WO2013159898A1

WO2013159898A1 - Cooling device

Info

Publication number: WO2013159898A1
Application number: PCT/EP2013/001199
Authority: WO
Inventors: Frank Günter LEHMANN
Original assignee: Hydac Cooling Gmbh
Priority date: 2012-04-26
Filing date: 2013-04-22
Publication date: 2013-10-31
Also published as: DE102012008480A1

Abstract

The invention relates to a cooling device (10) for cooling a fluid guided in a hydraulic system, comprising a heat exchanger (26) through which fluid can flow and flowing fluid cools and emits waste heat, and a fan (24) which can be driven to generate an air flow for dissipating waste heat emitted by the heat exchanger (26), characterised in that the fan (24) can be driven hydraulically by the cooling and/or cooled fluid.

Description

cooler

The invention relates to a cooling device for cooling a fluid guided in a hydraulic system, comprising: a heat exchanger, which can be flowed through by the fluid and cools fluid flowing through it with release of waste heat, and a fan, which is drivable to generate an air flow for the discharge of discharged from the heat exchanger waste heat.

In hydraulic systems, energy is converted and transported. In this energy conversion and the energy transport losses occur. It converts mechanical and hydraulic energy into heat. The task of a cooling device is to dissipate this heat from the hydraulic system. In known cooling devices, the fan is typically hydraulically driven, wherein the drive hydraulics, for example, for a hydraulic motor as a separate circuit, regardless of the circuit of the medium to be cooled or fluid executed. The hydromotor is controlled in cooling devices of known construction either mechanically via a thermocouple or electrically via a proportional valve, more precisely, the rotational speed of the hydraulic motor is varied via a corresponding volume flow. In a structure with mechanical control, the inlet temperature of the fluid to be cooled before the heat exchanger is detected and used as a control variable via the thermocouple. In structures with electrical control, the outlet temperature of the cooled fluids are used after the heat exchanger as a control variable.

Based on this prior art, the invention sets the task to realize a simplified, less susceptible to failure structure of the cooling device with reduced space requirement.

This object is achieved by a cooling device with the features of claim 1 in its entirety. A cooling device according to the invention is characterized in that the fan can be driven hydraulically by the fluid to be cooled and / or the cooled fluid.

According to the invention, the fluid to be cooled or cooled in the heat exchanger, for example hydraulic oil or another hydraulic fluid, is at the same time a drive medium for the fan. Thus, a separate circuit for the drive hydraulics or the drive medium can be omitted and corresponding hydraulic lines are dispensable. Overall, the cooling device according to the invention can be constructed from a smaller number of individual components and used in smaller installation spaces.

Typically, the hydraulic drive of the fan is fluid-conducting, in particular via hydraulic lines, connectable to the heat exchanger. Particularly short fluid or hydraulic lines and thus a compact design of the cooling device according to the invention can be realized siert that the heat exchanger, the fan and the hydraulic drive of the fan in a common structural unit, in particular arranged in or on a common housing are.

The object of the invention is also achieved by a cooling device with the features of claim 3 in its entirety. This cooling device according to the invention is characterized in that the cooling and / or the cooled fluid controls the drive of the fan. Here, the heat exchanger can be arranged in a first hydraulic circuit and the hydraulic drive of the fan in a second hydraulic circuit.

A preferred direct control of the hydraulic drive of the fan via the fluid to be cooled by the heat exchanger and / or the cooled in the heat exchanger fluid allows a flexible, adaptable to different requirements and installation space configuration of the cooling device according to the invention. A particularly simple control of the hydraulic drive of the fan is achieved by a control block with a controllable by the heat exchanger to be cooled or cooled fluid control piston. The control block, the hydraulic drive for the fan and the heat exchanger are expediently arranged in the hydraulic circuit for the cooled or cooled fluid, to achieve a simple construction advantageously on the control block fluid connections for connecting the cooling device with the rest of the hydraulic system are provided. The cooling device according to the invention and its individual components are typically designed for a desired cooling capacity and used according to requirements in a hydraulic system for cooling the fluid guided in the hydraulic system. In a first preferred embodiment of the invention, the hydraulic drive of the fan is realized such that a thermocouple is arranged in the control block in such a way that it can be flowed by the fluid and displaces the control piston according to the temperature of the inflowing fluid. The control piston defines according to its position in the control block to the hydraulic drive, for example to a hydraulic motor, guided volume or fluid flow and consequently the fan speed of the fan. For example, in the case of cool fluid coming from the heat exchanger, the control piston is displaced or left in such a position that the fan is driven with a small fluid flow and generates a comparatively small air flow at the heat exchanger with a low fan speed. In the case of warm fluid coming from the heat exchanger, the control piston is displaced or left in such a position that the fan is driven by a large fluid flow and generates a comparatively large air flow on the heat exchanger due to a large fan speed, in other words the cooling capacity of the heat exchanger elevated.

