DE2352170A1 - DEVICE FOR PRESSURE MEDIUM SUPPLY - Google Patents

Description

A 33 843

SOCIETE AIOIYMErPOCLAIN

60330 IE EGESSIS BELLEVILLE
FRAiJKHEICH

Device for pressure medium supply

The invention relates to a device for supplying pressure medium by at least one pump with constant pumping power and one pump with variable pumping power, these pimping through a single motor shaft can be driven.

If a hydraulic circuit is fed by several pumps, then the power of the drive motor for these pumps must at least equal to the sum of the input powers of the pumps, if the pumps are simultaneously at their maximum power consumption can work.

.This leads to the drive motor being oversized if one of the pumps has a low degree of utilization.

This is particularly the case with certain construction machines where the functions, namely locomotion of the machine and actuation

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their work equipment, carried out by means of various pumps will.

The machine is required to be extremely manoeuvrable and still have a maximum speed of movement. The for Pumps used for locomotion (e.g. double-body pumps with variable displacement and with power control by adding up the Pressures) therefore have such characteristics that they consumed the maximum power of the drive motor (e.g. 100 hp).

If the work equipment ^ are not operated, then the machine move at maximum speed, the pressure medium being variable through the double-body pump Stroke volume is delivered.

If, on the other hand, the machine that has stopped moving from the point of loading to the point of unloading or vice versa, If you have to exert maximum force with your work equipment at low speed, even at a standstill, then it would be It is important that the constant displacement pump, which supplies the working equipment circuit, has a significant priority Can have power that is equal to the power of the drive motor for the pumps, but reduced by the power required to drive the double-body pump with variable displacement, which is automatically reduced according to a curve up to a constant output, e.g. from 100 HP to 40 HP.

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In this way, one could have 100 HP to move and 60 HP to operate the work equipment by a drive motor is used for the pumps, which delivers an output power of only 100 hp, instead of 160 hp required with a conventional setup and under the same operating conditions. It is the goal according to the present invention to propose a new device which allows the same with regard to the machine construction how to ensure a significant economic efficiency with regard to the operating costs of the machine, with the rest of the operating efficiency is retained. With this new facility, the power will be transferred from the circle for locomotion to the work equipment circuit or vice versa is realized automatically thanks to a control system that controls the operating conditions of the pump or pumps with variable displacement and with control of the constant power (in the case of several pumps this is a regulation with keeping the power constant by adding up the operating pressures) and the operating conditions of the pump with constant displacement are taken into account.

The invention thus has a device for supplying pressure medium at least two consumer groups on the subject, of which each is supplied by a group of pumps with at least one pump and a pressure medium delivery line, one of the Groups of pumps with constant pump output and at least one other (second) group of pumps with variable pump output ' have, while the input drive shafts of the various

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Briipengruppen are coupled with a single Hotorwelle and the supply device has at least one power regulator, which is formed by a first hydraulic cylinder, the cylinder of which is fixed to the body of the Punroen of the second Gnroe is connected and its piston coupled to one another with a control element for controlling the pump output of the second pump group is subject to opposite effects on the one hand Effect of an elastic organ and, on the other hand, the effect of the pressure in the pressure delivery line of the second group of pumps contained pressure medium.

According to the invention, the device has in a manner known per se a second hydraulic cylinder, the cylinder of which is fixedly connected to the body of the pumps of the second pump group and whose Pistons coupled to the cylinder of the second hydraulic cylinder with the control element for controlling the pump output of the second pump group a chamber, limited, which is connected to the pressure delivery line of the pump group with constant pumping power through a connecting line is connected, furthermore a laminar hydraulic constriction (restriction) is provided in this connection line, and it is the effect of the pressure prevailing in the chamber on the piston of the second hydraulic cylinder opposite to the effect of the elastic organ and finally a second constriction is provided, the hydraulic resistance of which depends on the The position of the piston of the second hydraulic cylinder in the associated cylinder body is variable and the connection between the Chamber and tree with substantially zero pressure.

