Engineering machinery motor oil supplementing system, control method thereof and engineering machinery

Abstract

The invention discloses an engineering machinery motor oil recharging system, a control method thereof and engineering machinery, and the system comprises a rotary motor which is provided with an oil inlet, an oil return port and an oil recharging port; the main valve is respectively connected with the oil inlet and the oil return port, and the main valve is connected with an oil return path; the variable back pressure valve is arranged on the oil return path and comprises a first station and a second station, and the back pressure of the first station is larger than that of the second station; the oil recharging control valve and the oil recharging port are connected, the oil recharging control valve and the oil recharging port are connected with the position, located on the oil inlet side of the variable back pressure valve, of the oil return way, and the oil recharging control valve has a first state and a second state; the energy accumulator is connected with the oil recharging control valve in series, when the oil recharging control valve is in a first state, the oil return way is in one-way conduction with the energy accumulator, and the energy accumulator is not in conduction with the oil return way; and when the oil supplementing control valve is in a second state, the energy accumulator is conducted to the oil return path. Air suction on the oil inlet side of the rotary motor can be avoided, the oil supplementing capacity is high, the rotary motor can be suitable for various working conditions, and energy saving is facilitated.

Description

Technical Field

[0001] This invention relates to the field of motor lubrication technology, and more specifically, to a motor lubrication system for construction machinery and its control method, and construction machinery. Background Technology

[0002] For construction machinery such as excavators and cranes, a rotary motor is used to drive the working device to rotate.

[0003] In related technologies, when the working device is slewing and braking, the main valve cuts off the oil supply from the main pump to the slewing motor and the return oil from the slewing motor. However, due to the large rotational inertia of the working device, the working device drives the slewing motor to continue rotating under the action of rotational inertia, which causes high pressure to form on the return oil side of the slewing motor. This part of high-pressure oil can overflow through the overflow valve or be recovered through the energy storage system. At the same time, due to the pressure reduction on the oil inlet side of the slewing motor, cavitation is prone to occur.

[0004] Therefore, how to avoid the air suction phenomenon on the oil inlet side of the rotary motor during rotary braking is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an oil replenishment system for engineering machinery motors to avoid the phenomenon of air suction on the oil inlet side of the rotary motor during rotary braking.

[0006] Another objective of this invention is to provide a control method for an engineering machinery motor oil replenishment system applied to the above-mentioned engineering machinery motor oil replenishment system, so as to avoid the phenomenon of air suction on the oil inlet side when the rotary motor is braked.

[0007] Another objective of this invention is to provide an engineering machinery system including the above-mentioned oil replenishment system for the engineering machinery motor, so as to avoid the phenomenon of air suction on the oil inlet side of the rotary motor during rotary braking.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A lubrication system for an engineering machinery motor, comprising:

[0010] The rotary motor is equipped with an oil inlet, an oil return port, and an oil replenishment port;

[0011] The main valve is connected to the oil inlet and the oil return port respectively, and the main valve is connected to the oil return circuit;

[0012] A variable back pressure valve is provided in the return oil circuit, including a first station and a second station, wherein the back pressure of the first station is greater than the back pressure of the second station.

[0013] A replenishing oil control valve is provided, wherein the replenishing oil control valve and the replenishing oil port are connected and both are respectively connected to the return oil circuit at the position of the inlet side of the variable back pressure valve, and the replenishing oil control valve has a first state and a second state.

[0014] An accumulator is connected in series with the replenishing control valve. When the replenishing control valve is in the first state, the return oil circuit to the accumulator is unidirectionally connected, and the accumulator to the return oil circuit is not connected. When the replenishing control valve is in the second state, the accumulator to the return oil circuit is connected.

[0015] Optionally, it also includes:

[0016] The controller is connected to both the variable back pressure valve and the oil replenishment control valve, and is configured to:

[0017] When the pressure of the accumulator is lower than the first preset value, the variable back pressure valve is controlled to be in the first working position and the oil replenishment control valve is in the first state.

[0018] When the pressure of the accumulator is greater than or equal to the first preset value, the variable back pressure valve is controlled to be in the second working position and the oil replenishment control valve is in the first state.

[0019] When the pressure at the oil replenishment port is lower than the second preset value, the variable back pressure valve is controlled to be in the first position and the oil replenishment control valve is controlled to be in the second state.

[0020] Optionally, the oil replenishment control valve includes a first flow channel and a second flow channel connected in parallel. The first flow channel is provided with a first check valve, and the flow direction of the first check valve is from the return oil line to the accumulator.

[0021] The second flow channel is equipped with a switching valve. When the switching valve is closed, the oil replenishment control valve is in the first state; when the switching valve is open, the oil replenishment control valve is in the second state.

[0022] Optionally, the switching valve is connected to a first pilot valve, which is connected to a controller. The controller is used to control the switching valve to open or close by controlling the first pilot valve.

[0023] Optionally, the oil replenishment control valve includes:

[0024] A cartridge valve includes a control chamber, a control port, a first working oil port, and a second working oil port. The first working oil port is connected to the return oil circuit, and the second working oil port is connected to the accumulator.

