IT8148036A1 - HYDROSTATIC PROPULSION SYSTEM - Google Patents

Description

DOCUMENTATION

BOUND

TRANSLATION

FEDERAL REPUBLIC OF GERMANY

CERTIFICATE

.?? . signed. Zalixiradf a?rilc ^Friedrichghaf en ,A?G. in Friedrichshafen (German Federal Republic)

the . A1. .M?r.??. ?9.8.0. has deposited with

the German Central Patent Office an application for

patent entitled:

n Hydrostatic propulsion system. "

The attached documents are a correct and exact reproduction of the original documents of this patent application.

The application has been designated by the symbols F16H 39-44 and F15B 11-04 of the International Patent Classification.

Mflncheu, 30 December 19 80

The President of the German Patent Office Representing

No. of acts P 30 10 913.8

ZAHNRADEABRIK FRIEDRICHSHAFEN Aktiengesellschaft, in Friedrichshafen

Hydrostatic propulsion system

Claims

1.) Hydrostatic propulsion system with an open circuit, in which there is a 4/3-way valve between the hydraulic pump and the hydraulic motor for optional control of the flow of compressed liquid for inflow and outflow to the hydraulic motor and with the stop of said motor in the pressurized liquid tank, characterized in that in said circuit there is also a regulating device (3), which directly feeds a part or all of the pressurized liquid from the return flow (11,21') from the hydraulic motor (1) to the inflow (31,21) in the thrust mode.

2.) Hydrostatic propulsion system, according to claim 1,

characterized by the fact that the regulating device (3) is arranged between the hydraulic pump (4) and the pressurized liquid tank (5), on one side, and the 4/3-way valve, on the other side.

3.) Hydrostatic propulsion system, according to claim 1 or 2,

characterized in that the regulating device is designed as a regulating valve (3) which, depending on the pressure of a first connecting pipe (41, 32, 21) existing between the hydropump (4) and the hydromotor (1), partially or entirely closes a second connecting pipe (11, 21', 311) arranged between the hydromotor (1) and the pressurized liquid collector tank (5) and feeds the compressed liquid from said second connecting pipe proportionally or completely into the first connecting pipe. 4.) Hydrostatic propulsion system, according to claim 3,

characterized in that the regulating valve (30) has a first connection (301) from the hydropump (4) and a second connection (302) to the hydromotor (0), which are always connected to each other, and has a regulating piston (310), which is tapered (311) in the center and connects with two control edges (312,313) in a first terminal position the first and the second connection with a third connection (303) coming from the hydromotor (1) and connects in the second terminal position said third connection (303) with a fourth connection (304) to the pressurized liquid collector tank (5) and closes the first connection (301), and that a compression spring (320) holds the regulating piston (310) in the first terminal position, while the pressure between the hydropump (4) and the hydromotor (1) acts as an antagonist to said spring force, so that depending on the pressure of the compressed liquid and the compression spring (320) all intermediate positions of the regulating piston (310) and the continuous adjustment of the start of regulation are also possible?

5.)Hydrostatic propulsion system, according to claim 4,

characterized in that the regulating piston (310) has as a boundary of the taper (311) lying in the center two internally lying control edges (312,313), wherein the first control edge (312) acts in conjunction with the internal boundary (305') of the first annular space (305), which causes the connection of the piston space (308) with the pump connection (301) to the hydraulic motor (302), and the second control edge (313) acts in conjunction with the internal boundary (307') of the second annular space (307), which makes the connection (304) to the pressurized liquid tank (5) possible and which is there? a connecting channel (316) in the regulator piston (310) or in the housing (300) between the first annular space (305) and a pressure space on the front side (309), which connects to the second front side (315).

6.)Hydrostatic propulsion system, according to claim 4,

characterized in that the regulating piston (610) has two diameters (617,618), is tapered (611) in the center, and that the connecting line (61) leads from the hydropump (4) to the hydromotor (1) through the piston space (608), which results as a consequence of the tapering (611) of the regulating piston (610), that on the first larger front side in diameter (614) there is arranged a compression spring (620), the preload of which can be varied, that the half of a smaller diameter regulating piston (617) has externally lying control edges (612,613), which interact with control edges (605',606*) on annular spaces (605,606), wherein the first annular space (605) lying externally to the regulating piston (610) is connected to a fitting (603), which comes from the hydromotor (1), while said fitting (603) can be connected via a connecting channel (616) provided with a rebound valve (609) also to a second internally lying annular space (606), and that a second smaller front side of the regulating piston (610), which is designed simultaneously with this control edge (612), makes a connection from the hydromotor (1) to the pressurized liquid tank (5) possible.

