EP0976912B1 - Hydro-static axial piston machine with a secondary guiding device for an intermediary disk - Google Patents

Description

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

[State of the art]

An axial piston machine of this type is in the DE-AS 2 029 087. In this known embodiment are a cylinder drum and a in a housing Drive pulley connected and rotatable by pistons stored. On the end facing away from the drive pulley the cylinder drum has a control disc, which is part of a pot-shaped swing frame. The cylinder drum and the swivel frame and thus also the control disc form a swivel unit by an adjustment device adjustable in the swivel plane and in the the respective adjustment position can be positioned for the purpose of adjustment a desired throughput volume of the axial piston machine. Between the control disc, which is a floor or forms part of the bottom of the swing frame, and one opposite housing end wall is an intermediate washer also pivotally mounted in the swivel plane. For this has the control disc or the bottom of the swing frame one curved in the shape of a circular arc in the pivot plane Sliding surface on which the washer with a correspondingly curved sliding surface. Corresponding curved sliding surfaces also have the washer and the housing end wall on its mutually facing sides on. This results in guides running in the swivel plane both for the swivel frame and for the washer educated.

Between the housing and the washer on the one hand and between the washer and the bottom of the swing frame on the other hand is a tracking device for the washer effective, the purpose of which is to place the washer so to move or pivot that they are in the maximum swivel range the swing frame with respect to the latter Zero position is offset. This will in the area of Washer space gained for control slots that due to the pivoting movement of the pivot frame a considerable have length extending in the pivot plane. Without this relative mobility of the washer the required slot length for a large target Do not reach the swivel range or it should Control disc and the washer are widened or the swivel range can be reduced, which is undesirable is.

In this known embodiment, the tracking device for the washer by a stop for the Swing-out movement of the washer in a partially swung-out Position and a spring formed the Bias the intermediate washer towards the stop. On second movement stop is between the swing frame floor and the washer is provided in a position in which the washer is in a with respect to the Swivel frame or the cylinder drum central position located. The washer is thus tracked only in a part of the swivel range of the Cylinder drum, with the swiveling movements in this section the cylinder drum and the washer are the same are because the washer is in by the force of the spring Stop position is held with the swivel frame. If the washer when swinging out the swivel frame butts against the movement stop on the housing Movement limited, the swivel frame with the cylinder drum swings out to its maximum swivel position.

This known configuration is disadvantageous for several reasons. On the one hand is the motion control with stops disadvantageous because noises and load peaks when struck are generated, the life of the axial piston machine can affect. It also needs a relatively large spring force to prevent that z. B. in driving operation of the axial piston machine having vehicle the washer of their Stop lifts, which affects the function and rattling noises can be caused. However, an increased spring tension leads to Power losses. Another disadvantage is that in the area limited by the movement stop maximum swivel position of the washer sudden changes in shape and size of the control slots take place in the washer when the swing frame is moved further or moved back. This form and Changes in the size of the control slots hinder the Flow of the hydraulic medium in the area of Washer, which is undesirable. Another The disadvantage can be seen in the fact that in the event of a failure the spring makes the axial piston machine inoperable, which has serious consequences for various reasons can pull itself.

OBJECT OF THE INVENTION

The invention has for its object in an axial piston machine motion control of the type specified at the beginning the relative movement between the control disc and improve the washer.

This object is achieved by the features of claim 1 solved.

In the axial piston machine according to the invention Tracking device over the entire swivel range of the Control disc so effective that the displacement of the Control disc is larger than the displacement path of the Washer. The tracking of the Washer over the entire swivel range of the Control disc continuously, the control disc performs a larger displacement than that Washer. This will ensure continuity of Relative movement between the disks is achieved, whereby while ensuring a space-saving arrangement of the Control slots better flow conditions in the Functional operation can be achieved and hard limit stops for the disks and the resulting one the aforementioned disadvantages are avoided. It is advantageous tracking with a constant ratio between the executed tracking movements and between the speeds of movement of the control disc and the washer. Through this equalization the flow behavior of the hydraulic Medium in the area of the washer further improved and Flow restrictions further reduced.