[0025] A pilot control valve is connected between the control port and the control chamber, and has a third position and a fourth position. When the pilot control valve is in the third position, the control chamber is connected to the control port, so that the oil replenishment control valve is in the first state; when the pilot control valve is in the fourth position, the control chamber is connected to the oil tank, so that the oil replenishment control valve is in the second state.

[0026] Optionally, the variable back pressure valve is provided with a second check valve or throttle valve in the flow channel corresponding to the first station, and the variable back pressure valve is a channel with both ends completely connected in the flow channel corresponding to the second station.

[0027] Optionally, the variable back pressure valve is connected to a second pilot valve, which is connected to a controller. The controller is used to control the second pilot valve so that the variable back pressure valve switches between the first station and the second station.

[0028] Optionally, the inlet of the accumulator is provided with a first pressure sensor; and / or, the inlet of the variable back pressure valve is provided with a second pressure sensor.

[0029] A control method for an oil replenishment system for a construction machinery motor, applicable to any of the aforementioned oil replenishment systems for construction machinery motors, the control method comprising:

[0030] Determine whether the pressure of the accumulator in the oil replenishment system of the construction machinery motor is less than a first preset value;

[0031] If so, the variable back pressure valve of the oil replenishment system for the construction machinery motor is in the first position, and the oil replenishment control valve of the oil replenishment system for the construction machinery motor is in the first state.

[0032] If not, control the variable back pressure valve to be in the second position and control the oil replenishment control valve to be in the first state;

[0033] Determine whether the pressure at the oil supply port M of the rotary motor of the engineering machinery motor oil supply system is less than a second preset value;

[0034] If so, control the variable back pressure valve to be in the first working position, and control the oil replenishment control valve to be in the second state.

[0035] An engineering machinery, including any of the above-mentioned engineering machinery motor lubrication systems.

[0036] The oil replenishment system for engineering machinery motors provided by this invention has at least the following beneficial effects:

[0037] When the replenishing control valve is in the first state and the variable back pressure valve is in the first position, the high back pressure in the first position allows the hydraulic oil in the return oil circuit to flow to the accumulator via the replenishing control valve. This utilizes the hydraulic oil in the main valve's return oil circuit to charge the accumulator, ensuring it has sufficient hydraulic oil. Once the accumulator has sufficient hydraulic oil, the variable back pressure valve can be moved to the second position while the replenishing control valve remains in the first state. In this case, the hydraulic oil in the return oil circuit returns via the variable back pressure valve, for example, flowing into the oil tank. Since the back pressure of the variable back pressure valve in the first position is greater than that in the second position, energy consumption can be relatively reduced and energy can be saved when the variable back pressure valve is in the second position. When the pressure at the oil replenishment port M decreases, the variable back pressure valve can be in the first position and the oil replenishment control valve can be in the second state. At this time, the hydraulic oil in the accumulator can replenish the oil to the oil replenishment port M through the oil replenishment control valve. Therefore, when the hydraulic motor is in rotary braking, the hydraulic motor continues to rotate due to rotational inertia, which reduces the pressure on the oil inlet side of the hydraulic motor. The hydraulic oil supplied by the accumulator can replenish the hydraulic motor, thereby avoiding the phenomenon of air suction on the oil inlet side when the rotary motor is in rotary braking.

[0038] It is evident that this hydraulic motor replenishment system for construction machinery can solve the technical problem of air suction on the oil inlet side during the slewing braking of the rotary motor. Simultaneously, this system stores a portion of the return oil from the main valve's return line into an accumulator for replenishing the rotary motor, without adding extra energy to the system. Furthermore, when the accumulator is fully charged and its pressure meets requirements, the system is placed in a low back pressure state (i.e., the back pressure when the variable back pressure valve is in the second position) by setting the variable back pressure valve to its second position. This avoids the system being in a high back pressure state for extended periods (i.e., the back pressure when the variable back pressure valve is in the first position). In other words, this hydraulic motor replenishment system does not maintain a high back pressure state continuously, but rather a high back pressure state during the short period when the accumulator is charging, and a low back pressure state when the accumulator is not charging, thus achieving energy savings. In addition, regardless of whether the hydraulic oil on the return side overflows to the oil replenishment port M or enters the energy storage system during the slewing braking of the slewing motor, the accumulator can be used to replenish the oil to the slewing motor. This construction machinery motor oil replenishment system has strong oil replenishment capability and can be applied to various working conditions.

[0039] The control method for the lubrication system of the construction machinery motor provided by the present invention, when applied to the aforementioned lubrication system of the construction machinery motor, has at least the beneficial effects of the aforementioned lubrication system of the construction machinery motor.

[0040] The engineering machinery provided by the present invention includes the above-mentioned engineering machinery motor lubrication system, and has at least the beneficial effects of the above-mentioned engineering machinery motor lubrication system. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0042] Figure 1 A schematic diagram of the lubrication system for an engineering machinery motor provided in a specific embodiment of the present invention;

[0043] Figure 2 A schematic diagram of an engineering machinery motor oil replenishment system, which represents an alternative implementation of the oil replenishment control valve.

[0044] Figure 3 A schematic diagram of an engineering machinery motor oil replenishment system, which represents another implementation of a variable back pressure valve;

[0045] Figure 4 The flowchart illustrates the control method for an oil replenishment system for an engineering machinery motor, as provided in a specific embodiment of the present invention.

