EP1008748B1 - Axial piston machine - Google Patents

Description

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

An axial piston machine of this type is in the
DE-AS 1 017 468. This is a so-called oblique-axis design with a cylinder drum which displaceably receives the pistons in cylinder bores and which can be pivoted by an adjusting device about a pivot axis arranged in the region of the drive disk and can be fixed in the respective pivot position. By a more or less wide swinging the cylinder drum, the flow rate of the axial piston machine can be adjusted, as it is known.

In the present design of the axial piston machine forms the cylinder drum with a control disk attached to the Front side of the cylinder drum is arranged, which is the Drive pulley facing away, a pivoting unit that out and her is pivotable, with the control disc on one order the pivot axis curved arcuate Lagergleitfläche a bearing wall of the housing Axial piston machine rests and is guided sliding. Consequently, the control disk between the Lagergleitfläche and the associated end face of the cylinder drum positioned. This positioning and the attachment to the Lagergleitfläche can in functional operation of Axial piston machine can not always be guaranteed. It are therefore already based on spring force Pressure devices have been developed that the Permanently tension the cylinder drum against the control disk and thereby the plant of the cylinder drum on the Control disc and the system of the control disc at the Ensure bearing sliding surface. As a result, however, the Friction between the cylinder drum and the control disc as well as between the control disk and the bearing sliding surface increases and reduces the life.

In the described in DE-AS 1 017 468, on their Zero position beyond adjustable axial piston machine is the control disk by a holding device with two to arranged on both sides of the control disk and this engaging holding parts in the form of guide rollers in System held on the bearing sliding surface. The leadership roles are arranged centrally in the housing and each on one Threaded bolt freely rotatably mounted, in the adjacent Housing wall is screwed. In addition, the lie Guide rollers with their cylindrical lateral surfaces respectively on one of them or the cylinder drum facing Support surface on the control disk, wherein the support surfaces presumably parallel to the bearing sliding surface, ie arcuately concave curved. Based on these Design is the control disc in each position its pivotal position in rolling contact with the guide rollers, thus form-fitting the system of the control disc on the Secure bearing sliding surface.

This known construction has the disadvantage that in the swung-out position of the control disc this to the Guide rollers is supported off-center. This results itself for the end area of the control disk, which with the Guide rollers is in contact, a relatively short Support arm, while at the opposite end of the Control disk a relatively large moment is effective, to lift the control disc off the bearing sliding surface examined. This results in the area of the support to the Guide rollers relatively large support forces, stresses and surface pressures. Although is in this known Design the control disk in its swung out Schwenkendstellung in addition to the guide rollers on one Stop surface of the peripheral wall of the housing against a Lifting supported by the bearing sliding surface, however, applies this only for the Schwenkendstellungen. In every Pivoting before that are the disadvantages described above due to insufficient support of the control disc effective.

In the known embodiment is not only a large Prescribed manufacturing costs, because on the one hand Training with roles and on the other hand the additional Support at the end of the control disc specially created must become.

The invention is based on the object at a Axial piston machine of the type specified in the Support the control disc to improve and to stabilize.

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

In the axial piston according to the invention is due the parallel to the bearing sliding surface extending curvature of the Support surface a support point for the control disk for Available, in which the control disc in each Pivoting position is supported in its central area, whereby the above-described harmful tilting moments are diminished and the support of the control disc in the desired sense is improved and stabilized. The desired improvement and stabilization will then also achieved when the length of the support surface is slightly shorter is measured as the by the pivoting angle range given dimension, because due to the rounding of Support surface this even at a slightly shorter length yet is effective.

In the context of the invention, the bearing sliding surface a curvature corresponding to the support surface on. This results in a flat contact with these contact surfaces to each other, creating a low surface pressure and friction and a long life are guaranteed.

Moreover, the invention is characterized by a simple, small and inexpensive manufacturable construction, which is good in the construction of an axial piston machine integrate and also easy to mount or dismantle and is of safe function.

