Hydraulic pump lifespan determination system

Abstract

To provide a life determination system for a hydraulic pump that can accurately grasp its residual life.SOLUTION: A life determination system 4 for a hydraulic pump 11 to be driven by a motor 2 includes a pump controller 5. Every time a predetermined period elapses, the pump controller 5 calculates equivalent operation time of the hydraulic pump 11 in the predetermined period on the basis of actual operation time of the motor 2, transition of rotation speed of the motor 2, transition of discharge pressure of the hydraulic pump 11, and transition of temperature of hydraulic fluid in the predetermined time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a lifespan determination system for a hydraulic pump. [Background technology]

[0002] 2. Description of the Related Art Conventionally, hydraulic pumps that are driven by a prime mover such as an engine or an electric motor have been known. The manufacturer of the hydraulic pump may provide a lifespan for the hydraulic pump.

[0003] Although it is not a technology for determining the life span, Patent Document 1 discloses a technology for detecting wear of a hydraulic pump. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-280688 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the lifespan provided by manufacturers is based on the assumption that the hydraulic pump will be used under specified conditions, and therefore the remaining lifespan varies greatly depending on the operating conditions of the hydraulic pump.

[0006] Therefore, an object of the present disclosure is to provide a lifespan determination system for a hydraulic pump that can accurately determine the remaining lifespan. [Means for solving the problem]

[0007] The present disclosure provides a lifespan determination system for a hydraulic pump driven by a prime mover, the system including a pump controller that calculates, each time a predetermined period elapses, an equivalent operating time of the hydraulic pump during the predetermined period based on the actual operating time of the prime mover during the predetermined period, a change in the rotation speed of the prime mover, a change in the discharge pressure of the hydraulic pump, and a change in the temperature of the working fluid. [Effects of the Invention]

[0008] According to the present disclosure, a lifespan determination system for a hydraulic pump is provided that can accurately determine the remaining lifespan. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a lifespan determination system for a hydraulic pump according to an embodiment; [Figure 2] 2 is a graph showing changes over time in the rotation speed of a prime mover, the operation amount of an operating device, and the discharge pressure of a hydraulic pump when the life determination system shown in FIG. 1 is installed in a hydraulic excavator. [Figure 3A] 10 is a graph showing changes over time in the discharge pressure of a hydraulic pump during a predetermined period. [Figure 3B] 10 is a graph showing a histogram of the discharge pressure of a hydraulic pump over a predetermined period of time. [Figure 4A] 10 is a graph showing the relationship between the simple average value of the rotation speed of the prime mover within a predetermined period and the first coefficient. [Figure 4B] 10 is a graph showing the relationship between a weighted average value of the discharge pressure of the hydraulic pump within a predetermined period and a second coefficient. [Figure 4C] 10 is a graph showing the relationship between the average temperature of the working fluid within a predetermined period and the third coefficient. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 shows a lifespan determination system 4 according to one embodiment. The lifespan determination system 4 is a system for determining the lifespan of a hydraulic pump 11.

[0011] The lifespan determination system 4 can be installed in various machines together with the hydraulic pump 11. For example, machines on which the lifespan determination system 4 and the hydraulic pump 11 can be installed include construction machines such as hydraulic excavators and wheel loaders, and industrial machines such as press machines.

[0012] The hydraulic pump 11 is driven by a prime mover 2. The prime mover 2 may be an engine or an electric motor. The type of the hydraulic pump 11 is not particularly limited, and the hydraulic pump 11 may be, for example, any of a vane pump, a gear pump, a screw pump, and a piston pump.

[0013] In this embodiment, the hydraulic pump 11 is a variable displacement axial piston pump (a swash plate pump or a bent axis pump), and the displacement of the hydraulic pump 11 is changed by a regulator 12. Also, in this embodiment, the minimum displacement of the hydraulic pump 11 is greater than zero. However, the minimum displacement of the hydraulic pump 11 may be zero. Alternatively, the displacement of the hydraulic pump 11 may be fixed.

