate 4 open. In the piston holes 6 preferably cylindrical piston 9 are mounted longitudinally displaceable in cross-section, which limit work chambers 11 in the piston holes 6 in the direction of the swash plate 4 with their piston heads. The swashplate 4 facing the foot ends of the piston 9 are each supported by a hinge 12 on the facing inclined surface 4a of the swash plate 4, wherein sliding shoes 13 may be present, between which and the foot ends preferably formed as ball joints with a ball head and a ball recess joints 12th are arranged.

The cylindrical drum 5 rests with its face facing away from the swash plate 4 on a control disk 14, at the at least two control openings 15a and 15b are arranged diametrically opposite each other, the longitudinal sections of an indicated supply line 16 and a discharge line 17 form, which by an adjacent housing Transverse wall 18a extend, on which the control disk 14 is held. The cylinder drum 5 is arranged on a drive shaft 19 which is rotatable in the housing 2 is mounted and the axis of rotation 21 is coaxial with the central axis 7 of the cylinder drum 5.

In the present embodiment, the housing 2 is formed from a cup-shaped housing part 2a with a housing bottom 2b and a peripheral wall 2c and a lid-shaped flange 2d, which rests against the free edge of the peripheral wall 2c, which is thus screwed by a screw 22 with 22u screws 22a shown and which forms a front transverse wall 18b of the housing.

The drive shaft 19, which rotatably passes through the cylinder drum 5 in a bearing hole 5a is rotatably supported by means of suitable bearings 25, 25a on the housing bottom 2b and the front transverse wall 18b and the flange 2d, wherein the transverse wall 18b and the flange 2d in a Through hole 23 passes through axially, is sealed therein by a ring seal 24 and projects axially with a drive pin 19a from the housing 2. The pot-shaped housing part 2a and the flange 2d are with flat contact surfaces 2f to each other, whereby a dividing joint 26 is formed between these components, which is sealed in a manner not shown, for. B. by a ring seal. For coaxial positioning of the flange 2 d and the cup-shaped housing 2 a to each other a centering 27 is preferably provided, for. B. in the form of a protruding from the associated contact surface 2 f projection which fits into a matching recess in the opposite contact surface 2 f or in the inner edge of the inner space 3.

In the swash plate 4 is a through hole 28, z. B. coaxially arranged, which is bordered by the drive shaft 19 with radial movement play. The swash plate 4 is on the inside on the flange 2d axially forward, ie towards the drive pin 19a out, and radially supported, preferably positively supported.

The axial piston machine 1 may be one with a constant or variable throughput volume. In the latter case, it has an in Fig. 1 illustrated by a double arrow adjusting device 31, with the throughput volume is selectively reduced or increased, with different known constructions can be used.

In the present embodiment, the swash plate 4 in a pivot joint 32 about a transverse to the axis of rotation 21 and longitudinal center axis directed pivot axis 32a by an adjustment mechanism 31a in one or the other pivot direction adjustable and detectable in the respective adjustment position.

The pivot joint 32 may be formed by a so-called pivoting cradle, with a circular arc-shaped concave surfaces 32b arranged transversely or two on both sides of the drive shaft 19 on the inside of the flange 2d and a circular arc-shaped convex on either side of the throughthrough hole 28 Articulated surfaces 32c on the swash plate 4. In the embodiment, the pivot joint 32 is a sliding bearing. But it can also be formed by a roller bearing or needle roller bearings, which can be realized with arranged between the joint surfaces 32b, 32c rolling elements in a small construction.

The circumferential wall 2c of the housing 2 has a radial and in cross-section angular or U-shaped or roof-shaped elevation 34a, whose ridge 34d extends in the longitudinal direction of the tubular peripheral wall 2c. The elevation 34a is formed by two angularly or U-shaped circumferential wall sections 2e, which rise tangentially or sekantially with respect to a conceivable hollow-cylindrical peripheral wall and are connected to each other in the ridge 34d of the elevation 34a. In the exemplary embodiment, the elevation 34a extends over the axial length L1 of the peripheral wall 2c or as an elevation 34b over the thickness L2 of the rear transverse wall 18a of the pot housing 2a, wherein the flange 2d may preferably also have a corresponding elevation 34c, which may be approximately congruent with the elevation 34a in the axial projection and may extend across the thickness L3 of the front bulkhead 18b. It can thus be given an over the entire length L of the housing 2 extending survey 34, which is composed axially by the respective integrally formed elevations 34a, 34b, 34c, wherein the elevations 34a, 34b are also axially integrally connected to each other.

