JP3365646B2 - Adjustable axial piston machine in swash plate configuration - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adjustable axial piston machine in the form of a swash plate, which has a tilting axis which is swivelable about a swivel axis perpendicular to the rotational axis of a drive shaft or a driven shaft. A swash plate / position transmitter operatively connected to the control and / or adjusting mechanism.

[0002]

2. Description of the Prior Art Axial piston machines of this type are described in German Patent Application DE 31 36 519 A1.
It is known based on the specification. According to this publication
The swash plate / position transmitter, which is attached to the end surface of the swash plate of the cradle type and is configured in the form of a yoke, works for feedback of the moving distance to the pilot valve of the control and / or adjusting mechanism. / or adjustment mechanism, in the region of the swash plate and the cylinder drum attached to the outside of the machine casing, the machine casing so as to form a part of the casing cover. In this axial piston machine of the prior art, simply by replacing the casing cover and / or mounting additional components,
It is possible simply to use another type of control and / or adjusting mechanism, in which case the basic structure of the axial piston machine always remains the same.

However, in the known axial piston machines described above, a pressure medium supply for the pilot valve cooperating with the swash plate / position transmitter is provided in the casing cover forming the machine casing or part of the machine casing. Must be provided, which significantly complicates manufacturing and thus causes higher costs. Furthermore, this known axial piston machine has a large structural volume, which is disadvantageous when used, for example, as an axial piston motor. This is because it is desirable for an axial piston motor to be inserted as an insertion motor in a wheel hub transmission, in which case the wheel hub transmission will have available space based on a given wheel size. , Especially in the radial direction in the area between the swash plate and the cylinder drum.

Axial piston machines of smaller size in the radial direction by virtue of the fact that the control and / or adjusting mechanism are integrated into the adjusting piston of the swash plate are certainly also known (German Patent Publication No. 3).
No. 310747), however, this known arrangement does not offer the possibility of disassembling the control and adjustment of the axial piston machine. This is because in this case the control and / or regulating mechanism is an integral part of the axial piston machine and, furthermore, the space available inside the machine casing is very limited.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is therefore to improve the axial piston machine of the type mentioned at the beginning such that the manufacturing costs are low, the assembly is easy, the construction space is minimal, and An object is to provide an axial piston machine capable of using various control and / or adjustment mechanisms.

[0006]

In order to solve this problem, in the configuration of the present invention, the swash plate / position transmitter is mainly
It consists of two levers pivotally connected to each other, the first of which is greater than 0 ° in a longitudinal section through the axial piston machine and when viewed perpendicular to the swivel axis. At an angle of less than 90 °, preferably about 45 °, inclined with respect to the swivel axis and connected to the swash plate, the second lever being substantially inclined with respect to the rotational axis. parallel, be disposed between the inner wall and the cylinder drum of the machine housing, it is rotatably supported about its longitudinal axis, further
Relative twist to have the joint is provided preventing, the joint, and towards the end remote from the swash plate of the first lever, and the end closer to the swash plate of the second lever At the end of the second lever remote from the swash plate, the pickup being provided with a control bottom receiver of the axial piston machine.
It is located substantially axially inside .

[0007]

The main idea of the invention is therefore to eliminate the narrow spatial coupling between the displacement feedback and the control and / or adjusting mechanism, in this case the cylinder drum inside the machine casing. With swashplate
The area simply is arranged only swashplate-position transmitters, advantageously outside the axial piston machine in the region of the control base receptacle contrast, control and / or adjustment mechanism may be arranged . Therefore, the structural volume of the axial piston machine can be kept very small in the basic structure. In the axial piston machine according to the invention, a space-saving direct transmission of the swash plate movement to the control and / or adjusting mechanism takes place without loading adjacent components. When the swash plate is swiveled outward, this causes the second lever of the swash plate / position transmitter to rotate about its longitudinal axis. This rotary movement is picked up in a suitable manner by the control and / or adjusting mechanism.

