Device for controlling hydraulic pumps or hydraulic motors

Abstract

The present invention relates to a device (10) for controlling a hydraulic pump (12), comprising: a hydraulic fluid reservoir (18); a hydraulic pump (12) having an inlet (20) and an outlet (22); a regulating unit (27) acting in conjunction with the hydraulic pump (12) and capable of changing the delivery rate of the hydraulic pump (12), the regulating unit being arranged in a high-pressure secondary pipeline (36) connected to a high-pressure pipeline (26); and a high-pressure seat valve (40) arranged in the high-pressure secondary pipeline (36) and connected to the regulating unit. (27) Working together; a sensor (44) by which the actual value of at least one characteristic parameter that can be affected by the delivery volume of the hydraulic pump (12) can be detected; an adjusting element (46) by which a target value of the characteristic parameter can be specified; and a control device (42) that works together with the sensor (44) and the adjusting element (46) such that the high-pressure seat valve (40) can be activated taking into account the actual value detected by the sensor (44) and the target value specified by the control element (46). Furthermore, the present invention relates to a device for regulating a hydraulic motor (66).

Description

Technical Field

[0001] This invention relates to a device for controlling a hydraulic pump or a hydraulic motor. Background Technology

[0002] Hydraulic pumps are used in many technical applications to deliver hydraulic fluid, especially hydraulic oil, from a hydraulic fluid reservoir to a consumer. The consumer can be, for example, a hydraulic cylinder. Due to the delivery of the hydraulic fluid and the resistance introduced by the associated hydraulic system and / or the consumer located therein, pressure builds up in the hydraulic cylinder, which can be converted into motion or force. Such a component can be, for example, the boom of an excavator. The corresponding operating lever of the excavator is operated by the excavator operator, thus specifying a particular target value, such as the volumetric flow rate in the hydraulic cylinder. Therefore, the operating lever serves as an adjustment element, by which the delivery rate of the hydraulic pump is changed.

[0003] Controllers known in the prior art for controlling hydraulic pumps often alter the delivery rate by adjusting combinations of appropriate configurations of cylinders and diaphragms, springs, throttle valves, and valves, which in turn are passively pre-controlled by pressure feedback from the associated hydraulic system. Such controllers are known, for example, by DE 24 13 295 A1. For axial piston pumps, altering the delivery rate is also referred to as altering the oscillation angle.

[0004] Because known controllers in the prior art have specific combinations of diaphragms, springs, throttle valves, and valves, these controllers correspond specific control tasks to specific control characteristics that can only be changed to a limited extent during the operation of the consumer. For example, if the control characteristic needs to be changed, the spring or spring assembly must be further pre-tensioned, for example, manually, or replaced with a spring with different spring characteristics. The same applies to the associated controller or other hydraulic components of the hydraulic system.

[0005] Controllers with electro-proportional control axes are known in the prior art and offer some flexibility compared to previously described controllers; however, the flexibility of known controllers in the prior art is still insufficient. Furthermore, in many cases, the valves used are designed as spool valves or piston valves, which, due to their operating principle, are prone to leakage. This leakage leads to pressure loss within the hydraulic system and consequently reduces the efficiency of the hydraulic system operation.

[0006] For other relevant prior art, please refer to DE 36 44 736 A1, EP 3 308 236 A1, DE 102014 207 958 A1, DE 10 2011 120 767 A1, DE 20 2009 013 507 U1, DE 10 2018 003728 A1 and DE 10 2012 006 219 A1. Summary of the Invention

[0007] The purpose of embodiments or solutions of the present invention is to provide a device for controlling a hydraulic pump or hydraulic motor, which can flexibly achieve different control purposes using simple and identical components without requiring major adjustments to the hydraulic components. Furthermore, leakage in the device will be greatly reduced, thereby improving the dynamics and efficiency of control.

[0008] Embodiments of the present invention relate to a device for controlling a hydraulic pump, comprising:

[0009] - Hydraulic fluid reservoir, - A hydraulic pump with an inlet and an outlet, wherein The inlet is connected to the hydraulic fluid reservoir via a first low-pressure line. The output port connects to a high-pressure line that can be connected to a consumer. - A regulating unit that interacts with the hydraulic pump, allowing the pump's delivery rate to be changed, wherein the regulating unit is arranged in a high-pressure secondary pipeline connected to the high-pressure pipeline. - A high-pressure seat valve, which is arranged in the high-pressure secondary pipeline and interacts with the regulating unit. - A sensor, which can detect the actual value of at least one characteristic parameter that can be affected by the delivery volume of the hydraulic pump. - Adjust the component, specifying the target value, and - A control device that interacts with the sensor and the adjusting element, enabling the high-pressure seat valve to be activated taking into account the actual value detected by the sensor and the target value specified by the adjusting element.

[0010] Algorithms can be stored in the control device, and different control tasks and characteristics can be mapped using these algorithms. For example, the control device can be designed to simulate classic controllers, such as PI or PID controllers with and without fixed-value control. To achieve specific control characteristics, only the control device needs to be configured accordingly. Depending on the application, the desired control characteristics can be selected appropriately during operation. No hydraulic components need to be replaced. Therefore, the device for controlling a hydraulic pump according to the present invention offers maximum flexibility.

[0011] As suggested, the hydraulic pump's delivery rate changes hydraulically with the corresponding activation of the high-pressure seat valve. The speed of the hydraulic pump's drive motor does not change specifically, but the drive speed may vary with the load without adversely affecting the hydraulic system's function. This leads to the advantage that a relatively simple drive motor can be used, which can operate without speed control. For example, an internal combustion engine can be used, which can operate continuously within its optimal speed range, thus allowing for economical operation. Expensive drive motors, such as speed-controllable servo motors, are not required. However, depending on the application requirements, a variable-speed motor can also be used to add another control variable to take advantage of the control characteristics.

[0012] Hydraulic pumps can have any number of pistons. The proposed device operates on all pistons. Since there is no individual control of each piston, the proposed device remains simple in terms of design and control technology.

[0013] According to a further improved embodiment, the adjusting unit includes or is designed as an adjusting cylinder, wherein – The piston is slidably mounted in the adjusting cylinder. – The piston divides the regulating cylinder into a first pressure chamber and a second pressure chamber. - The first pressure chamber is connected to the high-pressure pipeline via a high-pressure secondary pipeline and a working pipeline. - The second pressure chamber is connected to the hydraulic fluid reservoir via a second low-pressure line, and - The piston is pre-tensioned relative to the first pressure chamber by a return spring and / or a counter-piston.

[0014] The high-pressure seat valve connects a high-pressure secondary line and a working line, with the working line located downstream of the high-pressure seat valve. Operation of the high-pressure seat valve may affect the pressure level in the working line.

[0015] Using a regulating cylinder as the regulating unit is technically simple to implement and has proven to be reliable.

[0016] According to another embodiment, between the high-pressure seat valve and the regulating unit, a secondary low-pressure line can branch off from the high-pressure secondary line and lead to a second low-pressure line, and a fixed or variable low-pressure throttle valve can be arranged in said secondary low-pressure line. The term "throttle valve" should be understood below to include each cross-sectional narrowing point in the relevant line. It can also be called a "nozzle" or diaphragm. The throttle valve can be designed to be fixed or variable. A variable throttle valve is understood to have a cross-sectional narrowing point that can be changed compared to a fixed throttle valve. For example, a variable throttle valve can specify two or more cross-sectional narrowing points that are different from each other, for example, which can be selected by the user by turning a handwheel. Selection can also be supported by a servo motor or electromagnet operated accordingly by the user. However, such electrical operation can also be initiated by a control device and thus integrated into the controller.

