A radially distributed high-pressure variable fuel injection pump lubricated with engine oil

Abstract

The present invention discloses a radially distributed high-pressure variable fuel injection pump lubricated by engine oil, which includes a pump body, a drive shaft, and a double-sided skeleton oil seal. The double-sided skeleton oil seal divides the inside of the pump body into an independent working chamber and a lubricating oil chamber; several fuel injection systems arranged along the circumferential direction of the pump body and a fuel transfer pump installed on the pump body; a cam is provided on the drive shaft, the cam abuts against several tappet bodies, and the upper end of each tappet body corresponds to a fuel injection system, and the fuel injection system is installed on the pump body through fasteners; a pressure balance oil passage is arranged on the pump body in the radial direction, and the pressure balance oil passage is respectively communicated with the lubricating oil chamber; a lubricating oil connector seat is installed at the inlet of the pump body; a fuel transfer pump is installed on the working chamber of the pump body, and in the pump body, the drive shaft is connected to the drive shaft of the fuel transfer pump through a coupling. The reasonable layout of the oil circuit in the present invention avoids interference and oil circuit connection in a limited volume.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-pressure variable fuel injection pumps for common rail systems of diesel engines, and particularly relates to a radially distributed high-pressure variable fuel injection pump lubricated with engine oil. Background Art

[0002] The high-pressure variable fuel injection pump (hereinafter referred to as the high-pressure pump) of the common rail system of diesel engines is a core component of the fuel injection system. Its fuel supply capacity directly determines the platform pressure and applicable range of the common rail system. Existing high-pressure pumps are mainly distributed in in-line and radial distributions according to the layout method. Due to the characteristics of their layout and the inheritance of the technical route, in-line high-pressure pumps are mostly lubricated with engine oil, while radial distributions are mostly lubricated with diesel. Due to their different lubrication methods, the applicable engines and their layouts on the whole machine are also different.

[0003] Due to the inherent lubrication characteristics of the engine oil lubricated high-pressure pump, the material requirements and cleanliness requirements of the high-pressure pump components are reduced, and it can withstand greater loads under the same conditions, so that higher oil pressure and better fuel supply capacity can be provided. However, the engine oil lubricated oil pump has an additional lubricating oil circuit, which also makes the high-pressure pump oil circuit more complex and more difficult to achieve under the constraints of limited space and cost.

[0004] Therefore, the present invention provides an oil circuit layout scheme of engine oil lubrication on a radially distributed high-pressure pump, as well as a reasonable layout of the diesel oil circuit, to avoid interference and oil circuit connection within a limited volume, thereby providing a radially distributed high-pressure variable fuel injection pump lubricated with engine oil. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a radially distributed high-pressure variable fuel injection pump lubricated with engine oil with a reasonable layout of the diesel oil circuit, which avoids interference and oil circuit connection within a limited volume.

[0006] The present invention is implemented as follows:

[0007] A radially distributed high-pressure variable fuel injection pump lubricated with engine oil, characterized in that: it includes a pump body (1) and a drive shaft (7), and a double-sided skeleton oil seal (22) is installed in the pump body. The double-sided skeleton oil seal divides the pump body into an independent working chamber (22-1) and a lubricating oil chamber (22-2);

[0008] Several fuel injection systems (9) arranged along the circumferential direction of the pump body and a fuel transfer pump (19) installed on the pump body; both ends of the drive shaft are installed in the pump body through bearings;

[0009] A cam (6-1) is provided on the drive shaft between two bearings. The cam abuts against several tappet bodies (6-2), and the upper end of each tappet body corresponds to a fuel pumping system. The fuel pumping system is installed on the pump body through fasteners. The above-mentioned bearings, cam, and tappet bodies are located in the lubricating oil cavity. The pump body has a pressure balance oil passage in the radial direction. The pump body is provided with an inlet for the forced lubrication pressure of the lubricating oil, and a lubricating oil joint seat (10) is installed.

[0010] An oil transfer pump (19) is installed on the working chamber of the pump body. In the pump body, the drive shaft (7) is connected to the drive shaft (20) of the oil transfer pump through a coupling (21). The pump body is provided with an oil inlet (11) and an oil outlet (15). The pump body is also installed with a proportional valve (16) for controlling the amount of oil entering the fuel pumping system. An overflow valve (12) is installed on the pump body, and the overflow valve is communicated with the oil outlet.

[0011] Preferably, the oil transfer pump (19) includes an oil transfer pump body (51), a driving gear (56) installed on the oil transfer pump body. The driving gear (56) is installed on the drive shaft (20). The driving gear meshes with a driven gear (55). The pump cover (53) is installed on the oil transfer pump body through fastening bolts (54).

[0012] Preferably, a pressure limiting valve (57) for preventing oil pressure overload and a plug (52) for sealing the processing oil passage are installed on the oil transfer pump body.

[0013] Preferably, an exhaust valve (13) communicated with the exhaust oil passage of the pump body is installed on the pump body.

[0014] Preferably, the drive shaft of the oil transfer pump adopts an integral structure, including a gear drive part (62) and a coupling claw (61) connected to the coupling (21).