7.)Hydrostatic propulsion system, according to claim 6,

characterized in that the second externally lying control edge (812) is formed as a boundary of a further taper to the control piston (810) and the second piston space (809) formed thereby has a connection (804) to the pressurized liquid collector tank (5) ? 8.) Hydrostatic propulsion system, according to one of the preceding claims,

characterized by the fact that in the inflow (31,21) for the hydromotor (1) there is also a connection (9) for the safety brake (6) arranged between the regulating valve (3) and said hydromotor.

9.) Hydrostatic propulsion system, according to claim 6,

characterised by the fact that in the connecting channel (816) between the inflow pipe (81) to the hydraulic motor (1) and the return pipe (803) from the latter there is also a throttling element (82).

10.)Hydrostatic propulsion system, according to claim 8,

characterised by the fact that the throttle organ (82) is movable.

11.)Hydrostatic propulsion system, according to claim 9,

characterized in that the adjustable throttle member (82) is designed as a rotating cassette.

12.) Hydrostatic propulsion system, according to claim 8,9 or 10,

characterized by the fact that the throttling organ has a minimum passage (821).

The invention concerns a hydrostatic propulsion system with an open circuit according to the superior concept of claim 1.

Drive systems of this type have proven themselves in normal traction operation due to the continuous, uninterrupted regulation of tractive force, easy reversibility, and generally easy operation, as well as the relatively simple design with spatial separation between the propulsion machine as the energy source and the terminal propulsion locations - hydromotors. This system can also be easily protected against overload by installing pressure relief valves.

However, special difficulties arise in such a system if the vehicle is operated in push mode and the hydromotor acts as a pump. Braking of this hydromotor is not possible due to the open circuit - the compressed liquid flows from the hydromotor into the open compressed liquid tank. Installing a re-suction valve in the inlet line, which is emptied by suction in push mode due to the pumping effect of the hydromotor, also did not bring any success. By installing an additional brake on the hydromotor, which, in addition to other functions, such as a safety brake, also becomes effective in push mode, there was, indeed, a possibility of reducing the susceptibility to failures. However, due to the current change between braking and normal operation, there was a possibility of reducing the susceptibility to failures. , a completely uneasy propulsion behavior - blow/blow - , which was equally completely unsatisfactory .

The object of the present invention is therefore to create a hydrostatic propulsion system with an open circuit according to the superior concept of claim 1, in which in push operation the hydraulic motor is braked in a simple manner in order to prevent overloading in the first place, the transition from normal operation to push operation and vice versa occurs smoothly and the advantages of the open system are optimally exploited in normal operation.

Is this purpose achieved by means of the features indicated in the characterizing part of claim 1?

As a result of the direct supply of the proportional or total reflux liquid into the inflow to the hydraulic motor, depending on the pressure in this inflow line, in thrust operation, in which the hydraulic motor functions as a pump, the open circuit becomes partially or completely a closed circuit with a pressure that depends on the level of the thrust effect in the hydraulic motor and the level of the spring preload, for example in the control valve. Any leakage losses that may occur are compensated for in this respect by the hydraulic pump, which is normally loaded in thrust operation at least by the idle power. An interruption of the liquid flow between the hydraulic pump and the hydraulic motor is prevented, and the sliding blocks on the hydraulic motor can no longer be raised, so that any overload in thrust operation is excluded. The liquid flow in the closed circuit can be reduced during thrust operation. be used by the pumping effect of the hydromotor also for general braking.

Advantageous designs of the invention are set forth in claims 2 to 12.

The arrangement of the control device between the hydraulic pump and the pressurized liquid collecting tank on one side and the 4/3-way valve on the other side according to claim 2 is particularly favorable, because the change in direction of the supply flow to the 4/3-way valve does not have to be taken into account.

The design of the invention according to claim 3 and more specifically according to claims 4, 5, 6 and 7 allows for optimal adaptation to all operating conditions of hydrostatic propulsion systems. The control valve is particularly sensitive and easily adjustable and supplies the inflow with precisely as much compressed fluid from the return flow as is required according to the operating conditions. In normal operation, no loss of power occurs as a result of the completely open circuit despite said adjustment in thrust operation.

As a result of the extremely fine adjustment of the inflow pressure for the hydromotor by means of the regulating valve, it is possible, according to claim 8, to use said inflow pressure also for charging the safety brake without further regulating or control devices. This makes it possible to use said safety brake in push operation, if nevertheless a small pressure drop occurs.