[0014] The hydraulic pump 11 supplies hydraulic fluid to at least one hydraulic actuator 14. In the illustrated example, the hydraulic actuator 14 is a double-acting cylinder, but the hydraulic actuator 14 may also be a single-acting cylinder. Alternatively, the hydraulic actuator 14 may be a hydraulic motor.

[0015] In this embodiment, the hydraulic pump 11 is connected to the hydraulic actuator 14 via the control valve 13. If the hydraulic pump 11 is a bidirectional pump in which the discharge direction of the hydraulic fluid changes depending on the rotation direction, the hydraulic pump 11 may be connected to the hydraulic actuator 14 so as to form a closed circuit.

[0016] The prime mover 2 is controlled by a prime mover controller 3. If the prime mover 2 is an engine, the prime mover controller 3 adjusts the fuel injection amount and engine speed. If the prime mover 2 is, for example, a servo motor, the prime mover controller 3 is a servo amplifier.

[0017] The lifespan determination system 4 includes a pump controller 5, a pressure sensor 8, and a temperature sensor 7. The pressure sensor 8 measures the discharge pressure P of the hydraulic pump 11, and the temperature sensor 7 measures the temperature T of the hydraulic fluid. In this embodiment, the pressure sensor 8 and the temperature sensor 7 are provided in a supply line between the hydraulic pump 11 and the control valve 13, but the temperature sensor 7 may also be provided in a tank that stores the hydraulic fluid.

[0018] Although not shown, an unloading line branches off from the supply line between the hydraulic pump 11 and the control valve 13, and an unloading valve is provided on this unloading line. When the control valve 13 is in the neutral position, the unloading valve is fully open, returning the hydraulic fluid discharged from the hydraulic pump 11 to the tank through the unloading line, and when the control valve 13 moves from the neutral position, the unloading valve reduces its opening depending on the amount of movement. In addition, a relief line branches off from the supply line, and a relief valve is provided on this relief line. The relief valve plays a role in maintaining the discharge pressure P of the hydraulic pump 11 at or below a predetermined value.

[0019] The pump controller 5 controls the regulator 12. The machine on which the hydraulic pump 11 is mounted includes an operating device for operating a hydraulic actuator 14 via a control valve 13. The pump controller 5 controls a regulator 12 so that the capacity of the hydraulic pump 11 increases as the operating amount of the operating device increases.

[0020] For example, the operating device is an electric joystick including an operating lever, and the electric joystick outputs an electric signal corresponding to the tilt angle of the operating lever to the pump controller 5. The operating device may be a pilot operated valve that outputs pilot pressure to the pilot port of the control valve 13. In this case, the pilot pressure output from the pilot operated valve is measured by a pressure sensor and input to the pump controller 5.

[0021] With respect to pump controller 5, the functionality of the elements disclosed herein may be implemented using general purpose processors, special purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or other similar devices configured or programmed to perform the disclosed functions. The functions can be implemented using circuits or processing circuits that include transistors and other circuitry, or combinations thereof. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. In the case of a processor, where the hardware is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0022] Furthermore, pump controller 5 transmits and receives various signals to and from prime mover controller 3. Prime mover controller 3 includes an hour meter (usually called an hour meter) that measures the actual operating time H of prime mover 2. The hour meter does not necessarily have to be included in prime mover controller 3, and may be electrically connected to prime mover controller 3. Prime mover controller 3 is also electrically connected to a rotation speed sensor that measures the rotation speed N of prime mover 2. Prime mover controller 3 inputs the actual operating time H and rotation speed N of prime mover 2 to pump controller 5.