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According to another important aspect, "the invention relates on a supply device for the pressure medium supply of at least three consumer circuits, each of which through a pump group is supplied with at least one pump and a pressure delivery line, one of the pump groups pumps with constant pump power and each of the two other pump groups has pumps with variable pump power, while The input drive shafts of the various pump groups are coupled with a single motor shaft and two power regulators are provided, of which a first regulator with a control element for controlling the pump output of a first group of the two Pump groups with variable pump output and a second desire with a control element for controlling the pump output of the second Group of the two pump groups is coupled with variable pump power. This device is characterized according to the invention that each desire is formed by three hydraulic cylinders, the pistons of which with the control element for controlling the Pump power of the corresponding group of pumps are coupled and limit the three chambers, namely each hydraulic cylinder each e. one chamber, these chambers being suitable for containing pressure medium, the effects of which are opposite to the effect of an elastic organ are that one of the two first chambers of each sailor with the pressure delivery line of a pump group with variable pump capacity and the other of the first two chambers of each regulator with the pressure delivery line of the Another pump group with variable pump capacity is associated that each the third of the three chambers of each Regulator through a connection line with the pressure delivery line

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the pumping group is connected to constant pumping power, and on the one hand there is a laminar hydraulic constriction is arranged in this connecting line and on the other hand two Second constrictions are provided, their respective hydraulic Resistance as a function of the position of the piston of each of the second, each having the third chambers Hydraulic cylinder is variable and each of the corresponding third chambers in connection with a tree with a pressure of bring essentially full.

According to a development of the invention, this device can also have a fourth consumer circuit, which selectively supplies constant pump power by a second pump group can be, which comprises at least one pump and a pressure delivery line, in which a manifold with at least two Positions is arranged, this distributor in the pressure delivery line of the second pump group with constant pump power his one position with the fourth consumer circuit via a secondary pressure delivery line in connection and in his other position connects to the pressure medium reservoir, and also connects a secondary connecting line to the secondary Pressure delivery line with the third chamber of one of the two desire, while also in the one connected to the third chamber Connection line between this third chamber and the laminar constriction contained in this connection line a check valve is arranged such that only the pressure medium passage from the laminar constriction sur third Chamber is enabled.

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For each of the versions described in the above goal, kmn it can often be advantageous, moreover, separate in each Muzzle line between the connection of the latter to the pressure delivery line the pump group with constant pumping power and the 'laminar constriction a tared valve is arranged and by the pressure of the in the "aforementioned pressure delivery line contained "pressure medium is controlled or actuated.

According to a further embodiment of the invention, the laminar constriction is preferably τ on a controllable type and is formed by a spiral external thread which is connected to a rod and can be arranged opposite a cylindrical bore, the length of the external thread arranged in this bore can be regulated using means known per se.

Furthermore, it can be part of the goal that the one or the two second constrictions each through one in the cylindrical Surface of the piston of the second hydraulic cylinder corresponding to this second constriction are formed, one variable depending on the position of this piston Length of the lut is effectively arranged opposite the cylinder in which said piston is slidably installed.

The aforementioned lut preferably has a spiral shape.

For a better understanding of the invention, its developments and its advantages, the following description of the leadership examples. Of course, the invention is not restricted to these exemplary embodiments.

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JCs reference is now made to the accompanying drawings, in FIG. show them:

. Figure 1 is a representation of a scheraatische supply device according to the invention, with partial sectional view;

FIG. 2 shows a completely schematic view of the supply device according to FIG. 1;

FIGS. 3 and 4 are graphic representations for explaining the

Functioning of the supply facility according to Figs. 1 and. 2;

FIG. 5 shows a schematic view corresponding to FIG. 2, which is now supplemented by the representation of an advantageous further development; FIG.

6 shows a schematic view of a further embodiment of a supply device according to the invention;

7 shows the mode of operation of the supply device

according to FIG. 6 explanatory graph and.

8 shows a schematic view of a further embodiment of a supply device according to the invention.

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A first embodiment of the invention is shown in FIGS emerged. An output shaft 2 of an engine 1, which in the exemplary embodiment shown is formed by a diesel engine, is coupled to a drive shaft 3 by means of a coupling 4. The shaft 3 forms the drive shaft of a pump 5 with variable Pump power, the organ for power control of which is denoted by 6 and connected by a movable or articulated at the point 7 Lever is formed. A connected to the shaft 5 gear 8 cooperates with a gear 9, which with a Drive shaft 10 of a pump 11 with constant pumping power is connected. The pump 5 with variable pumping capacity is through a Suction line 12 is connected to a pressure medium storage container 13 and through a pressure delivery line 14 to a consumer circuit 15. In a corresponding manner, the pump 11 is with constant pumping power through a suction line 16 with the reservoir 13 and through a Pressure delivery line 17 is connected to a consumer circuit 18.

It should "be pointed out that it would also be possible for each the pumps 5 and 11 to be replaced by a group of pumps with variable or constant pumping power. Finally, it is complementary It should also be noted that the consumer circuits in the exemplary embodiment shown, μηά as far as the circuit 15 acts, through a supply circuit for hydraulic motors for the motion drive of a construction machine for public buildings, and as far as the circuit 18 is concerned, by a supply circuit for actuating hydraulic cylinders for working devices of a Construction machine are formed. What the pump 5 with variable pump

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As far as performance is concerned, this can be done by all known pump types be formed, but in particular by a so-called axial piston pump, the Eoluene cylinder in a Eolben or. Pump boots (barillet) and both to each other and to Axis of rotation of the pump handle are directed parallel while the pistons on one that can be tilted with respect to this axis of rotation Come to support the ground. This is the soil that des Organ 6 for controlling the power of the pump forms. Such a pump is already known.