Advantageously, according to claim 9, said hydraulic drive system can also be used as a wear-free hydrostatic continuous brake during thrust operation by providing a throttle element in the control valve. The damping and braking effect, which by creating a completely or totally closed circuit has an influence on the hydromotor and prevents over-revving and thus damage, can be significantly increased under the influence of this throttle element.

If the design is carried out with a movable throttle element, then the differential pressure between inflow and outflow can be varied. Due to the dependence of the braking action on this pressure difference, a sensitive braking effect as desired is possible. This arrangement, therefore, leads to a fully functional and even wear-free brake, in which, nevertheless, protection of the hydraulic motor against damage as a result of over-revving is guaranteed in every throttle position.

By defining a minimum cross-section, which can be achieved with either a fixed or a movable throttle, it is possible, for example, to drive downhill as a result of the constantly effective throttle even with constant braking.

Further details of the object of the invention are illustrated in detail below with examples of embodiments and on the basis of the attached drawings. The drawings themselves show:

Figure 1 is a schematic representation of a hydrostatic propulsion system;

Figure 2 is a control valve according to 1? section II-II;

Figure 3 is a section III-III through the regulating valve according to Figure 2;

Figure 4 shows a control valve in cross-section in another embodiment;

Figure 5 The control valve according to Figure 4 with a throttling element.

Figure 1 shows a hydraulic motor 1 which can be operated by a hydraulic pump 4 via a 4/3-way valve 2 and a control valve 3. The compressed medium is drawn in from a pressurized medium collector tank 5. A safety brake 6 is also located on the hydraulic motor 1. In this example, the hydraulic motor 1 is protected against overload by a pressure limiting valve 7 for the inflow and the return flow. In this example, the supply to the safety brake occurs after the 4/3-way valve via two ball valves, so that the pressure in the respective inflow also releases the brake and the brake line is closed against the pressure-free return flow. If you are working with different inflow pressures for opening the control valve to the tank and for the operating pressure for the hydraulic motor and the safety brake, then it is also possible to arrange the safety brake between the control valve and the 4/3-way valve without ball valves?

The control valve 30 shown in figures 2 and 3 has in the casing, or body, 300 connections 301, 302, 303, 304 from the pump 4 to the hydraulic motor 1 and from the hydraulic motor 1 to the pressurized medium collector tank 5. A control piston 310 has a taper 311, resulting in two internally lying control edges 312 and 313. On one front side 314 the control piston 310 is loaded by the pressure of a spring 320. The second front side 315 can be loaded via the channel 316 with the inflow pressure to the hydraulic motor 1. The fittings 301,302, 303 and 304 are connected through annular spaces 305,306,307 with the space 308, which results from the tapering 311 of the piston 300.

In the idle stroke, the compressed liquid is fed by the hydraulic pump 4 through the 4/3-way valve 2 to the pressure medium collector tank 5. In this connection, the piston 310 temporarily closes the connection 304 to the pressure medium collector tank 5 under the action of the compression spring 320. The pressure rapidly building up as a result of the pumping effect in the pressure space 309 against the front surface 315 opposite to the spring causes the piston to move to the right, so that the connection to the pressure medium collector tank 5 is created through the annular space 306 and 307 by means of the opening at the corner of the piston 313.

After switching the 4/3-way valve to the shown position, the hydraulic motor 1 is charged with pressure and is driven by this means. The return flow of the compressed liquid into the pressurized liquid collector 5 takes place simply because, as a result of the inflow pressure between the hydraulic pump 4 and the hydraulic motor 1, the control valve 3 ensures the transition to the control edge 313, similar to the idle stroke. If the 4/3-way valve is operated in the other direction of action, then nothing changes in the control valve 3, only the hydraulic motor 1 is driven from the other side and the return flow takes place in the previous inflow line. In both switching positions of the 4/3-way valve 2, in which the hydraulic motor 1 is driven forwards and backwards, the safety brake is released as a result of the pressure building up in the respective inflow line. In the respective return line from the hydromotor, f is closed in this respect by a ball valve f? ..

In the push operation, in which the hydraulic motor 1 circulates faster than the hydraulic pump 4 and, therefore, the pressure drops in the inlet line and in the pressure space 309, the spring 320 pressing against the front surface 314 of the pressure piston 310 causes this piston to move to the left, so that the control edge 313 can close the connection of the annular spaces 306 and 307 and the control edge 312 in this respect opens the connection of the annular spaces 306 and 305, so that the pressurized liquid supplied by the hydraulic motor now as a pump is again fed to the inlet for the hydraulic motor and, therefore, no further pressure drop is possible. The control valve 3 therefore regulates the pressure in the inlet line to the hydromotor in a simple manner even in push operation.

and prevents interruption of the flow of pressurized liquid and, thus, damage to this motor. Any leakage losses are compensated by the hydromotor 4, which still operates in parallel to this. The resulting closed circuit between the hydromotor 1 and the control valve 3 in the thrust operation also enables a braking action in the hydraulic motor and

The fine adjustment of the control valve to the respective pumping effect of the hydromotor 1 in push operation ensures, in this respect, a shock-free running even with extremely variable propulsion conditions between normal propulsion and push operation.