[0023] In this embodiment, the lifespan determination system 4 also includes a rotation speed selection device 6 that allows the user to change the set rotation speed of the prime mover 2. For example, the rotation speed selection device 6 is a dial type that allows the user to select one of a plurality of set rotation speeds that are divided into a plurality of ranks at predetermined rotation speed intervals. For example, the set rotation speed for rank 1 is 1000 rpm, the set rotation speed for rank 2 is 1200 rpm, and the set rotation speed for rank 6 is 2000 rpm.

[0024] Pump controller 5 inputs set rotation speed Ns selected by rotation speed selector 6 to prime mover controller 3. Prime mover controller 3 controls prime mover 2 so that rotation speed N measured by the rotation speed sensor becomes the set rotation speed Ns.

[0025] Furthermore, the prime mover controller 3 controls the prime mover 2 so that the prime mover 2 performs idling operation when the hydraulic pump 11 is not supplying working fluid to the hydraulic actuator 14. Idling operation is an operation in which the rotation speed N of the prime mover 2 is kept lower than the set rotation speed Ns. In this embodiment, idling operation includes low idling operation at a relatively low rotation speed and high idling operation at a relatively high rotation speed. However, the prime mover 2 does not necessarily have to perform idling operation.

[0026] When the above-mentioned operating device is being operated, the pump controller 5 transmits an operation signal to the prime mover controller 3. When the operation signal is received while the prime mover 2 is idling, the prime mover controller 3 ends the idling operation and sets the rotation speed N of the prime mover 2. The engine shifts to normal operation, maintaining the constant rotation speed Ns. Furthermore, when a predetermined time has elapsed since the transmission of the in-operation signal was stopped, the engine controller 3 shifts from normal operation to idling operation.

[0027] For example, Fig. 2 shows changes over time in the rotation speed N of the prime mover 2, the operation amount of the operating device, and the discharge pressure P of the hydraulic pump 11 when the lifespan determination system 4 is installed on a hydraulic excavator. When the prime mover 2 is started at time t0, the discharge pressure P of the hydraulic pump 11 rises slightly because the minimum displacement of the hydraulic pump 11 is greater than zero as described above.

[0028] Immediately after starting the prime mover 2, the prime mover controller 3 performs low idling operation. The rotation speed N of the prime mover 2 during low idling operation (usually simply called idling rotation speed) is, for example, 20 to 95% of the set rotation speed Ns.

[0029] When the operating device is operated at time t1, the pump controller 5 sends an operating signal to the prime mover controller 3, and the prime mover controller 3 transitions from low idling operation to normal operation. In addition, the pump controller 5 controls the regulator 12 in accordance with the amount of operation of the operating device.

[0030] When operation of all operating devices is stopped at time t2, pump controller 5 stops sending the operation-in-progress signal to prime mover controller 3. When a predetermined time has elapsed since transmission of the operation-in-progress signal was stopped and time t3 has arrived, prime mover controller 3 transitions from normal operation to high idling operation (in other words, idling operation is restarted). The rotation speed N of prime mover 2 during high idling operation is higher than the rotation speed N during low idling operation, and is, for example, 25 to 95% of the set rotation speed Ns.

[0031] When any of the operating devices is operated at time t4, the pump controller 5 transmits an operation-in-progress signal to the prime mover controller 3, and the prime mover controller 3 transitions from high idling operation to normal operation.

[0032] Thereafter, for example, at time t5, when an even higher set rotation speed Ns is selected by the rotation speed selection device 6, the pump controller 5 inputs that set rotation speed Ns to the prime mover controller 3, and the prime mover controller 3 controls the prime mover 2 based on that set rotation speed Ns.

[0033] Next, a detailed description will be given of a method by which the pump controller 5 determines the lifespan of the hydraulic pump 11. Each time a predetermined period A elapses, the pump controller 5 calculates the equivalent operating time Li of the hydraulic pump 11 during the predetermined period A based on the actual operating time Ha of the prime mover 2 during the predetermined period A, the progress of the rotation speed N of the prime mover 2, the progress of the discharge pressure P of the hydraulic pump 11, and the progress of the temperature T of the working fluid.