There is a power regulator 19 is provided, which is used to Adjust the position of the control element ^ 6 and consequently ensure the power control or control of the pump 5. This Desire is formed by a body 20, which with .den housing the pump 5 is positively connected and in which three cylindrical bores 21, 22 and 23 are recessed. In the Bore 21, a piston 24 is slidably arranged and 'is located is supported on a further piston 25 which is arranged displaceably in the bore 22. The piston 25 is with a Spiral groove 26 recessed in its cylindrical surface is provided. The control member 6 is at one end of the piston 25 by one Axis 2? pivotally mounted. In addition, this end of the piston 25 strikes a plunger 28, with three springs 29, 30 and 31, the initial lengths of which are unequal and decreasing, are inserted between the joints 28 and the body 20 of the sailor, like this otherwise in the field of manufacturing sailors is known per se. ·

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ΛΑ

In the body 20 two ICnern 32 and 35 are recessed, the the ends of the pistons 24 and 25 contain, once that End of the piston 24, which is the one on the piston 25 Sum stop coming end of the piston 24 is opposite, and on the other hand that end of the piston 25 that is is opposite to the end of the piston reaching the stop at the plunger 28. The spiral groove 26 is only above a length Io of the piston 25 opposed to the cylindrical bore 22; on this Ivei se is between the bridle 33 and the storage container 15, a constrained, constrained tree 34 is arranged.

It is also noted that a rod 35 by means of a fastening thread 36 is screwed into the body 20 and held in position by a nut 37. The end of this screw is provided with a spiral thread 38, the outer diameter of which is below of the diameter of the bore 23, and "is located over a length la within this bore. Two chambers 39 and 40 are separated from one another by this end having the thread 38. That existing between the thread 38 and the bore 23 Play forms a laminar constriction or limitation 41.

A line 42 connects the chamber 32 to the pressure delivery line 14 of the pump 5 with variable pump power. In a corresponding manner, a line 43 connects the chamber 39 to the pressure delivery line 17 of the pump 11 with constant pumping power, while a Line 44 connects the chambers 33 and 40 with one another. The lines 43 and 44 together thus form a single one, the pressure

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Conveying line 17 with the chamber 55 connecting line, in which a laminar constriction 41 is arranged. In the end a line 45 connects the outlet of the constricted, limited germ 54 with the storage container 13.

More precisely, it is that of the piston 24, the bore 21 and the assembly 32 consisting of a first hydraulic cylinder Equivalent to and in a corresponding manner is the arrangement consisting of the piston 25, the bore 22 and the chamber 53 to equate to a second hydraulic cylinder.

FIG. 2 does not contain a supplementary definition in relation to the representation according to FIG. 1, but serves solely for the purpose of 'specifying the chosen symbolic representation, in particular the representation with regard to the restrictions or constrictions 54 and 41.

3 shows a curve 46 which is approximately a straight line and which shows a possible change in the pumping capacity Qc of the pump with per se constant pumping capacity as a function of the pressure Pc of the pressure medium flowing in the pressure delivery line 17. Here, three function points FI ₉ F2 and F3 are given by

the point F1 corresponds to the case in which the drive power of the pump 11 is zero ₉

the point F5 corresponds to the case in which the drive power of the pump 11 is at its maximum and in the selected exemplary embodiment is equal to 60 hp, 409816/0980

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the point F2 corresponds to a case in the middle lies between the points F1 and F3 and in which the drive power of the pump 11 is equal to half of the maximum power, that is 30 hp.

4 shows the change in the pump power Qv of the pump 5 with variable pump capacity depending on the pressure Pv.des represents pressure medium flowing in the pressure delivery line 14. Three curve pieces C1, C2, 03 represent the three modes of operation which correspond to the aforementioned points F1, F2 and F3, respectively. These curve pieces are hyperbolas and on each one of them, the product Pv χ Qv is constant and equal to the drive power of the pump 5 with variable pump power. In the chosen embodiment are. in the operating modes that correspond to curves C1, C2 and C3, the drive powers are the same 100 hp, 70 hp and 40 hp. It should also be noted that the diesel engine 1 develops a maximum output of 100 hp and that it does so Reasons of a simplified representation the power losses, be it mechanical or hydraulic, should be neglected, in particular the power losses in the transmission of the gears 8 and and in the pump drives.

