Eccentric transmission structure of high-pressure oil feed pump

Abstract

The utility model discloses an eccentric transmission structure of a high-pressure oil feed pump, which relates to the technical field of oil pumps, and comprises a pump body, a pump cover, a camshaft assembly, a plunger, a plunger sleeve and a plunger spring, the pump cover is fixedly arranged on the pump body, the plunger sleeve is vertically and fixedly arranged on the pump cover, the plunger sleeve is arranged in the pump body, the plunger is vertically and slidably arranged in the plunger sleeve, and the camshaft assembly is arranged in the plunger sleeve. The plunger sleeve is coaxially sleeved with the plunger spring, one end of the plunger spring is fixedly installed on the plunger sleeve, the end, away from the pump cover, of the plunger is fixedly installed at the other end of the plunger spring, the cam shaft assembly is rotationally connected into the pump body and abuts against the plunger, and the rotating center of the cam shaft assembly does not coincide with the vertical central axis of the plunger. The distance between the contact point of the cam shaft assembly and the plunger and the central axis of the plunger is reduced, so that the abrasion to the plunger sleeve can be reduced, the risk of plunger clamping stagnation failure is reduced, the service life of the oil pump can be prolonged, and the maintenance cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of oil pumps, and in particular to an eccentric transmission structure of a high-pressure oil supply pump. Background Art

[0002] The high-pressure fuel pump is a core component of the fuel system, and its performance stability and reliability are of great importance to the fuel system. In recent years, engine matching has required the common rail system to provide increasingly higher rail pressures and sufficient fuel supply. To meet these requirements, the speed of the high-pressure fuel pump has been designed to be higher and higher, which has placed stricter requirements on the operational stability and component reliability of the high-pressure fuel pump.

[0003] With the continuous increase in rail pressure and speed in common rail systems, eccentric cam structures are a common feature of high-pressure fuel pumps. Traditional eccentric cam structures typically utilize a camshaft, cam, roller, and plunger assembly to achieve the fuel delivery process. The camshaft's eccentric structure causes the roller to reciprocate, pushing the plunger to pressurize diesel into the high-pressure fuel line, completing the fuel delivery process. However, at high speeds, friction between the roller and the pump body can lead to significant power loss. Furthermore, friction between the moving parts can generate significant noise and vibration, impacting engine stability and comfort.

[0004] In order to solve the problems of large power loss, noise and vibration in the traditional eccentric cam structure, and to adapt to the installation, it is necessary to reduce the volume of the high-pressure oil supply pump, cancel the roller body configuration, and complete the oil supply process by combining the eccentric cam and the plunger. Figure 1 As shown, due to the eccentric setting of the eccentric cam, there is a certain horizontal distance between the force point of the plunger and the center axis of the plunger. When the horizontal distance is too large, the deflection torque applied to the plunger during the up and down reciprocating motion will be too large, resulting in skewness, which will in turn increase the friction of the plunger on the plunger sleeve and pose a risk of jamming failure. Utility Model Content

[0005] The purpose of the utility model is to provide an eccentric transmission structure of a high-pressure oil supply pump, which reduces the deflection moment suffered by the plunger, thereby reducing the wear suffered by the plunger sleeve.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions: an eccentric transmission structure of a high-pressure oil supply pump, comprising a pump body, a pump cover, a camshaft assembly, a plunger, a plunger sleeve and a plunger spring, the pump cover is fixedly mounted on the pump body, the plunger sleeve is vertically fixedly mounted on the pump cover, and the plunger sleeve is arranged in the pump body, the plunger can slide vertically in the plunger sleeve, the plunger spring is coaxially sleeved on the plunger sleeve, and one end of the plunger spring is fixedly mounted on the plunger sleeve, and the other end of the plunger spring is fixedly mounted on the end of the plunger away from the pump cover, the camshaft assembly is rotatably connected in the pump body, and the camshaft assembly is against the plunger, and the rotation center of the camshaft assembly does not coincide with the vertical center axis of the plunger.