[0046] Figure label:

[0047] 1-Slewing motor; M-Main oil port; 11-Third check valve; 12-Fourth check valve; 13-First relief valve; 14-Second relief valve; 2-Main valve; 21-Return oil circuit; 3-Variable back pressure valve; 31-Second check valve; 32-Throttle valve; 33-Second pressure sensor; 4-Main oil control valve; 41-First check valve; 42-Switch valve; 43-Cartridge valve; 44-Pilot control valve; 5-Accumulator; 51-First pressure sensor; 6-Controller; 7-First pilot valve; 8-Second pilot valve; 91-Slewing energy recovery valve; 92-Energy storage system; 10-Main pump system. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] The core of this invention is to provide an oil replenishment system for engineering machinery motors to prevent cavitation from occurring on the oil inlet side of the rotary motor during rotary braking. Another core aspect of this invention is to provide a control method for the aforementioned oil replenishment system for engineering machinery motors, to prevent cavitation from occurring on the oil inlet side of the rotary motor during rotary braking. A further core aspect of this invention is to provide engineering machinery including the aforementioned oil replenishment system for engineering machinery motors to prevent cavitation from occurring on the oil inlet side of the rotary motor during rotary braking.

[0050] Please refer to Figure 1 This invention provides an oil replenishment system for an engineering machinery motor, including a rotary motor 1, a main valve 2, a variable back pressure valve 3, an oil replenishment control valve 4, and an accumulator 5. The rotary motor 1 has an oil inlet, an oil return port, and an oil replenishment port M. The main valve 2 is connected to the oil inlet and the oil return port, and is connected to a return oil path 21. The variable back pressure valve 3 is located in the return oil path 21 and includes a first position and a second position, where the back pressure of the first position is greater than that of the second position. The oil replenishment control valve 4 is connected to the oil replenishment port M, and both are connected to the return oil path 21 at the oil inlet side of the variable back pressure valve 3. The oil replenishment control valve 4 has a first state and a second state. The accumulator 5 is connected in series with the oil replenishment control valve 4. When the oil replenishment control valve 4 is in the first state, the return oil path 21 is unidirectionally connected to the accumulator 5, and the accumulator 5 is not connected to the return oil path 21. When the oil replenishment control valve 4 is in the second state, the accumulator 5 is connected to the return oil path 21.

[0051] In other words, when the replenishing control valve 4 is in the first state and the variable back pressure valve 3 is in the first position, the high back pressure in the first position allows the hydraulic oil in the return oil circuit 21 to flow to the accumulator 5 via the replenishing control valve 4. This allows the hydraulic oil in the return oil circuit 21 of the main valve 2 to fill the accumulator 5, ensuring that the accumulator 5 has sufficient hydraulic oil. Once the accumulator 5 has sufficient hydraulic oil, the variable back pressure valve 3 can be moved to the second position while the replenishing control valve 4 remains in the first state. At this time, the hydraulic oil in the return oil circuit 21 returns via the variable back pressure valve 3, for example, flowing into the oil tank. Since the back pressure of the variable back pressure valve 3 in the first position is greater than that in the second position, when the variable back pressure valve 3 is in the second position, energy consumption can be relatively reduced, saving energy. When the pressure at the oil replenishment port M decreases, the variable back pressure valve 3 can be in the first position and the oil replenishment control valve 4 can be in the second state. At this time, the hydraulic oil in the accumulator 5 can replenish the oil to the oil replenishment port M through the oil replenishment control valve 4. Therefore, when the hydraulic motor is in rotary braking, the hydraulic motor continues to rotate due to rotational inertia, which reduces the pressure on the oil inlet side of the hydraulic motor. The hydraulic oil supplied by the accumulator 5 can replenish the hydraulic motor, thereby preventing the cavitation phenomenon on the oil inlet side of the rotary motor 1 from occurring during rotary braking.

[0052] It is evident that this oil replenishment system for construction machinery motors can solve the technical problem of air suction on the oil inlet side of the rotary motor 1 during rotary braking. Simultaneously, this system stores a portion of the return oil from the main valve 2's return oil circuit 21 into the accumulator 5 to replenish the rotary motor 1, without adding extra energy to the system. Furthermore, when the accumulator 5 is fully charged and its pressure meets requirements, the system is placed in a low back pressure state (i.e., the back pressure when the variable back pressure valve 3 is in the second position) by setting the variable back pressure valve 3 to the second position. This avoids the system being in a high back pressure state for extended periods (i.e., the back pressure when the variable back pressure valve 3 is in the first position). In other words, this oil replenishment system for construction machinery motors does not maintain a high back pressure state continuously, but rather a high back pressure state for a short period while the accumulator 5 is charging, and a low back pressure state when the accumulator 5 is not charging, thus achieving energy savings.