Fig. 1

eine Axialkolbenmaschine in vorbekannter Bauweise und im Axialschnitt, die den Stand der Technik verdeutlicht;

Fig. 2

den Teilschnitt II-II in Fig. 1 in erfindungsgemäßer Ausgestaltung;

Fig. 3

die erfindungsgemäße Ausgestaltung in der Blickrichtung auf eine Steuerscheibe der Axialkolbenmaschine von innen entsprechend einem in Fig. 2 dargestellten Blickrichtungspfeil X;

Fig. 4

den Teilschnitt IV-IV in Fig. 3;

Fig. 5

eine der Fig. 4 entsprechende Schnittdarstellung in abgewandelter Ausgestaltung der Erfindung.

The invention and further achievable by them advantages will be explained in more detail with reference to preferred embodiments. Show it:

Fig. 1

an axial piston machine of prior art design and in axial section, which illustrates the prior art;

Fig. 2

the partial section II-II in Figure 1 in accordance with the invention.

Fig. 3

the embodiment according to the invention in the direction of view of a control disk of the axial piston from the inside according to a sight line arrow X shown in Figure 2.

Fig. 4

the partial section IV-IV in Fig. 3;

Fig. 5

one of Fig. 4 corresponding sectional view in a modified embodiment of the invention.

The illustrated in Fig. 1 in longitudinal section Axial piston machine 1 is in Schiefachsenbauweise, more precisely in Schwenkschlittenbauweise trained.

The axial piston machine 1 comprises a in a housing 2 in Rolling 3, 4 rotatably mounted drive shaft 5, on which a drive shaft flange or a so-called drive disk 6 is arranged or molded. The housing 2 encloses a housing interior, in which a cylinder drum 7, in which multiple cylinder bores 8, 9 on a pitch circle are provided evenly distributed, is arranged. In the Cylinder bores 8, 9 are pistons 10, 11 back and forth slidably guided, the articulated on the drive pulley. 6 supported, z. B. by ball heads 12, 13, in spherical bearings 14, 15 of the drive disk 6 supported are. The cylinder drum 7 is connected via a center pin 16 stored in the drive disk 6, wherein a ball head 17 of the Center pin 16 in a spherical bearing 18 of the Drive disk 6 is also pivotally mounted.

The cylinder drum 7 is supported by a known Way with steered control disc 19 at a Lagergleitfläche 21 from which on a bearing wall 22nd is formed by a housing wall, in particular a so-called end plate of a cup-shaped housing. 2 can be formed.

The flow rate of the axial piston machine 1 is in known manner by pivoting the Cylinder drum 7 and the control disk 19, the one Form pivot unit, with respect to the central axis of the Drive shaft 5 adjustable. Here is the maximum Throughput volume or the minimum throughput volume an externally adjustable threaded bolt adjustable, the in each case one movement stop A1, A2 for the control disk 19 form.

To pivot the pivot unit is a Adjusting device 23 is provided, which in the present Embodiment is arranged in a housing 24, which as Housing wall forms the bearing wall 22. In the housing 24 is a in or parallel to the pivot plane E transverse to the axis of rotation the cylinder drum 7 slidably mounted back and forth Adjusting piston provided with an adjusting member 25th articulated on the control disk 19 attacks. The Adjustment member 25 may by a transverse from the adjusting piston be formed protruding adjusting pin on his free end of a spherical or spherical section-shaped Adjusting head 26, in a him with a low Movement play receiving engagement recess 27 in the Control disc 19 engages and one between the Control disk 19 and the adjusting piston 24 existing Durchgriffsausnehmung 28 in the associated wall of the Housing 24 passes through.

The Lagergleitfläche 21 is a concave base of a Guide recess 29 in the bearing wall 22, whose parallel to the pivoting plane E arranged lateral guide surfaces 21a, the control disk 19 laterally with low Cause movement play.

The cylinder drum 7 has at its the control disk 19th facing front a concave, spherical Lagergleitfläche 7b and it is thus at one correspondingly convex spherical bearing surface 19a of the Control disk 19 on. This indicates on its outside at least one of the bearing sliding surface 21 accordingly curved sliding surface 19b.