[0007] The technical principle of the present invention is as follows: by arranging the rotation center of the camshaft assembly and the vertical center axis of the plunger to be non-coincidental, the distance between the contact point between the camshaft assembly and the plunger and the center axis of the plunger can be reduced, thereby reducing the deflection torque on the plunger.

[0008] Furthermore, the distance between the rotation center of the camshaft assembly and the central axis of the plunger is one quarter of the lift of the camshaft assembly.

[0009] Furthermore, the camshaft assembly includes a camshaft and a sliding sleeve. The camshaft is rotatably mounted in the pump body. The sliding sleeve is sleeved on the camshaft, and the sliding sleeve abuts against the plunger.

[0010] Furthermore, the surface of the plunger is coated with a high temperature resistant coating.

[0011] The beneficial effects of the utility model are:

[0012] 1. By reducing the distance between the contact point between the camshaft assembly and the plunger and the center axis of the plunger, the wear on the plunger sleeve can be reduced, and the risk of plunger sticking failure can be reduced, thereby increasing the service life of the oil pump and reducing maintenance costs.

[0013] 2. By setting up a high temperature resistant coating, the service life of the plunger can be further improved and the maintenance cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the oil pump in the background technology;

[0015] Figure 2 It is a structural diagram of the present utility model.

[0016] In the above drawings:

[0017] 1. Pump cover; 2. Pump body; 3. Plunger sleeve; 4. Plunger; 5. Plunger spring;

[0018] 6. Camshaft assembly; 601. Cam; 602. Sleeve. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; the structures described in various embodiments can be freely combined without any conflict in structure or principle.

[0020] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0021] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is typically placed when in use. These terms are intended solely to facilitate the description of this utility model and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., etc., are used solely for distinction and description, and should not be construed as indicating or implying relative importance.

[0022] Below with reference to accompanying drawing some embodiment of the present utility model is described:

[0023] like Figure 1 As shown, the utility model proposes an eccentric transmission structure of a high-pressure oil supply pump, including a pump body 2, a pump cover 1, a camshaft assembly 6, a plunger 4, a plunger sleeve 3 and a plunger spring 5. The pump cover 1 is fixedly mounted on the pump body 2 by bolts, the plunger sleeve 3 is vertically fixedly mounted on the pump cover 1, and the plunger sleeve 3 is arranged in the pump body 2, the plunger 4 is vertically slidably arranged in the plunger sleeve 3, the plunger spring 5 is coaxially sleeved on the plunger sleeve 3, and one end of the plunger spring 5 is fixedly mounted on the plunger sleeve 3, and the end of the plunger 4 away from the pump cover 1 is fixedly mounted on the other end of the plunger spring 5, the camshaft assembly 6 is rotatably connected in the pump body 2, and the camshaft assembly 6 is against the plunger 4, and the rotation center of the camshaft assembly 6 does not coincide with the vertical center axis of the plunger 4.

[0024] When changing the horizontal distance between the rotation center of the camshaft assembly 6 and the vertical center axis of the plunger 4, the contact point between the camshaft assembly 6 and the plunger 4 should be as close to the center axis of the plunger 4 as possible to reduce the deflection torque on the plunger 4. However, the space inside the pump body 2 is limited. The optimal choice is when the rotation center of the camshaft assembly 6 is at a distance from the center axis of the plunger 4 of one-quarter of the lift of the camshaft assembly 6. At this time, under the condition of limited space inside the pump body 2, the deflection torque on the plunger 4 is minimized.

[0025] By changing the horizontal distance between the rotation center of the camshaft assembly 6 and the vertical center axis of the plunger 4, the distance between the rotation center of the camshaft assembly 6 and the center axis of the plunger 4 is made to be one quarter of the lift of the camshaft assembly 6. This can reduce the distance between the contact point between the camshaft assembly 6 and the plunger 4 and the center axis of the plunger 4, thereby reducing the deflection torque on the plunger 4, thereby reducing the wear on the plunger sleeve 3, reducing the risk of the plunger 4 being stuck and failing, thereby increasing the service life of the oil pump and reducing maintenance costs.