[0034] The predetermined period A is from the start of the prime mover 2 or the end of idling operation to the stop of the prime mover 2 or the start of idling operation. That is, in Fig. 2, the first predetermined period A is from time t1 to time t3. Note that the predetermined period A may be from the start of the prime mover 2 to the stop of the prime mover 2, or from the end of idling operation to the restart of idling operation.

[0035] Furthermore, if the set rotation speed Ns of the prime mover 2 is changed after the idling operation has ended, the pump controller 5 changes the start point of the predetermined period A from the time when the idling operation has ended to the time when the set rotation speed Ns of the prime mover 2 was changed. In other words, the second predetermined period A starts from time t5.

[0036] To calculate the equivalent operating time Li, the pump controller 5 determines a first coefficient Kn from the change in the rotation speed N of the prime mover 2 during the predetermined period A, determines a second coefficient Kp from the change in the discharge pressure P of the hydraulic pump 11 during the predetermined period A, and determines a third coefficient Kt from the change in the temperature T of the working fluid during the predetermined period A. Thereafter, as shown in the following equation (1), the equivalent operating time Li of the hydraulic pump 11 during the predetermined period A is calculated by multiplying the actual operating time Ha of the prime mover 2 during the predetermined period A by the first coefficient Kn, the second coefficient Kp, and the third coefficient Kt. Therefore, the equivalent operating time Li of the hydraulic pump 11 can be calculated using a simple equation. Li = Kn × Kp × Kt × Ha (1)

[0037] The calculation of the equivalent operating time Li of the hydraulic pump 11 is performed during a period B after the predetermined period A. After the predetermined period A, the pump controller 5 stores the discharge pressure P of the hydraulic pump 11 measured by the pressure sensor 8 during the predetermined period A shown in Fig. 3A in the form of a histogram as shown in Fig. 3B. For example, the histogram in Fig. 3B is obtained by extracting pressure values ​​for each short time (for example, 0.01 to 0.05 s) from the pressure waveform shown in Fig. 3A and tallying these pressure values ​​for each 5 MPa interval.

[0038] Similarly, after a predetermined period A has elapsed, the pump controller 5 creates a histogram of the temperature T of the working fluid measured by the temperature sensor 7 during the predetermined period A and stores the histogram, and also creates a histogram of the rotation speed N of the prime mover 2 obtained from the prime mover controller 3 during the predetermined period A and stores the histogram.

[0039] In determining the first coefficient Kn, the pump controller 5 calculates a simple average value Na of the rotation speed N of the prime mover 2 over a predetermined period A. Then, as shown in Fig. 4A, when the simple average value Na is equal to the reference rotation speed Nr, the pump controller 5 determines the first coefficient Kn to be 1.0. Furthermore, when the simple average value Na is smaller than the reference rotation speed Nr, the pump controller 5 decreases the first coefficient Kn as the simple average value Na decreases, and when the simple average value Na is greater than the reference rotation speed Nr, the pump controller 5 increases the first coefficient Kn as the simple average value Na increases.

[0040] In Fig. 4A, the minimum value of the first coefficient Kn is 0.8 and the maximum value is 1.15, but these can be changed as appropriate. Also, in Fig. 4A, the line showing the relationship between Na and Kn is a broken line made up of two straight lines with different slopes, but the line showing the relationship between Na and Kn may be a single straight line or a curve that is convex upward or downward.

[0041] To determine the second coefficient Kp, the pump controller 5 calculates a weighted average value Pa of the discharge pressure P of the hydraulic pump 11 over a predetermined period A. For example, the pump controller 5 calculates the weighted average value Pa using the following equation.

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[0042] 4B, when the weighted average value Pa is equal to the reference discharge pressure Pr, the pump controller 5 determines the second coefficient Kp to be 1.0. When the weighted average value Pa is smaller than the reference discharge pressure Pr, the pump controller 5 decreases the second coefficient Kp as the weighted average value Pa decreases, and when the weighted average value Pa is greater than the reference discharge pressure Pr, the pump controller 5 increases the second coefficient Kp as the weighted average value Pa increases.

