DE3441966A1 - CONTROL FOR A HYDROSTATIC PISTON ENGINE - Google Patents

Description

3U1966

G. Düsterloh GmbH, 4322 Sprockhövel 1

Control for a hydrostatic piston engine

The invention is directed to a control for a hydrostatic piston engine according to the features in Preamble of claim 1.

The previously known controls for hydrostatic piston engines, in particular hydraulically actuated Radial piston motors are all mechanical in nature. Here, one end of the motor shaft is designed accordingly used to distribute the incoming volume flow to the working cylinders as well as the back flowing To collect volume flow.

For this purpose, it is known in radial piston engines with internal piston support to provide control rings that with the. Motor housing and an eccentric connected to the motor shaft form an outer and an inner annulus » By moving the control rings between the control plate and a. Housing cover through the eccentric is alternating the inner and outer annulus are brought into communication with the working cylinders. The annular spaces open outwards into the Motor pressure connections.

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It is also known to provide one end of the motor shaft with grooves and recesses in order to. the working medium bring the rotation angle dependent on the working cylinder or to be transferred from them.

Such motor controls have basically proven themselves in practice. But since it is always self-contained Systems, they cannot be influenced from outside. The effective displacement of the engines is therefore not changeable and therefore requires im. open circuit additional flow and directional control valves. An effective one once employed Swallowing volume is over all acceleration or. Delay phases of the motor effective. As a comparison between the mechanical control and the working cylinders Long channels and holes are present, here is a relative one large harmful compression volume present. A hydraulic one In the known case, positioning can only be achieved by incorporating additional valves into the line sections before and / or after the engine control unit will. Also, the second end of the motor shaft could not be driven be grooved, since the mechanical control of a shaft feedthrough always stood in the way.

The invention is based on the object, the control described in the preamble of claim 1 for a hydrostatic piston engine so zn that the influencing the effective displacement and thus / the engine torque In any operating position without additional Flow and directional control valves is possible.

This object is achieved according to the invention in the features listed in the characterizing part of claim 1.

The one previously provided on a motor shaft end mechanical control is now by the individual work cylinders directly assigned directional control valves, in particular Proportional valves, in the form of τοη servo or proportional valves according to claim 2, replaced, which are actuated electromagnetically in dependence on the position of the motor shaft. To this The purpose is, the respective position of the motor shaft by a Detected angle encoder, which is connected to a microprocessor. The microprocessor is exactly on the excitation or de-excitation of the proportional valves can be programmed depending on the angle. This means that it is now possible to set any desired acceleration and Specify the deceleration curve of the piston motor. For example, in the event of a heavy start, the motor can be exactly upper and lower dead center are initially operated with the maximum displacement. Then the engine has run up and the mass to be driven has been accelerated, this can be achieved by an angle-dependent adjustment of the proportional valves effective displacement and thus also the torque can be reduced. It is therefore no longer like a mechanical one Control of an effective swallowing volume, once set, over all acceleration and deceleration phases of the motor effective, but the effective displacement in each case is now geared towards optimal use of the existing pressure.

Furthermore, hydraulic blocking is now possible. So z. B. in a winch arrangement of the motor be put under full pressure immediately, even though it is still standing still. The brake can then be completely released without having to fear that if the pressure is too low, the load will spin the motor or that if the pressure is too high Pressure of the motor dragging against the applied brake is working. Due to the precise positioning of the proportional valves, the motor can be pressurized, whereby leakage losses are automatically supplemented by any external stresses exerted on the motor. This Yorteil is particularly noticeable where external ^ Forces such as downhill forces wanting to turn the engine.

<> The invention also makes it possible to return energy

to win. If the motor is connected to a lowering load, energy can now be fed into the supply network in a targeted manner.

The invention also enables an engine

now without further ado to a hydraulic network, with constant. Pressure connected and yet the available energy is optimally used in every load situation of the motor '' can be.

Another advantage is that a freewheeling circuit can also be set up. It is to this through appropriate programming only required to bring all proportional valves into a position in which they either with the pressure side or the return side on both sides are connected.