[0026] Further, if Figure 1 As shown, the camshaft assembly 6 includes a camshaft 601 and a sliding sleeve 602 . The camshaft 601 is rotatably mounted in the pump body 2 . The sliding sleeve 602 is sleeved on the camshaft 601 , and the sliding sleeve 602 abuts against the plunger 4 .

[0027] The sliding sleeve 602 has a self-lubricating property, which can reduce the friction between the sliding sleeve 602 and the plunger 4 and further increase the service life of the plunger 4.

[0028] Further, if Figure 1 As shown, the surface of the plunger 4 is coated with a high temperature resistant coating (not shown in the figure).

[0029] High-temperature resistant coatings include polytetrafluoroethylene (PTFE) and diamond-like carbon (DLC). PTFE coatings are anisotropic, allowing for good orientation even under sliding friction conditions. Their coefficient of friction is lower than that of graphite and MoS2, and under high load conditions, it can be reduced from 0.04 to 0.016. This is due to their excellent corrosion resistance, high-temperature resistance, insulation, and low friction coefficient.

[0030] The hardness of the DLC coating can reach 2000-3000HV, which is several times higher than that of ordinary metal materials, and can effectively improve the wear resistance and corrosion resistance of the material; the friction coefficient of the DLC coating is very low, which can effectively reduce the friction and wear between mechanical parts, thereby extending the service life of mechanical parts; the DLC coating has excellent thermal stability and can maintain its excellent performance in high temperature environments, making it suitable for applications in high temperature environments.

[0031] Here, DLC coating is preferably used, and the DLC coating is covered on the surface of the plunger 4 to play the role of wear resistance, corrosion resistance and high temperature resistance. By setting the high temperature resistant coating, the service life of the plunger 4 can be further increased and the maintenance cost can be reduced.

Claims

1. An eccentric transmission structure of a high-pressure oil supply pump, comprising a pump body (2), a pump cover (1), a camshaft assembly (6), a plunger (4), a plunger sleeve (3) and a plunger spring (5), wherein the pump cover (1) is fixedly mounted on the pump body (2), the plunger sleeve (3) is vertically fixedly mounted on the pump cover (1), and the plunger sleeve (3) is arranged in the pump body (2), the plunger (4) is vertically slidably arranged in the plunger sleeve (3), the plunger spring (5) is coaxially sleeved on the plunger sleeve (3), and one end of the plunger spring (5) is fixedly mounted on the plunger sleeve (3), and the other end of the plunger spring (5) is fixedly mounted on the end of the plunger (4) away from the pump cover (1), characterized in that The camshaft assembly (6) is rotatably connected in the pump body (2), and the camshaft assembly (6) abuts against the plunger (4), and the rotation center of the camshaft assembly (6) does not coincide with the vertical center axis of the plunger (4).

2. The eccentric transmission structure of a high-pressure oil supply pump according to claim 1, characterized in that: The distance between the rotation center of the camshaft assembly (6) and the central axis of the plunger (4) is one quarter of the lift of the camshaft assembly (6).

3. The eccentric transmission structure of a high-pressure oil supply pump according to claim 1 or 2, characterized in that: The camshaft assembly (6) comprises a camshaft (601) and a sliding sleeve (602). The camshaft (601) is rotatably mounted in the pump body (2). The sliding sleeve (602) is sleeved on the camshaft (601), and the sliding sleeve (602) abuts against the plunger (4).

4. The eccentric transmission structure of a high-pressure oil supply pump according to claim 1 or 2, characterized in that: The surface of the plunger (4) is coated with a high-temperature resistant coating.

5. The eccentric transmission structure of a high-pressure oil supply pump according to claim 3, characterized in that: The surface of the plunger (4) is coated with a high-temperature resistant coating.

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