A plunger assembly for a heavy machinery assembly pump
Patent Information
- Application Number
- CN202522152927.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2035-10-11
AI Technical Summary
[0016]与现有技术相比，本实用新型具有的优点和积极效果是：
Smart Images
Figure CN224885791U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of mechanical combination pumps for diesel engines, specifically relating to a plunger assembly for a heavy machinery assembly pump. Background Technology
[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.
[0003] In the field of high-power, high-speed diesel engines, the heavy-duty mechanical combination pump, as a core fuel supply component, directly determines the power output, operational stability, and service life of the diesel engine. This combination pump includes a mechanical injection pump and a governor. The plunger assembly within the mechanical injection pump is a key pumping unit for pressurizing low-pressure fuel and precisely controlling the fuel supply. It consists of a plunger sleeve and a plunger, and works in conjunction with the delivery valve, roller body, and camshaft to form an independent fuel supply unit, completing precise fuel supply according to the diesel engine cylinder's power stroke sequence.
[0004] With the increasing power demands and complex operating conditions of heavy machinery, existing plunger assemblies are gradually exhibiting certain problems, making it difficult to meet the design requirements of high-performance oil pumps. Firstly, the inlet and outlet ports of existing plunger assemblies are arranged on the same horizontal plane, meaning they are connected and do not form an independent circuit. This causes cavitation in both ports during pressure relief and return. Secondly, during the operation of high-power, high-speed diesel engines, the delivery valve operates under high pressure and high frequency for extended periods, leading to continuous heat accumulation and potential high-temperature failure, directly affecting fuel supply accuracy. When slight leakage occurs in the delivery valve, the leaked diesel fuel will seep directly outside the oil pump. Finally, leaked diesel fuel generated by the clearance between the plunger and plunger sleeve cannot be discharged in time and will naturally leak into the oil pump, mixing with the engine oil. This dilutes the engine oil, reduces lubrication performance, and can lead to serious malfunctions such as camshaft scoring, significantly shortening the overall lifespan of the oil pump and increasing equipment maintenance costs and downtime losses. Utility Model Content
[0005] To address the aforementioned problems, this utility model provides a plunger assembly for a heavy machinery assembly pump, which can effectively prevent cavitation and extend the service life of the plunger after rotation; it also cools the oil outlet valve through the cooling oil passage to prevent failure and collects micro-leaking oil; and it discharges leaked oil through the sludge return oil passage to avoid oil dilution.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A plunger assembly for a heavy machinery assembly pump includes a plunger and a plunger sleeve. The plunger sleeve is fitted onto the plunger, and the lower end of the plunger extends out of the plunger sleeve. One end of the plunger sleeve is provided with an oil inlet, and the other end of the plunger sleeve is provided with an oil return hole. The horizontal height of the oil return hole is higher than that of the oil inlet.
[0007] As a further technical solution, an anti-cavitation screw is provided at one end of the oil return hole, and the anti-cavitation screw is installed on the plunger sleeve.
[0008] As a further technical solution, the anti-cavitation screw is detachably connected to the plunger sleeve.
[0009] As a further technical solution, the plunger sleeve is also provided with an oil outlet valve cooling oil passage, a plunger leakage oil return passage, and a sludge oil return passage, which are arranged from top to bottom.
[0010] As a further technical solution, the oil outlet valve cooling oil passage is located at the upper end of the plunger sleeve, and the oil outlet valve cooling oil passage is arranged obliquely.
[0011] As a further technical solution, a plunger leakage oil return channel is provided at the lower end of the oil outlet valve cooling oil channel.
[0012] As a further technical solution, the plunger leakage oil return passage is set obliquely, and the inclination direction of the plunger leakage oil return passage is opposite to the inclination direction of the outlet valve cooling oil passage.
[0013] As a further technical solution, a sludge return channel is provided at the lower end of the plunger leakage oil return channel.
[0014] As a further technical solution, the waste oil return channel is inclined, and the inclination direction of the waste oil return channel is the same as that of the plunger leakage oil return channel, while the inclination direction of the waste oil return channel is opposite to that of the outlet valve cooling oil channel.