[0053] In addition, some related technologies involve using an overflow valve to allow high-pressure oil from the return oil side of the rotary motor 1 to overflow to the oil replenishment port M during rotary braking. This high-pressure oil, combined with a check valve connected in series at the oil replenishment port M, generates back pressure to replenish oil to the oil inlet side of the rotary motor 1, thus preventing cavitation on the oil inlet side. However, this solution still results in cavitation on the oil inlet side of the rotary motor 1 when an energy storage system 92 is connected to the oil inlet and return oil ports. When the oil inlet and outlet of the rotary motor 1 are connected to the energy storage system 92, the hydraulic oil on the return side of the rotary motor 1 enters the energy storage system 92 during rotary braking to recover rotary energy. In this case, the hydraulic oil on the return side of the rotary motor 1 does not enter the replenishment port M during rotary braking. At this time, the small cavity hydraulic oil formed by the back pressure of the check valve connected in series at the replenishment port M is insufficient to meet the replenishment needs of the oil inlet side of the rotary motor 1, resulting in cavitation at the oil inlet side of the rotary motor 1. It can be seen that the replenishment capacity of the motor replenishment system in the related technology is weak and cannot be applied to the case where the rotary motor 1 is connected to the energy storage system 92. However, the engineering machinery motor replenishment system provided in this embodiment of the invention can replenish the rotary motor 1 using the accumulator 5 regardless of whether the hydraulic oil on the return side of the rotary motor 1 overflows to the replenishment port M or enters the energy storage system 92 during rotary braking. That is, the replenishment capacity of this engineering machinery motor replenishment system is strong and can be applied to various working conditions.

[0054] In addition, it should be noted that the oil replenishment system for the construction machinery motor is not only suitable for replenishing oil to the rotary motor 1 when it is braking, but also for replenishing oil to the rotary motor 1 when it starts. It is understood that when the rotary motor 1 starts, there may be a phenomenon of air suction on the oil inlet side of the rotary motor 1. At this time, the accumulator 5 can also be used to replenish oil to the rotary motor 1.

[0055] Furthermore, in some embodiments, the oil replenishment system for the construction machinery motor also includes a controller 6, which is connected to the variable back pressure valve 3 and the oil replenishment control valve 4 respectively. The controller 6 is configured to: control the variable back pressure valve 3 to be in the first position and the oil replenishment control valve 4 to be in the first state when the pressure of the accumulator 5 is lower than a first preset value; control the variable back pressure valve 3 to be in the second position and the oil replenishment control valve 4 to be in the first state when the pressure of the accumulator 5 is greater than or equal to the first preset value; and control the variable back pressure valve 3 to be in the first position and the oil replenishment control valve 4 to be in the second state when the pressure of the oil replenishment port M is lower than a second preset value.

[0056] In other words, this embodiment utilizes the controller 6 to automatically control the variable back pressure valve 3 and the oil replenishment control valve 4, thereby achieving automatic switching of the variable back pressure valve 3 between the first and second positions, and automatic switching of the oil replenishment control valve 4 between the first and second states. The controller 6 controls the variable back pressure valve 3 to be in the first or second position based on whether the pressure of the accumulator 5 is lower than a first preset value and whether the pressure at the oil replenishment port M is lower than a second preset value. Simultaneously, it controls the oil replenishment control valve 4 to be in the first or second state.

[0057] Understandably, the control logic of controller 6 is as follows: controller 6 receives the pressure signal of accumulator 5 in real time and determines whether the pressure of accumulator 5 is lower than the first preset value. When the pressure of accumulator 5 is lower than the first preset value, controller 6 controls the variable back pressure valve 3 to be in the first position and controls the oil replenishment control valve 4 to be in the first state to fill accumulator 5 with liquid. It should be noted that if the variable back pressure valve 3 is in the first position, controller 6 controls the variable back pressure valve 3 to remain in the first position. If the variable back pressure valve 3 is in the second position, controller 6 controls the variable back pressure valve 3 to switch from the second position to the first position. Similarly, if the oil replenishment control valve 4 is in the first state, controller 6 controls the oil replenishment control valve 4 to remain in the first state. If the oil replenishment control valve 4 is in the second state, controller 6 controls the oil replenishment control valve 4 to switch from the second state to the first state. When the pressure of accumulator 5 is greater than or equal to the first preset value, it indicates that accumulator 5 has completed filling. At this time, the variable back pressure valve 3 is controlled to be in the second position, and the oil replenishment control valve 4 is controlled to remain in the first state. That is, the accumulator 5 is not connected to the return oil circuit 21, and the hydraulic oil in the return oil circuit 21 flows into the oil tank through the variable back pressure valve 3. In addition, during operation, the controller 6 receives the pressure of the oil replenishment port M of the rotary motor 1 in real time and determines whether the pressure of the oil replenishment port M of the rotary motor 1 is less than the second preset value. When the pressure of the oil replenishment port M of the rotary motor 1 is less than the second preset value, the controller 6 controls the variable back pressure valve 3 to be in the first position and controls the oil replenishment control valve 4 to be in the second state.