FIG. 5 shows schematically the embodiment according to FIG. 2, which, however, is now provided with a supplementary organ, which results in further training. In the line 43 is between the connection of the line 43 to the pressure delivery line 17 and the controllable laminar constriction 41, a tared valve 47 is arranged. This valve 47 is, by means of a line 48 through the

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lit

Pressure of the pressure medium contained in the pressure delivery line 17 ■ controlled.

Fig. 6 illustrates an important further embodiment that has two pumps 5a and 5b with variable pump capacities. the "Organs already described can largely be found in FIG. 6 with the same reference numerals as in the preceding ones.

It should be noted that the shaft 3 drives the pump 11 directly with a constant pumping power. A gear 8a is with this • Uelle 3 firmly connected and works with another gear 9a together, which is connected to a drive shaft 1Qa of a first pump 5a with variable pumping power, and to another Gear 9b, which is connected to a drive shaft 10b of a second pump 5b is associated with variable pump power, whose characteristics ?, in the present case are identical to those of the pump 5a. The pumps 5a and 5b are each connected by suction lines 12a, 12b the storage container 13 and connected by pressure delivery lines 14a, 14b to two consumer circuits 15a, 15b.

Each pump 5a, 5b is provided with a power regulator 19a, 19b, which is similar to the Eegler 19. The regulator 19a is through a constriction 34a, a chamber 33a and two pistons 24ab and 24aa, the ends of which are contained in the chambers 32ab, 32aa for the regulator 19a, while the regulator 19b is constricted 34b, a chamber 33b and pistons 24ba and 24bb are formed, the ends of which are in the chambers 32ba, 32bb for the regulator 19b.

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hold are "Sine from the pressure delivery line 14a branching off · line 42a is divided into two lines 49a '50a, which are respectively connected to the chambers 32aa or _o 32ba, while in the same Heise one of the pressure-delivery line branches off line 14b 42b is divided into two conduits 49b and 50b which are respectively connected to the chambers 32ab or 32bb _o. The "movable member of each glider is coupled with a control member 6a, 6b for power control of each of the pumps 5ε, 5b with variable pump power. In addition, the chambers 33a, 35b are connected to the laminar output by lines 44a, 44b adjustable constriction 41 connected »

The graphic representation according to FIG. 7 shows a curve C with respect to a predetermined operating state and shows the change in the pump output Qv of any of the two pumps 5a ₉ 5b with variable pump outputc, which in the present case are identical, as a function of the sum of the pressures Pva and Pvb des pressure medium contained in the two pressure delivery lines 14a and 14b. On the other hand, it goes without saying that in the selected embodiment the constrictions 34a and 34b are identical, in the same way the pistons 24aa _{9 24ab, 24ba and 24bb s} and that therefore the two pumps 5a, 5b have the same value of the pumping power Qv "

The Figo8 finally shows a further embodiment, in which For the most part, the design of the device shown in Fig. 6 is retained, but still has the following additions: On the one hand, the individual laminar constrictions 41 and

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the individual tared valve 47 is divided and by two identical laminar constrictions 41a, 41b "or by two identical tared valves 47a and 47b have been replaced. On the other hand, there is now the pressure medium supply to a fourth Consumer price 53a and a fifth consumer circuit 53b provided by means of a further pump 51 with constant pumping power.

An additional gear 54 is connected to the shaft 2 and meshes with a gear 55, which itself is connected to a drive shaft 56 of the pump 51 is connected to a constant pump power. These Pump 51 is connected to storage container 13 by a suction line 57 and pumps the pressure medium into a line 58. Two lines 62a, 62b each extend the line 58, wherein they in In parallel, branch off from the line 58 and each switch on a manifold 63a or 63b with two positions are connected which can be actuated by a pedal, preferably by a stepless pedal. On the other hand, two lines 64a, 64b connect the distributors 63a, 63b each with a fourth consumer circuit 53a or with a fifth consumer circuit 53b. A line 65 connects the line 62b to a tared valve 59, the is controlled by means of a line 60 by the pressure of the pressure medium contained in the line 62b. This tared valve is also connected to the storage container 15 via a line 61. In their first position, the distributors 63a and 63b bring the lines 62a and 64a and the lines 62b and 64b, respectively in communication with one another and in their second position, the lines 62a, 64a or 62b and 64b are at the level of the said manifolds locked. It will also be noted that a line 66a is the

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Line 64a connects to chamber 33a, while line 66b the line 64b connects to the chamber 33b,