[0017] If the regulating unit and piston, designed to interact with each other completely leak-free, then once pressure is established in the first pressure chamber, it will no longer decrease. The regulating cylinder will remain in a position such that the hydraulic pump's delivery rate cannot be changed. As mentioned above, this is purely theoretical, because the piston and regulating cylinder will always have some leakage in principle, and therefore there will always be a certain volume of hydraulic fluid flowing from the first pressure chamber to the second pressure chamber. Therefore, a certain amount of leakage is a prerequisite for the normal operation of the device. However, this can also lead to pressure loss due to leakage and thus reduce the operating efficiency of the device. In this regard, the goal is to minimize leakage, which can be achieved by improving the manufacturing precision of the piston and regulating cylinder. However, residual leakage will always exist. However, the lower the leakage, the slower the pressure in the first pressure chamber decreases, which negatively impacts the dynamics of the control. By using a low-pressure throttle valve arranged in the secondary low-pressure line, another way to reduce the pressure in the first pressure chamber is achieved, in addition to the leakage between the first and second pressure chambers. This increases the dynamics of the control.

[0018] In another embodiment, a secondary low-pressure line can branch off from the high-pressure secondary line and lead to a second low-pressure line between the high-pressure seat valve and the regulating unit. The low-pressure seat valve can be located within this secondary low-pressure line and can be activated by a control device, taking into account the actual value detected by the sensor and the target value specified by the regulating element. This embodiment differs from the previously discussed embodiments only in the use of a low-pressure seat valve instead of a low-pressure throttle valve. While throttle valves cannot or almost cannot be integrated into the control loop because they are passive elements, low-pressure seat valves can be integrated well into the control loop. In this respect, pressure drop can be selected very precisely when using a low-pressure secondary line. The dynamics and accuracy of control can be significantly improved compared to a low-pressure throttle valve.

[0019] In another embodiment, the high-pressure seat valve can be designed as a seat valve with integrated pressure limiting. In this embodiment, the pressure limiting function is integrated into the high-pressure seat valve. When the pressure in the hydraulic system, particularly in the consumer, rises above a certain value, the high-pressure seat valve will open independently of any operation caused by the control device. Therefore, it can be ensured that the hydraulic pump pivots back and the pressure in the hydraulic system does not exceed a certain value, regardless of the functionality of the control device. This protects the components of the hydraulic system.

[0020] In another embodiment, the high-pressure secondary line may have a bypass line through which the high-pressure seat valve is bypassed. Furthermore, a pressure-limiting valve may be arranged in the bypass line. The pressure-limiting valve may, for example, be implemented as a spring-loaded check valve. This also achieves a pressure-limiting function, which can be provided as an alternative or additional solution to a seat valve with integrated pressure-limiting functionality. All pressure-limiting valves prevent pressure from rising above a certain value, regardless of the functionality of the high-pressure seat valve or its switching state. It should be noted that within the scope of this disclosure, the term "pressure-limiting valve" differs from the commonly used definition, according to which a pressure-limiting valve is directly connected to a hydraulic reservoir. However, apart from the proposed arrangement of the pressure-limiting valve, it is functionally no different from a pressure-limiting valve according to the conventional definition. Alternatively, pressure-related switching valves may also be mentioned in this regard.

[0021] Embodiments of the present invention relate to a device for controlling a hydraulic pump, comprising: - Hydraulic fluid reservoir, - A hydraulic pump with an inlet and an outlet, wherein The inlet is connected to the hydraulic fluid reservoir via a first low-pressure pipeline. The output port is connected to a high-pressure pipeline that can be connected to a consumer. - A regulating unit that interacts with the hydraulic pump, allowing the pump's delivery rate to be changed, wherein the regulating unit is arranged in a high-pressure secondary pipeline connected to the high-pressure pipeline. - A low-pressure secondary pipeline that branches off from the high-pressure secondary pipeline. - A low-pressure seat valve, which is arranged in the secondary low-pressure line and interacts with the regulating unit. - A sensor, which can be used to detect the actual value of at least one characteristic parameter affected by the hydraulic pump's delivery volume. - Adjustment element, which allows specifying target values, and - A control device that interacts with the sensor and the adjustment element, enabling the low-pressure seat valve to be activated taking into account the actual value detected by the sensor and the target value specified by the adjustment element.

[0022] In this embodiment, the device does not include a high-pressure seat valve, but rather a low-pressure seat valve. Therefore, the pressure level used for the consumer is always set in the first pressure chamber. The hydraulic pump's delivery rate is primarily affected by the control of the low-pressure seat valve.

[0023] According to a further improved embodiment, the adjusting unit includes or is designed as an adjusting cylinder, wherein – The piston is slidably mounted in the adjusting cylinder. – The piston divides the regulating cylinder into a first pressure chamber and a second pressure chamber. - The first pressure chamber is connected to the high-pressure pipeline via a high-pressure secondary pipeline and a working pipeline. - The second pressure chamber is connected to the hydraulic fluid reservoir via a second low-pressure line, and – The piston is pre-tensioned relative to the first pressure chamber by a return spring and / or a counter-piston.

[0024] Using a regulating cylinder as the regulating unit is technically simple to implement and has proven to be reliable.

[0025] In another embodiment, a fixed or variable high-pressure throttle valve may be specified for placement in the high-pressure secondary pipeline. In this case, the pressure in the first pressure chamber does not automatically match the pressure on the consumer; instead, the reduced pressure level depends on the system conditions. The pressure load on the regulating cylinder is correspondingly lower.

[0026] Embodiments of the present invention relate to a device for controlling a hydraulic motor, comprising: - Hydraulic fluid pressure reservoir, - A hydraulic motor with input and output, wherein The input port is connected to the hydraulic fluid pressure reservoir via a high-pressure pipeline. The output port is connected to the hydraulic fluid reservoir via a return line. - An adjustment unit that interacts with the hydraulic motor, allowing the adjustment of the amount of fluid to be received by the hydraulic motor per revolution. - A high-pressure seat valve, which is arranged in the high-pressure secondary pipeline and interacts with the regulating unit. - A sensor, which can detect the actual value of at least one characteristic parameter affected by the amount of fluid injected per revolution to be received by the hydraulic motor. - Adjustment element, which allows specifying a target value, and - A control device that interacts with the sensor and the adjusting element, enabling the high-pressure seat valve to be activated taking into account the actual value detected by the sensor and the target value specified by the adjusting element.

[0027] The fluid flow rate per revolution of a hydraulic motor is similar to that of a hydraulic pump. The fluid flow rate per revolution can affect the power or torque provided by the hydraulic motor.

[0028] Embodiments of the present invention relate to a device for controlling a hydraulic motor, comprising: - Hydraulic fluid pressure reservoir, - A hydraulic motor with an input port and an output port, wherein The input port is connected to a hydraulic fluid pressure storage tank via a high-pressure pipeline. The output port is connected to the hydraulic fluid reservoir via a return line. - A regulating unit, which interacts with the hydraulic motor, allows for the alteration of the fluid flow rate per revolution to be received by the hydraulic motor. This regulating unit is located in a high-pressure secondary pipeline connected to the high-pressure pipeline. - A low-pressure seat valve, which is arranged in the secondary low-pressure line and interacts with the regulating unit. - A sensor, which can detect the actual value of at least one measuring unit that is related to the amount of fluid injected per revolution and can be received by the hydraulic motor. - Adjustment element, which allows specifying target characteristic values, and - A control device that interacts with the sensor and the adjustment element, enabling the low-pressure seat valve to be activated taking into account the actual value detected by the sensor and the target value specified by the adjustment element.