[0043] In Fig. 4B, the minimum value of the second coefficient Kp is 0.9 and the maximum value is 1.15, but these can be changed as appropriate. Also, in Fig. 4B, the line showing the relationship between Pa and Kp is a single straight line, but the line showing the relationship between Na and Kn may be a broken line made up of two straight lines with different slopes, or may be a curve that is convex upward or downward.

[0044] To determine the third coefficient Kt, the pump controller 5 calculates the average value Ta of the temperature of the working fluid over a predetermined period A. Then, as shown in Fig. 4C, when the average value Ta is equal to or lower than the reference temperature Tr, the pump controller 5 determines the third coefficient Kt to be 1.0. Furthermore, when the average value Ta is greater than the reference temperature Tr, the pump controller 5 increases the third coefficient Tt as the average value Ta increases.

[0045] In FIG. 4C, the line showing the relationship between Ta and Kt when Ta≧Tr is a single straight line, but the line showing the relationship between Ta and Kt when Ta≧Tr may be a curve that is convex upward or downward.

[0046] As described above, the lifespan determination system 4 of this embodiment can calculate the equivalent operating time Li of the hydraulic pump 11 taking into account the operating status of the hydraulic pump 11 for each predetermined period A. Therefore, by accumulating the equivalent operating time Li of the hydraulic pump 11, the remaining lifespan of the hydraulic pump 11 can be accurately determined.

[0047] For example, each time a predetermined period A elapses, the pump controller 5 may calculate the remaining life La of the hydraulic pump 11 after the predetermined period A by subtracting the equivalent operating time Li from the remaining life Lb of the hydraulic pump 11 before the predetermined period A, as shown in the following equation (2). La = Lb - Li (2)

[0048] According to this configuration, the remaining life time of the hydraulic pump 11 can be updated every time the predetermined period A elapses.

[0049] Furthermore, in this embodiment, the predetermined period A is from the start of the prime mover 2 or the end of idling operation (if the set rotation speed Ns of the prime mover 2 is changed after idling operation has ended, when the set rotation speed of the prime mover 2 is changed) to the stop of the prime mover 2 or the start of idling operation. Therefore, the period during which the hydraulic pump 11 supplies hydraulic fluid to the hydraulic actuator 14 can be set as the predetermined period A. Furthermore, during idling operation after the predetermined period A or while the prime mover 2 is stopped, data measured during the predetermined period A can be processed. Note that this effect can also be obtained when the predetermined period A is from the start of the prime mover 2 to the stop of the prime mover 2, or from the end of idling operation to the restart of idling operation.

[0050] (Variation) The present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present disclosure.

[0051] For example, the pump controller 5 may store the discharge pressure P of the hydraulic pump 11 measured during the predetermined period A as is. However, in this case, the amount of data becomes enormous. In contrast, in the above embodiment, the pump controller 5 stores the discharge pressure P of the hydraulic pump 11 in a histogram for each predetermined period A, so the amount of data can be reduced.

[0052] The equivalent operating time Li of the hydraulic pump 11 may be calculated using the following equation (3). Li=Kn×Kp×Kt×Kw×Ko×Kc×Ha (3)

[0053] In equation (3), in addition to the first coefficient Kn, the second coefficient kp, and the third coefficient Kt, the fourth coefficient Kw, the fifth coefficient Ko, and the sixth coefficient Kc are used. The fourth coefficient Kw is a damage coefficient determined from information (e.g., the warm-up time) related to the warm-up operation (the operation for warming up the machine from the start of the prime mover 2 until the operation of the hydraulic actuator 14). When the warm-up operation is performed properly, the fourth coefficient Kw is 1.0, and when the warm-up operation is not performed properly, the fourth coefficient Kw is less than 1.0. The fifth coefficient Ko is a damage coefficient determined from the history of hydraulic fluid replacement, and the sixth coefficient Kc is a damage coefficient determined from the amount of impurities in the hydraulic fluid (measured by a contamination sensor). Note that one or more of the fourth coefficient Kw, the fifth coefficient Ko, and the sixth coefficient Kc may not be used.