In addition, there are two lines 43a ₉ 43b, which are similar to the line 43 mentioned above and which are connected to the pressure-F overhead line 17 of the pump 11 with constant pumping power and are also each connected to a tared valve 47a, 47b _o one Constriction 41a, 41b is each connected to the output of the tared valve 47a ₉ 47b and is similar to the constriction 41 described above, while a check valve 52a ₉ 52b is in turn connected to the output of the corresponding constriction. "Finally, a line 44aa _? 44bb, similar to the above-mentioned line 44a or "44b _9, the output of the check valve 52a, 52b with the chamber 33a ₉ 33b _o In addition, it can be pointed out that the consumer _{circuits 53a 9} 53b in the present embodiment through supply lines of a hydraulic direction control for a construction machine can be formed, one circle being assigned to a change in direction of the machine to the right and the other to a change of direction to the left "

The ways in which the utilities described are used will now be discussed explained in more detail, whereby the advantages that can be achieved with them are emphasized.

First of all, the functioning of the device described with reference to FIGS. 1 and 4 is to be examined. The pressure medium (Hydraulic fluid) that is conveyed through line 43,

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passes through the laminar constriction 41 hinduoh »The Buvdk flow rate q of this pressure medium has the value:

In this formula Ii ^ is a constant and ρ ^ the 'BrimtsJj case of the pressure medium between the chambers 39 and 40 · «bite pressure fluid at the flow rate q ₉ ¥ ith by the controlled lisri the constriction 41 ₀ v / ith duroh the line 44 liisinrch conveyed into the Eammer 33 and besitst an effect _r the ά ^ ειι tends to ΕοΓοβη 25 against 'the effect of one or all iredern 29, move zn 31 3O _S "Similarly, Sas has chireh the line 42 to the earner 32 The pressure siitsl promoted to the "Γιγ-bingt tends to the piston 24 and thus also the loltsn 25 against the action of one or all of the aforementioned sr. Fs-isrn to Tersohiebei2", it is noted that this in the Kasner 33 entlial No pressure medium is in the same above-mentioned office fluid risk, this Kasmier escapes through the variable lens ear 34 which is formed by the hat 26 arranged opposite the length Io of the eclectic 25 34 b So is the flow rate q the ¥ srt?

q = ι (pAo) (2)

and approximate-t is

q = K ₂ p / lo C3);

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in the formula (3) is 3C? a constant and ρ is the pressure difference between the hydraulic fluid contained in the chamber 33 and in the line 45 _o The variation of the value of the hydraulic resistance 34 as a function of Io could, on the other hand, be equivalent to a variation as a function of a variable depth of the lut 26 "In addition," a given length Io corresponds to a given position of the control element β for controlling the output of the pump 5 with variable pump output, ZoBo the position of the support base for the pistons of the axial piston pump ₉ if such a pompe has been chosen _o A comparison of the formula Ci) and (2) permit su writing

= g (| p ι lo / la)

or even if one sees the formulas (1) and (3), in approximation

ρ = E ^ xMsv ^x lo / la

where Kx is a constant "

In continuation of the explanation with the approximate formulas _{9 in} order to simplify the position, where Wc denotes the power consumption of the pump 11 with constant pumping power and one also recalled that Pc and Qc represent the pressure and the flow rate per unit of time (correspondingly the pump power) • the pressure medium passing through the pressure delivery line 17 of the named pump, one can also write

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P = Pc - / ip (6)

νε-.s represents a statement about the function of the constriction 41, U.N

lic - Pc ζ Qc (7)

Tics represents a statement about the power consumption of the pump 11, which is known to be equal to the product, the pressure and the pumping capacity is.

The comparison of formulas (5) and (6) allows Pc ε-Is To express the function of ρ. On the other hand, since Qc is constant, finds nan with K. as a constant:

ρ = K ₄ χ Wc (3).

The pressure p that acts on the piston 25 is therefore approximate proportional to the power consumption Uc of the pump 11 with constant pumping power, as well as the displacement of the piston 25 and thus the displacement of the control member β dependent thereon is. Now the properties of the springs 29, 30 and 31 are known to be such that the displacement of the piston 24 and thus the Piston 25 under the action of the pressure of the liquid in the chamber 52 the power consumption Wv of the pump with variable Keep the pump power constant on one of the curves C1, C2 or C3 according to FIG. 4 or on a similar one in between Curve. * The action of the hydraulic fluid in chamber 33

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on the piston 25 allows this and consequently also the control member 6 to be displaced only over a distance which ^{corresponds to the power consumption, - v} ' ^r v of the pump 5 with variable pump output minus -lcr Leirjtunr; sLuzm: line Wc of the pump 11 with constant pump output, this subtraction being carried out automatically for each value of VJc, as it allows the pump 5 with a variable pump capacity to continue to work continuously with a constant drive power, the value VJc being of course lower than that which occurs when it is absent of the pump 11 with constant pumping power would represent the operating power consumption.