In a second preferred embodiment of the invention, the hydraulic drive of the fan is realized such that the control block detects the differential pressure between the fluid flowing into the heat exchanger and the fluid flowing out of the heat exchanger and displaces the control piston in accordance with the detected differential pressure. The differential pressure is the difference between the inlet pressure of the fluid flowing into the heat exchanger and the outlet pressure of the fluid flowing out of the heat exchanger. Due to the cooling of the fluid as it flows through the heat exchanger, the outlet pressure differs from

Input pressure. In this second embodiment, the control piston can be acted upon on one side with the inlet pressure and on the other side with the outlet pressure of the heat exchanger and move in the control block linearly to the respective differential pressure. For this purpose, at least one spring element is advantageously provided in the control block, which is designed accordingly and arranged to engage the control piston.

In a preferred embodiment of the cooling device according to the invention, the hydraulic drive of the fan is designed as a hydraulic motor. The hydraulic motor drives the fan advantageously directly, it is However, also conceivable to realize an indirect drive, for example via an electric motor.

Further, it is advantageous that parallel to the hydraulic motor, an engine bypass is guided from the control block to the heat exchanger, and that fluid from the control block according to the position of the control piston in a hydromotor passing drive partial flow and in a bypass passage passing through the motor bypass Istrom is divisible. The drive substream is set according to the desired or required fan speed of the fan. The rest, not required as a drive partial flow fluid flow component is passed as Bypassti Istrom the hydraulic motor over to the heat exchanger.

Conveniently, the drive partial flow and the Bypasstei Istrom are merge before entering the heat exchanger. For simplified specification of the drive partial flow and / or the bypass partial flow, one or more control grooves are preferably provided in the control block, which define the drive partial flow and / or the bypass flow and can be at least partially closed or released by the control piston in accordance with its position in the control block. The control grooves are arranged in the inlet-side fluid passage for fluid flowing through the control block and set by the respectively released opening cross-section the drive partial flow or the Bypasstei Istrom. The control grooves can, for example, be formed in a typically sleeve-like housing part for guiding the control piston and can be closed or covered by the control piston in a position-dependent manner.

The invention further relates to a hydraulic system with a cooling device according to the invention, in particular as part of a wind turbine or a mobile plant. The use of the cooling device according to the invention in a wind power plant is advantageous with regard to the reduced susceptibility to interference, in other words the lower maintenance intensity. Further advantages and features of the invention will become apparent from the figures and the following description of the drawing. According to the invention, the above-mentioned and the further mentioned features can be realized individually or in any desired combinations with one another. The features shown in the figures are purely schematic and not to scale. It shows:

Fig. 1 a and 1 b an embodiment of the cooling device according to the invention in plan view and in perspective view;

Fig. 2 is a simplified circuit diagram for the cooling device of Figures 1 a and 1 b.