[0029] The technical effects and advantages achievable using the proposed device for controlling a hydraulic motor correspond to those discussed regarding the device for controlling a hydraulic pump according to the present invention. In summary, it should be noted that, on the one hand, leakage within the device can be significantly reduced compared to controllers known in the prior art, thereby improving control efficiency and dynamism. On the other hand, different control tasks and control characteristics can be flexibly and quickly implemented without altering the hydraulic components of the device. Furthermore, various parameters can be considered during the control process, thereby improving control accuracy. These parameters can be detected by other sensors.

[0030] According to another embodiment of the present invention, - High-pressure seat valves are designed as high-pressure digital seat valves and / or - Low-pressure seat valves are designed as low-pressure digital seat valves and / or - High-pressure seat valves with integrated pressure limiting function are designed as high-pressure digital seat valves with integrated pressure control function.

[0031] Digital seat valves are particularly characterized by the following: they are completely or almost completely leak-free in the closed state, thus causing little or no leakage in the device of this application when closed, and therefore have a larger opening cross-section in the open switching state compared to conventional standard controllers. This improves control dynamics and efficiency. The improved dynamics result in better responsiveness of the associated adjusting elements and increased ease of use. Digital seat valves not only have two switching states (open and closed), but can also be used for dosage control via corresponding electronic control of the control unit. Furthermore, their switching time is extremely short, only 5 milliseconds or less. The volumetric flow rate of the hydraulic fluid flowing through the associated digital seat valve can be very precisely regulated by the frequency of opening and closing. In addition to the aforementioned pulse width modulation, other control variations exist, such as frequency modulation or combinations thereof.

[0032] Furthermore, the digital seat valve can be operated by a control device, which may include power electronics. This control device is capable of considering multiple parameters when operating the digital seat valve to adjust the actual value of the characteristic parameter (e.g., the volumetric flow rate of the hydraulic fluid) as precisely as possible to the target value specified by an adjusting element. The actual value can be detected using a sensor. The adjusting element can, for example, be designed as an operating lever of an excavator. This controller represents a significant improvement over controllers known in the prior art.

[0033] As described above, a leak-free regulating cylinder can be used according to embodiments. Technically, by arranging corresponding seals on the piston, which seal the piston relative to the regulating cylinder, a regulating cylinder that is at least virtually leak-free can be provided. Also as described above, pressure losses associated with leakage during operation of the device of this application can be significantly reduced or eliminated, thereby improving efficiency. However, the seals increase friction in the regulating cylinder, meaning that the friction of the seals must be overcome to slide the piston. This can lead to delayed response behavior. To counteract this, the digital seat valve can be operated by a control device using a so-called "boost and hold" strategy. Clock control results in pulsed pressure increases in the first and second pressure chambers, which allows for precise adjustment of the piston even in the event of static / sliding friction (stick-slip effect).

[0034] In a further aspect of the invention, a pressure sensor can be used to detect the pressure present in the working line, wherein the pressure sensor interacts with a control device such that the high-pressure seat valve and / or low-pressure seat valve can be activated taking into account the pressure detected by the pressure sensor. Therefore, the pressure in the working line can be included as an additional value in the system control. The pressure detected in the working line corresponds to the pressure present in the regulating unit. By including the pressure in the working line in the control, the regulating unit can be more directly affected by the control device. The regulating unit typically regulates the delivery rate of the hydraulic pump or the fluid intake per revolution of the hydraulic motor. If other parameters of the hydraulic pump or hydraulic motor are known, any delivery rate can be applied to the hydraulic pump or any fluid intake per revolution can be applied to the hydraulic motor using the device of a further aspect of this application. Therefore, the hydraulic power of the hydraulic pump can be adjusted to drive the power of the motor. If the device is designed to control the hydraulic motor, the hydraulic power of the hydraulic motor can be adjusted to the power obtained from the shaft.

[0035] The control device can be designed to determine the position of the regulating unit based on the pressure detected by a pressure sensor, wherein the high-pressure seat valve and / or low-pressure seat valve can be activated taking into account the position of the regulating unit determined by the control device. If the regulating unit is designed as a regulating cylinder, the position of the regulating unit is preferably described by the position of the piston in the regulating cylinder. The pivot angle of the hydraulic pump or hydraulic motor can also be determined by the position of the piston. With this arrangement, the pivot angle can therefore be determined without the availability of a pivot angle sensor. This simplifies the manufacture of the hydraulic pump or hydraulic motor. Furthermore, active influence of the pivot angle can be achieved.

[0036] According to a further aspect of the invention, the high-pressure seat valve and / or the low-pressure seat valve can be activated by a control device based on a start-up value. In this case, a reference value for the start-up value can be stored in the control device, the reference value depending on the actual value of a characteristic parameter that can be affected by the delivery volume of the hydraulic pump or by the fluid inflow per revolution to be received by the hydraulic motor. The control device is preferably designed to detect the actual value of the start-up value corresponding to the actual value of the characteristic parameter, and to determine the state characteristic value of the hydraulic pump or hydraulic motor based on a comparison of the actual value of the start-up value with a reference value of the start-up value related to the actual value of the characteristic parameter. A particular advantage of this further aspect of the invention is that no further components are required for implementation; only the control device must be adapted accordingly.

[0037] A method for controlling a hydraulic pump with a hydraulic motor, wherein the high-pressure seat valve and / or low-pressure seat valve can be activated by a start value, the method comprising the following steps: - Detect the actual value of at least one characteristic parameter that can be affected by the flow rate of the hydraulic pump or the amount of fluid injected per revolution to be received by the hydraulic motor. - Detect the corresponding actual value of the startup value. - The state characteristic values ​​of a hydraulic pump or hydraulic motor are determined by comparing the actual value of the starting value with a reference value of the starting value associated with the actual value of the characteristic parameter.

[0038] As previously mentioned, the characteristic parameter can be the volumetric flow rate of the hydraulic fluid. The starting value can be determined by the intensity of the control current and / or the control time of the high-pressure seat valve and / or the low-pressure seat valve, or their starting frequency and / or cycle time. Typically, the control current has a periodic process, where the intensity of the control current varies within the cycle. The duration of the control current intensity that typically opens the valve is referred to herein and hereinafter as the drive duration. A reference relationship between, for example, the volumetric flow rate and the intensity and / or drive duration of the control current can be stored in the control device, so that for a given volumetric flow rate, the actual value of the control current and / or drive duration can be compared with the corresponding reference value. The reference relationship can be stored, for example, in the form of a characteristic curve or a combination of characteristic curves. For example, state characteristic values ​​can be specified in the form of percentage deviations.

[0039] Typically, leakage in hydraulic pumps or motors increases with wear. To achieve the same effective delivery rate in the case of a hydraulic pump or the same mechanical power in the case of a hydraulic motor, the high-pressure seat valve must be opened, for example, more frequently or further. In this regard, the wear condition of the hydraulic pump or motor can be described based on its condition characteristic values. Attached Figure Description

[0040] Exemplary embodiments of the invention will now be explained in more detail with reference to the accompanying drawings. The drawings show... Figure 1 This is a first embodiment of the proposed device for controlling a hydraulic pump with a high-pressure seat valve. Figure 2 This is a second embodiment of the proposed device for controlling a hydraulic pump having a high-pressure seat valve and a throttle valve. Figure 3 This is a third embodiment of the proposed device for controlling a hydraulic pump having a high-pressure seat valve and a low-pressure seat valve. Figure 4 This is a fourth embodiment of the proposed device for controlling a hydraulic pump having a high-pressure seat valve and a low-pressure seat valve, including pressure limiting valves. Figure 5 This is the fifth embodiment of the proposed device for controlling a hydraulic pump having a high-pressure seat valve and a low-pressure seat valve, including pressure limiting valves. Figure 6This is the sixth embodiment of the proposed device for controlling a hydraulic pump having a low-pressure seat valve and a high-pressure throttle valve. Figure 7 This is an embodiment of the proposed device for controlling a hydraulic motor. Figure 8 This is a schematic diagram illustrating the principle of the second embodiment of the adjustment unit. Figure 9 This is the seventh embodiment of the proposed device for controlling a hydraulic pump having a high-pressure seat valve and a low-pressure seat valve, including a pressure limiter and a pressure sensor. Figure 10 This is a schematic diagram illustrating the principle of an embodiment of a control device for performing a method of controlling a hydraulic pump or hydraulic motor. Detailed Implementation

[0041] Figure 1 The diagram shows a first embodiment of the proposed device 101 for controlling a hydraulic pump 12, based on a schematic diagram. Device 101 is part of a hydraulic system 14, which can operate an undefined consumer 16. The hydraulic system may include hydraulic components not shown, such as valves, diaphragms, etc. Consumer 16 may be, for example, a hydraulic cylinder through which components such as construction machinery can be moved.