.Figure 4 shows a further embodiment. The control valve 60 is made with a stepped control piston 610, which has two different diameters 617, 618, and has a taper 611 between them. The hydraulic motor 1 is connected to the pump 4 via the piston space 608 resulting from said taper and the connecting line 61. The connection 603 comes from the hydraulic motor and leads into a first annular space 605 and, with the ball valve 609 open, also into a second annular space 606. * The control piston still has at its largest diameter two small control edges 612 and 613, which interact with the control edges 6051 and 606*, which in each case delimit the annular spaces 605 and 606 towards the outside. The connection 604 leads to the compressed liquid reservoir 5. On the larger front side in the diameter 614 of the regulating piston 610 there is a compression spring 620, the preload of which is variable.

The operation of said regulating valve 60 is similar to that of the previously described regulating valve 30. During normal operation between the pump and the hydraulic motor in the connecting line 61, a pressure f is also built up in the piston space 608, which moves the regulating piston 610 against the pressure of the spring 620. In the initial phase, said piston space 608 is closed for this purpose by the ball valve 609 towards the connection 603. Within the operating pressure, said connection is separated by the control edge 613, and the control edge 612 enables the connection from the hydraulic motor via the connection 603 to the connection 604 and, therefore, to the compressed liquid tank 5.

In the push operation, in which the hydraulic motor acts as a pump, the pressure in the piston space 600 is reduced and the control piston 610 is pushed back completely by the pressure of the spring 620 or in accordance with the pressure conditions in the connecting line 61 parallel. For this purpose, the control edge 612 regulates the connection 605 from the hydraulic motor to the connection 604 leading to the compressed liquid tank. The pressure building up opens the ball valve and a compressed liquid can flow through the connecting channel 616 and the annular space 606 into the piston space 608, so that an interruption of the liquid flow between the hydraulic pump and the hydraulic motor as a result of the pumping effect of the hydraulic motor is prevented.

In FIG. 5, the control valve 80, which corresponds in principle to the control valve 60 according to FIG. 4, is again formed with a throttle element 82 in the connecting channel 816 between the annular space 806 and the return flow 803 from the hydraulic motor 1, while the entire remaining structure, except for a further design of the control valve, corresponds to that of FIG. 4. The throttle element 82 can, for this purpose, be provided with a variable throttle cross-section, for example in the form of a rotary slide, and said throttle cross-section can also have a downward limitation, i.e. a minimum cross-section. With this design, the hydrostatic drive system can be used in push operation as a wear-free continuous brake. The throttle 82 can be used to influence the differential pressure between the inlet line 81 - which acts as a suction line for the hydromotor 1 in push mode - and the return line 803. If, in other words, the throttle cross-section is reduced, the pressure increases with a corresponding thrust effect in the hydromotor 1 in the return line - connection 803 - compared to the inlet line 81. The achievable pressure difference is, in this context, a quantity for the braking effect which is exerted on the hydromotor 1 and, thereby, on the propulsion, for example a driving propulsion. Any cooling of the pressurized fluid in the closed circuit, whether partially or completely, for push mode, can be achieved in this case by means of a radiator which is usually present in the open circuit, but of course also in the closed circuit.

Fam m i t L/jjciu/e Rogan? 1

?lUUUU Mf w l

ZAHNRADFABRIK FRIEDRICHSHAFEN Aktiengesellschaft, Akte 5673 in Friedrichshafen (Federal Republic of Germany). -

"Hydrostatic propulsion system"

Summary :

The present invention relates to a hydrostatic propulsion system with an open circuit, in which

a valve is placed between the hydropump and the hydromotor

2 O

4/3 ways for optional current control

oo compressed liquid for the inflow and the reflux to the hydromotor and with the stop or the idle running of said motor to the compressed liquid tank, and between the inflow and reflux pipe still a device for optionally connecting or separating this inflow and reflux pipe, the whole being substantially characterised by the fact that said regulating device is a regulating valve (3) with a first regulating device (3') between the inflow pipe (41,31,21)

from the hydropump (4) to the hydromotor (1) and the pipeline

reflux (11,21',31') from the hydromotor (1) to the tank

for compressed liquid (5) and a second regulating device (3") between the first regulating device (3') and the

compressed liquid tank (5) and that the two regulating devices (3?,3") are in active connection,

have a common recording device (3"*) and are

connected to the inflow pipe (41) through

a conduit (41') for spontaneous regulation.