Fig. 3a and 3b, respectively, the circuit diagram of Fig. 2 with a detailed in

Section shown exemplary control block, each with a different position of the control piston;

4a and 4b each show a section through another exemplary

Control block, each with a different position of the control piston;

5a and 5b each show a section through another exemplary

Control block, each with a different sectional view of the control piston;

Fig. 6 is a more detailed representation of the control piston from the

Fig. 3a and 3b;

Fig. 7 is a detailed circuit diagram for an exemplary hydraulic system according to the invention;

8 shows a circuit diagram for a further embodiment of the cooling device according to the invention; and

9 shows the circuit diagram from FIG. 8 with the exemplary control block shown in detail in FIG. 3a. In a plan view and Fig. 1 b shows in perspective view a cooling device 10 with a housing 12. In a central, round recess on a square top of the housing 12 is a fan guard 14 for a rotatable inside the housing 12 fan (Not shown in Fig. 1 a and 1 b) used. The fan is driven by a hydraulic motor 16 arranged outside on the fan guard 14. Via fluid connections 18a, 18b, fluid is conducted through a hydraulic line 20a to the hydraulic motor 16 and from there through further hydraulic lines 20b-20d through a heat exchanger (not shown in FIGS. 1a and 1b) arranged inside the housing 12 and further back to the Fluid connections 18a, 18b out. The fluid connections 18 a, 18 b are part of a control block 22 for controlling the hydraulic motor 16.

The volume or fluid flow flowing through the hydraulic line 20a to the hydraulic motor 16 is determined by a control piston of the control block 22 and thus the fan speed of the fan of the cooling device 10 is predetermined. The further fluid component supplied via the one fluid connection 18a is guided over the hydraulic bypass 16 past the hydraulic motor 16 to the heat exchanger via an engine bypass 28 extending to a large extent in the interior of the housing 12. The engine bypass 28 consists of the hose 20d and the collecting box 20c located in the cooling element. The fluid flow guided through the hydraulic line 20a to the hydraulic motor 16 is predetermined by the temperature of the fluid cooled in the heat exchanger in the further fluid line 20d such that the cooled fluid in the control block 22 flows against a thermocouple, in other words flows past it, and the position of the Control piston changes by a corresponding displacement. Via the fluid connections 18a, 18b, which are designed to achieve a compact construction of the cooling device 10 on the control block 22, the cooling device 10 is connected to a hydraulic system, for example a wind turbine, which can be connected to cool the fluid carried in the hydraulic system. The simplified circuit diagram of Fig. 2 shows that the hydraulic motor 16 drives a fan 24 for generating an air flow to a heat exchanger 26. The control block 22 is supplied via the one fluid port 18a fluid from a hydraulic system, not shown. From the control block 22, fluid is fed via the hydraulic line 20a to the hydraulic motor 16 or to the motor bypass 28 connected in parallel with the hydraulic motor 16. The further hydraulic line 20b coming from the hydraulic motor 16 and the hydraulic line 20c of the engine bypass 28 open into a common hydraulic line 20c leading to the heat exchanger 26. Via the hydraulic line 20d, cooled fluid in the heat exchanger 26 is supplied to the control block 22 for adjusting the corresponding fluid flow in the hydraulic line 20a leading to the hydraulic motor 16 and is led further into the hydraulic system via the other fluid port 18b of the control block 22. In the control block 22 optimally finds no

Mixing of cooled fluid coming from the heat exchanger 26 via the hydraulic line 20d and fluid to be cooled via the hydraulic line 20a or the hydraulic line 20c of the engine bypass 28 to the heat exchanger 26 takes place.

FIGS. 3a and 3b respectively show the circuit diagram of FIG. 2 with the control block 22. The control block 22 has a control block housing 40 in which a control piston 32 is displaceably arranged along a longitudinal direction L. In addition to the fluid connections 18a, 18b, three additional connections are provided in the control block housing 40 for a partial drive flow A guided via the hydraulic line 20a to the hydraulic motor 16, a bypass partial flow B guided via the hydraulic line 20c past the hydraulic motor 16 and one from the heat exchanger 26 through the Via the one fluid port 18a the control block 22 supplied fluid reaches a first fluid chamber 30a and can branch off from this at least partially as a bypass Istrom B. Control grooves 34 are fed through a second fluid chamber 30b. The control grooves 34 are formed in a longitudinal section of a sleeve-like housing part 38, preferably running regularly on the circumference. The housing part 38 serves as a guide for the control piston 32, which at the end arranged in the second fluid chamber 30b has a widened front part 50, the cam grooves 34 at least partially or, as shown in Fig. 3b, completely close, in other words, cover. In the position of the control piston 32 shown in FIG. 3b, a fluid passage from the first fluid space 30a to the second fluid space 30b is blocked by the front part 50 of the control piston 32, so that fluid flowing into the cooling device 10 at one fluid port 18a is completely in the form of drive partial flow A to the hydraulic motor 16 to be led. The control position illustrated in FIG. 3b corresponds to the maximum fan speed or power of the fan 24 to be set. The control position shown in FIG. 3a, in which the opening cross-section of the respective control groove 34 is completely released, corresponds to the maximum bypass partial flow B to be set, in other words the minimum The fan speed to be set or the power of the fan 24. The hydraulic motor 20 a, 20 b guided, the Hy-