Since the elevation 34b does not delimit the interior 3 of the housing 2 at the circumference of the rear transverse wall 18a or the housing bottom 2b, no interior extension is present in this embodiment. In this embodiment according to the invention, the elevation 34b is bounded by lateral surface portions 34e, which are arranged in an angular or U-shaped manner and enclose the elevation 34b between them. This also applies to the elevation 34c on the circumference of the flange 2d.

The elevation 34a bounded with its peripheral wall portions 2e with z. B. substantially the same thickness d a radially enlarged interior portion 36 which is suitable for space protected space protected for selective arrangement and yet to be described detail structures or components of the axial piston machine 1.

The peripheral wall 2c may have two surveys 34a or more arranged transversely opposite one another, e.g. B. three or four, in the circumferential direction, z. B. offset by about 90 °, arranged elevations have 34a. In the presence of four distributed on the circumference arranged elevations 34 a, the peripheral wall 2 c may have a substantially quadrangular or rectangular cross-sectional shape, wherein the corners may be rounded in the sense of round corners and between them extending side walls 2g - seen in cross section - may be slightly curved outwards, as it Fig. 3 and 4 demonstrate. In this case, the side walls 2g may each be formed by the two peripheral wall sections 2e facing away from both elevations 34a adjacent to one another in the circumferential direction.

Preferably, the circumferential portions 34e of the housing bottom 2b and of the flange 2d extending between the elevations 34b, 34c are also adapted to the shape and size of the side wall sections 2g of the peripheral wall 2c.

It can, for. B. an adjusting device 31 associated adjusting mechanism 31a may be disposed in an interior portion 36, with respect to the cylinder barrel 5 space-wise outward or along the pivot axis 33 and thus be obliquely or diagonally offset.

In order to improve the mechanical connection of the adjusting mechanism 31a with the swash plate 4, this also has at least one radial elevation 37, which is axially opposite the associated interior portion 36, so that the in Fig. 2 as directed against the survey 37 arrow or as a double arrow clarified adjustment mechanism 31a at the survey 37 in the sense of pressure and / or Zugausübung can attack.

Preferably, each cavity section 36 axially arranged on the swash plate 4 a survey 37 are arranged, wherein in the presence of four elevations 37, the swash plate 4 may have a quadrangular or rectangular shape and the corners of the swash plate 4 may be rounded.

The adjusting device 31 may have two adjusting mechanisms 31a1, 31a2 which are axially effective in opposite directions and which can be arranged at a radial distance on both sides of the pivot axis 33 and with respect to the Pivot axis 33 can be arranged transversely or obliquely opposite each other. The latter can be done Fig. 2 remove. Such mutually oppositely effective adjustment mechanisms 31a1, 31a2 can, for. Example, be formed by a hydraulic Ausschwenkkolben and a hydraulic Rückschwenkkolben, which can be effective axially in the same direction or in the same direction on the swash plate 4, wherein in the latter case one of the two pistons overruns the other piston.

In at least one radially widened interior section 36, a pivot limiting device 41 can also be disposed in a space-saving manner for limiting the maximum and / or minimum pivot angle of the swashplate 4. Fig. 2 and 4 show two pivot limiting devices 41, one of which is provided for the maximum and the other for the minimum pivoting angle position. The at least one pivot limiting device 41 may, for. Example, be formed by a stop screw 41a, which is screwed into a thread of an inner projection of the peripheral wall 2c, not shown, and in a respect to the pivot axis 33 transversely or obliquely directed distance against the swash plate 4 and the corresponding elevation 37 either screwed back and forth is, for. B. by means of an attacking on the head of the stop screw screwdriver.

In order to improve the accessibility to the at least one adjustable pivot limiting device 41 or stop screw 41a, this or a hole or threaded hole receiving it in the peripheral wall 2c may preferably extend obliquely outwards, so that the pivot limiting device 41 or the screw head is accessible from the outside , This is exemplary in Fig. 3 dargstellt, in which the top right arranged pivot limiting device 41 has a stop screw 41 a, which are arranged obliquely upwards and backwards in a corresponding oblique Hole or threaded hole extends to the outside and thus accessible from the outside. Accordingly, the other pivot limiting device 41 or stop screw 41a can be arranged accessible from the outside. The at least one elevation 34a, 34b, 34c and the at least one adjusting mechanism 31a or pivoting limiting device 41 can therefore be arranged axially between the longitudinal plane E1 containing the pivot axis 33 and a longitudinal center plane E2 perpendicular thereto.