[0008] Therefore, when configured as in the present invention,
Supplying a pressure medium through the wall of the machine casing,
It is possible to dispense with the multi-part construction of the machine casing and the tedious machining of the casing cover provided for receiving the control and / or adjusting mechanism. Further, since the swash plate / position transmitter is configured as described above, the following great advantages can be obtained. That is, it is not necessary to provide the mechanical casing with a supporting portion for the swash plate / position transmitter, and as a result, it is not necessary to machine the mechanical casing for feedback of the moving distance. Instead, a pot-shaped casting is screwed onto the plate-shaped control bottom receptacle, which makes it possible to easily manufacture the machine casing. The control and / or adjusting mechanism is fixed to the control bottom receptacle and is in the region of this control bottom receptacle , that is to say about the axial length of the control bottom receptacle.
Inside, there is a pickup for the swash plate and position transmitter. Therefore, the area of the machine casing in which the swash plate and the cylinder drum are arranged can be made very small in the radial direction.

In a technically advantageous construction of the joint, the joint has a fork formed on one lever end of the lever ends connected to one another and a connecting plate formed on the other lever end. It consists of a pin connecting the fork and the connecting plate. Further, when the swash plate is swung inward, the axial center of the pin is arranged to be substantially perpendicular to the swivel axis and the rotation axis, whereby the axial piston machine can be dimensioned particularly compactly.

In order to simplify the connection between the first lever and the swash plate, in another configuration of the present invention, the end of the first lever closer to the swash plate is formed into a pin shape. Is rotatably arranged in the hole of the swash plate about its longitudinal axis and a second lever extends through the hole provided in the control bottom receptacle. According to this structure, in order to support the swash plate / position transmitter, the through hole for the first lever is machined into the oscillator, and the through hole for the second lever is controlled. It is sufficient to process the receiving part. In addition to the two bearing points on the control bottom receiving part and the swash plate, no further bearing points are required on the machine casing, as already mentioned, so that the production of the machine casing is considerably simplified. Furthermore, the arrangement according to the invention is insensitive in terms of manufacturing error.

In another aspect of the invention, the first lever comprises a pin which is formed on a component fixed to the swash plate and which projects into the sleeve. Is pivotally connected by means of a pin to a fork arranged at the end of the second lever closer to the swash plate. With this configuration, it is not necessary to provide the through hole in the swash plate.

In an axial piston machine in which the working piston is supported by a sliding disc, in addition to utilizing the swash plate / position transmitter for its original function, namely the distance traveled feedback, the first lever or component is It is particularly advantageous if it is constructed as a sliding disk / holding body. Also likewise, in an axial piston machine in which the working piston can be loaded by means of a retracting device towards the swash plate, it is advantageous if the first lever or component is designed as a restraining body for the retracting device. is there.

In still another configuration of the present invention, the end of the second lever remote from the swash plate is bent outward in the radial direction with respect to the rotation axis, and the control bottom receiving portion is provided. It is guided outward from the axial piston machine through a notch provided. In other words, the coupling between the pickup, which is located outside the machine casing, and the mechanism of the swash plate / position transmitter that detects the position of the swash plate,
Via a control-bottom receptacle, in which case the control-bottom receptacle is, in any case, a bore for the high-pressure connection and a bore for the low-pressure connection and a bore for receiving or fixing the adjusting cylinder. As a result, there is no problem in guiding the end of the second lever outward through the notch provided in the control bottom receiving portion.

The rotational movement of the second lever about the longitudinal axis, which occurs when the swash plate pivots, is converted into a movement of the bent lever end along an arcuate line, whereby For example, the piston in the control and / or adjusting mechanism cooperating with this bent lever end can move linearly.

Instead of the above-described second lever construction, in which the end, which is constructed in one piece and which is remote from the swash plate, is bent radially outwards, another alternative of the invention is provided. In an advantageous configuration, the second lever is arranged in force connection with the first part, which is arranged substantially parallel to the cylinder drum, and at the end remote from the swash plate. A portion which is form-connected and which extends radially outward. A two-part lever arrangement is thus advantageous in some cases.