Odromotor 16 passing drive part stream A and guided over the hydraulic line 20c of the engine bypass 28 Bypassteilstrom B are brought together again after the hydraulic motor 16 in the hydraulic line 20d and passed as a common fluid flow through the heat exchanger 26. The fluid flow F corresponds to the sum of drive partial flow A and bypass partial flow B.

The position of the control piston 32 relative to the control block housing 40 depends on the temperature of the fluid passed from the heat exchanger 26 via the hydraulic line 20d as fluid flow F into the control block 22. The fluid flow F reaches a third fluid space 30c and further inside the Control piston 32 arranged thermocouple (not shown in Fig. 3a and 3b). Corresponding to the thermal expansion of the thermocouple, the control piston 32, which is movably connected to a housing-fixed, coaxial, pin-like guide element 42, moves against the force of a spring element 36 in the longitudinal direction L or by the spring force of the spring element 36 back into that shown in Fig. 3a , the control grooves 34 led at least partially releasing position. The spring element 36 is screw-shaped, surrounds the control piston 32, is attached at one end to the housing part 38 and at the other end to the third fluid space 30 c associated end of the control piston 32.

The embodiment of the control block 22 shown in FIGS. 4 a and 4 b differs from the illustration shown in FIGS. 3 a and 3 b in that the control piston 32 is of a racy, linder-like nature and extends from the third 30 c into the first fluid space 30 a. The longitudinal section T-piece-like housing part 38 separates the two fluid chambers 30a, 30c from each other. The input side of a fluid port 18a opposite at least one control groove 34 as an output for the Bypasstei Istrom B and offset another output for the drive part of the current A in the control block housing 40 is formed. In the control position shown in FIG. 4a, the control groove 34 is at least partially released by the control piston 32, in other words the corresponding control channel is opened, so that a Bypassteil- stream B can flow out of the first fluid chamber 30a. In the control position shown in FIG. 4b, the control groove 34 is completely closed by the control piston 32 covering it so that fluid supplied to the first fluid space 30a at one fluid port 18a is completely the maximum drive partial flow A to the hydraulic motor (not shown in FIGS. 4a and 4b) ) is supplied. The position or position of the control piston 32 in the control block housing 40 depends on the temperature of the in the heat exchanger (in Fig. 4a and 4b not shown) cooled fluid flow F from. Depending on the temperature, a thermocouple (not shown in FIGS. 4a, 4b) inside the control piston 32 expands and displaces the control piston 32 guided along the guide element 42 in the longitudinal direction L. In this linear movement of the control piston For closing the control groove 34 or the corresponding control channel, the spring element 36 arranged between the control piston 32 and the housing part 38 in the third fluid space 30c is compressed. For the return movement from the control position shown in Fig. 4b, which adjusts itself at a comparatively warm fluid flow F, in the control position shown in Fig. 4a, which adjusts itself at a comparatively cold fluid flow F, the control piston 32 by a return movement of the spring element 36th , In other words, by the restoring force of the spring element 36, against the longitudinal direction L moved back.