It will be understood that the power Wc to be withdrawn can be regulated by changing the value of CX P. For this it is sufficient to screw the rod 35 more or less and thus to select the desired fourth of the length la.

In this way, for example, the following three modes of operation can be obtained:

Wc = 0 and Wv = 100 HP when the machine is in free motion at maximum speed and none your iku equipment is operated; this corresponds to point F1 and curve C1;

VJc = 60 hp and VJv = 40 hp when at the machine, though this continues its movement, primarily its work equipment be operated. One therefore takes a momentary one

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Reduce the propulsion speed of the machine in Ι.υ.ιιϊ, give priority to using more work equipment. This corresponds to the option J ¹ ;; and curve 03;

"; c = YJ PS and Uv - 70 PS, y & s represents an operating mode, dir _; between the first two. and the point F2 in J corresponds to the? '_ curve C 2.

In all of these abundances , the sum of the power consumptions \? R and ~:; c is at most equal to the power of engine 1, in the present case of the 100 hp diesel engine, because, as already mentioned, the power required to drive the pump 11 with constant Pump power necessary power consumption lic has been subtracted from the power consumption Wv

However, it can happen that the maximum power consumption of the pump b with variable pump power is below the power of the motor 1. In this case it must be avoided to cut back the part of the motor power still available for driving the pump 11 with constant pumping power. In order to achieve this goal, the execution according to FIG. 2 must be completed and the device according to FIG. 5 must then be used. In the exemplary embodiment according to FIG. 5, the motor 1 can develop a maximum output of 120 HP, while the pump 5 with variable pump output has a maximum power consumption of 100 HP. On the other hand, the maximum power consumption of the pump 11 with constant pumping power is 60 HP. Since the sum of the

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OWGfNAL

nrxiinal power consumption Ιίν + V / c is equal to 160 HP and is above the power (120 HP) of the diesel engine 1, the surane of this power consumption must be limited to 120 HP in order to thereby achieve a free power consumption of 20 HP by the pump 11 to enable, so these 20 HP are never consumed by the pump 5 and created the performance silver, represent the diesel engine 1 in relation to the maximum power consumption of the pump 5. The tared valve 47 is provided to allow the pressure medium passage from the line 4i> and the line 17 to the constriction only when the pressure medium pressure in the line and consequently also in the line 46 is higher than the pressure threshold, at which the pump 11 with constant pumping power takes up a maximum of 20 hp. As long as the pressure prevailing in line 17, lower odc-r, is equal to the threshold corresponding to 20 PS, the tared valve 47 remains shut off; the pressure in the chamber 33 is then zero, so that no power is subtracted from the maximum power that can be consumed by the pump 5 with variable pump power, this maximum power consumption of the pump 5 being equal to 100 hp. On the other hand, when the pressure in the line 17 exceeds the threshold corresponding to 20 PS, the tared valve 47 controlled by the pressure medium in the line opens, whereby the function of the power regulator 19 is enabled, its function, already in connection above with FIGS. 1 to 4 has been described. The power regulator 19 makes it possible to subtract that power from the maximum power of the 120 hp diesel engine that is required to drive the pump 11 with constant pumping power, which is

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be driven in rank nut. Therefore, if the for the pump 11 required drive power is equal to 60 hp, the desire is at best to drive the pump 5 with variable pump power Let only an output of 120 HP - 60 HP = 60 HP become available.

Incidentally, it will be understood that so far this is in context with supply devices having only a single pump 5 with variable pump power, also described in the case of supply devices Is used that have several pumps with variable pumping power. This is when setting up the case according to FIG. 6, the same pumps 5a and 5b with having variable pump power, of which in the example shown one pump feeds the hydraulic motor to drive one of the two caterpillar chains of a construction machine and the other Pump the hydraulic motor to drive the other construction chain. the In the present case, pumps 5a and 5b have identical characteristics, as well as their respective power regulators 19a and 19b so that the construction chains are driven at the same speed can be. The power regulator 19a has two pistons 24ab and 24aa and the power regulator 19b has two pistons 24ba and 24bb, which is the sum of the effects in the pressure delivery lines 14a and 14b of the two pumps mentioned contain pressure medium flows are subject. So these power regulators are of the type of sailors with pressure summing. 7 shows a curve C. with regard to the variation of the pump power Qv of one of the pumps 5a, 5b as a function of the sum of the pressures Pva + Pvb of the two Pumping with constant power consumption. Considering

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the equality of the supply circuits ¹ sine the Punpleistungen of the two pumps 5a, 5b, with variable pump output equal to each other. Iian also readily sees that the control circuit of each of the pumps 5a, 5b is similar to the control circuit of the pump 5 shown in FIG -uf, of which one will flow through the variable constriction 54a, the other through the variable constriction 54b. There is also the possibility of neutralizing the actuation of the regulators 19a and 19b by means of the tared valve 47 if the sum of the maximum powers required to drive the two pumps 5a and 5b with variable pump powers is lower than the maximum power of the motor 1, and if, on the other hand, the power required to drive the pump 11 with constant pumping power is lower than the difference between the maximum power of the motor 1 and the aforementioned sun "of the maximum power consumptions of the pumps 5a and 5b.