[0058] It is understandable that when the pressure at the oil replenishment port M of the rotary motor 1 is less than the second preset value, this could be during the start-up or braking of the rotary motor 1. To further clarify the control of oil replenishment during the rotary braking of the rotary motor 1, the controller 6 can also receive the rotary signal and determine whether the change in the rotary signal meets the requirements (e.g., whether the rotary reduction exceeds the third preset value). If the change in the rotary signal meets the requirements and the pressure at the oil replenishment port M is less than the second preset value, then the variable back pressure valve 3 is controlled to be in the first position, and the oil replenishment control valve 4 is controlled to be in the second state. If the change in the rotary signal does not meet the requirements, then the variable back pressure valve 3 is controlled to be in the second position, and the oil replenishment control valve 4 is controlled to be in the first state. In addition, it is understandable that when the rotary braking stops, the controller 6 controls the variable back pressure valve 3 to be in the second position to reduce the system back pressure, and controls the oil replenishment control valve 4 to be in the first state so that the hydraulic oil in the return oil circuit 21 returns through the low back pressure, and continues to monitor whether the accumulator 5 needs to be charged.

[0059] It should be noted that the above embodiments do not limit the specific structure of the oil replenishment control valve 4, as long as the oil replenishment control valve 4 can switch between the first state and the second state.

[0060] like Figure 1 As shown, in some embodiments, the oil replenishment control valve 4 includes a first flow channel and a second flow channel connected in parallel. The first flow channel is provided with a first check valve 41, and the flow direction of the first check valve 41 is from the return oil line 21 to the accumulator 5. The second flow channel is provided with a switching valve 42. When the switching valve 42 is closed, the oil replenishment control valve 4 is in a first state. When the switching valve 42 is open, the oil replenishment control valve 4 is in a second state.

[0061] In other words, in this embodiment, by closing the switching valve 42, the first flow channel is kept in a first state by the first check valve 41. That is, the first flow channel is used to allow the hydraulic oil in the return oil circuit 21 to flow to the accumulator 5, while the hydraulic oil in the accumulator 5 cannot flow back into the return oil circuit 21 through the first flow channel. The second flow channel is in a conducting state or a closed state by switching the state of the switching valve 42. When the switching valve 42 is opened, the second flow channel is open. At this time, if the pressure at the oil replenishment port M decreases, the hydraulic oil in the accumulator 5 can flow from the second flow channel. The hydraulic oil flows to the oil replenishment port M, thereby replenishing the rotary motor 1 with oil. When the switching valve 42 is closed, the second flow channel is shut off. At this time, the hydraulic oil cannot pass through the second flow channel and can only enter the accumulator 5 through the first flow channel from the return oil line 21 to fill the accumulator 5. Moreover, when the switching valve 42 is closed, due to the presence of the first check valve 41, the hydraulic oil in the accumulator 5 cannot flow to the return oil line 21. At this time, the variable back pressure valve 3 can be switched to the second position, so that the system is in a low back pressure, which is conducive to the return oil of the main valve 2. The structure is simple and ingenious, which facilitates the switching of the state of the oil replenishment control valve 4. Moreover, by keeping the switching valve 42 in the normally closed state, the first one-way valve 41 of the first flow channel ensures that the first flow channel can always be filled with liquid to the accumulator 5 under the high back pressure of the variable back pressure valve 3. It also ensures that the first flow channel is always kept in a non-conductive state from the accumulator 5 to the return oil circuit 21, avoiding the controller 6 frequently switching the oil replenishment control valve 4, which would cause the system to repeatedly switch between the states of filling the accumulator 5 and returning oil under low back pressure. The controller 6 only needs to control the switching valve 42 to switch the state to replenish oil to the rotary motor 1 or stop replenishing oil, which simplifies the control.

[0062] Furthermore, such as Figure 1 As shown, in order to facilitate the control of the switching valve 42, in some embodiments, the switching valve 42 is connected to the first pilot valve 7, the first pilot valve 7 is connected to the controller 6, and the controller 6 is used to control the switching valve 42 to open or close by controlling the first pilot valve 7.

[0063] In other words, this embodiment controls the switching valve 42 by controlling the first pilot valve 7. When the controller 6 outputs a signal to the first pilot valve 7, the first pilot valve 7 outputs a signal to the switching valve 42, thereby enabling the switching valve 42 to switch from closed to open or from open to closed. When it is necessary to replenish oil to the rotary motor 1, the controller 6 controls the first pilot valve 7 to open the switching valve 42, opening the second flow channel to replenish oil to the oil replenishment port M through the accumulator 5. It can be understood that when the controller 6 receives the stop signal of the rotary motor 1, that is, when the rotary braking is completed, the controller 6 controls the switching valve 42 to switch from open to closed.

[0064] Of course, the oil replenishment control valve 4 can also be implemented in other ways, for example, such as Figure 2 and Figure 3As shown, in some other embodiments, the replenishing control valve 4 includes a cartridge valve 43 and a pilot control valve 44. The cartridge valve 43 includes a control chamber, a control port, a first working oil port, and a second working oil port. The first working oil port is connected to the return oil circuit 21, and the second working oil port is connected to the accumulator 5. The pilot control valve 44 is connected between the control port and the control chamber. The pilot control valve 44 has a third position and a fourth position. When the pilot control valve 44 is in the third position, the control chamber is connected to the control port, so that the replenishing control valve 4 is in the first state. When the pilot control valve 44 is in the fourth position, the control chamber is connected to the oil tank, so that the replenishing control valve 4 is in the second state.