The invention concerns a propulsion system

hydrostatic with an open circuit according to the superior concept of claim 1 ,

Propulsion systems of this kind have

given good results in normal traction operation? as a result of the continuous adjustment without inter-

CD

traction force, easy reversibility and generally easy use as well as a consequence of the relatively simple structure with spatial separation between the propulsion machine as

energy source and terminal propulsion locations - hydromotors -. Against overload this system

It can also be easily protected by fitting pressure relief valves.

Particular difficulties arise, however,

in such a facility, if you travel in the exercise

pushed and the hydromotor acts as a pump. Can't you? have

place a braking of this hydromotor as a consequence

of the open circuit - the compressed liquid passes from the hydromotor into the open compressed liquid tank -. Even the application of a re-intake valve in the line did not bring any success.

of inflow, which in the push exercise is

emptied by suction as a result of the effect

pumping element of the hydromotor. With the application of a

additional brake to the hydromotor, which next to

to other functions, for example as a safety brake, it can also be effective in the operation

push, there was, in fact, a possibility of reducing

the sensitivity to failures, as a consequence of the S-change

current relationship between braking process and normal fc operation and, however, it presented a completely uneasy propulsion behaviour - shock/recoil - which was equally completely unsatisfactory.

the purpose of the present invention is , therefore,

to create a hydrostatic propulsion system with a

open circuit according to the superior concept of claim 1, wherein in the push operation the

hydraulic motor is braked in a simple way for

First of all, prevent overloading, the transition from normal exercise to pushing exercise and vice versa

00187 ROME takes place without shocks and the advantages of the open system

they yield excellent results in normal operation.

This purpose is achieved by means of the features indicated in the characterizing part of claim 1.

As a result of the direct supply of liquid

of proportional or global reflux in the inflow to

the hydromotor, depending on the pressure in this inlet pipe, in the push operation, in the

which the hydromotor works as a pump, becomes partially or entirely from an open circuit a closed circuit with a pressure, which depends on the height of the pushing effect in the hydromotor and

from the height of the spring preload, for example in the-?

< the regulating valve. Leaks due to leaks - 2

O OC

teas that may arise are compensated,

or is it in this respect, from the hydraulic pump, which is normally loaded in the thrust operation at least

from the no-load operating power 0 An interruption of the liquid flow between the hydraulic pump and the hydraulic motor is prevented and the skids on the hydraulic motor can no longer be raised, so that any overload during pushing operation is excluded. The liquid flow in this closed circuit during the pushing operation can also be used for general braking due to the pumping effect of the hydraulic motor.

Of the advantageous designs of the invention

are set out in claims 2 to 12?

The arrangement of the regulating device between the hydraulic pump and the pressurized liquid collector tank

on one side and the 4/3 way valve on the other side if

According to claim 2, this is particularly favorable, because the change in direction of the supply current to the 4/3-way valve does not have to be taken into account.

The design of the invention according to claim 3 and constructively more concrete according to claims 4, 5, 6 and 7 makes adaptation possible?

< optimal for all operating conditions of 2 or O Ic ? d a hydrostatic propulsion systems. The control valve ? 00

O >S o o particularly sensitive and adaptable simply and <\J brings to the inflow precisely as much liquid compressed by the reflux as is necessary according to the condition

in normal operation. In normal operation, no losses are recorded.

a loss of power as a result of the circuit being completely open despite this adjustment in push operation.

As a result of the very fine regulation of the

inflow pressure for the hydromotor by means of the

regulating valve? According to claim 5, it is possible to use said inflow pressure also for charging the safety brake without any further regulating or control devices. This makes it possible to use said safety brake in push operation if there is nevertheless a small pressure drop.

Advantageously, according to claim 9, said hydraulic propulsion system can be

used for the arrangement of a throttling organ in the control valve during operation

thrust also as a continuous hydrostatic brake free from

wear? The attenuation and braking, which for V7 I

by means of creating the closed circuit entirely .. LU or totally has an influence on the hydromotor and avoids a 2<o1c O K

if it is "over-revving" and thus damaged, it can be significantly strengthened under the action of this throttling device.