The control disk 19 is a generally designated 31 Holding device associated with the bearing wall 22nd arranged or fixed and the control disk 19 at engages behind the cylinder drum 7 side and thereby secures to the inward side. in the Under the invention, a holding part 32 this Hold function that the control disk 19 with a Shoulder surface 33 engages behind, parallel to Lagergleitfläche 21 curved and thus circular arc section runs, wherein the Shoulder surface 33 opposite surface part of the Control disk 19 a with the shoulder surface 33rd cooperating support member 34 with a support surface 34a forms. The support surface 34a may be perpendicular to the Swing plane E seen - just extend like it can be seen in particular from Fig. 4, or it can - at right angles to the pivoting plane E - parallel to the Curvature of the shoulder surface 33 run and thus the Curvature of the shoulder surface 33 correspond, as shown in FIG. 5 shows.

Which is between the shoulder surface 33 and the Lagergleitfläche 21 extending free distance a is under Considering a small movement game to the over the oppositely curved sliding surface 19 a on the Control disk 19 and the support surface 34 measured thickness b adapted, so that the control disk 19 between the Shoulder surface 33 and the support surface 34 fits and this Surfaces form a pivot guide track 35. This results At least one punctiform attachment between the Shoulder surface 33 and the support member 34th

The shoulder surface 33 and the support surface 34 are preferably surfaces that are - perpendicular to the axis of rotation the cylinder drum 7 and in or parallel to the pivot plane E - at right angles to the pivot plane E extend. at the embodiment of FIG. 3, wherein the support surface 34 a at right angles to the swivel plane - straight extends, this results in a linear system between the shoulder surface 33 and the support surface 34a.

In the embodiment according to FIG there curvature and orientation of these surfaces one flat system with a correspondingly reduced Surface pressure in functional operation.

In the embodiment according to the invention, the Holding device 31 on two holding parts 32, the two Side of the pivot plane E arranged on the bearing wall 22 or are attached and the control disk 19 to the c designated dimension in lateral recesses 19c of Overflow control disk 19. The holding parts 32 are strip-shaped parts by screws 36 with screwed the bearing wall 22 and optionally by pins 36a are pinned. The support surface 34a is respectively at least in the control disk 19 cross-section (Dimension c) arranged. In the present embodiment is the entire base area of the holding parts 32 accordingly cylindrical section shaped, d. H. she is through one extending parallel to the bearing sliding surface 21 Cylinder-shaped surface formed. Here it is advantageous, the associated contact surface 37 on the bearing wall 22 form with a corresponding shape, which is a recess 38 results in each of the associated Holding part 32 can be used. The width of the recess 38 is dimensioned smaller by the dimension c than the width d of the Holding parts 32, so that a positive Positioning for the holding part 32 in the transverse direction results. The at least one screw 36 or a pin 36a fixes the respective holding part 32 in parallel to the pivot plane E extending longitudinal direction. With 32a are Recesses on the inside of the holding parts 32 for the Cylinder drum 7 is arranged, in which the cylinder drum. 7 dips to save floor space. In Fig. 3 is in order simplified representation of the recess 32 a broken away shown.

As can be seen from FIG. 3 to FIG. 5, there are the holding parts 32 in the middle or symmetrically to a Swivel plane E arranged at right angles and the axis of rotation 7a of the cylindrical drum longitudinally intersecting transverse plane E1, when the cylinder drum 7 is in its pivoted position or zero position. Such a design is also suitable for an axial piston machine 1, whose Cylinder drum 7 beyond the zero position to the other Side is pivotally z. B. in order to reverse the direction of rotation. This also makes it clear that the holding parts 32 only in from the central axes 7a in the pivoted and swung Position of the cylinder drum 7 enclosed Angular ranges can be arranged. If the length L of the Holding parts 32 approximately at least twice as large as the resulting length of an angular range e, then suitable the two above-described pivoting ranges.

In particular, Fig. 4 makes it clear that in the inventive design, the control disk 19 in each pivot position in its middle, her support element 34 forming area B and thus centrally through the respective Support member 32 is supported. This is special Advantage, since in each pivot position tilting moments avoided be, as in the known described above Design occur.