The control block 22 has a control block housing 40, in which along a longitudinal direction L a control piston 32 is guided in a longitudinal bore 41 and slidably disposed. In addition to the fluid connections 18a, 18b, three further connections are provided in the control block housing 40 for a drive partial flow A guided via the hydraulic line 20a to the hydraulic motor 16, a bypass partial flow B bypassing the hydraulic motor 16 via the hydraulic line 20c and one coming from the heat exchanger 26 through the hydraulic line 20d Fluid flow F. Fluid supplied to the control block 22 via a fluid connection 18a reaches a first fluid space 30a and can be supplied at least partially as a bypass partial flow B branching off through control grooves 34 to a second fluid space 30b. The control grooves 34 are formed in a longitudinal section of the control piston 32 assigned to the first fluid space 30 a. When the control piston 32 is displaced in the longitudinal direction L, the control grooves 34 are moved in the direction of the second part. space 30b moves and at least partially covered by the disposed between the first fluid chamber 30a and the second fluid chamber 30b portion of the longitudinal bore 41 and the Bypasstei Istrom B reduced accordingly.

In the illustrations of FIG. 5a with the control piston 32 shown in plan view and FIG. 5b with the control piston 32 shown in longitudinal section, the largest possible bypass current I current B is set by the completely released control grooves 34. In other words, the control position illustrated in FIGS. 5a and 5b corresponds to the fan speed or power to be set at a minimum. The drive partial flow A passing through the hydraulic lines 20a, 20b and the hydraulic motor 16 passing through the hydraulic line 20c of the engine bypass 28 Istrom B are reunited after the hydraulic motor 16 in the hydraulic line 20d and passed through the heat exchanger 26 as a common fluid flow. The fluid flow F corresponds to the sum of drive partial flow A and bypass flow I current B.

The position of the control piston 32 relative to the control block housing 40 depends on the temperature of the fluid passed from the heat exchanger 26 via the hydraulic line 20d as fluid flow F into the control block 22. The fluid flow F reaches a third fluid space 30c and further a thermocouple (not shown in FIGS. 5a and 5b) disposed internally, more specifically in a thermocouple portion 47 of the control piston 32. According to the thermal expansion of the thermocouple, the control piston 32, which is movably connected to a housing-fixed, coaxial, pin-like guide member 42 is moved against the force of a spring element 36 in the longitudinal direction L and at a decrease in the temperature of the fluid idstroms F by the spring force of Spring element 36 back into the shown in Figs. 5a and 5b, the control grooves 34 releasing led out. The spring element 36 is helical, surrounds the control piston 32, is fixed at one end to a corresponding transverse surface of the control block housing 40 and at the other end to the third fluid chamber 30 c associated end of the control piston 32. At this end, the thermocouple portion 47 is formed in the control piston 32.

In the subsequent remaining length section of the control piston 32 is formed like a tube cylinder. For the operation of the control piston 32 according to the invention, however, it is sufficient if this at the first fluid chamber 30a and the control grooves 34 and the second fluid chamber 30b associated end facing or tubular cylinder-like design and in this way a fluid path for the Bypasstei Istrom B from the first Fluid space 30a through the control grooves 34 through the second fluid chamber 30b allows. The third fluid space 30c and the first fluid space 30a are spatially connected to one another by a corresponding section of the longitudinal bore 41, but are guided by the one in the longitudinal bore 41

Control piston 32 fluid-tightly separated. In the embodiment shown in FIGS. 5a and 5b, the control unit or control block 22 according to the invention reduces to the thermocouple in the thermocouple section 47 with the associated spring element 36, the control tube or the tubular control piston 32 and the valve housing 40th

Further details of the control piston 32 shown in Figures 3a and 3b are Fig. 6 can be removed. The front part 50 of the control piston 32 which is movable in the second fluid space 30b along the longitudinal direction L has parallel to the longitudinal direction L, in other words to the direction of movement of the

Control piston 32, extending fluid passages 44f, 44g for fluid-conducting connection of the two defined by the front part 50 subspaces of the second fluid chamber 30b. Further, an extension 51 may be formed on the front part-side free end of the control piston 32. At the rear part 52 of the control piston 32 arranged opposite the front part 50, fluid passages 44a, 44c are provided in order to keep the rear part 52 fixed. ten Tei spaces of the third fluid chamber 30c fluidly connect to each other and lead Fl uid into the interior or in the thermocouple section 47 of the control piston 32. Further fluid passages 44d, 44e are provided in the middle part 53 of the control piston 32.