Due to the possibility that the work cylinder in. top and bottom dead center z. B. with pre-inflow can be controlled precisely, a very smooth running of the motor and an optimization of the efficiency is achieved. The acceleration, deceleration and speed progression can be set perfectly in advance. It is In addition, a stepless change in the effective swallowing volume possible through gate control. For example, it is conceivable to increase the pressure over an angle of rotation of 270 ° and carry out the return over the remaining angle of rotation of 90 °. In this way the hydraulic energy, e.g. in the case of a constant pressure network. Beyond that the lowest speeds are possible. This is ensured by the fact that leakage losses have no negative influence can do more to stop the engine. Losses are added automatically. It can also be a direct one Reversal can be made via proportional valves. Because the proportional valves are assigned directly to the working cylinders Is it possible to supply the working medium depending on the angular position of the motor shaft without to reverse another.

The pressure and return connections are located directly on the motor housing. The paths between the valves and, the working cylinders are short. This will increase the compression volume considerably reduced. Another advantage of the short distances is the improved cooling of the working medium, since the working medium fed in continuously after a work cycle is almost completely discharged again and replaced by fresh working medium.

Finally, another advantage of the invention is that both ends of the motor shaft can now be used. In the known case, the mechanical control of a shaft feed-through always stood in the way. So it is ζ .. B. conceivable to make the second shaft end hollow. In this way, two motors can then be mechanically connected to one another directly. Consequently, without special measures and with comparatively little effort, even what the space requirement is concerned - the power of a drive unit can be increased.

According to claim 3, the angle encoder can interact with a gear attached to a motor shaft end.

In place of such an embodiment can an arrangement with greater resolution, as characterized in claim 4, for example, occurs.

The invention makes it possible to use the electromagnetically controllable proportional valves not only in hydrostatic radial piston engines with internal piston support (claim 5) ₅ but also in hydrostatic piston engines of the so-called resolved type (claim 6). In the resolved design, the pistons provided with rollers can then be supported on a cam track according to claim T or they are eccentrically connected to a connecting rod according to the features of claim 8. Articulated large meshing pinions. In the last embodiment, as many working cylinders are then arranged on the circumference of the large wheel as is necessary to ensure uniform operation.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings. Show it:

Figure 1 in vertical longitudinal section a hydrostatic Radial piston engine with internal piston support;

Figure 2 shows a piston engine with supported on a curved path Rolls in the schematic cross-section and

FIG. 3 shows a diagram of a section from a piston engine arranged with the circumference of a large wheel, pinions driven by working cylinder »

With 1 in the figure 1 is the housing of a hydrostatic radial piston motor with internal piston support designated. The housing 1 is penetrated by a Mbtorwelle 2, which is supported in bearings 3 in housing 1. the The axial position of the motor shaft 2 is determined by a cover 4 fixed, which is penetrated by a stub shaft 5 of the motor shaft 2. Between the stub shaft 5 and the cover 4 A sealing element 6 is provided which seals the interior of the housing from the environment.

The other end T of the motor shaft 2 is hollow. Between the. hollow shaft section 7 and the Housing 1 A sealing element 8 is provided which seals the interior of the housing 1 from the outside.

The middle length section of the motor shaft is designed as an eccentric 9. On the eccentric 9 are based In Arbeltszylindern 10 of the housing 1 to and fro Piston 11 slidingly off via connecting rod 12 and connecting rod shoes 13. For example, there are five working cylinders 10 with pistons 11 arranged distributed on the circumference of the radial piston motor. However, one of the two is used for ease of illustration illustrated working cylinder 10 in the circumferential direction verse tz, t drawn.

In the radial extension of each working cylinder 10 a proportional valve 14 is attached to the circumference of the housing 1, that is electromagnetically controllable. To simplify the illustration, the proportional valves 14 are only symbolic illustrated.

The hydraulic working medium is fed to the continuous valves 14 via a pressure connection P into an annular channel 15 and from this annular channel 15 via radial branch channels 16 to the continuous valves 14. The return flow from the continuous valves 14 also takes place via radial branch channels 17 into an annular channel 18 and from this ring channel 18 in a return flow connection R.

On the. hollow end T of the motor shaft 2 is a ZaI wheel 19 attached, which rotates past an angle encoder 20 mounted in the housing 1. The angle encoder 20 protrudes a line 21 in connection with a microprocessor 22, which in turn is connected to the magnets 24 of the proportional valves 14 via lines 23.

The microprocessor 22 is programmable, and z.wa] specifically, depending on the angle, on the excitation or de-excitation of the proportional valves 14. By appropriate programming, a

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exact acceleration, deceleration and: speed progression of the radial piston motor adjustable.