[0042] Device 101 includes a hydraulic fluid reservoir 18 in which hydraulic fluid, particularly hydraulic oil, can be stored. Furthermore, device 101 includes a hydraulic pump 12 equipped with an inlet 20 and an outlet 22. The inlet 20 of the hydraulic pump 12 is connected to the hydraulic fluid reservoir 18 via a first low-pressure line 24, allowing the hydraulic pump 12 to draw hydraulic fluid from the reservoir 18. The outlet 22 of the hydraulic pump 12 is connected to the aforementioned consumer 16 via a high-pressure line 26. As a result, the hydraulic fluid drawn in by the hydraulic pump 12 can be delivered to the consumer 16, where pressure can be built up due to resistance from the hydraulic system or the consumer 16.

[0043] Furthermore, device 101 includes an adjustment unit 27 that interacts with and can be structurally integrated into the hydraulic pump 12. The delivery volume of the hydraulic pump 12, i.e., the volumetric flow rate provided by the hydraulic pump 12, can be varied via the adjustment unit 27. In the illustrated embodiment, the adjustment unit 27 is designed as an adjustment cylinder 28, which allows for the alteration of the so-called pivot angle α. The pivot angle α can be changed such that the delivery volume of the hydraulic pump 12 varies between 0% (theoretically) and 100%. The term "pivot angle" is commonly used for axial piston pumps, but the use of this device 101 is not limited to the control of axial piston pumps. The adjustment cylinder 28 has a piston 30 movably mounted axially within it, and is divided into a first pressure chamber 32 and a second pressure chamber 34. The first pressure chamber 32 is connected to the high-pressure line 26 via a high-pressure secondary line 36 or a working line 37, while the second pressure chamber 34 is directly or indirectly connected to the housing of the hydraulic pump 12 via a second low-pressure line 38 having the already mentioned hydraulic fluid reservoir 18. The second low-pressure line 38 can also be referred to as the leakage line or the tank line. The piston 30 is pre-tensioned relative to the first pressure chamber 32 by the return spring 39.

[0044] Furthermore, a high-pressure seat valve 40 is arranged in the high-pressure secondary line 36. In this embodiment, the high-pressure seat valve is designed as a high-pressure digital seat valve 41, which can be operated by a control device 42, for which an electrical wire is used. By actuating the high-pressure seat valve 40, the pressure level in the subsequent installed section of the high-pressure secondary line 36 can be affected. This section of the high-pressure secondary line 36 is referred to below as the working line 37.

[0045] The control device 42 is connected to at least one sensor 44 via wires. The sensor determines the actual value of the parameter and provides it to the control device 42, which adjusts according to the delivery volume of the hydraulic pump 12. Furthermore, the control device 42 is connected to an adjusting element 46 via wires, through which target values ​​for the characteristic parameters can be specified. The adjusting element 46 can, for example, be designed as an operating lever for construction machinery.

[0046] The control device 42 can also be connected via wires to one or more additional sensors 48, which can detect parameters that can affect control. When operating the high-pressure seat valve 40, the control device 42 can take these parameters into account to more quickly adapt the actual value to the target value. Sensors 44 and other sensors 48, as well as the adjusting element 46, provide their signals to the control device 42 electronically. Wireless connectivity can also be provided instead of wires.

[0047] The proposed device 101 operates as follows: First, the drive motor 62 of the hydraulic pump 12 is turned on, thereby starting the hydraulic pump 12. The hydraulic pump 12 delivers hydraulic fluid from the hydraulic fluid reservoir 18 to the consumer 16, where a certain pressure is established due to fluid resistance and delivery. Pressure also exists in the high-pressure line 26 and the high-pressure secondary line 36, viewed from the flow direction upstream of the high-pressure seat valve 40. The pressure in the working line 37 is lower than the pressure in the high-pressure secondary line 36 to create force balance within the regulating unit 27. For example, a user of construction machinery can now specify a specific target value for a characteristic parameter using the adjusting element 46, which can correspond to, for example, a specific volumetric flow rate of the hydraulic fluid in the consumer 16. The target value is fed to the control device 42. Simultaneously, the sensor 44 detects the actual value of the characteristic parameter at another appropriate location in the consumer 16 or the hydraulic system 14. To match the actual value with the target value, the high-pressure seat valve 40 is now actuated by the control device 42. Figure 1 As shown, the high-pressure seat valve 40 is a 2 / 2 seat valve, which can move between the open and closed positions. Furthermore... Figure 1 This shows that the high-pressure seat valve 40 is not electrically closed, meaning it is designed as a "normally closed" valve. Because the high-pressure seat valve 40 is designed as a seat valve, there is no leakage when closed.

[0048] In the following text, it is assumed that the high-pressure seat valve 40 is not initially actuated by the control device 42. Therefore, the high-pressure seat valve 40 is closed. The pressure built up in the consumer 16, and therefore in the high-pressure line 26 and the high-pressure secondary line 36 up to the high-pressure seat valve 40, is not transmitted to the first pressure chamber 32. Therefore, the return spring 39 of the pre-tensioned piston 30 is in a state corresponding to the minimum spring pre-tension. In this state, the regulating cylinder 28 interacts with the hydraulic pump 12, causing the hydraulic pump to occupy its maximum pivot angle α and output its maximum delivery. Due to the resistance of the consumer 16 or the hydraulic system and the further delivery of hydraulic fluid, the pressure in the consumer 16, the high-pressure line 26, and the high-pressure secondary line 36 further increases. The pressure increase is detected by the sensor 44. If the control device 42 determines that the actual value does not correspond to the target value, the delivery of the hydraulic pump 12 can be reduced. To this end, the control device 42 opens the high-pressure seat valve 40, allowing hydraulic fluid to flow through the high-pressure seat valve 40 to the first pressure chamber 32. The volume in the first pressure chamber 32 can be adjusted according to the pulse width of opening and closing the high-pressure seat valve 40. As the volume in the first pressure chamber 32 increases, the pressure there increases, thereby moving the piston 30 to the second pressure chamber 34, and compressing the return spring 39. Due to the movement of the piston, the pivot angle α and the delivery rate of the hydraulic pump 12 decrease. Once the actual value corresponds to the target value, the delivery rate no longer changes.

[0049] If piston 30 seals the first pressure chamber 32 and the second pressure chamber 34 leak-proofly, the piston position will remain unchanged. This also means that the pump's delivery rate cannot be increased again. However, in principle, there is always a certain leakage between the first pressure chamber 32 and the second pressure chamber 34, allowing a certain volume to flow from the first pressure chamber 32 into the second pressure chamber 34. Due to this leakage, the volume of hydraulic fluid in the first pressure chamber 32 decreases more or less rapidly, causing piston 30 to move back from the return spring 39 to the first pressure chamber 32. This displacement leads to an increase in the adjustment angle, resulting in an increase in the delivery rate of the hydraulic pump 12. This will cause the actual value to deviate from the target value again. To counteract this, control device 42 opens high-pressure seat valve 40, making the actual value correspond to the target value.