As indicated by arrows, fluid flows from the fluid passage 44a to the fluid passage 44d and from the fluid passage 44b to the fluid passage 44e, a thermocouple 46 disposed inside the control piston 32, which deforms depending on the temperature of the fluid flowing around and a corresponding linear movement of the control piston 32 in the longitudinal direction L causes. The thermocouple 46 is formed of a suitable thermally deformable material, such as a waxy or wax-like material, and connected to the guide member 42 fixed to the housing so that upon thermal expansion of the thermocouple 46, the control piston 32 is "depressed" on the guide member 42 and longitudinally is moved against the spring force of the spring element 36. A comparable thermocouple 46 can in the control block 22 of Fig. 4a and 4b or according to Fig. 5a and 5b ausgebi LODES, more precisely in the control piston 32 and arranged in the thermocouple 47.

FIG. 7 shows a circuit diagram for a hydraulic system 54 according to the invention with a cooling device 10 according to the invention. From a sump or tank T, fluid is conveyed via a motor-pump unit 55 to a first filter unit 56a with a filter fineness of 10 μνη and further a second filter unit 56b with a filter fineness with 50 μιτι out. Parallel to the first filter unit 56a is a first check valve 58a with an opening pressure of 4 bar and after the series-connected filter units 56a, 56b, a second check valve 58b arranged with an opening pressure of 0.2 bar. In the hydraulic system 54, a control unit 60 as well as a manuel l actuated drain valve 62 for emptying the hydraulic iksystems 54 is further provided. To protect the hydraulic system 54, Two further, a third check valve 58c with an opening pressure of 12 bar and a fourth check valve 58d with an opening pressure of 20 bar connected in parallel to the motor-pump unit 55. A control block 22 'is set such that the hydraulic system 54 at a temperature of the fluid, such as hydraulic oil, below 45 ° C, as hitherto usual, via the third check valve 58c, which represents a pressure relief valve so far, with 12 bar is secured. At a temperature of the fluid above 45 ° C, the hydraulic system 54 via the fourth check valve 58d, which also represents a pressure relief valve so far, secured with 20 bar. The control block 22 'is fluid temperature controlled. At a fluid temperature below 45 ° C., fluid coming from the filter units 56a, 56b is guided by a further fluid temperature-controlled control block 22 "controlled via a branch 64 back to the tank T. At a fluid temperature above 45 ° C, the fluid to the cooling device 10 and through a further control block 22 "'to the heat exchanger 26, which is secured by a fifth check valve 58e with an opening pressure of 6 bar out. The hydraulic motor 16 for the fan 24 of the cooling device 10 is driven by the fluid cooled by the heat exchanger 26 and / or by the further control block 22 "'fluid-dependent via the further branch 64. The hydraulic motor 16 can, for example, be designed for low pressure <20 bar Fluid is fed back to the tank T or sump via the hydraulic motor 16. It is understood that, instead of 45 ° C, any suitable one for the application of the hydraulic system 54

Temperature value of the control unit 60, the control blocks 22-22 "'and the cooling device 10 can be specified.

The circuit diagram from FIG. 8 shows that fluid is conducted from the reservoir T via a first circuit I and a second circuit II to the control block 22 and back to the reservoir T. In the first cycle I are one the first Fluid connection 18 a associated first motor-pump unit 55 a, the control block 22 and the hydraulic motor 16 arranged as a hydraulic drive of the fan 24. From the control block 22 lead hydraulic lines 20a, 20b to

Hydromotor 16 and on to a back to the reservoir T leading ers i

Return line 21 a and a the hydraulic motor 16 bypassing, by-pass-like hydraulic line 20 c, which opens into the first return line 21 a. In the second circuit II, fluid reaches the heat exchanger 26 through a second motor-pump unit 55b assigned to the second fluid connection 18b, and the control block 22 continues via the hydraulic line 20d. From the control block 22, a second return line 21b is led to the reservoir T.