In order to convert the movement of the end of the lever along the circular trajectory into the linear movement of the piston of the control and / or adjustment mechanism, the end of the second lever remote from the swash plate.
Part is, be configured to form a spherical head and is provided as a pick-up, it is advantageous.

In another advantageous configuration of the invention, the second lever is spring-loaded towards the joint. With this configuration, the swash plate / position transmitter will not only perform its original task
It can also function as a restraining device, which can prevent the swash plate from lifting from its bearing. As a result, a separate restraining device can be omitted.

It is also advantageous if the joint center point is arranged on the pivot axis. With this construction, when the swash plate turns, a pure rotational movement of the second lever about its own longitudinal axis is produced, which causes the swash plate / position transmitter to move in the axial direction. The position at does not change.

However, in a further advantageous embodiment of the invention, the joint center point is axially spaced from the pivot axis when viewed in a longitudinal section through the axial piston machine. According to this structure, not only the rotational movement of the swash plate but also the axial movement of the second lever is generated when the swash plate turns, and this axial movement causes
It can act on the restraining spring to increase the preload of the restraining spring. Furthermore, the axial movement also has an advantageous effect on the bearing points. This is because the rotary movement no longer takes place in a fixed position.

In a further advantageous development of the invention, the swash plate is supported on the machine casing on a bearing surface provided with hydrostatic pressure relief grooves, in which case both levers and joints are hydrostatic. A passage is provided for supplying a pressure medium to the pressure relief groove of the formula.
With this configuration, the swash plate / position transmitter can also assume the function of a pressure medium / supply device for hydrostatic swash plate pressure release.

[0021]

Embodiments of the present invention will now be described with reference to the drawings.

The adjustable axial piston machine of the swash plate type shown in FIG. 1 has a drive shaft or driven shaft 1
And a cylinder drum 2 which is non-rotatably connected to the drive shaft or the driven shaft, and a plurality of working holes 3 are concentrically arranged in the cylinder drum.
Working pistons 4 are respectively movable in the working holes 3 in the longitudinal direction, and each of the working pistons 4 is provided with a retracting device 5 and a sliding shoe 5a. In this case, the sliding shoe 5a is supported by a swash plate 7 in the form of a squirrel cage. And can be swiveled using an adjusting device not shown in the drawing. The swash plate 7 is supported by a bearing shell 8 having a hydrostatic pressure release groove 9.
A plurality of passages 10 are provided in a plate-shaped control bottom receiver 11 for supplying and discharging pressure medium to and from the working hole 3, which control bottom receiver is pot-shaped, preferably cast. It is connected to the machine casing 12, for example by screwing, and together with the machine casing 12 and the components arranged inside the machine casing form an axial piston machine.

At an angle of approximately 45 ° with respect to the swivel axis S, a hole 13 is provided in the swash plate 7 at the transition from the end face 14 to the working face 6 and extends towards the bearing shell 8. ing. This hole 13 is larger than 0 ° and 90
It is also possible to provide it at another angle smaller than °. As can be seen from FIG. 2, the hole 13 is arranged in the center of the swash plate 7.

A pin-shaped first lever 15 is rotatably supported in the hole 13 about its longitudinal axis. When the swash plate 7 occupies the 0 stroke position, that is, when the working surface 6 is arranged perpendicular to the rotation axis D, the lever 15 is deep enough to contact the ball 16 which acts as a stopper. It projects into the hole 13. The end of the lever 15, which is located further from the swash plate and projects from the hole 13, is molded into a connecting plate 17, which is provided with a lateral hole 18.
The central axis of this lateral hole 18 is swiveled inward,
That is, the swash plate 7 occupying the 0 stroke position is arranged perpendicular to the turning axis S and the rotation axis D.