[0050] If the user of the construction machinery wants, for example, to perform faster cylinder movements, the delivery capacity of the hydraulic pump 12 must be increased. This is in Figure 1 In the illustrated embodiment, the leakage, as before, allows hydraulic fluid to flow from the first pressure chamber 32 into the second pressure chamber 34. Also as above, the return spring 39 returns the piston 30 to the first pressure chamber 32, thereby increasing the pivot angle α or the delivery volume. In this way, the hydraulic pump 12 can be controlled accordingly. It should be mentioned at this point that parameters can be incorporated into the controller via an additional sensor 48, and these parameters also affect the controller.

[0051] exist Figure 2 The diagram also shows a second embodiment of the proposed device 102 according to a principle switching diagram. The structure of the device 102 according to the second embodiment corresponds to... Figure 1 The structure of the first embodiment of the device 101 shown includes a secondary low-pressure line 50 branching off from the high-pressure secondary line 36 and opening into the second low-pressure line 38, in addition to the high-pressure seat valve 40 and the regulating cylinder 28. A low-pressure throttle valve 52 is arranged in the secondary low-pressure line 50. Hydraulic fluid can flow from the first pressure chamber 32 into the hydraulic fluid reservoir 18 via the secondary low-pressure line 50, without having to flow into the second pressure chamber 34 between the piston 30 and the regulating cylinder 28. Therefore, the regulating cylinder 28 can be designed to be leak-free, which is impossible by principle. However, leakage can be reduced through appropriate manufacturing precision. Reduced leakage keeps the pressure loss in the hydraulic system 14 low, thereby improving the operating efficiency of the hydraulic system 14.

[0052] As before, in order to increase the pivot angle α or the delivery capacity of the hydraulic pump 12, the piston 30 must move toward the first pressure chamber 32, in which a certain amount of hydraulic fluid must be discharged from the first pressure chamber 32. Although in the first embodiment of the proposed device 101 (as Figure 1In the example shown, the hydraulic fluid only maintains a path from the first pressure chamber 32 to the second pressure chamber 34. However, in the second embodiment, the hydraulic fluid can also be discharged from the first pressure chamber 32 via the secondary low-pressure line 50 and the low-pressure throttle valve 52. Because the hydraulic fluid can be discharged from the first pressure chamber 32 more quickly in the second embodiment, the control becomes more dynamic, thereby improving the response behavior.

[0053] exist Figure 3 The diagram also shows a third embodiment of the proposed device 103. The device 103 according to the third embodiment is similar to that according to... Figure 2 The apparatus 102 of the second embodiment shown is largely similar, except that the low-pressure seat valve 54 is arranged in the secondary low-pressure line 50 instead of the low-pressure throttle valve 52. The low-pressure seat valve is also designed as a low-pressure digital seat valve 55 and can be operated by the control device 42, just like the high-pressure seat valve 40. In the third embodiment, the hydraulic fluid flowing from the first pressure chamber 32 can be affected more purposefully than in the second embodiment, because the volumetric flow rate of the hydraulic fluid flowing from the first pressure chamber 32 can be specified by accordingly activating the low-pressure seat valve 54. If the adjusting element 46 requires an increase, for example, a target value for a relevant characteristic parameter in the consumer 16, the control device 42 can accordingly open the low-pressure seat valve 54, thereby increasing the pivot angle α or delivery rate of the hydraulic pump 12.

[0054] Figure 4 A fourth embodiment of the proposed device 104 is shown, which substantially corresponds to the one described in the figure below. Figure 3 The third embodiment differs primarily in that the high-pressure seat valve 40 is designed as a high-pressure seat valve 56 with integrated pressure limiting, in this case, as a high-pressure digital seat valve 57 with integrated pressure limiting function. Therefore, the high-pressure seat valve 40 has a pressure limiting function, which can be variably configured according to system specifications. If the pressure in the consumer 16, and therefore in the high-pressure line 26 and the high-pressure secondary line 36 up to the high-pressure seat valve 40, exceeds a certain value, the high-pressure seat valve 40 opens regardless of whether it is correspondingly activated by the control device 42. Due to the opening of the high-pressure digital seat valve 40, hydraulic fluid flows into the first pressure chamber 32, thereby causing the piston 30 to move upwards to the second pressure chamber 34, thus reducing the pivot angle α or delivery rate of the hydraulic pump 12. Therefore, the pressure in the supply lines cannot exceed the maximum pump pressure. This prevents damage to the hydraulic components of the hydraulic system 14.

[0055] Figure 5 A fifth embodiment of the proposed device 105 is shown, which largely corresponds to the one described in the figure below. Figure 3The third embodiment. However, a bypass line 58 is provided in the high-pressure secondary line 36, through which the high-pressure seat valve 40 can be bypassed. Therefore, hydraulic fluid can flow into the first pressure chamber 32 through the high-pressure seat valve 40 and through the bypass line 58. A pressure relief valve 60 is arranged in the bypass line 58. Figure 4 In the fourth embodiment of the device 104 shown in the invention, when the pressure in the high-pressure line 26 and the high-pressure secondary line 36 exceeds a certain value, the pressure relief valve 60 of the bypass line 58 also opens. Similarly, due to the opening of the pressure relief valve 60, the pivot angle α and the delivery volume of the hydraulic pump 12 decrease, thereby limiting the pressure in the hydraulic system 14.

[0056] Figure 6 A sixth embodiment of the proposed device 106 is shown, wherein the high-pressure secondary line 36 opens directly into the first pressure chamber 32 without arranging the high-pressure seat valve 40 in the high-pressure secondary line 36. However, a high-pressure throttle valve 64 is arranged in the high-pressure secondary line 36. A low-pressure seat valve 54 is arranged in the secondary low-pressure line 50, which can be operated by the control device 42 as in the various embodiments described above. The operation of the device 106 according to the sixth embodiment is as follows: as hydraulic fluid is delivered from the hydraulic reservoir 18 to the consumer 16, the pressure applied in the high-pressure secondary line 36 also increases in the consumer 16. However, in the first pressure chamber 32, the pressure applied in the high-pressure line 26 and the consumer 16 is not applied, but rather a pressure correspondingly reduced by the high-pressure throttle valve 64 is applied. Moreover, as described many times, the depressurization in the first pressure chamber 32 ensures a reduction in the pivot angle α of the hydraulic pump 12 and the delivery volume. In order to increase the pivot angle α and delivery capacity of the hydraulic pump 12, the low-pressure seat valve 54 is opened accordingly by the control device 42.

[0057] Figure 7 A device 72 for controlling the hydraulic motor 66 is shown, wherein the device 72 generally corresponds to the one shown according to the... Figure 3The device 103 for controlling the hydraulic pump 12 shown in the third embodiment is illustrated. However, in this case, the high-pressure line 26 is not connected to the consumer 16, but to the hydraulic fluid pressure reservoir 74, in which the hydraulic fluid is maintained at a certain pressure. The high-pressure line 26 is connected to the input port 20 of the hydraulic motor 66. The output port 22 of the hydraulic motor 66 is connected to the hydraulic fluid reservoir 18 via the return line 68. Therefore, the hydraulic fluid flows from the hydraulic fluid pressure reservoir 74 to the hydraulic fluid reservoir 18 and flows through the hydraulic motor 66. During this flow, the shaft 70 is driven, and the shaft is also connected to the consumer 76. Using the power transmitted by the shaft 70, the consumer 76 can be operated in a desired manner. Furthermore, the control method of the hydraulic motor 66 or the power generated therefrom is the same as that of the device 103 for controlling the hydraulic pump 12 according to the third embodiment. All embodiments of the devices 101 to 106 for controlling the hydraulic pump 12 can also be similarly used as the device 72 for controlling the hydraulic motor 66.