According to the temperature of the fluid in the second circuit II via the hydraulic line 20d from the heat exchanger 26 to the control block 22, the fluid flow from the first motor-pump unit 55a in the first circuit I to the control block 22 is supplied as a drive partial flow via the hydraulic line 20a to the hydraulic motor 16 or as Bypassteilstrom over the hydraulic line 20c on the hydraulic motor 16 passed over. The fluid flow of the guided over the hydraulic line 20 a to the hydraulic motor 16 fluid is the fan speed of the fan 24 and consequently its ventilation or. Cooling capacity for cooling the heat exchanger 26 before. By means of the control block 22, the two fluidically separated, in other words independent, circuits I, II are coupled together in such a way that the temperature and / or the pressure of the fluid coming from the heat exchanger 26 in the second circuit II to that in the first circuit I to Hydraulic motor 16 guided fluid or volumetric flow controls.

Fig. 9 shows the circuit diagram of Fig. 8 with the control block 22, which is formed according to the illustration of Fig. 3a. In the embodiment shown in FIG. 9, the flow forces on the control piston 32 of the control block 22 are minimized and thus a low restoring force required via the spring element 36, which increases the load capacity and the life of the thermocouple 46. The embodiment of the solution according to the invention shown in FIGS. 8 and 9 with two working groups separated from one another by fluid technology finds particular application in the mobile market.

Claims

P a n t a n s p r e c h e

Cooling device (10) for cooling one in a hydraulic system

(54) guided fluid, comprising:

a heat exchanger (26) through which the fluid can flow and which cools the fluid flowing through while releasing waste heat; and a fan (24) which can be driven to generate an air flow for removing waste heat emitted by the heat exchanger (26),

characterized in that the fan (24) is hydraulically driven by the cooled and / or the cooled fluid.

Cooling device according to claim 1, characterized in that the hydraulic drive of the fan (24) fluid-conducting, in particular via hydraulic lines (20a-20d), with the heat exchanger (10) is connectable.

A cooling device (10) for cooling a fluid carried in a hydraulic system (54), comprising:

a heat exchanger (26) which can be traversed by fluid and cools fluid flowing through it with release of waste heat, and a fan (24) which is drivable for generating an air flow for the removal of waste heat emitted by the heat exchanger (26),

- characterized in that the cooling and / or the cooled fluid controls the drive of the fan (24).

Cooling device according to claim 3, characterized in that the heat exchanger (10) in a first hydraulic circuit (I) and the hydraulic drive of the fan (24) in a second hydraulic circuit (II) is arranged. Cooling device according to one of the preceding claims, characterized in that a control block (22) for controlling the hydraulic drive of the fan (24) is provided with a controllable from the heat exchanger (26) to be cooled or cooled fluid control piston (32).

Cooling device according to one of the preceding claims, characterized in that in the control block (22) for controlling the hydraulic drive of the fan (24), a thermoelement (46) is arranged such that it can be flowed by fluid and the control piston (32) of the control block (22) shifts according to the temperature of the inflowing fluid.

Cooling device according to one of the preceding claims, characterized in that the control block (22) for controlling the hydraulic drive of the fan (24) detects the differential pressure between the fluid flowing into the heat exchanger (26) and the fluid flowing out of the heat exchanger (26) and the control piston (32) of the control block (22) shifts according to the detected differential pressure.

8. Cooling device according to one of the preceding claims, characterized in that the hydraulic drive of the fan (24) is designed as a hydraulic motor (16).

Cooling device according to one of the preceding claims, characterized in that parallel to the hydraulic motor (16) an engine bypass (28) from the control block (22) for controlling the hydraulic drive of the fan (24) to the heat exchanger (26) is guided and that fluid from the control block (22) according to the position of the control piston (32) of the control block (22) in a hydraulic motor (16) passing Drive part of the current (A) and in a bypass of the motor (28) passing Bypasstei Istrom (B) is subdivided.

Cooling device according to one of the preceding claims, characterized in that the drive part stream (A) and the Bypassteil- stream (B) before entering the heat exchanger (26) are merge.

Cooling device according to one of the preceding claims, characterized in that in the control block (22) one or more control grooves (34) are provided which define the drive part flow (A) and / or the Bypasstei Istrom (B) and from the control piston (32) corresponding thereto Position in the control block (22) are at least partially closed or released.

Hydraulic system (54) with a cooling device (10) according to one of the preceding claims, in particular as part of a wind turbine or a mobile plant.