[0065] In other words, in this embodiment, the cartridge valve 43 and the pilot control valve 44 form a logic valve. It can be understood that the pilot control valve 44 is externally connected between the control port and the control chamber of the cartridge valve 43. In this embodiment, by switching the position state of the pilot control valve 44, the conduction of the cartridge valve 43 is switched, thereby achieving the switching of the replenishment control valve 4 between the first and second states. Specifically, when the pilot control valve 44 is in the third position, it connects the control port and the control chamber. At this time, under the elastic force of the spring in the control chamber, the cartridge valve 43 is closed, that is, the first working port is disconnected from the second working port. At this time, when the variable back pressure valve 3 is in the first position, under the high back pressure of the first position, the hydraulic oil in the return oil circuit 21 can enter the cartridge valve 43 and push it open, connecting the first working port and the second working port, thus charging the accumulator 5. When the variable back pressure valve 3 is in the second position, the cartridge valve 43 is closed, allowing the return oil from the main valve 2 to enter the oil tank via the variable back pressure valve 3. When the pressure at the replenishment port M is lower than the second preset value, the pilot control valve 44 is placed in the fourth position, connecting the control chamber to the oil tank and depressurizing the control chamber. At this time, the pressure of the accumulator 5 overcomes the spring force of the control chamber of the cartridge valve 43, connecting the first working port and the second working port, thereby allowing the hydraulic oil of the accumulator 5 to flow into the replenishment port M via the cartridge valve 43.

[0066] In addition, it should be noted that the above embodiments do not limit the specific structure of the variable back pressure valve 3, as long as the variable back pressure valve 3 can switch between the first position and the second position, and the back pressure of the variable back pressure valve 3 in the first position is greater than the back pressure in the second position.

[0067] like Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the flow channel of the variable back pressure valve 3 corresponding to the first station is provided with a second check valve 31 or a throttle valve 32, and the flow channel of the variable back pressure valve 3 corresponding to the second station is a channel with both ends completely connected.

[0068] In other words, this embodiment uses the second one-way valve 31 or the throttle valve 32 to generate back pressure, and makes the flow channel of the variable back pressure valve 3 corresponding to the second station a channel with both ends completely connected, so that the back pressure of the flow channel corresponding to the second station is low.

[0069] Furthermore, such as Figure 1 As shown, in order to facilitate the switching of the variable back pressure valve 3 between the first and second positions, in some embodiments, the variable back pressure valve 3 is connected to the second pilot valve 8, the second pilot valve 8 is connected to the controller 6, and the controller 6 is used to control the second pilot valve 8 to switch the variable back pressure valve 3 between the first and second positions.

[0070] In other words, in this embodiment, the controller 6 controls the second pilot valve 8 to control the operation of the variable back pressure valve 3, thereby switching the variable back pressure valve 3 between the first and second positions. It should be noted that this embodiment does not limit the initial position of the variable back pressure valve 3; it can be either the first or the second position. For example, when the initial position of the variable back pressure valve 3 is the first position, when the accumulator 5 needs to be filled, the controller 6 does not output a signal to the second pilot valve 8, causing the second pilot valve 8 to not output a signal to the variable back pressure valve 3, thus keeping the variable back pressure valve 3 in the first position. Conversely, when the initial position of the variable back pressure valve 3 is the second position, when the accumulator 5 needs to be filled, the controller 6 outputs a signal to the second pilot valve 8, causing the second pilot valve 8 to output a signal to the variable back pressure valve 3, thus switching the variable back pressure valve 3 from the second position to the first position. That is, the control logic of the controller 6 for the second pilot valve 8 is determined by the initial state of the variable back pressure valve 3.

[0071] like Figure 1 As shown, in order to facilitate the real-time acquisition of the pressure of the accumulator 5 and the pressure of the oil replenishment port M, in some embodiments, the inlet of the accumulator 5 is provided with a first pressure sensor 51; and / or, the inlet of the variable back pressure valve 3 is provided with a second pressure sensor 33.

[0072] In other words, this embodiment utilizes a first pressure sensor 51 to monitor the pressure of the accumulator 5 in real time. It can be understood that the first pressure sensor 51 is connected to the controller 6 to send the pressure of the accumulator 5 detected by the first pressure sensor 51 to the controller 6, allowing the controller 6 to determine whether the accumulator 5 needs to be refilled based on the received pressure. Additionally, this embodiment utilizes a second pressure sensor 33 to monitor the inlet pressure of the variable back pressure valve 3 in real time. It can be understood that the connection between the oil replenishment port M and the return oil circuit 21 is located on the oil inlet side of the variable back pressure valve 3. Therefore, the inlet pressure of the variable back pressure valve 3 is also the pressure of the oil replenishment port M. That is, the second pressure sensor 33 can monitor the pressure of the oil replenishment port M in real time. The second pressure sensor 33 is connected to the controller 6 to send the pressure detected by the second pressure sensor 33 to the controller 6, allowing the controller 6 to determine whether oil needs to be replenished to the rotary motor 1 based on the received pressure of the oil replenishment port M.

[0073] It should be noted that in this embodiment, the second pressure sensor 33 is located at the inlet of the variable back pressure valve 3, which facilitates the integration of the variable back pressure valve 3 and the second pressure sensor 33 into one unit, thereby enabling the overall valve assembly integrating the variable back pressure valve 3 and the second pressure sensor 33 for integral installation. Additionally, the first pressure sensor 51 can be integrated with the oil replenishment control valve 4, facilitating the integral installation of the oil replenishment control valve 4 and the first pressure sensor 51.

