Crawler crane motor long-distance oil drainage active backflow system
The combined system of an electronically controlled hydraulic pump and a pressure switch solves the problems of poor hydraulic oil fluidity and overflow caused by the long drain pipe of large-tonnage crawler cranes, achieves automatic reflux of hydraulic oil and eliminates waste, thus extending the life of the motor and reducing environmental pollution.
Patent Information
- Application Number
- CN202423093415.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-16
AI Technical Summary
The oil drain line of large-tonnage crawler cranes is too long, resulting in poor fluidity of the hydraulic oil at low temperatures, high friction, and easy damage to the motor housing. The existing oil drain system is prone to overflowing hydraulic oil, causing waste and pollution, and requires manual processing.
A combined system of an electronically controlled hydraulic pump and a pressure switch is used to automatically return the hydraulic oil through the electronically controlled hydraulic pump, avoiding the use of a one-way valve and an oil drain pot, ensuring that the pressure at the oil drain port is lower than 1Mpa, and achieving full hydraulic oil return.
It realizes the automatic return of hydraulic oil, avoids overflow and waste, prolongs the life of the motor, reduces environmental pollution and reduces the burden on operators.
Smart Images
Figure CN223483051U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of crawler cranes, and in particular to a long-distance active oil drain and return system for crawler crane motors, and a long-distance active oil drain and return system for large-tonnage crawler crane motors. Background Technology
[0002] As cranes become increasingly larger in lifting capacity, the displacement of their accompanying travel motors also increases. Larger displacement motors require larger oil drain volumes. Furthermore, due to the structural limitations of crawler cranes, the length of the oil drain line for small-tonnage crane motors is typically between 10 and 20 meters, while the length for large-tonnage crane motors can exceed 30 meters.
[0003] The hydraulic oil drain circuit of a large-tonnage crawler crane motor needs to overcome the weight of the hydraulic oil itself and the friction between the hydraulic oil and the pipeline to return it to the oil tank. A large amount of hydraulic oil accumulates in the extremely long pipeline. Furthermore, due to the physical properties of hydraulic oil, its fluidity decreases at lower temperatures, increasing the friction with the pipeline and thus the pressure on the motor during draining. The travel motor housing has a very low pressure resistance rating (≤1 MPa). If it is subjected to excessive pressure for a long period, the lifespan of the motor shaft end seal will be greatly reduced or even directly damaged. This will also damage the reducer, causing significant losses.
[0004] The existing solution is to install a bypass on the main return line, consisting of a check valve (opening pressure 1 MPa) and a drain reservoir. When the pressure in the main return line is higher than 1 MPa, the excess hydraulic oil can flow into the drain reservoir in time through the check valve, ensuring that the pressure in the motor housing is below 1 MPa.
[0005] However, if issues such as excessively long drain lines, excessively low hydraulic oil temperatures, and frequent blockages in the return lines occur, the hydraulic oil in the drain reservoir will quickly fill up. If the operator does not notice and empty it in time, the hydraulic oil will overflow, contaminating the equipment and the environment. Furthermore, the hydraulic oil flowing into the reservoir cannot be reused, and the operator must periodically replenish the hydraulic oil in the tank, resulting in waste.
[0006] Therefore, it is necessary to develop a new type of long-distance active oil return system for large-tonnage crawler crane motors to overcome the above problems. Utility Model Content
[0007] Purpose of the utility model: In view of the shortcomings and defects of the existing technology, this utility model provides a long-distance active oil drain return system for crawler crane motors. While ensuring that the pressure at the motor drain port is below 1 MPa, it allows all the hydraulic oil to flow back to the oil tank. It does not use a check valve or drain can, does not require manual emptying of the hydraulic oil in the drain can, and does not require concern about hydraulic oil overflow.
[0008] Technical solution: The present invention relates to a long-distance active oil return system for a crawler crane motor, characterized in that: it includes a hydraulic oil tank equipped with an electro-hydraulic pump, two branch pipes of the hydraulic oil tank are connected to the motor, pressure switches are provided on the two branch pipes, and the two pressure switches are respectively connected to the electro-hydraulic pump through control lines.
[0009] The electro-hydraulic pump is equipped with a motor.
[0010] The oil inlet and outlet of the electro-hydraulic pump are connected to the main pipeline of the hydraulic oil tank.
[0011] The motor is equipped with an oil drain port.
[0012] The drain port is connected to the branch pipe of the hydraulic oil tank.
[0013] The hydraulic oil tank's pipeline includes a main pipeline and two branch pipelines.
[0014] The motor is located on the crawler crane.