The second lever 19 is arranged substantially parallel to the rotation axis D between the inner wall of the machine casing 12 and the cylinder drum 2. The end of the lever 19 closer to the swash plate is configured into a fork 20, which is transverse to the transverse bore 18 of the first lever 15 and has the same diameter. It has a hole 21. Both levers 15, 19 have both lateral holes 18, 21
It is pivotally connected to each other in a relatively twist-free manner by means of a pin 22 inserted in the. The end of the second lever 19 remote from the swashplate is rotatable and movable longitudinally in the hole 24 of the control bottom receptacle 11 (almost free of radial play) by means of the spherical section 23. ), And it projects into the inside of the control bottom receiving part 11. Inside the control bottom receiving part 11, the lever end has a region 25 which is bent radially outward with respect to the axis of rotation D, which region is provided with a cutout 2.
6 is guided outwardly from the control bottom receiving part 11 through 6 and there is a pickup 2 configured as a spherical head.
Finished at 7.

In principle, instead of arranging the holes 13 from the upper right to the lower left in the drawing, it is also possible to provide them perpendicularly to the position shown, ie from the upper left to the lower right. In this case, the lever 19 must extend towards the left side of the drawing. In this case too, an angle between 0 ° and 90 ° (more precisely 45 °) is obtained between the pivot axis and the lever 15 or the bore 13.

The second lever 19 is provided with a pressure spring 28 arranged in an axial extension of the hole 24 in the control bottom receiving part 11.
By means of a ball 29 towards the swash plate 7, whereby on the one hand the joint formed by the connecting plate 17, the fork 20 and the pin 22 is kept play-free and on the other hand The swash plate 7 is pressed down on the bearing shell 8. Ball 29 is lever 1
It is located at the transition between the linear region of 9 and the folded region 25. The spring 28 has an adjusting screw 30.
Supported by. The pin 30 arranged on the adjusting screw 30
The a serves as a ball stopper when the swash plate 7 is lifted from the bearing shell 8.

Both levers 1 pivotally connected to each other
Reference numerals 5 and 19 form a swash plate / position transmitter. When the swash plate 7 is swung outward from the position shown in FIG. 2, for example, in the counterclockwise direction (see FIG. 3), the arrangement of the first lever 15 and the joint in which the relative twist is prevented are changed. Due to the type of connection between the first lever 15 and the second lever 19 via the rotary movement of the second lever 19 is caused about its longitudinal axis, which results in the pickup 27 in a circular path. Exercise along. The movement of the pickup 27 is detected, for example, by a piston, in which case the piston is connected by means of a slide guide with the pickup 27 acting as a slide, and in this case the piston position is controlled and / or adjusted. Used for various purposes.

The piston is part of a control and / or adjusting mechanism which, due to the spatial arrangement according to the invention of the pick-up 27, controls the axial piston machine and preferably the control. ho of the bottom receptacle 11
They are connected within the axial length, so that the machine casing 12 can be kept small and the surrounding area also becomes free space. In principle, it is also possible to directly detect the rotational movement of the second lever 19 if the control and / or adjusting mechanism is appropriately configured, and in such a case the corresponding The element constructed in accordance with claim 1 must extend into the control bottom receptacle.
Furthermore, the following configuration is also possible. That is, a lever 19 extends axially through the control bottom receiving part 11 and a rotary movement by the control bottom receiving part 11 on the right-hand side in FIG. 1 has a control and / or adjustment arranged there. It may be performed by a mechanism.

As shown in FIG. 2, the joint center point or the center axis of the pin 22 is axially spaced from the pivot axis S. As a result, when the swash plate 7 turns, not only the rotational movement of the second lever 19 but also the longitudinal movement of the second lever 19 is caused, whereby the crimping force of the crimping spring 28 is changed. In another case, which is not shown in the drawing, a pure rotational movement of the lever 19 is produced when the joint center point coincides with the pivot axis.