Is suitable for a tracking device according to the invention preferably a mandatory in both pivot directions Tracking so that deviations from a predetermined Movement excluded even under extreme operating conditions and the disadvantages mentioned are avoided, that occur with a non-compulsory tracking can.

Mandatory tracking also makes it possible to use the Adjustment device on the control disc or on the Attack the washer. The latter is constructive Reasons advantageous because the adjustment device in the area the housing head can be arranged in a space-saving manner and a Adjusting element for adjusting the intermediate disc in a simple way Design implemented the associated housing wall enforcing can be.

The subclaims contain features that lead to simple, small and inexpensive to manufacture as well lead safe designs, the management and control of the Washer as well as improve the function and also a simple and easy-to-use installation or ensure disassembly.

[Examples]

Fig. 1

eine erfindungsgemäße hydrostatische Axialkolbenmaschine im Längsschnitt;

Fig. 2

den Teilschnitt II-II in Fig. 1,

Fig. 3

den Teilschnitt III-III in Fig. 2.

The invention and further advantages which can be achieved by means of preferred configurations and simple drawings are explained in more detail below. Show it

Fig. 1

a hydrostatic axial piston machine according to the invention in longitudinal section;

Fig. 2

the partial section II-II in Fig. 1,

Fig. 3

the partial section III-III in Fig. 2nd

The axial piston machine that functions as a pump or motor 1 is in a sliding axis construction or more precisely in a swivel carriage construction educated. However, the invention is not based on a sliding axis design or swivel slide design limited and it is suitable for the function as a pump or engine. The axial piston machine 1 comprises one in one Housing 2 in roller bearings 3 and 4 rotatably mounted drive shaft 5, on which a drive shaft flange 6 is formed. The Housing 2 encloses a cylinder drum 7, in which several cylinder bores 8 preferably on a pitch circle are evenly distributed. In the cylinder bores 8 on the front side facing the drive pulley 5 open the cylinder drum 7, pistons 9 are movable performed with spherical ends 11 in spherical Bearings 12 of the drive shaft flange 6 are supported. The Cylinder drum 7 is also via a central pin 13 with an end ball head 14 in a spherical bearing 15 of the drive shaft flange 6 is pivotally mounted. The The central axis of the axial piston machine 1 is designated 10, and it is kinked at hinge point 24.

The cylinder drum 7 has the drive shaft flange on it facing away from a spherical segment-shaped concave Bearing sliding surface 17 on which one is in functional operation non-rotating control disc 18 with a correspondingly convex curved bearing section surface 19 is applied. The cylinder drum 7 and the control disk 18 form a swivel unit, which will be described later Way through an adjusting device 21 in an axial Swivel level 22 for setting a desired throughput volume the axial piston machine 1 adjustable and in the respective adjustment position against an unwanted adjustment is positionable. On their facing away from the cylinder drum 7 The end face of the control disk 18 preferably has one cylindrical sliding bearing surface 23 on the by one through the center of the ball head 14 and at right angles to the pivot plane 22 extending pivot axis 14a is curved. Between the control disk 18 and one preferably releasably attached housing end wall 24 is a Washer 25 mounted transversely, which with a according to the bearing sliding surface 23, preferably in the form of a cylindrical section concave curved bearing sliding surface 26 on the Bearing sliding surface 23 slidably abuts and on the End wall 24 facing the side facing the bearing sliding surface 26 parallel convex and preferably has cylindrical-section-shaped bearing sliding surface 27, with which they on a corresponding preferably cylindrical section concave bearing surface 28 on the inside the housing end wall 24 is slidably mounted. The Bearing sliding surface 28 is the base surface of a guide recess 28a with guide side surfaces 28b in which the washer 25 is guided.

In the intermediate disc 25 with conventional control kidneys N1, N2 in the control disk 18 connected control slots S1, S2 arranged, the feed and discharge in functional operation of the hydraulic medium to the cylinder spaces 8a in the cylinder drum 7 from a feed line and to ensure a discharge line. The control slots are in the transverse direction extending transversely to the pivot plane 22 narrow and parallel to the swivel plane 22 extending transverse direction long to be in all Swivel positions of the swivel range the flow passage to ensure by the washer 25.