[0058] In all embodiments, the control device 42 may include power electronic devices that can be operated by software. Algorithms simulating different control characteristics can be stored in the software. Thus, the control device 42 may operate, for example, as a PI controller, a PID controller, or one of the above combined with fixed-value control. Different control characteristics can be selected depending on the application on the control device 42. No adjustments or replacements of components of the device 10 are required. Furthermore, the number of sensors 44 and other sensors 48 is unlimited. The measurement units measured by them can also be chosen with considerable freedom, wherein the unique limitation of the measurement units determined by the sensors 44 must be ensured, and these measurement units are also actually affected by the hydraulic pump 12 or the hydraulic motor 66.

[0059] It should be noted here that the terms "high-pressure line," "low-pressure line," etc., should not be interpreted as meaning that high or low pressure must always be present. These terms are primarily used to distinguish the relevant components of this device 10 and 72.

[0060] Figures 1 to 7 and Figure 9 The high-pressure secondary line 36, the working line 37, the second low-pressure line 38, the secondary low-pressure line 50, and the bypass line 58 are shown in dashed lines. This is intended to symbolize that these lines are control lines used to control the hydraulic pump 12 or the hydraulic motor 66, rather than primarily used to supply hydraulic fluid to the consumer 16.

[0061] also, Figures 1 to 7 and Figure 9 Circuits with and without pre-tensioned tank pressure are shown, but the proposed device for controlling hydraulic pump 12 or hydraulic motor 66 can also be used for closed circuits.

[0062] Figure 8A second embodiment of the regulating unit 27 based on a schematic diagram is shown. In the second embodiment of the regulating unit 27, when the piston 30 of the regulating unit 27 according to the first embodiment is pre-tensioned relative to the first pressure chamber 32 by the return spring 39, a counter-piston 78 is used for this purpose. The counter-piston 78 is slidably mounted in the reverse cylinder 79. Therefore, the function of the regulating unit 27 can be provided even at lower pressures, and thus the effective surface of the reverse cylinder 79 is smaller than the effective surface of the regulating cylinder 28, for example, at a ratio of 1:4. The counter-piston 78 closes the first reverse pressure chamber 80. The piston 30 is connected to the counter-piston 78 by a movably mounted connecting rod 86, which, in the example of an axial piston pump, is a pivot support. If the piston 30 moves to the second pressure chamber 34 due to an increase in pressure in the first pressure chamber 32, the connecting rod 86 transmits the movement to the counter-piston 78, causing the counter-piston 78 to move in the opposite direction to the first reverse pressure chamber 80. The medium contained therein is thus displaced, and the medium may correspond to the hydraulic fluid of the remaining device 10. As the first reverse pressure chamber 80 actively supplies the medium, the piston 30 is moved back to the first pressure chamber 32.

[0063] It is conceivable that the opposing piston 78 divides the reverse cylinder 79 into the previously mentioned first reverse pressure chamber 80 and second reverse pressure chamber 82. The first reverse pressure chamber 80 and the second reverse pressure chamber 82 can be integrated into the device 10, allowing the pressure in both chambers to be selectively altered to achieve specific control characteristics. The piston 30 and the opposing piston 78 have a specific area ratio to generate the advantage of piston 30 at the same pressure level. A combination of the opposing piston 78 and an additional spring for returning piston 30 is also possible (not shown).

[0064] Figure 9 The seventh embodiment of the proposed device 107 is shown, which substantially corresponds to the one described in the figure below. Figure 3 The fourth embodiment differs primarily in that the pressure present in the working line 37 can be detected by a pressure sensor 88. The pressure sensor 88 interacts with the control device 42, allowing the high-pressure seat valve 40 and / or the low-pressure seat valve 54 to be activated in consideration of the pressure detected by the pressure sensor 88. Therefore, the pressure in the working line 37 can be included as an additional variable in the system control. The pressure detected in the working line 37 corresponds to the pressure applied to the regulating unit 27. By including the pressure in the working line 37 in the control, the regulating unit 27 can be more directly influenced by the control device 42. The regulating unit 27 typically regulates the delivery rate of the hydraulic pump 12. If other parameters of the hydraulic pump are known, any delivery rate can be imprinted using a further embodiment of the hydraulic pump 12. Therefore, the hydraulic power of the hydraulic pump 12 can be matched with the power of the drive motor 62.

[0065] The control device 42 can be designed to determine the position of the piston 30 in the regulating cylinder 28 based on the pressure detected by the pressure sensor 88, thereby activating the high-pressure seat valve 40 and / or the low-pressure seat valve 54 by taking into account the position of the piston 30 determined by the control device 42. The position of the piston 30 can also be used to determine the pivot angle α of the hydraulic pump 12. Therefore, with this arrangement, the pivot angle α can be detected without a pivot angle sensor. This allows for a simpler design of the hydraulic pump 12. Furthermore, active influence of the pivot angle α is also possible.

[0066] The detection of pressure in the working pipeline 37 and the interaction between the pressure sensor 88 and the control device 42 can be applied in the manner described above. Figure 1 , Figure 2 and Figures 4 to 6 The illustrated embodiment. The pressure sensor 88 can also interact with the control device 42, allowing the high-pressure seat valve 40 and / or the low-pressure seat valve 54 to be activated based on the pressure detected by the pressure sensor 88.

[0067] like Figure 7 As shown, if the device is designed to control the hydraulic motor 66, the pressure in the working line 37 can be detected accordingly by the pressure sensor 88. Figure 9 As described in the embodiment, any amount of fluid injected per revolution can be imprinted on the hydraulic motor 66. Therefore, the hydraulic power of the hydraulic motor 66 can be matched to the power consumed on the shaft 70. The pivot angle α of the hydraulic motor 66 can also be detected accordingly and actively influenced.

[0068] In the above embodiments, the high-pressure seat valve 40 and / or the low-pressure seat valve 54 can be activated by the activation value of the control device 42, such as... Figure 10 As shown. In this case, the reference value 92 of the start-up value can be stored in the control device 42, depending on the actual value 94 of the characteristic parameter that can affect the delivery of the hydraulic pump 12 or the amount of fluid per revolution to be received by the hydraulic motor 66. The control device 42 is preferably designed to detect the actual value 94 of the characteristic parameter and the corresponding actual value 90 of the start-up value, and to determine the state characteristic 96 of the hydraulic pump 12 or the hydraulic motor 66 based on a comparison of the actual value 90 of the start-up value with the reference value 92 of the start-up value belonging to the actual value 94 of the characteristic parameter. In this further embodiment of the invention, it is particularly advantageous that no further components are required to implement them, and only the control device 42 must be adapted accordingly.

[0069] A method for controlling a hydraulic pump 12 of a hydraulic motor 66, wherein a high-pressure seat valve 40 and / or a low-pressure seat valve 54 can be activated according to a start value, includes a first step 101 in which an actual value 94 of at least one characteristic parameter that may affect the input quantity of the hydraulic pump 12 or the amount of fluid to be received by the hydraulic motor 66 per revolution is detected. In a second step 102, an actual value 90 of the start value corresponding to the actual value of the characteristic parameter is also detected, so that in a third step 103, a state characteristic value 96 of the hydraulic pump 12 or the hydraulic motor 66 is determined by comparing the actual value 90 of the start value with a reference value 92 belonging to the start value of the actual value 94 of the characteristic parameter.