If the design is with a movable throttle, then the differential pressure between inflow and outflow can be varied, as a result of the dependence of the braking action on this.

pressure difference? A sensitive braking is possible as desired. This arrangement, that is,

leads to a fully functional and even wear-free brake, which is nevertheless guaranteed in

each choke position protects the hydromotor against damage as a result of a

"out of revs" 0

By defining a minimum cross-section, which can occur either with a fixed throttle or with a movable throttle1 t

For example, downhill driving is possible due to the constantly effective throttle.

even with constant braking g

Further details of the object of the invention

are illustrated in detail below, with examples of implementation and on the basis of the attached drawings. The drawings themselves show:

Figure 1 shows a hydrostatic propulsion system in schematic form;

Figure 2 a regulating valve according to section II-II;

Figure 3 is a section III-III through the regulating valve according to Figure 2;

Figure 4 a cross-sectional view of a control valve

another achievement ;

Figure 5 The control valve according to Figure 4 with a throttling element.

In figure 1 a hydromotor 1 is represented,

which can be operated through a valve

4/3 way 2 and a regulating valve 3 from a hydropump

4. The compressed medium is sucked, in this regard, from a pressurized medium collector tank

5. Is there a safety brake 6 on the hydraulic motor 1? In this example, the hydraulic motor 1

it is protected against overload from time to time

by means of a pressure relief valve 7 for the inflow and outflow. In this example, the supply to the safety brake occurs after the relief valve

4/3 way with two ball valves, so that the pressure in the respective inflow also releases the brake and

?*? the brake line is closed with respect to the pressure-free return flow. If working with different pressures in the inflow due to the opening of the regulating valve < ? ? regulating valve to the tank and for the operating pressure

? > for the hydromotor and the safety brake, then it is also possible to arrange the safety brake between the regulator and the 4/3 way valve without valves

sphere,

The regulator valve 30 shown in figures 2 and 3 has in its casing, or body, 300 connections 301,302,303,304 from the pump 4 to the hydromotor 1 and from the hydromotor 1 to the collector tank of the medium in

pressure 5 . A control piston 310 has a taper 311 , resulting in two control edges

lying internally 312 and 313. On one front side

314 the control piston 310 is loaded by the

pressure of a spring 320 . The second front side

315 ? can be loaded through channel 316 with the inflow pressure to the hydromotor 1 . The fittings 301,302,

303 and 304 are connected through annular spaces

305,306,307 with space 308, which results in

work of the taper 311 of the piston 300.

In the idle stroke the compressed liquid is fed from the hydropump 4 from the 4/5 way valve 2 to the

collector tank of the pressurized medium.5. The piston 310 closes, in this respect, for the moment, the

connection 304 to the pressurized medium collector tank 5 under the action of the compression spring 320.

IU

The pressure rapidly building up as a result of the S 1 l I ? 2 O ? the pumping effect in the pressure space 309 with ? X I ti ? o > ? against the front surface 315 opposing the spring o ocw causes the piston to move to the right, so that the connection to the medium collector tank is produced through the annular space 306 and 307.

under pressure 5 by means of the opening at the edge of

command 313 .

After switching the 4/3-way valve in the

position drawn hydromotor 1 is loaded with

pressure and is operated by this means. The reflux of the compressed liquid into the collector tank

for pressurized liquid 5 takes place in a simple way f because? as a consequence of the inflow pressure

between hydropump 4 and hydromotor 1 the regulating valve

3 ensures the passage to the control edge 313,

similar as in the idle stroke. If the 4/3 valve

way is maneuvered in the other direction of action, to

Now nothing changes at the control valve 3, only the hydraulic motor 1 is activated on the other side and the backflow occurs in the inflow pipe that was there until now. In both operating positions of the valve

4/3 way 2 , in which the hydromotor 1 is operated

forwards and backwards, the safety brake is released as a result of the pressure building up in the respective inflow pipe. The respective reflux pipe from the hydromotor is closed at a rate of ?o <>

? *-' regarding them, from a ball shut-off valve 8 . N In the push operation, in which the hydromotor1

circulates faster than the hydropump 4 and, therefore, the

pressure drops in the inflow pipe and in the

pressure space 309, spring 320 pressing against

the front surface 314 of the piston 310 causes this piston to move to the left, so that

the control edge 313 can close the connection

of the annular spaces 306 and 307 and the control edge

312 opens, in this respect, the connection of the annular spaces 306 and 305, so that the pressurized liquid supplied by the hydraulic motor now as a pump is again fed to the inflow for i-1 hydraulic motor

and , therefore t a further fall of is not possible

pressure. The regulating valve 3 therefore regulates

even in the push exercise in a simple way the

pressure in the inflow pipe to the hydromotor

and prevents the interruption of the liquid flow

under pressure and, with that, damage to this

engine. Any leaks due to leaks are

compensated by the hydropump 4 still operating in parallel to this. The resulting closed circuit

between hydromotor 1 and control valve 3 in operation

< a push also makes possible a braking action in the 2nd oc UJ O

hydraulic motor . CO o > ? or the fine adjustment of the control valve to the respective pumping effect of the hydraulic motor 1 in the push operation ensures, in this respect, a stroke

shock-free even with propulsion conditions that vary greatly between normal propulsion and push-pull operation.