[0054] Furthermore, the pump controller 5 may calculate the equivalent operating time Li of the hydraulic pump 11 in the predetermined period A based not only on the actual operating time Ha of the prime mover 2 in the predetermined period A, the change in the rotation speed N of the prime mover 2, the change in the discharge pressure P of the hydraulic pump 11, and the change in the temperature T of the working fluid, but also on the change in the coolant temperature of the prime mover 2, the change interval of the lubricating oil for the prime mover 2, output information from a lubricating oil contamination sensor, etc. This configuration can also be combined with the fourth coefficient Kw, the fifth coefficient Ko, and the sixth coefficient Kc described above.

[0055] (summary) The present disclosure provides a lifespan determination system for a hydraulic pump driven by a prime mover, the system including a pump controller that calculates, each time a predetermined period elapses, an equivalent operating time of the hydraulic pump during the predetermined period based on the actual operating time of the prime mover during the predetermined period, a change in the rotation speed of the prime mover, a change in the discharge pressure of the hydraulic pump, and a change in the temperature of the working fluid.

[0056] According to the above configuration, the equivalent operating time of the hydraulic pump can be calculated taking into account the operating status of the hydraulic pump for each predetermined period. Therefore, by accumulating the equivalent operating time of the hydraulic pump, the remaining life of the hydraulic pump can be accurately determined.

[0057] The hydraulic pump supplies hydraulic fluid to at least one hydraulic actuator, and the prime mover idles when the hydraulic pump is not supplying hydraulic fluid to the at least one hydraulic actuator. The predetermined period may be from the start of the prime mover or the end of the idling operation to the stop of the prime mover or the restart of the idling operation. Alternatively, the predetermined period may be from the start of the prime mover to the stop of the prime mover, or from the end of the idling operation to the restart of the idling operation. With these configurations, the period during which the hydraulic pump supplies hydraulic fluid to the hydraulic actuator can be defined as the predetermined period. Furthermore, data measured during the predetermined period can be processed during idling operation or when the prime mover is stopped after the predetermined period.

[0058] For example, if the set rotation speed of the prime mover is changed after the idling operation ends, the pump controller may change the start point of the specified period from the time when the idling operation ends to the time when the set rotation speed of the prime mover is changed.

[0059] The pump controller may calculate the remaining life of the hydraulic pump after the predetermined period by subtracting the equivalent operating time from the remaining life of the hydraulic pump before the predetermined period each time the predetermined period elapses. With this configuration, the remaining life of the hydraulic pump can be updated each time the predetermined period elapses.

[0060] The pump controller may determine a first coefficient from the change in rotation speed of the prime mover during the predetermined period, a second coefficient from the change in discharge pressure of the hydraulic pump during the predetermined period, and a third coefficient from the change in temperature of the working fluid during the predetermined period, and calculate an equivalent operating time of the hydraulic pump during the predetermined period by multiplying the actual operating time of the prime mover during the predetermined period by the first coefficient, the second coefficient, and the third coefficient. With this configuration, the equivalent operating time of the hydraulic pump can be calculated using a simple formula.

[0061] For example, the actual operating time and rotation speed of the prime mover may be input to the pump controller from a prime mover controller that controls the prime mover, and the above-mentioned life determination system may further include a pressure sensor that measures the discharge pressure of the hydraulic pump and a temperature sensor that measures the temperature of the working fluid.