FIGS. 4 and 5 show a variant of the axial piston machine according to the invention, the variant being different from the variant shown in FIGS. 1 and 2. The points are as follows. That is, in the embodiment shown in FIGS. 4 and 5, the second lever 19 has a conical shape at its end remote from the swash plate, rather than being bent. In this case, an arm 32 extending outward in the radial direction is fixed to the conical portion 19a by a screw 31 in a force-connecting manner, and the arm 32 has a pickup 27. That is, the second lever is composed of two parts. In this case, it is also possible to use force-connecting or form-connecting connection types other than the illustrated connection type of the lever part.

In the embodiment shown in FIGS. 4 and 5, further, instead of the first lever 15, a component member 33 screwed to the swash plate 7 is provided. This component has a pin 34, in which case the position, in particular the angular position, of the pin 34 coincides with the angular position of the end of the lever 15 remote from the swash plate. The pin 34 is pivotally connected to the fork 20 of the second lever 19 by means of the sleeve 35 and the pins 36 and 37 shown by broken lines, while preventing relative twisting. The effect obtained by this arrangement form is exactly the same as the effect obtained by the arrangement form shown in FIGS. The component 33 is configured as a retainer for the retractor 5 of the working piston 4 by means of the integrally formed projection 33a. Similarly, it is possible to configure the component member 33 as a sliding disk / holding body.

FIGS. 6 and 7 show a second variant of the axial piston machine according to the invention. In this second variant, the first lever 15 shown in FIG. 1 is provided, but in this case this lever 15
Is configured as a fork 38 at its end remote from the swash plate, while the second lever 1
The end of the 9 closer to the swash plate has the shape of the connecting plate 39. Also in this embodiment, a pin 22 is provided to connect both levers 15 and 19. Lever 19
The lever 15 and the pin 22 are each provided with a passage 40 which is connected to each other. These passages 40 are on the inlet side, that is, the second lever 19
Is connected to the pressure medium source at its end remote from the swash plate and is provided on the swash plate 7 on the outlet side, i.e. in the pin-shaped area of the first lever 15. Is connected to a passage that is not
Hydrostatic pressure relief groove 9 arranged on swash plate 8.
Work for pressure medium supply to. With this configuration, it is not necessary to provide a separate pressure medium / supply device for hydrostatic swash plate pressure release.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing an axial piston machine according to the present invention.

FIG. 2 is a plan view showing the end face side of the swash plate shown in FIG. 1 at the 0 stroke position of the swash plate.

FIG. 3 is a diagram showing a part of the swash plate together with a joint of the swash plate and the position transmitter when the swash plate is swung outward.

FIG. 4 is a partial vertical sectional view showing a first modification of the axial piston machine according to the present invention.

5 is a plan view showing the end face side of the swash plate shown in FIG. 4 at the 0 stroke position of the swash plate.

FIG. 6 is a partial longitudinal sectional view showing a second modified embodiment of the axial piston machine according to the present invention.

FIG. 7 is a plan view showing a joint portion in detail.

[Explanation of symbols]

1 drive shaft or driven shaft, 2 cylinder drum,
3 working holes, 4 working pistons, 5 retractor,
6 Working surface, 7 Swash plate, 8 Bearing shell, 9
Pressure relief groove, 10 passage, 11 control bottom receiving part, 12
Machine casing, 13 holes, 14 end faces, 1
5, 19 levers, 16 balls, 17 connecting plates,
18 lateral holes, 20 forks, 21 lateral holes, 22 pins, 23 sections, 24 holes, 25
Area , 26 Notches, 27 Pickups, 28
Crimping spring, 29 balls, 30 adjusting screw, 3
1 Screw, 32 Arms, 33 Components, 34
Pin, 35 Sleeve, 36, 37 Pin, 3
8 forks, 39 connecting plates, 40 passages

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Fukui 2-132868 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04B 1/00-15/08

Claims (14)