Also in the embodiment of FIG Working cylinder 25 arranged in a star shape with Arbelt piston

26 Seen a goal. The Arbeltskolben 26 are supported on rollers

27 on a curved track 28 in the housing 29.

Each cylinder 25 is an electromagnetically controllable proportional valve 14 is assigned, the magnets 24 are connected via lines 23 to a microprocessor 22, the 1st turn is connected to an angle encoder 20 via a line 21, the _f on the motor in conjunction with a wave-2 attached gear 19 determines the respective position of the motor shaft 2. ^s

The supply and discharge of the hydraulic working medium to the continuous valves 14 and thus also to and from the working cylinders 25 again via annular channels 15, 18 with not connections P and R shown in more detail (corresponding to the embodiment of Figure 1).

In the embodiment of Figure 3, a hydrostatic Piston engine, several working cylinders 31 are provided on the circumference of a large wheel 30, which again Electromagnetically controllable proportional valves 14 are assigned, which according to the embodiments of the figures 1 and. 2 can be displaced via a microprocessor 22 depending on the respective position of the motor shaft.

The pistons 32, which can move back and forth in the working cylinders 31, engage with piston rods 33 through an end face of the cylinder housing 34. Connecting rods 35 are articulated to the free ends of the piston rods 33 and their other end sections are off-center from pinions J> 6, which are attached to the. The circumference of the large wheel 30 comb. There are as many working cylinders 31 arranged on the circumference as is necessary for uniform operation.

In this embodiment too, the positions of the pistons 32 in the working cylinders can be determined via an angle encoder 20 31 recognized and by means of the microprocessor 22 the corresponding activation of the Y-valves 14 is carried out will.

110/31252 · '- - - XR / Mon

34A1966

3 reference characters

1 motor housing

2 motor shaft

3 bearings

4 lids

5 stub shaft

6 Sealing element Γ shaft end

8 sealing element

9 eccentrics

10 working cylinders

It piston

12 connecting rods

13 connecting rod shoes

14 proportional valve

15 ring channel

16 branch channels IZ "

18 ring channel

19 gear

20 angle sensors

21 management

22 microprocessor

23 lines

24 magnets

25 working cylinders

2β working piston

27 roles

28 curved track

29 housing

30 large wheel

31 working cylinders

32 pistons

33 piston rods ■

34 housing

35 connecting rods

36 pinions

P pressure connection R reflux connection

Claims (8)

PAT £ "MTA NW ALTS DR.-ING. W. STUHLMANN - DIPL.-ING. R. WILLERT DR.-ING. PH OIDTMANN -,," - - _ 344Ί 96 6. R. 110/31252 4630BOCHUM 1. 15.11. 1984 Post office box 1O 24 BO YP / Mo hr sign - Bergstrasse 159 Λη / Fernruf O234 / 519 «57 Telegr. Stuhlmann patent Telex 825 361 swop d Patent claims: 1. Control for a hydrostatic piston engine with several reciprocating pistons in cylinders, the translational kinetic energy of which is converted at least indirectly into rotational energy of a common motor shaft, whereby the application of the working cylinder with the hydraulic working medium is dependent on the angle of rotation of the motor shaft in that (the work 1O ₃ 25 3D an electromagnetically controllable directional valve (14), r particular proportional valve, for supply and removal |) at each working cylinder is provided medium and the driving of the proportional valves (14) via a function of 'takes place the position of the motor shaft (2) programmable microprocessor (22) which is connected to an angle encoder (20) assigned to the motor shaft (2). 2. Control according to claim I _9, characterized in that the continuous valves (14) in the form of servo or proportional valves elnz.eln are attached to the working cylinders (10, 25, 31). 3- control according to claim 1, characterized that the angle encoder (20) with a gear (19) attached to a motor shaft end (7) cooperates. COPY & 3U1966 4. Control according to claim 1 or 3 , characterized in that the angle encoder (20) is designed as an analog or digital encoder. 5. Control according to one of claims 1 to 4 in the application to a hydrostatic radial piston engine with inner piston support. 6. Control according to one of claims 1 to 4 in the application to a hydrostatic piston engine resolved design. 7 '. Control according to Claim 6, characterized in that the _{pistons (26) provided with rollers (27 ^ j, v} ) are supported on a curved track (28). 8. Control according to claim 6 _S, characterized in that the pistons (32) via connecting rods (35) are articulated eccentrically to Ritz.el (36) which meshes with a large wheel (30). EPO COPY