[0074] In addition, such as Figure 1 As shown, in some embodiments, the oil replenishment system for the engineering machinery motor further includes a rotary energy recovery valve 91 and an energy storage system 92. The rotary energy recovery valve 91 is connected to the oil inlet and oil outlet of the rotary motor 1, respectively. The energy storage system 92 is connected in series with the rotary energy recovery valve 91 and is used to recover the high-pressure oil on the braking side of the rotary motor 1 during rotary braking.

[0075] In other words, in this embodiment, when the rotary motor 1 brakes, the high-pressure oil on the brake return oil side of the rotary motor 1 is recovered through the rotary energy recovery valve 91 and enters the energy storage system 92 to recover the rotary braking energy. The recovered energy can be reused to avoid energy waste.

[0076] It should be noted that this embodiment does not limit the specific structure of the rotary energy recovery valve 91 and the energy storage system 92, and relevant technologies can be referenced.

[0077] Furthermore, the above embodiments do not limit the specific structure of the rotary motor 1, for example, as Figure 1As shown, the rotary motor 1 is equipped with a third check valve 11 and a fourth check valve 12. The third check valve 11 is connected to the oil inlet and the oil replenishment port M of the rotary motor 1, respectively. The fourth check valve 12 is connected to the oil return port and the oil replenishment port M of the rotary motor 1, respectively, so that oil can be replenished to the rotary motor 1 through the oil replenishment port M via the third check valve 11 or the fourth check valve 12. It can be understood that the oil inlet and the oil return port of the rotary motor 1 are relative concepts. For example, when the rotary motor 1 rotates forward, oil enters through the oil inlet and exits through the oil return port; when the rotary motor 1 rotates in reverse, oil enters through the oil return port and exits through the oil inlet. In addition, in some embodiments, the rotary motor 1 is provided with a first overflow valve 13 and a second overflow valve 14. The first overflow valve 13 is connected between the oil inlet and the oil replenishment port M of the rotary motor 1, and the second overflow valve 14 is connected between the oil return port and the oil replenishment port M of the rotary motor 1.

[0078] Furthermore, in the above embodiments, the specific structure of the main valve 2 and the oil supply method of the main valve 2 are not limited. The structure of the main valve 2 can refer to relevant technologies, such as... Figure 1 As shown, the oil inlet and return port of the main valve 2 can be connected to the main pump system 10 respectively. The structure of the main pump system 10 can be referred to relevant technologies.

[0079] Please refer to Figure 4 In addition to the aforementioned oil replenishment system for construction machinery motors, this embodiment of the invention also provides a control method for an oil replenishment system for construction machinery motors. This control method is applied to the oil replenishment system for construction machinery motors disclosed in any of the above embodiments, and includes steps S1-S5:

[0080] S1: Determine whether the pressure of the accumulator 5 in the oil replenishment system of the construction machinery motor is less than the first preset value;

[0081] S2: If so, the variable back pressure valve 3 of the control system for replenishing oil to the motor of the construction machinery is in the first position, and the oil replenishment control valve 4 of the control system for replenishing oil to the motor of the construction machinery is in the first state.

[0082] S3: If not, control the variable back pressure valve 3 to be in the second position and control the oil replenishment control valve 4 to be in the first state;

[0083] S4: Determine whether the pressure at the oil supply port M of the rotary motor 1 in the oil supply system of the construction machinery motor is less than the second preset value;

[0084] S5: If so, control the variable back pressure valve 3 to be in the first position and control the oil replenishment control valve 4 to be in the second state.

[0085] It can be seen that the control method for the oil replenishment system of the construction machinery motor is used to control the aforementioned oil replenishment system of the construction machinery motor to achieve functions such as filling the accumulator 5 with liquid during operation, keeping the system in a low back pressure state after the accumulator 5 is filled with liquid, and replenishing the oil at the oil replenishment port M of the rotary motor 1 when oil replenishment is required. It at least has the beneficial effects of the aforementioned oil replenishment system of the construction machinery motor, which will not be elaborated further here. In addition, the control logic of this control method for the oil replenishment system of the construction machinery motor is the same as the control logic of the controller 6 described above, and will not be described in detail here. Please refer to the control logic content of the controller 6 described above.

[0086] In addition to the above-mentioned construction machinery motor lubrication system and control method, this invention also provides a construction machinery including the construction machinery motor lubrication system disclosed in the above embodiments. The structure of other parts of the construction machinery is described in the prior art and will not be repeated here.

[0087] It is understood that the engineering machinery provided in the embodiments of the present invention includes a working device that needs to rotate, such as an excavator. The excavator includes a lower carriage and an upper carriage, and a slewing bearing is connected between the upper carriage and the lower carriage. The slewing bearing is driven to rotate by a slewing motor 1, causing the upper carriage to rotate relative to the lower carriage. Of course, the engineering machinery can also be other engineering machinery such as cranes and pile drivers.

[0088] The focus of this embodiment is to use the above-described engineering machinery motor oil replenishment system to replenish oil for the rotary motor 1, which at least has the beneficial effects of the above-described engineering machinery motor oil replenishment system, and will not be repeated here.