Of course, the pumps 5a and 5b have one as an equivalent. single pump with double pump body. Likewise, the applied principle of supply can find other applications and that in a case in which the corresponding devices have more than two pumps with variable pumping power. Furthermore it is possible to limit different performance in the drive performance for several pumps with variable pump performance or 'suppress that one separately the amount of the flow rates regulates, which is determined by the corresponding variable sin-

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the lacing of every sailor, especially by making the "".; cross section of the constrictions forming Rites or their active lengths changed.

Finally, the supply device shown in FIG. 6 can be used for their part still improve or perfect and at least one more supply with constant flow rate realize during limited periods of time. I-ian then dials For the purpose of supplying the two further circuits 53a and 53b, a supply device, as can be seen from FIG. 8 is. At normal time, when the machine is moving in a straight line, the manifolds 63a and 65b are each in their second position angeord.net and the Pampe 51 pumps through the line 53, through part of the line 62b, through the line 65, through the .tarierte Valve 5S and through line 61 to the reservoir 13 back.

if, on the other hand, one of the consumer circuits, e.g. circuit 53a, supplies power must be, the machine stirrer actuates the foot lever of the Manifold 63a to bring it into its first position. The pump 51 with constant pumping power pumps the pressure medium now in the circuit 53a through the line 58, through the distributor 63a and through the line 64a. It is now supposed to be accepted that the supply of the circle 53a is a priority. It must therefore be of the drive power of one of the pumps 5c or 5b with variable pump power, in the present case from the drive power of the pump 5a, a power that is equal to the drive power for the pump 51. This is the.

A09816 / 0980

- 27 -

BATH

Basically, the line 66a connects the line 64a with the chamber 33a. Herr now the pump 51 is to supply the circuit 53b with constant pump power, since care is taken for the synchronization of the device, the power required to drive the pump 51 from the drive power of the pump 5b with variable pump power by means of the line 66b, which connects the line 64b with the chamber 33b, withdrawn. Ks must of course be avoided that the pressure medium flows are funded by the constrictions 41a or 41b in the lines 66a and 66b, and this ^T: J _o ise cause harmful interference to operation of other equipment.

This is why in lines 44aa and 44bb, respectively Check valves 52a and 52b are provided.

In addition, according to a further modification, the pump 11 is also included two laminar constrictions 41a and 41b associated with constant Puap power. This design obviously allows separate Regulations of the pressure drops and, as a result, separate regulations that enforce each of the constrictions 41a, 41b To effect flow rates and thus the maximum power consumption to regulate the pumps 5a and 5b to different values. Of course, the distributors 63 a and 63 b can otherwise have actuations that are separate from one another or coupled to one another in a known manner.

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409 816/0980

BAD G & GINAL

The invention is not limited to the embodiments described above; rather, other embodiments are also possible, without departing from the scope of the invention.

- patent claims -

409816/0980

Claims (1)