The one or both pivoting limiting devices 41 can thus be arranged on both sides of the pivot axis 33 with respect to this transverse to each other or obliquely opposite. The in Fig. 1 not shown other pivot limiting device 41 may be formed accessible from the outside, as has been described for the top right arranged pivot limiting device 41, z. B. be arranged in a mirror image with respect to the longitudinal plane E1 and the longitudinal plane E2.

The at least one elevation 34 a, 34 b is also space favorable for the arrangement of hydraulic functional elements, such. B. at least one connection point 38 with a connection opening for the supply or discharge or flushing of the hydraulic medium, in particular hydraulic oil. In the region of the connection opening 38a1, 38a2 and fasteners 39a are provided, the parts of a fastening device 39 for attaching connection fittings or connecting lines, for. B. the supply or discharge line 16, 17, or a leakage line.

In the exemplary embodiments, one or two connection openings 38a1, 38a2 are arranged in the ridge 34d of the elevation 34a and / or 34b, specifically in the longitudinal area L2 in which the rear transverse wall 18a or the housing base 2b is located and / or in the longitudinal area L1 of the Peripheral wall 2c. The connection opening 38a1 or 38a2 is formed by a hole passing through the peripheral wall 2c or the housing bottom 2b in the ridge 34d, wherein the center axis 38b of the connection opening 38a1, 38a2 or the hole is located in the bisector of the peripheral wall sections 2e or lateral surface sections 34e Thus, for example, an obtuse angle W1 of about 135 ° or in the presence of an approximately 45 ° fitting includes an acute angle W2 of about 45 °.

In the invention, the hole 38a1 forming the hole according to Fig. 3 left directly serve as a fastener for an associated hydraulic line, z. B. in the sense of a threaded connection, so that the hole itself is a fastener 39 a of the fastening device 39.

The embodiment in Fig. 3 on the right shows as fastening elements 39a extending approximately at right angles to the central axis 38b and surrounding the connection opening 38a2 mounting surface 39b and two or more oppositely arranged mounting holes 39c, preferably in the mounting surface 39b, which serve to screw a connection fitting for a hydraulic line, which at the cultivation area 39b attachable and can be screwed by means not shown screws to the peripheral wall 2c.

The mounting surface 39b and / or the connection opening 38a1 is preferably located on or in a second elevation 42, which rises in the sense of an approach from the first elevation 34a, 34b.

A second connection opening 38a1 or 38a2 may be arranged in the region of one of the other circumferentially offset elevations 34a, 34b, e.g. B. in the diametrically opposite elevation 34 a, 34 b, as it Fig. 4 shows. In this case, this connection opening 38a1, 38a2 same or different fasteners 39 a of a fastening device 39 for fixing an associated hydraulic line, for. B. of the existing circuit, be assigned.

As can be seen in particular Fig. 4 can recognize the arranged at the junction 38 top right connection fitting 38c may have a connection element 38d for an associated line whose central axis 38e extends parallel to the contact surface 39b or parallel to the abutting contact surface of the connection fitting 38c and with the central axis 38b is an approximately right Includes angle. In such an arrangement, the central axis 38e of the connection fitting 38c with the adjacent side wall portion 2g includes the acute angle W2 of about 45 °.

In the context of the invention, however, the connection fitting 38c may be integrally connected to the elevation 34a, 34b.

Thus, regardless of the above-described embodiment of the connection points 38 for the hydraulic circuit, it is likewise advantageous to arrange a connection point 38 for a leakage line only in the at least one elevation 34a, this connection point being arranged in the longitudinal area L1 of the interior space 3.

The peripheral wall portions 2e of the peripheral wall 2c also lead to a broadening and improvement of an investment in the side wall sections forming it, in particular if at least one survey question 34a and / or 34b is not rounded but square, as it Fig. 3 above and Fig. 4 show top left. Such a peripheral wall section 2e is particularly suitable, when its outer surface is flat, as the mounting surface 45 for a drive device 46 for driving the adjustment mechanism 31a arranged in the associated interior section 36. The drive unit 46 has Connections for an electrical and / or hydraulic supply.

The flange 2d is detachably connected by a screw 51 with a plurality of distributed circumferentially arranged screws 51a with the pot housing 2a, which pass through holes in the flange 2d and are screwed into threaded holes in the edge region of the peripheral wall 2c.