[0015] As a further technical solution, the outer surface of the plunger sleeve is provided with a spiral structure, and the spiral structure is symmetrically arranged.
[0016] Compared with the prior art, the advantages and positive effects of this utility model are: In this invention, the horizontal height of the return oil hole is higher than that of the inlet oil hole, thus cavitation is concentrated only on the return oil side. There is no need to install additional anti-cavitation screws on the inlet oil side; a single anti-cavitation screw on the return oil side is sufficient to effectively control cavitation. Furthermore, since cavitation only affects the return oil side of the plunger, and considering the plunger's symmetrical double-helix structure, when the return oil side helix fails due to cavitation, the plunger can be rotated, allowing the original inlet oil side helix to align with the plunger sleeve's return oil hole. This extends the effective service life of the plunger assembly, reducing equipment replacement frequency and costs. This invention features a plunger sleeve outlet valve cooling oil passage. The low-pressure oil chamber is connected to the outlet valve via this cooling oil passage. The low-pressure fuel continuously carries away the heat accumulated in the outlet valve during high-pressure, high-frequency operation, effectively suppressing temperature rise and preventing performance failure of the outlet valve due to high temperature, thus ensuring stable fuel supply accuracy. When slight leakage occurs in the outlet valve, the cooling oil passage can directly collect the leaked diesel fuel, preventing it from seeping directly outside the fuel pump and reducing fuel waste. This invention features a waste oil return channel, through which leaked diesel fuel is directly led out of the pump, blocking its flow and mixing with the engine oil. This avoids the lubrication performance degradation caused by engine oil dilution, extends the overall lifespan of the oil pump, and reduces equipment maintenance costs. Attached Figure Description
[0017] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.
[0018] Figure 1 This is a schematic diagram of the structure of the plunger assembly for a heavy machinery assembly pump according to this utility model. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the plunger assembly for a heavy machinery assembly pump according to this utility model. Figure 2 ; In the diagram: 1. Plunger; 2. Plunger sleeve; 3. Oil inlet; 4. Oil return hole; 5. Anti-cavitation screw; 6. Oil outlet valve cooling oil passage; 7. Plunger leakage oil return passage; 8. Waste oil return passage. Detailed Implementation
[0019] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0020] With the increasing power demands and complex operating conditions of heavy machinery, existing plunger assemblies are gradually exhibiting certain problems, making it difficult to meet the design requirements of high-performance oil pumps. Firstly, the inlet and outlet ports of existing plunger assemblies are arranged on the same horizontal plane, meaning they are connected and do not form an independent circuit. This causes cavitation in both ports during pressure relief and return. Secondly, during the operation of high-power, high-speed diesel engines, the delivery valve operates under high pressure and high frequency for extended periods, leading to continuous heat accumulation and potential high-temperature failure, directly affecting fuel supply accuracy. When slight leakage occurs in the delivery valve, the leaked diesel fuel will seep directly outside the oil pump. Finally, leaked diesel fuel generated by the clearance between the plunger and plunger sleeve cannot be discharged in time and will naturally leak into the oil pump, mixing with the engine oil. This dilutes the engine oil, reduces lubrication performance, and can lead to serious malfunctions such as camshaft scoring, significantly shortening the overall lifespan of the oil pump and increasing equipment maintenance costs and downtime losses.
[0021] The present invention will now be described in detail with reference to the accompanying drawings. This embodiment discloses a plunger assembly for a heavy machinery assembly pump, such as... Figure 1 As shown, it includes a plunger 1 and a plunger sleeve 2. The plunger sleeve 2 is fitted onto the plunger 1, and the lower end of the plunger 1 extends out of the plunger sleeve 2. One end of the plunger sleeve 2 is provided with an oil inlet hole 3, and the other end of the plunger sleeve 2 is provided with an oil return hole 4. The horizontal height of the oil return hole 4 is higher than the horizontal height of the oil inlet hole 3.