1 '55 845 patent claims üche Device for "pressure medium supply at least two consumer circuits, each of which by a group of Pumps with at least one pump and a pressure medium delivery Line is supplied, with one of the groups of pumps with constant pumping power and at least one other (second) of the groups have pumps with variable pumping power, while the input drive shafts of the different Pump groups are coupled to a single motor shaft and the supply device with at least one Has power regulator, which is formed by a first hydraulic cylinder, the cylinder with the body of the Pumps of the second group is firmly connected and its with a control element for controlling the pumping capacity of the second Pump group of coupled pistons is subject to mutually opposite effects, on the one hand the effect an elastic organ and on the other hand the effect of the pressure in the pressure delivery line of the second group by pumps contained pressure medium, characterized in that the device in a known manner a second Hydraulic cylinder (22), the cylinder of which is fixed to the body of the pumps of the second pump group (5; 5a, 5b) is connected and its with the StBnerorgan (6) for control 409816/0980 the pumping capacity of a second group of pumps coupled piston (25) with the cylinder of the ζ many hydraulic cylinder (22) is limited by a Kanner (55) which is connected to the pressure delivery line (17) of the pump group (11) with constant pumping capacity through a connecting line ( 45) is connected, that in this connecting line a laminar hydraulic constriction (41) is provided that the effect of the pressure prevailing in the chamber (55) on the piston (25) of the second hydraulic cylinder (22) is opposite to the effect of the elastic member ( 29,30,51) and that a second constriction (54) is provided, the hydraulic resistance of which is a function of the position of the piston (25) of the second hydraulic cylinder (22) in the associated cylinder body r Taris.bel and which is a connection between the cannier (55) and a tree (15) with a pressure of ire sent union full. 2. Supply device for the pressure medium supply of at least three consumer groups, each of which by a point group is supplied with at least one pump and a pressure delivery line, one of the pump groups with pumps constant pumping capacity and each of the other two pump groups Pumps with variable pump power, while the input drive shafts of the various pump groups are coupled with a single Hotorwelle and two power regulators are provided, of which a first controller with a 40981 6/0980 BATH C Control element for controlling the pump output of the first group of the "two Puiapengruppen with variable pump output and a second glider with a control member for controlling the pumping capacity of the second group of the two Pump groups with variable pump power is coupled, characterized in that each controller (19a, 19b) by three hydraulic cylinders is formed, the piston of which with the control member (6a, 6b) to control the pumping capacity of the corresponding group of pumps CSa, 5b) are coupled and delimit the three chambers, and each hydraulic cylinder has one chamber, these chambers being suitable for To contain pressure means, the effects of which are opposite to .the effect of an elastic organ, that the one of two first chambers of each regulator (19a, 19b) with the pressure delivery line (14a) of one pump group (5a) with variable pump capacity and the other of the first two chambers of each regulator with the pressure delivery line (14b) the other pump group (5b) is associated with variable pump power, the third of the three Chambers of each regulator (19a, 19b) through a connecting line (44 ^, 44b) with the pressure delivery line (17) of the Point group (11) is connected with constant pumping power, and that on the one hand a laminar hydraulic constriction (41) is arranged in this connecting line and, on the other hand, two second constrictions (34a, 34b) are provided. _ 4 _ 4098 16/0 980 23521 can be seen, their respective hydraulic resistance depending on the position of the piston of each of the 3 ^T. rides, each of the third chambers (33c., 33b) having hydraulic cylinders is variable and which bring each of the corresponding third chambers (33a, 33b) into communication with a space (15) with a pressure of essentially ITuIl (Fig. 6 ). Establishment-after. Claim 2, characterized in that ie also has a fourth consumer circuit (53a), which is selectively controlled by a second pump group with constant pumping power can be supplied, which comprises at least one pump (51) and a pressure delivery line (53) in which a Distributor (63a) is arranged with at least two positions, this distributor (63a), the pressure delivery line (53) of the second pump group (51) with constant pumping power in its one position with the fourth consumer circuit (55a) via a secondary pressure delivery line (64a) in connection brings and in its other position with the pressure medium supply sb he keeps (13) connects, and that a secondary Connection line (66a) the lower pressure delivery line (64a) with the third chamber (33a) of one of the two desire (19a) connects, while also in the connecting line (44aa) connected to the third chamber (33a) between this third chamber and the laminar constriction (41a) contained in this connecting line is a check valve (52a) is arranged, i.e. in such a way that only the pressure 409818/0980 - 5 - BATH central passage from the laminar constriction (41c.) to the third chamber (55a) is made possible (Fig. S). 4. Device according to one of the preceding claims, characterized in that also in each connecting line (45) between the connection of the latter to the pressure delivery line (17) of the pump group (11) with constant pumping power and the laminar constriction (41) eir tared valve (47) is arranged and by the pressure of the in the pressure delivery line (17) contained pressure medium is controlled or actuated. 5. Device according to one of the preceding claims, characterized in that the laminar constriction (41) of adjustable Type and is formed by a spiral external thread (53) which is connected to a rod (55) and can be arranged opposite a cylindrical bore (25), the length of which is arranged in this bore (25) External thread (58) using known means is adjustable. 6. Device according to one of the preceding claims, characterized in that the one or the two second constrictions (54; 54a, 54b) each through one in the cylindrical surface of the piston (25) of the second, this second Constriction corresponding hydraulic cylinder recessed hat (26) are formed, one depending on the 409816/0980 - 6 - ' Position of this piston (25) variable lung of the flit efective is arranged opposite the cylinder (22) in which the piston (25) vers chi ebbt r ■ 9 incobcait is. 7. device n-ch inclaim 6, characterized in that the I ¹ Ut (26) has ei ^ G Spirclforn. 409816/0980 BATH 03 ^{1 SGtNAL} Blank page