[0070] Characteristic parameters may include the volumetric flow rate of the hydraulic fluid. The starting value may be formed by the intensity of the control current and / or the control time of the high-pressure seat valve and / or the low-pressure seat valve, as well as their starting frequency and / or cycle time. A reference relationship 98 between the actual volumetric flow rate 94a and the actual intensity 90a and / or the actual drive duration 90b of the control current can be stored in the control device 42, so that for a specific value of the actual volumetric flow rate 94a, the actual intensity 90a and / or the actual control time 90b can be compared with the corresponding reference value 92. The state characteristic value 96 may be given, for example, as a percentage deviation.

[0071] List of reference numerals 10 devices Devices 101–107 12 hydraulic pumps 14 Hydraulic System 16 Consumables 18 hydraulic storage tank 20 input ports 22 output ports 24 First Low-Pressure Pipeline 26 High-pressure pipelines 27 adjustment units 28 regulating cylinder 30 pistons 32 First Pressure Chamber 34 Second Pressure Chamber 36 High-voltage secondary pipelines 37 working pipelines 38 Second Low-Pressure Pipeline 39 return spring 40 High-Pressure Seat Valve 41 High-pressure digital seat valve 42 Control Device 44 sensors 46 Adjustment Components 48 Other Sensors 50 secondary low-pressure pipeline 52 Low-pressure throttle valve 54 Low-pressure seat valve 55 Low-pressure digital seat valve 56 High-pressure seat valve with integrated pressure limiting 57 High-pressure digital seat valve with integrated pressure limiting 58 Bypass pipeline 60 pressure relief valve 62 drive motors 64 High-pressure throttle valve 66 hydraulic motor 68 Return line 70 axis Device 72 74 Hydraulic Pressure Storage Unit 76 Consumables 78 top piston 79 reverse cylinder 80 First Reverse Pressure Chamber 82 Second Reverse Pressure Chamber 86-link 88 pressure sensor The actual value of the 90 startup value Actual intensity of 90A control current 90b Actual Control Time 92 Startup Value Reference Value Actual values ​​of 94 characteristic parameters 94a Actual Volume Flow Rate 96 state eigenvalues 98 Reference Relationship 101 First Step 102 Second Step 103 Third Step α Pivot angle.

Claims

1. A device (10) for controlling a hydraulic pump (12), comprising: Hydraulic fluid reservoir (18). A hydraulic pump (12) having an inlet (20) and an outlet (22), wherein The inlet (20) is connected to the hydraulic fluid reservoir (18) via a first low-pressure line (24). The output port (22) is connected to a high-pressure line (26) that can be connected to the consumer (16). An adjustment unit (27) interacts with the hydraulic pump (12) and can change the delivery rate of the hydraulic pump (12). The adjustment unit (27) is located in a high-pressure secondary pipeline (36) connected to the high-pressure pipeline (26). A high-pressure seat valve (40) is arranged in the high-pressure secondary pipeline (36) and interacts with the regulating unit (27). Sensor (44), which is capable of detecting the actual value of at least one characteristic parameter affected by the delivery volume of the hydraulic pump (12), The adjustment element (46) allows the specification of a target value for the characteristic parameter, and A control device (42) interacts with the sensor (44) and the adjusting element (46) to enable the high-pressure seat valve (40) to activate taking into account the actual value detected by the sensor (44) and the target value specified by the adjusting element (46). The high-pressure seat valve (40) is implemented as a high-pressure seat valve (56) with integrated pressure limiting function; The adjustment unit (27) includes or is designed as an adjustment cylinder (28), wherein The piston (30) is slidably mounted in the adjusting cylinder (28). The piston (30) divides the regulating cylinder (28) into a first pressure chamber (32) and a second pressure chamber (34); the second pressure chamber (34) is connected to the hydraulic fluid reservoir (18) via a second low-pressure line (38). Between the high-pressure seat valve (40) and the regulating unit (27), a secondary low-pressure line (50) branches off from the high-pressure secondary line (36) and leads to a second low-pressure line (38), and A low-pressure seat valve is arranged in the secondary low-pressure line (50), which can be activated by the control device (42) taking into account the actual value detected by the sensor (44) and the target value specified by the adjustment element (46).

2. The apparatus (10) according to claim 1. The first pressure chamber (32) is connected to the high-pressure pipeline (26) via a high-pressure secondary pipeline (36) and a working pipeline (37). The piston (30) is pre-tensioned relative to the first pressure chamber (32) by a return spring (39) and / or a counter-piston (78).

3. The apparatus (10) according to claim 1. Its features are, The high-pressure secondary pipeline (36) has a bypass pipeline (58) that bypasses the high-pressure seat valve (40), and A pressure relief valve (60) is arranged in the bypass line (58).

4. A device (10) for controlling a hydraulic pump (12), comprising: Hydraulic fluid reservoir (18). A hydraulic pump (12) having an inlet (20) and an outlet (22), wherein The inlet (20) is connected to the hydraulic fluid reservoir (18) via a first low-pressure line (24). The output port (22) is connected to a high-pressure line (26) that can be connected to the consumer (16). An adjustment unit (27) interacts with a hydraulic pump (12) and can change the delivery rate of the hydraulic pump (12). The adjustment unit (27) is located in a high-pressure secondary pipeline (36) connected to the high-pressure pipeline (26). The secondary low-pressure pipeline (50) branches off from the high-pressure secondary pipeline (36). A low-pressure seat valve (54) is arranged in the secondary low-pressure line (50) and interacts with the regulating unit. Sensor (44), which is capable of detecting the actual value of at least one characteristic parameter that is affected by the delivery volume of the hydraulic pump (12) and is related to the consumer (16), The adjustment element (46) allows the specification of a target value for the characteristic parameter, and A control device (42) interacts with the sensor (44) and the adjustment element (46) to enable the low-pressure seat valve to be activated taking into account the actual value detected by the sensor (44) and the target value specified by the adjustment element (46).

5. The apparatus (10) according to claim 4. characterized in that The adjustment unit (27) includes or is designed as an adjustment cylinder (28), wherein, The piston (30) is slidably mounted in the adjusting cylinder (28). The piston (30) divides the regulating cylinder (28) into a first pressure chamber (32) and a second pressure chamber (34). The first pressure chamber (32) is connected to the high-pressure pipeline (26) via a high-pressure secondary pipeline (36) and a working pipeline (37). The second pressure chamber (34) is connected to the hydraulic fluid reservoir (18) via a second low-pressure line (38), and The piston (30) is pre-tensioned relative to the first pressure chamber (32) by a return spring (39) and / or a counter-piston (78).

6. The apparatus (10) according to claim 4 or 5. Its features are, A fixed or variable high-pressure throttle valve (64) is arranged in the high-pressure secondary pipeline (36).