In Fig. 1 is a central and funnel-shaped, transverse continuous, slot shown with a channel system for lubrication and, if necessary, hydrostatic storage of various contributes further components of the axial piston machine and with the interior 2b of the housing 2 is connected.

The cylinder drum 7, the control plate 18 and the intermediate plate 25 form one with the adjusting device 21 movable swivel unit, the cylinder drum 7, the Control disc 18 and the intermediate disc 25 at the same time be pivoted, d. H. with an adjustment the Parts moved at the same time, their pivotal movements start and stop at the same time. This is the adjustment device 21 driven by a swivel device 30 connected to the swivel unit, being in the swivel device 30 a tracking device 31 is integrated, the inevitably ensures that the control disc 18 with is swiveled at a greater swiveling speed than that Swing speed of the intermediate plate 25 so that the Control disc 18 executes a larger swivel path a than the intermediate disc 25, the pivot path designated by b is. The translation of movement between the intermediate plate 25 and the control disk 18 is inserted into the swivel device 30 or integrated into the tracking device 31 Translation device in both tracking devices inevitably brought about.

In the present embodiment, the adjustment device engages 21 with a driver 21a on the intermediate disk 25 on, the tracking device 31 between the washer 25 and the control disc 18 is effective. In the In the present embodiment, the driver 21a is a Driver pin formed by an adjusting piston 21b protrudes transversely to the longitudinal central axis 10 in a piston bore 21c of the housing end wall 24 can be moved hydraulically is stored. The driver pin is for the purpose of taking the Intermediate plate 25 through a link guide with a recess 21d in the intermediate disk 25 connected to the latter, the driver pin being spherical or spherical Driver head, which in the driver recess 21d borders with little movement. The scenery guide allows changes in distance that due to the Pivotal movement of the intermediate plate 25 are predetermined and when swiveling different immersion depths of the driver pin cause in the driver recess 21d.

A mechanism is used for this purpose, which is located on the intermediate disk 25 and is supported or supported on the housing end wall 2a and attacks on the control disc 18 and this exploiting the relative movement between the intermediate disk 25 and the housing 2 pivoted transversely and in the respective Swivel position to prevent unwanted Adjustment positioned. This mechanism forms one Positive control, so that in the entire range of motion a respective movement positions of the control disk 18 secured are.

In the present embodiment, the tracking device 1 by a lever drive with one or two to both Drives levers arranged on the sides of the center pivot plane 32 formed. Each drive lever 32 is pivotable in each case one end region mounted on the end wall 24, in its middle area connected to the intermediate plate 25 and in its other end region on the control disk 18 mounted attacking and always in parallel pivot plane 33 extending to the pivot center plane 22 guided. In the present embodiment, two are closed arranged on both sides of the intermediate plate 25 Tracking mechanisms in the form of drive levers 32 mirror image of each other but otherwise arranged the same. Therefore, only the tracking system in the Area of a side drive lever 32 described.

The drive lever 32 extends transversely to the double arrow illustrated pivoting movement b of the washer 25, being by means of a fixed bearing 34 and two along the Central axis 10 movable floating bearings 35, 36 with the control disc 18, the intermediate plate 25 and the housing end wall 24 is connected. The fixed bearing 34 can be between the drive lever 32 and the control disc 18, between the drive lever 32 and the housing end wall 24 or between the Drive lever 32 and the intermediate plate 25 may be provided as is the case with the present exemplary embodiment. The other two camps are then floating camps. The Fixed bearing 34 is formed by a swivel joint and the floating bearings 35, 36 are each by a sliding joint, z. B. formed by a guide link.