[0022] Specifically, the horizontal height of the return oil hole 4 is higher than that of the inlet oil hole 3. Cavitation is concentrated only on the return oil side, eliminating the need for additional anti-cavitation screws 5 on the inlet side. A single anti-cavitation screw 5 on the return oil side is sufficient to effectively control cavitation. Furthermore, since cavitation only affects the return oil side of the plunger 1, and considering the symmetrical double-helix structure of the plunger 1, when the return oil side helix fails due to cavitation, the plunger 1 can be rotated to allow the original inlet side helix to engage with the return oil hole 4 of the plunger sleeve 2. This extends the effective service life of the plunger assembly and reduces equipment replacement frequency and costs.
[0023] The outer surface of the plunger sleeve 2 is provided with a spiral structure, which is symmetrically arranged. By using the independent oil inlet hole 3 and oil return hole 4, cavitation of the plunger 1 only occurs on the oil return side. The plunger sleeve 2 has a symmetrical double spiral structure design, which can be rotated. After the oil pump performance fails due to cavitation of the plunger 1 on the oil return side, the plunger 1 can be rotated 180°, and the oil inlet side of the plunger 1 can be used in conjunction with the oil return hole 4 of the plunger sleeve 2.
[0024] An anti-cavitation screw 5 is provided at one end of the oil return hole 4, and the anti-cavitation screw 5 is installed on the plunger sleeve 2. The anti-cavitation screw 5 is detachably connected to the plunger sleeve 2.
[0025] Specifically, when assembling the plunger assembly for the heavy machinery assembly pump, the anti-cavitation screw 5 is aligned with the mounting position at one end of the oil return hole 4 of the plunger sleeve 2 and assembled, and the anti-cavitation screw 5 is fixed to the plunger sleeve 2 by means of threaded connection.
[0026] When the plunger assembly is put into use, cavitation occurs during the pressure relief and oil return process. The anti-cavitation screw 5 can directly block and alleviate cavitation on the oil return side, preventing damage to the oil return hole 4 of the plunger sleeve 2 and the surrounding structure. If the anti-cavitation screw 5 wears out after long-term use, the operator can directly unscrew the old screw and replace it with a new anti-cavitation screw 5 without disassembling the entire plunger assembly.
[0027] like Figure 2 As shown, the plunger sleeve 2 is also provided with an oil outlet valve cooling oil passage 6, a plunger leakage oil return passage 7, and a sludge oil return passage 8, which are arranged from top to bottom. The oil outlet valve cooling oil passage 6 is located at the upper end of the plunger sleeve 2 and is arranged obliquely.
[0028] Specifically, an oblique delivery valve cooling oil passage 6 is machined on the upper end of the plunger sleeve 2 according to the design trajectory, ensuring that one end of the cooling oil passage is connected to the low-pressure oil chamber and the other end extends to the location of the delivery valve. When the plunger assembly is working, the low-pressure fuel in the low-pressure oil chamber will continuously flow to the delivery valve along the delivery valve cooling oil passage 6.
[0029] During the flow of fuel through the outlet valve, the fuel carries away the heat generated by the valve's high-pressure, high-frequency operation, keeping the outlet valve at a suitable operating temperature. This effectively prevents performance failure due to high temperatures and ensures accurate fuel supply. Simultaneously, if slight leakage occurs in the outlet valve, the leaked diesel fuel is collected by the cooling oil passages, preventing it from directly leaking outside the pump and maintaining the pump's internal cleanliness and sealing performance.
[0030] The low-pressure oil chamber is connected to the delivery valve via a cooling oil passage. The low-pressure fuel continuously carries away the heat accumulated in the delivery valve during high-pressure, high-frequency operation, effectively suppressing temperature rise and preventing performance failure of the delivery valve due to high temperature, thus ensuring stable fuel supply accuracy. When slight leakage occurs in the delivery valve, the cooling oil passage can directly collect the leaked diesel fuel, preventing it from seeping directly outside the fuel pump and reducing fuel waste.
[0031] A plunger leakage oil return passage 7 is provided at the lower end of the oil outlet valve cooling oil passage 6. The plunger leakage oil return passage 7 is inclined, and the inclination direction of the plunger leakage oil return passage 7 is opposite to the inclination direction of the oil outlet valve cooling oil passage 6.