[0015] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The present invention ensures that the pressure at the motor drain port is below 1 MPa while allowing all the hydraulic oil to flow back to the oil tank. It does not use a check valve or drain can, does not require manual emptying of the hydraulic oil in the drain can, and does not require worrying about hydraulic oil overflow. Attached Figure Description
[0016] Figure 1 It is a structural diagram of the utility model;
[0017] Figure 2 This is a schematic diagram of the structure of the electro-hydraulic pump of this utility model;
[0018] Figure 3 This is a schematic diagram of the pressure switch of this utility model;
[0019] Figure 4 This is a schematic diagram of the motor structure of this utility model;
[0020] In the diagram, 1 is the electro-hydraulic pump; 2 is the pressure switch; 3 is the control circuit; 4 is the motor; 5 is the electric motor; 6 is the oil suction port; 7 is the oil outlet port; and 8 is the oil drain port. Detailed Implementation
[0021] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0022] Motor oil drain: Hydraulic motors are equipped with oil drain ports, whose main function is to discharge excess oil from the motor housing to prevent excessive internal pressure from causing the housing to rupture. Draining also removes hot oil from the motor, aiding in cooling. Additionally, draining removes impurities from the motor, extending its lifespan. Oil return system: The return oil pressure comes from the pressure generated during motor operation. Excess hydraulic oil flows back to the hydraulic tank through hydraulic lines under pressure. In open systems, the back pressure connected to the hydraulic tank is very low, so the hydraulic oil at the motor drain port only needs a very low pressure (around 0.1 MPa) to flow back to the tank.
[0023] This utility model discloses a long-distance active oil drain and return system for a crawler crane motor. It includes a hydraulic oil tank equipped with an electro-hydraulic pump 1. Two branch pipes of the hydraulic oil tank are connected to a motor 4. Pressure switches 2 are installed on the two branch pipes, and each pressure switch 2 is connected to the electro-hydraulic pump 1 via a control circuit 3. The electro-hydraulic pump 1 includes a motor 5. The pump 1's suction port 6 and outlet port 7 are connected to the main pipeline of the hydraulic oil tank. The motor 4 has a drain port 8, which is connected to the branch pipes of the hydraulic oil tank. The hydraulic oil tank's piping includes a main pipeline and two branch pipes. The motor 4 is located on the crawler crane.
[0024] The pressure switch 2 of this utility model is a device that converts pressure into an electrical signal. It sends a signal when the pressure exceeds a set value. This utility model selects a pressure switch with an opening pressure of 1 MPa. The electro-hydraulic pump 1 is a hydraulic pump driven by an electric motor, powered by the vehicle's battery. It has an internal electrical switch that starts operating when it receives a signal from the pressure switch.
[0025] In use, the electro-hydraulic pump 1 draws excess hydraulic oil from the pipeline and motor 4 back to the oil tank. At the same time, a pressure switch 2 is connected in series on the main oil line. When it detects that the pressure is greater than 1 MPa, it will send a signal. The electro-hydraulic pump 1 receives the signal and starts to pump oil. Under the action of the electro-hydraulic pump 1, the oil pressure will drop rapidly. When the pressure is less than 1 MPa, the signal is disconnected and the electro-hydraulic pump 1 stops running.
[0026] This invention ensures that the pressure at the motor drain port remains below 1 MPa while allowing all hydraulic oil to flow back to the tank. It eliminates the need for a check valve and drain can, eliminating the need for manual emptying of the drain can and preventing hydraulic oil overflow. Excess hydraulic oil is automatically pumped back to the tank without operator intervention, and there is no concern about spillage or contamination. There is no hydraulic oil waste, and operators do not need to periodically replenish the hydraulic oil.
Claims
1. A long-distance active oil drain and return system for a crawler crane motor, characterized in that: It includes a hydraulic oil tank equipped with an electro-hydraulic pump (1), the ends of two branch pipes of the hydraulic oil tank are connected to a motor (4), and pressure switches (2) are provided on the two branch pipes. The two pressure switches (2) are respectively connected to the electro-hydraulic pump (1) through control lines (3).
2. The long-distance active oil drain and return system for crawler crane motors according to claim 1, characterized in that: The electro-hydraulic pump (1) is equipped with a motor (5).
3. The long-distance active oil drain and return system for crawler crane motors according to claim 1, characterized in that: The oil inlet (6) and oil outlet (7) of the electro-hydraulic pump (1) are connected to the main pipeline of the hydraulic oil tank.
4. The long-distance active oil drain and return system for tracked crane motors according to claim 1, characterized in that: The motor (4) is provided with an oil drain port (8).
5. The long-distance active oil drain and return system for tracked crane motors according to claim 4, characterized in that: The drain port (8) is connected to the branch pipe of the hydraulic oil tank.
6. The long-distance active oil drain and return system for tracked crane motors according to claim 1, characterized in that: The hydraulic oil tank has a main pipeline and two branch pipelines.
7. The long-distance active oil return system for tracked crane motors according to any one of claims 1-6, characterized in that: The motor (4) is located on the crawler crane.