In the present embodiment, the drive lever 32 arranged laterally next to the intermediate plate 25, with it on can lie on their side surface or in a side Can pass through recess 25a and by means of a hinge pin 37 is pivotally mounted by one of these two Components, here from the pivot lever 32, protrudes laterally and in an articulated bore 38 of the other part or in both parts is pivotally mounted. The floating bearing 35 in the housing end wall 24 is characterized by a in the longitudinal direction of the Guide link extending central axis 10 of the axial piston machine 1 39 with two opposing guide surfaces 41 formed. The drive lever 32 has one end rounded slide head 42, with which it in the Longitudinal direction of the central axis 10 displaceable and around itself Pivot axis 43 extending at right angles to the pivot plane 22 of the hinge pin 37 is pivotally mounted. The second floating camp 36, which here between the drive lever 32 and the Control disc 18 is formed, one also has approximately corresponding guide link in the longitudinal direction of the central axis 10 44 in the form of a lateral groove in the control disc 18 on, in which the relevant end of the drive lever 32 with a cylindrical hinge pin 45 around it extending at right angles to the pivot center plane 22 Pivot axis 46 is pivotable and approximately along the central axis 10 is slidably mounted.

The drive lever 32 can in in its central region one formed by a slot 47 in the housing wall 24 Be pivot guide 47a. The slot 47 extends from the guide link 39 - transversely to the pivot center plane 22 seen - preferably divergent inwards, the associated slot dimension to the through the swivel range the drive lever 32 required space is adjusted. For technical reasons, the can Slot 47 adjoining guide link 39 in one after outside opening hole formed in the housing end wall 24 be closed by a plug 48, in particular a screw plug.

As can be seen in particular in FIG. 3, this is on the housing end wall 24 arranged bearings 34 apart from the compensating movements in the guide setting 39 a stationary one Bearing around which the bearings 34, 36 during pivoting movements of the Drive lever 32 perform arc movements due to the Articulated sliding connections in the floating bearings 35, 36 in Pivotal movements of the intermediate disc 25 and the control disc 18 to be converted. Because the ratio of effective Distances c, d of the bearings 34, 36 from the stationary bearing 35 when swiveling remains the same, swivel movement lengths result a, b for the control plate 18 and the intermediate plate 25, the ratio of which is essentially the same. Because of the shorter distance c of the bearing 34 on the intermediate disk 25 from the bearing 35 in comparison with the distance d of the bearing 36 the control disc 18, the speed of movement and the movement length a of the control disk 18 with respect to the Movement speed and the movement length b the Intermediate disk 25 translated. That is, the movement length b of the Intermediate disk 25 is in every pivoting movement Size ratio of the distances c / d smaller than the movement length a of the control disc 18, however, the movements of the Intermediate control plate 25 and the control plate 18 on the entire swivel range simultaneously and continuously occur. In the present embodiment the size ratio of the distances c / d is about 1 / 1.4.

The width e extending in the swivel plane Control disc 18 is preferably smaller than the width f the washer 25. The difference in widths e, f can correspond to the maximum difference in the movement lengths a, b. In particular, the tracking device 31 or the tracking area 9, which corresponds to the swivel range h, arranged symmetrically with respect to the pivoting range h.

The aforementioned adjustment device 21 can be in the frame the invention on the intermediate plate 25 (Fig. 1) or on the Attack control disk 18 (not shown). The swivel movement converts the tracking device 31 into one translated or reduced tracking movement.

In the present embodiment, the adjustment device engages 21 on the intermediate plate 25 so that the translation takes place.

The adjusting piston 21b is part of a hydraulic adjusting cylinder 51, its design and function in the older German patent application DE 196 53 165 of the applicant is described.

In the position of the control disk 18 shown in FIG. 2 and the intermediate disc 25, these are in the maximum pivoting position of the cylinder drum 7, in the this is set to a maximum throughput volume. In this position is the control disk 18 with respect to that in the Transversely dimensioned intermediate washer 25 laterally staggered, these two parts on the outside can complete with each other. With a return movement in the zero position, the control disc 18 with it stored cylinder drum 7 inevitably and continuously for pivotal movement of the intermediate plate 25 with a translation pivoted. The control disc 18 in the Zero position with respect to the intermediate plate 25 to the other be staggered on the side and finish with this on the outside.

To limit the two pivot end positions are preferred Stops 56, 57 provided on the housing 2, with the Part, here with the washer 25, cooperate on the the adjusting device 21 attacks. In the present Design are the stops 56, 57 by the respective Adjusting screws 58, 59 are formed through the housing wall and thus adjustable and from the outside for adjustment accessible.