(57) [Claims] 1. An adjustable axial piston machine in the form of a swash plate, the swash plate being pivotable about a pivot axis perpendicular to the axis of rotation of the drive or driven shaft, and control and / or. Alternatively, in the type in which a swash plate / position transmitter operatively connected to the adjusting mechanism is provided, the swash plate / position transmitter is mainly composed of two levers (15, 19) pivotally connected to each other. The first lever (15) of the two levers is made up of more than 0 ° and 90 ° in a longitudinal section through the axial piston machine and perpendicular to the swivel axis (S). Is placed at a smaller angle than the tilt axis (S),
The second lever (19), which is connected to the swash plate (7), is arranged substantially parallel to the axis of rotation (D), so that the mechanical casing (1
It is arranged between the inner wall of 2) and the cylinder drum (2), is rotatably supported about its longitudinal axis, and is further provided with a joint for preventing relative twisting, The joint is connected to the first lever (1
And the end which is remote from the swash plate 5), and an end portion closer to the swash plate of the second lever (19) attached to each other, the swash plate of the second lever (19) At the remote end, a pickup (27) is provided, which is arranged substantially axially inside the control bottom receiver (11) of the axial piston machine. Adjustable axial piston machine in swash plate construction type. 2. A fork (20) having a joint formed on one lever end of one of the lever ends joined together.
And a connection plate (17) formed on the other lever end,
2. An axial piston machine according to claim 1, comprising a pin (22) connecting the fork and the connecting plate. 3. The pin (2) is rotated when the swash plate (7) is swung inward.
The center axis of 2) is arranged so as to be substantially perpendicular to the turning axis (S) and the rotation axis (D).
Axial piston machine described. 4. The end of the first lever (15) closer to the swash plate is formed into a pin shape, and the hole (1) of the swash plate (7) is formed.
3) rotatably arranged about its longitudinal axis, a second lever (19) is provided with a control bottom receiver (1).
Extended through a hole (24) provided in 1),
The axial piston machine according to any one of claims 1 to 3. 5. The first lever (15) consists of a pin (34) which is formed on a component (33) fixed to the swash plate (7) and which has a sleeve (35). Projecting in and the sleeve is pivotally connected by means of a pin (36) to a fork (20) arranged at the end of the second lever (19) close to the swashplate, The axial piston machine according to any one of claims 1 to 3. 6. The working piston is supported on a sliding disc, the first lever (15) or the component (33).
Is configured as a sliding disk / holding body.
The axial piston machine according to any one of items 1 to 5. 7. The working piston can be loaded towards the swash plate by means of a retracting device, the first lever (15) or the component (33) being constructed as a restraining body for the retracting device (5). The axial piston machine according to any one of claims 1 to 6, which is provided. 8. The control bottom receiving part (11), wherein the end of the second lever (19) remote from the swash plate is bent outward in the radial direction with respect to the rotation axis (D). )
8. Axial piston machine according to claim 1, which is guided outwardly from the axial piston machine through a notch (26) provided in the axial piston machine. 9. A first part (1) in which a second lever (19) is arranged substantially parallel to the cylinder drum (2).
9 and 19a), and a portion (32) which is connected to the first portion in a force-connecting or form-connecting manner at the end remote from the swash plate and extends radially outward. An axial piston machine according to any one of claims 1 to 8, which is made of The end which is remote from the swash plate of 10. The second lever (19) be configured to form a spherical head is provided as a pick-up (27), claims 1-9
The axial piston machine according to any one of items 1 to 7. 11. Axial piston machine according to claim 1, wherein the second lever (19) is spring-loaded towards the joint. 12. The joint center point is a turning axis (S).
Arranged in any one of claims 1 to 11
Axial piston machine described in paragraph. 13. The joint center point is located axially spaced from the swivel axis (S) when viewed in a longitudinal section through the axial piston machine. Axial piston machine described in paragraph. 14. A swash plate is supported on the machine casing on a bearing surface provided with hydrostatic pressure relief grooves, in which case the hydrostatic pressure relief is applied to both levers (15, 19) and the joint. 14. Axial piston machine according to any one of claims 1 to 13, wherein the groove (9) is provided with a passage (40) for supplying a pressure medium.