Figure 4 shows a further example of implementation. The regulating valve 60 is made

to this?, with a stepped regulator piston 610, having two different diameters 617,618, and has between these

a taper 611? Through the piston space 608 resulting on said taper and the connecting pipe 61 the hydromotor 1 is connected to the

pump 4 . The fitting 603 comes from the hydromotor and leads into a first annular space 605 and with the valve

open sphere 609 also in a second annular space 606.

The regulator piston still has its diameter at its lowest point.

small two control edges 612 and 613, which interact with the control edges 605? and 606', which delimit the annular spaces 605 in each case

and 606 towards the outside. The connection 604 leads to the compressed liquid tank 5 - On the larger front side

in the diameter 614 of the regulator piston 610 ? a compression spring 620 is arranged, the preload of which is 2 O at variable uQf ?

The operation of the said regulating valve 60 ? OCU is similar to that of the regulating valve already described.

30 . In normal operation between pump and hydraulic motor in the connecting pipe 61 and, therefore, also in the

pressure is built up in the piston space 608, which moves the regulating piston 610 against the pressure.

of the spring 620. In the initial phase said piston space 608 is closed in this respect by the

ball valve 609 towards fitting 603. In the scope

of the operating pressure said connection is separated by the control edge 613 and the control edge 612 makes it possible to connect from the hydromotor via the fitting 603 to the fitting 604 and, therefore, to the compressed liquid tank 5.

In the sp?nta exercise, in which the hydromotor

it acts as a pump, lowering the pressure in the space

of piston 608 and the regulator piston 610 is

pushed back by the pressure of the spring 620 entirely or correspondingly to the pressure ratios

in the connecting pipe 61 partially. The

control edge 612 regulates, in this regard, the connection 605 coming from the hydromotor to the connection t;-?'-604 leading to the compressed liquid tank.

< The pressure that builds up opens the ball valve and at 2

O

? through the connecting channel 616 and the annular space 606 a compressed liquid can pass into the space

of piston 608, so that an interruption of the liquid flow between the hydropump and the hydromotor as a result of the pumping effect of the hydromotor is prevented.

Leila figure 5 the regulating valve 80 corresponding in principle to the regulating valve 60

according to figure 4 ? still formed with a restriction member 82 in the connecting channel 816 between the

annular space 806 and the reflux 803 coming from the

hydraulic motor 1, while the entire remaining structure

except for a further design of the regulator valve corresponds to that of figure 4. The throttle member 82 can be provided, for this, with a

variable constriction cross-section, for example in the shape of a rotating drawer, and said cross-section between

The choke can also have a downward limitation, i.e. a minimum cross-section. With this structure the propulsion system

Hydrostatic? Can it also be used as a wear-free, continuous brake in push mode? Is it possible?

to exert an influence with the throttling organ 82

on the differential pressure between the inflow pipe 81 - which acts as a suction pipe in the 2nd or cc thrust operation for the hydromotor 1 - and the reflux pipe h?

CO

o o so 803 . If the cross-section of the constriction is reduced, then the pressure increases with a corresponding pushing action in the hydromotor 1 in the

backflow pipe - connection 803 - compared to the

inflow pipe 81. The achievable pressure difference? , in this regard, a quantity for

the braking action, which is exerted on the hydromotor

1 and, thus, to propulsion, for example a driving propulsion. Any cooling of the pressurized liquid in the partially or completely closed circuit necessary for pushing operation can

occur, in this regard, through the action of a radiator

existing mostly in the open circuit, but also of course by a separate radiator.

Claims

1./Hydrostatic propulsion system with an open circuit, in which the hydropump and

hydromotor a 4/3-way valve for optional control of the compressed liquid flow for inflow

and the reflux to the hydromotor and with the stop or the run

when the said engine is empty, to the compressed liquid tank, and between the inflow and reflux lines again

S

a device for optionally connecting or separating

this inflow and outflow conduit, *

> ? characterized in that said regulating device is a regulating valve (3) with a first device?

regulator (31) between the inflow pipe (41,31,21)

from the hydropump (4) to the hydromotor (1) and the pipeline

reflux (11,21?,31') from the hydromotor (1) to the tank

for compressed liquid (5) and a second regulating device (3") between the first regulating device (3') and the

compressed liquid tank (5) and that the two regulating devices (3'3") are in active connection,

oo8i7ROMA have a common recording device (3,f') and are

connected to the inflow pipe (41) through

a conduit (41') for spontaneous regulation.