In the embodiment of the invention can be the Mount or disassemble the control disk easily, as the Holding parts 32 before mounting the control disk 19th can be pre-assembled, and that can be the Control disk 19 along the arc of the pivot guide track 35th insert into the leadership thus formed. Preferably the adjusting member 25 is formed so that it is mounted thereafter can be z. B. by as a through hole in the Control disk 19 formed engagement recess 27th

In the embodiment according to the invention is the Control disk 19 by means of the holding device 31st positively held in their working position in which they flat against the bearing sliding surface 21 rests. To one permanently effective pressure between the Control disk 19 and the Lagergleitfläche 21 to have and thereby the seal in the intervening joint to improve, it is beneficial in addition to Holding device 31 to provide a pressing device 41. This can, for. B. by a between the center pin 16 and the cylinder drum 7 be formed effective spring. In the present embodiment, the center pin 16 a in Direction of the control disc 19 open coaxial blind hole 42, in which a compression spring 43 is arranged, whose Control disk 19 facing the end against a shoulder surface 44 of the cylinder drum 7 is biased, the z. B. by one arranged in the cylinder drum 7 and at a shoulder-supporting disc 45 may be formed.

Claims (10)

1. Axial piston machine (1) with a cylinder drum (7), which is rotatably mounted in a housing (2) and in which pistons (9) are displaceable in cylinder bores (8), the piston ends of which pistons are pivotably supported on a rotatably mounted driving plate (6), it being possible for the cylinder drum (7) and a control plate (19), arranged on the side of the cylinder drum (7) facing away from the driving plate (6), to be pivoted transversely in a pivoting plane (E) by an adjusting device (21), the control plate (19) being mounted, so as to be pivotable in the pivoting plane (E), on a bearing sliding surface (21) which faces the control plate, is curved in the shape of a circular arc and is located in a guiding recess (29) in a bearing wall (22), two holding parts (32) which extend parallel to the pivoting plane (E) being arranged on the bearing wall (22) on both sides of the pivoting plane (E) and each engaging, with a shoulder surface (33), behind at least one supporting element (34) facing the cylinder drum (7) and located on the control plate (19),
   characterised in that the shoulder surfaces (33) on the holding parts (32) are curved parallel to the bearing sliding surface (21) and extend at least approximately in the angular region (e) enclosed by the centre axis (7a) of the control plate (19) in the pivoted-out and -in position,
   and in that the holding parts (32) are separate strip-shaped parts which are screwed onto the bearing wall (22) beside the guiding recess (29) and, with the shoulder surface (33), project beyond the associated lateral edge of the guiding recess (29) (dimension c).
2. Axial piston machine according to Claim 1,
   characterised in that the shoulder surface (33) extends over a length (L) corresponding at least approximately to twice the dimension of the angular region (e) resulting thereon.
3. Axial piston machine according to Claim 2,
   characterised in that the shoulder surface (33) is arranged symmetrically to the centre axis (7a) of the control plate (19) in the pivoted-in position or zero position of the latter.
4. Axial piston machine according to one of the preceding claims,
   characterised in that the shoulder surface (33) and a supporting surface (34a) forming the supporting element (34) extend parallel when viewed on the centre axis (7a) of the control plate (19) and along the pivoting plane (E).
5. Axial piston machine according to one of the preceding claims,
   characterised in that a supporting surface (34a) forming the supporting element (34) is a plane surface which extends secantly with respect to the bearing sliding surface (21).
6. Axial piston machine according to one of the preceding claims,
   characterised in that the supporting surface (34a) is curved parallel to the shoulder surface (33).
7. Axial piston machine according to one of the preceding claims,
   characterised in that the holding parts (32) engage behind the lateral edges of the control plate (19).
8. Axial piston machine according to Claim 7,
   characterised in that the holding parts (32) engage behind the control plate (19) in lateral recesses (19c).
9. Axial piston machine according to one of Claims 7 and 8,
   characterised in that the holding parts (32) are arranged in a manner partially or completely sunk in recesses (38) of the bearing wall (22).
10. Axial piston machine according to one of Claims 7 to 9,
    characterised in that the shoulder surfaces (33) each extend over the entire associated side of the holding part (32) concerned and form the bottom surface of the latter, and the recesses (38) are each formed by a correspondingly concavely curved surface.

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