It is advantageous to track the device 31 with respect to the maximum swivel position and the zero position in the middle and train symmetrically. This not only results in Both sides of the middle position are the same, but mirror images Positions and relationships, but it can also the existing in the intermediate plate 25 for the control slots Make the most of space and make optimal use of it, if possible large cross-sections for the control slots in the control disc 18 and in the intermediate disc 25 to realize can.

Claims (12)

1. Hydrostatic axial piston machine (1) with a cylinder drum (7), mounted in a housing (2) in which pistons (9) are displaceably mounted in cylinder bores (8), the piston ends of which are pivotably supported on a rotatably mounted drive disk (6), wherein the cylinder drum (7) and a cam disk (18) arranged on the side of the cylinder drum (7) turned away from the drive disk (6) can be swung horizontally by an adjustment device (21) in a pivot plane (22), whereby an intermediate disk (25) is pivotably mounted between the cam disk (18) and a housing wall (24) lying opposite, by means of circular arc-shaped curved bearing sliding faces (23, 26, 27, 28) along the pivot plane (22), whereby the intermediate disk (25) has control slots (S1, S2) corresponding with control ducts in the cam disk (18), and whereby a tracking device (31) is provided, which brings about a relative displacement between the cam disk (18) and the intermediate disk (25), characterized in that the tracking device (31) is effective over the entire pivotal range of the cam disk (18) in such a way that the displacement distance (a) of the cam disk (18) is greater than the displacement distance (b) of the intermediate disk (25).
2. Axial piston machine according to Claim 1, characterized in that the adjustment device (21) engages the intermediate disk (25) and the tracking device (31) tracks the cam disk (18).
3. Axial piston machine according to Claim 1 or 2, characterized in that the ratio between the displacement distances (a/b) of the cam disk (18) and of the intermediate disk (25) is roughly equal in the adjustment range.
4. Axial piston machine according to any one of the previous claims, characterized in that the tracking range or the tracking device (31) is symmetric relative to the pivotal range of the cam disk (18).
5. Axial piston machine according to any one of the previous claims, characterized in that the tracking device (31) has at least a pinion lever with an actuating lever (32), which with its one end is pivotably supported by a bearing (36) on the cam disk (18) and with its other end by a bearing (35) on the housing front wall (24) adjacent the intermediate disk (25), and which is pivotably supported in its central area by a bearing (34) on the intermediate disk (25).
6. Axial piston machine according to Claim 5, characterized in that one of the bearings is a fixed bearing and the other two bearings are movable bearings, which permit a balance movement in the bearing, directed transversally to the housing front wall (24).
7. Axial piston machine according to Claim 6, characterized in that the fixed bearing is formed by a swivel joint and preferably one or both movable bearings are formed by a respective guide link (39, 44).
8. Axial piston machine according to any one of Claims 5 to 7, characterized in that the actuating lever (32) is displaceably mounted in a guide slot (47) in the housing front wall (24).
9. Axial piston machine according to any one of the previous claims, characterized in that two tracking devices (31) are arranged in mirror-image on either side of the cam disk (18) and the intermediate disk (25).
10. Axial piston machine according to any one of the previous claims, characterized in that the adjustment device (21) is arranged in the vicinity of a housing front wall (24) lying opposite the intermediate disk (25) and has a driving spigot (21a), which is displaceably mounted transversally to the centre axis (10) of the cylinder drum (7) and is preferably joined with the intermediate disk (25) in the vicinity of a guide link.
11. Axial piston machine according to any one of the previous claims, characterized in that for limiting the in and/or out swing movement two stop shoulders (56, 57) are provided on the housing (2), which preferably can be adjusted and in particular are accessible from the outside.
12. Axial piston machine according to any one of the previous claims, characterized in that the difference between the widths (e, f) of the cam disk (18) and the intermediate disk (25) corresponds to the maximum difference between the displacement distances (a, b) of the cam disk (18) and the intermediate disk (25).

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