7. A device (72) for controlling a hydraulic motor (66), comprising: Hydraulic fluid pressure storage device (74). A hydraulic motor having an input port (20) and an output port (22), wherein The inlet (20) is connected to the hydraulic fluid pressure reservoir (74) via a high-pressure pipeline (26). The output port (22) is connected to the hydraulic fluid reservoir (18) via the return line (68). An adjustment unit (27) interacts with the hydraulic motor and is capable of changing the amount of fluid to be received by the hydraulic motor (66) per revolution. The adjustment unit (27) includes or is designed as an adjustment cylinder (28). A high-pressure seat valve (40) is arranged in the high-pressure secondary pipeline (36) and interacts with the regulating unit (27). Sensor (44) is capable of detecting the actual value of at least one characteristic parameter affected by the fluid flow rate per revolution, which can be received by the hydraulic motor (66). The adjustment element (46) allows the specification of a target value for the characteristic parameter, and A control device (42) interacts with the sensor (44) and the adjustment element (46) to enable the high-pressure seat valve (40) to be activated taking into account the actual value detected by the sensor (44) and the target value specified by the adjustment element (46); The piston (30) is slidably mounted in the adjusting cylinder (28). The piston (30) divides the regulating cylinder (28) into a first pressure chamber (32) and a second pressure chamber (34); the second pressure chamber (34) is connected to the hydraulic fluid reservoir (18) via a second low-pressure line (38). Between the high-pressure seat valve (40) and the regulating unit (27), a secondary low-pressure line (50) branches off from the high-pressure secondary line (36) and leads to a second low-pressure line (38), and A low-pressure seat valve is arranged in the secondary low-pressure line (50), which can be activated by the control device (42) taking into account the actual value detected by the sensor (44) and the target value specified by the adjustment element (46).

8. The device (10) for controlling the hydraulic pump (12) according to claim 1. Its features are, The low-pressure seat valve (54) is designed as a low-pressure digital seat valve (55) or The high-pressure seat valve (56) with integrated pressure limiting function is designed as a high-pressure digital seat valve (57) with integrated pressure limiting function.

9. The device (10) for controlling the hydraulic pump (12) according to claim 4. Its features are, The low-pressure seat valve (54) is designed as a low-pressure digital seat valve (55).

10. The device (10) for controlling a hydraulic motor (66) according to claim 7. Its features are, The high-pressure seat valve (40) is designed as a high-pressure digital seat valve (41) or The low-pressure seat valve (54) is designed as a low-pressure digital seat valve (55).

11. The device (10) for controlling the hydraulic pump (12) according to claim 2. Its features are, The pressure present in the working line (37) can be detected by a pressure sensor (88), wherein the pressure sensor (88) interacts with the control device (42) so that the high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated taking into account the pressure detected by the pressure sensor (88).

12. The device (10) for controlling the hydraulic pump (12) according to claim 5. Its features are, The pressure present in the working line (37) can be detected by a pressure sensor (88), wherein the pressure sensor (88) interacts with the control device (42) so that the low-pressure seat valve (54) can be activated taking into account the pressure detected by the pressure sensor (88).

13. The device (72) for controlling a hydraulic motor (66) according to claim 7. Its features are, The first pressure chamber (32) is connected to the high-pressure pipeline (26) via a high-pressure secondary pipeline (36) and a working pipeline (37). The pressure present in the working line (37) can be detected by a pressure sensor (88), wherein the pressure sensor (88) interacts with the control device (42) so that the high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated taking into account the pressure detected by the pressure sensor (88).

14. The device (10) for controlling the hydraulic pump (12) according to claim 11. Its features are, The control device (42) is designed to determine the position of the regulating unit (27) based on the pressure detected by the pressure sensor (88), wherein the high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated taking into account the position of the regulating unit (27) determined by the control device (42).

15. The device (10) for controlling the hydraulic pump (12) according to claim 12. Its features are, The control device (42) is designed to determine the position of the regulating unit (27) based on the pressure detected by the pressure sensor (88), wherein the low-pressure seat valve (54) is able to be activated taking into account the position of the regulating unit (27) determined by the control device (42).

16. The device (72) for controlling a hydraulic motor (66) according to claim 13. Its features are, The control device (42) is designed to determine the position of the regulating unit (27) based on the pressure detected by the pressure sensor (88), wherein the high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated taking into account the position of the regulating unit (27) determined by the control device (42).

17. The device (10) for controlling the hydraulic pump (12) according to claim 1. Its features are, The high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated by the control device (42) according to the activation value. The reference value for the starting value is stored in the control device (42), and the reference value depends on the actual value of the characteristic parameter affected by the delivery volume of the hydraulic pump (12), and The control device (42) is designed to detect the actual value of the start-up value corresponding to the actual value of the characteristic parameter, and to determine the state characteristic value of the hydraulic pump (12) based on a comparison between the actual value of the start-up value and a reference value of the start-up value associated with the actual value of the characteristic parameter.

18. The device (10) for controlling the hydraulic pump (12) according to claim 4. Its features are, The low-pressure seat valve (54) can be activated by the control device (42) according to the activation value. The reference value for the starting value is stored in the control device (42), and the reference value depends on the actual value of the characteristic parameter affected by the delivery volume of the hydraulic pump (12), and The control device (42) is designed to detect the actual value of the start-up value corresponding to the actual value of the characteristic parameter, and to determine the state characteristic value of the hydraulic pump (12) based on a comparison between the actual value of the start-up value and a reference value of the start-up value associated with the actual value of the characteristic parameter.

19. The device (72) for controlling a hydraulic motor (66) according to claim 7. Its features are, The high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated by the control device (42) according to the activation value. The reference value for the starting value is stored in the control device (42), and the reference value depends on the actual value of the characteristic parameter affected by the fluid flow rate per revolution to be received by the hydraulic motor (66), and The control device (42) is designed to detect the actual value of the start value corresponding to the actual value of the characteristic parameter, and to determine the state characteristic value of the hydraulic motor (66) based on a comparison between the actual value of the start value and a reference value of the start value associated with the actual value of the characteristic parameter.

20. A method for controlling a hydraulic pump (12) according to claim 1, The high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated according to the activation value, including the following steps: The actual value of at least one characteristic parameter that can be affected by the delivery volume of the hydraulic pump (12) is detected. Detect the corresponding actual value of the startup value. The state characteristic value of the hydraulic pump (12) is determined by comparing the actual value of the start-up value with a reference value of the start-up value associated with the actual value of the characteristic parameter.

21. A method for controlling a hydraulic pump (12) according to claim 4, The low-pressure seat valve (54) can be activated according to the activation value, including the following steps: The actual value of at least one characteristic parameter that can be affected by the delivery volume of the hydraulic pump (12) is detected. Detect the corresponding actual value of the startup value. The state characteristic value of the hydraulic pump (12) is determined by comparing the actual value of the start-up value with a reference value of the start-up value associated with the actual value of the characteristic parameter.

22. A method for controlling a hydraulic motor (66) according to claim 7, The high-pressure seat valve (40) or the low-pressure seat valve (54) can be activated according to the activation value, including the following steps: The actual value of at least one characteristic parameter affected by the amount of fluid injected per revolution, which can be received by the hydraulic motor (66), is detected. Detect the corresponding actual value of the startup value. The state characteristic value of the hydraulic motor (66) is determined by comparing the actual value of the start-up value with a reference value of the start-up value associated with the actual value of the characteristic parameter.

23. The device (10) for controlling the hydraulic pump (12) according to claim 17. Its features are, The conveying capacity forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the high-pressure seat valve (40) or the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

24. The device (10) for controlling the hydraulic pump (12) according to claim 18. Its features are, The conveying capacity forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

25. The device (72) for controlling a hydraulic motor (66) according to claim 19. Its features are, The amount of liquid injected per revolution forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the high-pressure seat valve (40) or the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

26. The method of the apparatus for controlling the hydraulic pump (12) according to claim 20, Its features are, The conveying capacity forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the high-pressure seat valve (40) or the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

27. The method of the apparatus for controlling the hydraulic pump (12) according to claim 21, Its features are, The conveying capacity forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

28. The method of the apparatus for controlling a hydraulic motor (66) according to claim 22, Its features are, The amount of liquid injected per revolution forms characteristic parameters. and / or The starting value is formed by the intensity of the control current and / or control time of the high-pressure seat valve (40) or the low-pressure seat valve (54), or by its starting frequency and / or cycle time.

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