For attachment of the axial piston machine 1 to a carrier, not shown, for. As a machine frame, a second indicated screw 52 is provided, which distributes several distributed on the circumference, for. B. in the elevations 34c, arranged screw holes 52a in the flange 2d, for screws, not shown, which are inserted therein and screwed into threaded holes, not shown, of the carrier. The screw holes 52a may be formed by circumferentially open slots.

The flange 2d can also serve as an adapter for adapted attachment of the axial piston machine 1 to different carriers (eg from different manufacturers). For such a case, two flanges 2d are provided, the screw holes 51a are formed the same for a same hole pattern of a same screw 51, while the two flanges 2d screw holes 52a have different hole patterns, which are respectively adapted to the associated hole pattern of the respective carrier.

The invention is not limited to the described embodiment and is suitable for. B. also for axial piston machines in bent axis design. All described and / or drawn features can be combined with each other within the scope of the invention.

Claims (10)

1. Hydrostatic axial piston engine (1), having

   - a housing (2) which surrounds an inner space (3) by two transverse walls (18a, 18b) and a circumferential wall (2c) connecting these longitudinally to one another,

   - a drive shaft (19) which extends longitudinally in the housing (2) and is mounted rotatably in the housing (2), and

   - a swashplate (4) which is mounted longitudinally in the housing (2) next to the cylinder drum (5) and on which are supported in an articulated manner pistons (9) which are mounted, so as to be displaceable to and fro, in the cylinder drum (5) in piston holes (6) extending per se approximately longitudinally,

   the circumferential wall (2c) having at least one radial elevation (34a) which is formed in an elongate fashion in the longitudinal direction of the housing (2) and which is formed by two circumferential wall sections (2e) which are arranged angularly or in a U-shaped manner and delimit a radially extended inner space section (36),
   characterized
   in that a hydraulic connection point (38) with a connection orifice (38a1; 38a2) is arranged in the ridge (34d) of the elevation (34a; 34b).
2. Hydrostatic axial piston engine according to Claim 1,
   characterized
   in that the elevation (34a) extends over the length (L1) of the inner space (3).
3. Hydrostatic axial piston engine according to Claim 1 or 2,
   characterized
   in that two elevations (34a) are arranged opposite one another or a plurality of, for example three or four, elevations (34a) are arranged so as to be offset with respect to one another in the circumferential direction.
4. Hydrostatic axial piston engine according to one of the preceding claims,
   characterized
   in that the cylinder drum (5) bears with its inside facing away from the swashplate (4) against a control disc (14) arranged between the said cylinder drum and a transverse wall (18a), and the at least one elevation (34a) extends longitudinally also over the transverse wall (18a) or over both transverse walls (18a, 18b).
5. Hydrostatic axial piston engine according to one of the preceding claims,
   characterized
   in that the throughput volume of the axial piston engine (1) can be selectively increased or reduced by means of an adjusting device (31) having an adjusting mechanism (31a), and preferably the swashplate (4) is mounted, as part of the adjusting device (31), pivotably about a directed pivot axis (32a) in a pivot joint (32).
6. Hydrostatic axial piston engine according to Claim 5,
   characterized
   in that the adjusting mechanism (31a) and/or a pivot-limiting device (41) are/is formed in an elongate fashion and extend/extends in the longitudinal direction of the axial piston engine (1), in the or one of the extended inner space sections (36), so as to be offset transversely with respect to the pivot axis (33).
7. Hydrostatic axial piston engine according to one of the preceding claims,
   characterized
   in that one or two elevations (34a, 34b, 34c) which are at a transversely directed distance from one another are arranged so as to be offset transversely with respect to the pivot axis (33).
8. Hydrostatic axial piston engine according to Claim 6 or 7,
   characterized
   in that two radial elevations (34a) which are at a transverse distance from one another and have extended inner space sections (36) are arranged on both sides of the pivot axis (33), and, preferably, an adjusting mechanism (31a) and a pivot-limiting device (41) are arranged, in particular arranged obliquely opposite one another, on each side of the pivot axis (33).
9. Hydrostatic axial piston engine according to Claim 4,
   characterized
   in that the transverse wall (18a) is formed by the bottom wall (2b) of a pot housing (2a).
10. Hydrostatic axial piston engine according to one of the preceding claims,
    characterised
    in that the housing (2) has, at least in the region of the at least one elevation (34a, 34b, 34c), a cross-sectional shape delimited by four sidewall sections (2g), in particular a square or rectangular cross-sectional shape, preferably with rounded corners.

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