2.) Hydrostatic propulsion system, according to claim 1,

characterized by the fact that the regulating valve (3)

? placed between the hydropump (4) and the liquid tank in

pressure (5) , on one side , and 4/3 way valve (2) ,

on the other side.

3.)Hydrostatic propulsion system, according to

one of the previous claims,

characterized by the fact that the regulating valve (30)

has a first connection (301) coming from the hydropump

(4) and a second fitting (302) leading to the hydromotor (1), in which the two fittings are connected to each other at 20°, and has a regulating piston (310), which is tapered (311) in the centre and connects with two

control edges (312,313) in a first terminal position the first and second connection with a third connection (303) coming from the hydromotor (1) and connects

in the second terminal position called third connection

(303) with a fourth connection (304) to the collector tank for compressed liquid (5) and closes the first connection (301), and that a compression spring (320) holds

the regulator piston (310) in the first position

1 VIA DEL TRITONE, terminal, while the pressure between the hydropump (4) and

hydromotor (1) acts as an antagonist to the said elastic force,

so that depending on the pressure of the liquid

compressed and the compression spring (320) also make all intermediate positions of the regulator plunger (310) and the continuous adjustment of the start of regulation possible.

4.) Hydrostatic propulsion system, according to

claim 3,

characterized by the fact that the regulator piston

(310) has as its limit the tapering (311)

lying in the center two internally lying control edges (312,313), in which the first control edge (312) co-acts in union with the internal delimitation

(305') of the first annular space (305), which causes the S<| s connection of the piston space (308) with the rac ~ ?

!O s> connection from the hydraulic pump (301) to the hydraulic motor

(302) , and the second control edge (313) co-acts

in conjunction with the internal deliciation (307') of the second

annular space (307), which makes the connection possible

(304) to the pressurized liquid tank (5), and that

there is a connecting channel (316) in the regulator piston (310) or in the housing (300) between the first annular space (305) and a pressure space on the side

front (309), which joins the second front side (315).

5.)Hydrostatic propulsion system, according to

claim 3,

characterized by the fact that the regulator piston

(610) has two diameters (617,618), ? tapered

(611) in the center, and that the connecting pipe

(61) leads from the hydropump (4) to the hydromotor (1) at

through the piston space (608), which results

as a consequence of the tapering (611) of the regulating piston (610), which on the first larger front side

a compression spring is located in the diameter (614)

(620) , whose preload can be varied, that the

half of the smaller regulator piston in diameter (617)

has externally lying control edges (612,613),

< St that coact with command edges (605',606') on z or CE

!*? to annular spaces (605,606), where the first space rings CO O or O

re (605) lying externally to the regulated piston ?M re (610) ? is connected with a fitting (603), which comes from the hydromotor (1), while said fitting (603) is connectable through a connecting channel (616)

equipped with a rebound valve (609) also with a

second annular space lying internally (606), and

that a second, smaller front side of the regulator piston (610), which is simultaneously designed as a control edge (612), enables a connection from the hydromotor (1) to the liquid reservoir in

pressure (5) .

6.)Hydrostatic propulsion system, according to

claim 5,

characterized by the fact that the second externally lying control edge (812) is formed as a delimitation of a further taper at the stan

Claims (1)

regulator plunger (810) and the second piston space (809) formed thereby has a connection (8?4) to the pressurized liquid collector tank (5) ? 7.)Hydrostatic propulsion system, according to one of the previous claims, characterized by the fact that in the inflow (31,21) for the hydromotor (1) is arranged between the regulating valve Z (3) and said hydromotor still a connection (9) for the < 5 g X xO safety brake (6). CO or ? > 8.)Hydrostatic propulsion system, according to claim 5 or 6, characterized by the fact that in the connecting channel (816) between the inflow line (81) to the hydraulic motor (1) and the return line (803) from this there is also a fixed or movable throttle member (82). 9.)Hydrostatic propulsion system, according to claim 8, characterized by the fact that the choke organ movable (82) ? a rotating drawer (82') with 0 without minimum passage (821). -# ZA IINRA DEA BR I K PRIE DUI 0 HSHA FEN Akt^ehgesellschaft p.i. : Lenzi ??? 'v Ufficiai Ro98nr? ?? : 0