[0089] It should also be noted that, in this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0090] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0091] The above provides a detailed description of the motor lubrication system for engineering machinery and the engineering machinery itself provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of this invention.

Claims

1. A lubrication system for an engineering machinery motor, characterized in that, include: The rotary motor (1) is equipped with an oil inlet, an oil return port and an oil replenishment port (M); The main valve (2) is connected to the oil inlet and the oil return port respectively, and the main valve (2) is connected to the oil return circuit (21). A variable back pressure valve (3) is provided in the return oil circuit (21), including a first station and a second station, wherein the back pressure of the first station is greater than the back pressure of the second station. The oil replenishment control valve (4) is connected to the oil replenishment port (M) and both are respectively connected to the return oil circuit (21) at the oil inlet side of the variable back pressure valve (3). The oil replenishment control valve (4) has a first state and a second state. The accumulator (5) is connected in series with the oil replenishment control valve (4). When the oil replenishment control valve (4) is in the first state, the return oil path (21) to the accumulator (5) is unidirectionally connected, and the accumulator (5) to the return oil path (21) is not connected. When the oil replenishment control valve (4) is in the second state, the accumulator (5) to the return oil path (21) is connected.

2. The oil replenishment system for engineering machinery motors according to claim 1, characterized in that, Also includes: The controller (6) is connected to the variable back pressure valve (3) and the oil replenishment control valve (4) respectively, and the controller (6) is configured to: When the pressure of the accumulator (5) is lower than the first preset value, the variable back pressure valve (3) is controlled to be in the first working position and the oil replenishment control valve (4) is in the first state. When the pressure of the accumulator (5) is greater than or equal to the first preset value, the variable back pressure valve (3) is controlled to be in the second working position and the oil replenishment control valve (4) is in the first state; When the pressure at the oil replenishment port (M) is lower than the second preset value, the variable back pressure valve (3) is controlled to be in the first working position and the oil replenishment control valve (4) is controlled to be in the second state.

3. The oil replenishment system for engineering machinery motors according to claim 1, characterized in that, The oil replenishment control valve (4) includes a first flow channel and a second flow channel connected in parallel. The first flow channel is provided with a first check valve (41). The flow direction of the first check valve (41) is from the return oil line (21) to the accumulator (5). The second flow channel is provided with a switching valve (42). When the switching valve (42) is closed, the oil replenishment control valve (4) is in the first state; when the switching valve (42) is open, the oil replenishment control valve (4) is in the second state.

4. The oil replenishment system for engineering machinery motors according to claim 2, characterized in that, The switching valve (42) is connected to the first pilot valve (7), and the first pilot valve (7) is connected to the controller (6). The controller (6) is used to control the switching valve (42) to open or close by controlling the first pilot valve (7).

5. The oil replenishment system for engineering machinery motors according to claim 1, characterized in that, The oil replenishment control valve (4) includes: The cartridge valve (43) includes a control chamber, a control port, a first working oil port and a second working oil port. The first working oil port is connected to the return oil circuit (21) and the second working oil port is connected to the accumulator (5). A pilot control valve (44) is connected between the control port and the control chamber, and has a third position and a fourth position. When the pilot control valve (44) is in the third position, the control chamber is connected to the control port, so that the oil replenishment control valve (4) is in the first state; when the pilot control valve (44) is in the fourth position, the control chamber is connected to the oil tank, so that the oil replenishment control valve (4) is in the second state.

6. The oil replenishment system for engineering machinery motors according to claim 1, characterized in that, The variable back pressure valve (3) is provided with a second one-way valve (31) or a throttle valve (32) in the flow channel of the first station, and the variable back pressure valve (3) is a channel with both ends completely connected in the flow channel of the second station.

7. The oil replenishment system for engineering machinery motors according to claim 6, characterized in that, The variable back pressure valve (3) is connected to the second pilot valve (8), and the second pilot valve (8) is connected to the controller (6). The controller (6) is used to control the second pilot valve (8) so that the variable back pressure valve (3) switches between the first station and the second station.

8. The oil replenishment system for engineering machinery motors according to any one of claims 1-7, characterized in that, The inlet of the accumulator (5) is provided with a first pressure sensor (51); and / or, the inlet of the variable back pressure valve (3) is provided with a second pressure sensor (33).

9. A control method for an oil replenishment system for a motor in engineering machinery, characterized in that, The method for controlling the oil replenishment system for the motor of construction machinery, as described in any one of claims 1-8, includes: Determine whether the pressure of the accumulator in the oil replenishment system of the construction machinery motor is less than a first preset value; If so, the variable back pressure valve of the oil replenishment system for the construction machinery motor is in the first position, and the oil replenishment control valve of the oil replenishment system for the construction machinery motor is in the first state. If not, control the variable back pressure valve to be in the second position and control the oil replenishment control valve to be in the first state; Determine whether the pressure at the oil supply port M of the rotary motor of the engineering machinery motor oil supply system is less than a second preset value; If so, control the variable back pressure valve to be in the first working position, and control the oil replenishment control valve to be in the second state.

10. An engineering machinery, characterized in that, The system includes the oil replenishment system for engineering machinery motors as described in any one of claims 1-8.

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