[0062] The pump controller may store the discharge pressure of the hydraulic pump measured by the pressure sensor during the predetermined period in a histogram after the predetermined period. According to this configuration, if the discharge pressure measured during the predetermined period is stored as is, the amount of data becomes enormous. In contrast, if the discharge pressure is stored as a histogram for each predetermined period, the amount of data can be reduced. [Explanation of symbols]

[0063] 11 Hydraulic pump 14 Hydraulic Actuator 2. Prime Mover 3 Prime Mover Controller 4. Lifespan Judgment System 5 Pump Controller 7 Temperature Sensor 8 Pressure Sensors

Claims

1. A lifespan determination system for a hydraulic pump driven by a prime mover, comprising: a pump controller that calculates an equivalent operating time of the hydraulic pump during each predetermined period based on an actual operating time of the prime mover during the predetermined period, a change in the rotation speed of the prime mover, a change in the discharge pressure of the hydraulic pump, and a change in the temperature of the hydraulic fluid, the pump controller determines a first coefficient from the change in rotation speed of the prime mover during the specified period, determines a second coefficient from the change in discharge pressure of the hydraulic pump during the specified period, determines a third coefficient from the change in temperature of the working fluid during the specified period, and calculates an equivalent operating time of the hydraulic pump during the specified period by multiplying the first coefficient, the second coefficient, and the third coefficient by the actual operating time of the prime mover during the specified period.

2. the hydraulic pump supplies hydraulic fluid to at least one hydraulic actuator; the prime mover performs an idling operation when the hydraulic pump is not supplying hydraulic fluid to the at least one hydraulic actuator; 2. The system for determining the lifespan of a hydraulic pump according to claim 1, wherein the predetermined period is from the time when the prime mover is started or the time when the idling operation ends to the time when the prime mover is stopped or the time when the idling operation starts.

3. the hydraulic pump supplies hydraulic fluid to at least one hydraulic actuator; the prime mover performs an idling operation when the hydraulic pump is not supplying hydraulic fluid to the at least one hydraulic actuator; 2. The system for determining the lifespan of a hydraulic pump according to claim 1, wherein the predetermined period is from the start of the prime mover to the stop of the prime mover, or from the end of the idling operation to the restart of the idling operation.

4. 4. The system for determining a lifespan of a hydraulic pump according to claim 2, wherein, when the set rotational speed of the prime mover is changed after the idling operation ends, the pump controller changes the start point of the predetermined period from the time when the idling operation ends to the time when the set rotational speed of the prime mover is changed.

5. 5. The hydraulic pump lifespan determination system according to claim 1, wherein the pump controller calculates the remaining lifespan of the hydraulic pump after the predetermined period by subtracting the equivalent operating time from the remaining lifespan of the hydraulic pump before the predetermined period each time the predetermined period elapses.

6. the actual operating time and rotation speed of the prime mover are input to the pump controller from a prime mover controller that controls the prime mover; a pressure sensor that measures the discharge pressure of the hydraulic pump; and a temperature sensor that measures the temperature of the hydraulic fluid. The life determination system for a hydraulic pump according to any one of claims 1 to 5, further comprising:

7. 7. The system for determining the lifespan of a hydraulic pump according to claim 6, wherein the pump controller stores the discharge pressure of the hydraulic pump measured by the pressure sensor during the predetermined period in a histogram after the predetermined period.

8. A lifespan determination system for a hydraulic pump driven by a prime mover, comprising: a pump controller that calculates an equivalent operating time of the hydraulic pump during each predetermined period based on an actual operating time of the prime mover during the predetermined period, a change in the rotation speed of the prime mover, and a change in the discharge pressure of the hydraulic pump, the pump controller determines a first coefficient from the change in rotation speed of the prime mover over the specified period, determines a second coefficient from the change in discharge pressure of the hydraulic pump over the specified period, and calculates an equivalent operating time of the hydraulic pump over the specified period by multiplying the first coefficient and the second coefficient by the actual operating time of the prime mover over the specified period.

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