[0032] Specifically, when diesel fuel leaks due to the clearance between plunger 1 and plunger sleeve 2, the leaking oil will flow downwards under gravity and enter the plunger leakage oil return passage 7. Because the return passage is designed at an angle, and the direction of inclination is opposite to that of the outlet valve cooling oil passage 6, it guides the leaking oil downwards along a specific path, preventing it from flowing randomly inside the plunger sleeve 2 and causing contamination from contact with other components. Simultaneously, it guides the leaking oil to be collected in the subsequent waste oil return passage 8, ensuring the orderly discharge of the leaking oil.
[0033] A sludge return passage 8 is provided at the lower end of the plunger leakage oil return passage 7. The sludge return passage 8 is inclined, and the inclination direction of the sludge return passage 8 is the same as that of the plunger leakage oil return passage 7, while the inclination direction of the sludge return passage 8 is opposite to that of the outlet valve cooling oil passage 6.
[0034] Specifically, the end of the sludge return channel 8 is connected to a recovery device outside the oil pump. When leaking oil from plunger 1 flows through plunger leak return channel 7 to sludge return channel 8, it will continue to flow towards the recovery device outside the oil pump along the oblique trajectory of sludge return channel 8. During this process, the leaking oil is completely drawn out of the pump and will not leak into the oil pump to mix with the engine oil, effectively avoiding the problem of engine oil dilution due to diesel fuel mixing, and ensuring the lubricating performance of the engine oil.
[0035] Leaked diesel fuel is directly drained from the pump through the sludge return oil passage, blocking the path for it to leak and mix with the engine oil. This avoids the problem of reduced lubrication performance caused by engine oil dilution, extends the overall life of the oil pump, and reduces equipment maintenance costs.
[0036] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.
Claims
1. A plunger assembly for a heavy machinery assembly pump, characterized in that, It includes a plunger (1) and a plunger sleeve (2), with the plunger sleeve (2) fitted on the plunger (1) and the lower end of the plunger (1) extending out of the plunger sleeve (2); one end of the plunger sleeve (2) is provided with an oil inlet hole (3), and the other end of the plunger sleeve (2) is provided with an oil return hole (4), the horizontal height of the oil return hole (4) being higher than the horizontal height of the oil inlet hole (3).
2. The plunger assembly for a heavy machinery assembly pump as described in claim 1, characterized in that, One end of the oil return hole (4) is provided with an anti-cavitation screw (5), which is installed on the plunger sleeve (2).
3. A plunger assembly for a heavy machinery assembly pump as described in claim 2, characterized in that, The anti-cavitation screw (5) is detachably connected to the plunger sleeve (2).
4. A plunger assembly for a heavy machinery assembly pump as described in claim 1, characterized in that, The plunger sleeve (2) is also provided with an oil outlet valve cooling oil passage (6), a plunger leakage oil return passage (7) and a sludge oil return passage (8), which are arranged from top to bottom.
5. A plunger assembly for a heavy machinery assembly pump as described in claim 4, characterized in that, The oil outlet valve cooling oil passage (6) is located at the upper end of the plunger sleeve (2), and the oil outlet valve cooling oil passage (6) is arranged obliquely.
6. A plunger assembly for a heavy machinery assembly pump as described in claim 4, characterized in that, The lower end of the oil outlet valve cooling oil passage (6) is provided with a plunger leakage oil return passage (7).
7. A plunger assembly for a heavy machinery assembly pump as described in claim 6, characterized in that, The plunger leakage oil return passage (7) is inclined, and the inclination direction of the plunger leakage oil return passage (7) is opposite to the inclination direction of the oil outlet valve cooling oil passage (6).
8. A plunger assembly for a heavy machinery assembly pump as described in claim 4, characterized in that, The lower end of the plunger leakage oil return channel (7) is provided with a sludge oil return channel (8).
9. A plunger assembly for a heavy machinery assembly pump as described in claim 8, characterized in that, The waste oil return channel (8) is set at an angle. The tilt direction of the waste oil return channel (8) is the same as that of the plunger leakage oil return channel (7). The tilt direction of the waste oil return channel (8) is opposite to that of the outlet valve cooling oil channel (6).
10. A plunger assembly for a heavy machinery assembly pump as described in claim 1, characterized in that, The outer surface of the plunger sleeve (2) is provided with a spiral structure, and the spiral structure is symmetrically arranged.