[0015] Advantages and technical effects of the present invention: The present invention provides an oil lubrication oil circuit arrangement solution for a radially distributed high-pressure pump, and independently designs a pressure balance oil passage for each cylinder, so that it can be applied to a radially distributed high-pressure pump or an in-line high-pressure pump with multi-cylinder distribution. In addition, the functional oil passages, mounting holes, and fastening bolt holes of the pump body are well-arranged in the pump body, and most of the functional oil passages are parallel or perpendicular to the main functional surface, and the processing technology is simple, which is convenient for machining centers to process. A distributed structure high-pressure pump using roller bearings and lubricated with engine oil is adopted, which effectively prolongs the service life of the oil pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the present invention;

[0017] Figure 2 is a schematic structural diagram of the pump body of the present invention;

[0018] Figure 3 is the fuel circuit layout diagram of the present invention;

[0019] Figure 4 is the schematic structural diagram of the fuel transfer pump;

[0020] Figure 5 is the schematic structural diagram of the transmission shaft;

[0021] Figure 6 is the schematic principle diagram of the fuel circuit control of the present invention. Specific embodiments

[0022] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] Please refer to Figures 1 to 5 , a high-pressure variable fuel injection pump with radial distribution lubricated by engine oil, characterized in that: it includes a pump body 1 and a drive shaft 7, and a double-sided skeleton oil seal 22 is installed in the pump body. The double-sided skeleton oil seal divides the pump body into an independent working chamber 22-1 and a lubricating oil chamber 22-2;

[0024] Several fuel pumping systems 9 arranged along the circumferential direction of the pump body and a fuel transfer pump 19 installed on the pump body; both ends of the drive shaft are installed in the pump body through bearings; the bearings adopt tapered roller bearings 2 and 3, wherein the shaft 2 is installed in the pump body 1, the bearing 3 is installed in the bearing seat 5, and at the same time the bearing seat 5 is fastened to the pump body 1 through a screw assembly 4.

[0025] A cam 6-1 is installed on the drive shaft between the two bearings. The cam abuts several tappet bodies 6-2. The upper end of each tappet body corresponds to a fuel pumping system. The fuel pumping systems 9 are distributed around the drive shaft 7 at a certain angle in the circumferential direction; the fuel pumping systems are installed on the pump body through fasteners 8; the drive shaft 7 rotates to drive the tappet bodies 6 to reciprocate up and down in the pump body 1 through a cam mechanism to drive the fuel pumping systems 9 to pump fuel; the above-mentioned bearings, cam and tappet bodies are located in the lubricating oil chamber; a pressure balance oil passage is arranged on the pump body in the radial direction; a lubricating oil joint seat 10 is installed at the inlet of the lubricating oil forced lubrication pressure on the pump body; the lubricating oil joint seat is used to connect the forced lubricating oil delivered by the engine to lubricate the bearings, tappet bodies, etc. The pressure balance oil passage is for the pressure balance requirement of the engine oil chamber of the oil pump itself. The lubricating oil enters the pump body lubricating oil passage through it to lubricate the tappet bodies 6, bearings 2, 3 and the drive shaft 7.

[0026] An oil transfer pump 19 is installed on the working chamber of the pump body. Inside the pump body, the drive shaft 7 is connected to the drive shaft 20 of the oil transfer pump through a coupling 21. The pump body is provided with an oil inlet 11 and an oil outlet 15. The drive shaft 7 drives the drive shaft 20 of the oil transfer pump 19 fastened to the pump body 1 by a screw group 18 to rotate. Thus, the oil transfer pump 19 sucks in fuel, enters the pump body 1 from the inlet 11. A proportional valve 16 for controlling the oil volume entering the fuel supply system is also installed on the pump body through a screw assembly 14. An overflow valve 12 is installed on the pump body. The overflow valve is communicated with the oil outlet. The excess oil is regulated by the overflow valve 12 and flows back from the oil outlet 15.

[0027] Preferably, the oil transfer pump 19 includes an oil transfer pump body 51, a driving gear 56 installed on the oil transfer pump body, the driving gear 56 is installed on the drive shaft 20, the driving gear meshes with a driven gear 55, and a pump cover 53 is installed on the oil transfer pump body through fastening bolts 54.

[0028] Preferably, a pressure limiting valve 57 for preventing oil pressure overload and a plug 52 for sealing the processing oil passage are installed on the oil transfer pump body.

[0029] Preferably, an exhaust valve 13 communicated with the exhaust oil passage of the pump body is installed on the pump body.

[0030] Preferably, the drive shaft of the oil transfer pump adopts an integral structure, including a gear driving part 62 and a coupling claw 61 connected to the coupling 21. Thus, the machining can be completed by one clamping on the machine tool, avoiding the instability or even failure of the oil transfer pump caused by the asymmetry between the coupling claw 61 and the coupling claw 62.

[0031] The working oil supply control process of the present invention:

[0032] Diesel oil passage of the pump body: After the oil discharged from the oil transfer pump 19 enters the pump body from the joint seat 11, it enters the oil passage 32 through the installation hole 31 of the proportional valve 16, then enters the oil passage 34, and forms high-pressure oil after passing through the oil passage 34 and entering the fuel supply system.

[0033] Lubricating oil passage of the pump body: The lubricating oil enters the pump body from the joint seat 10, forms a pressure oil cavity in the cavity 41, enters the tappet body and the drive shaft through the oil passage 42 for lubrication, and after lubrication, the pressure is relieved and flows into the cavity of the pump body through the oil passage 43, and then flows out from the bearing seat.

[0034] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A radially distributed high-pressure variable fuel injection pump lubricated with engine oil, characterized in that: It includes a pump body (1) and a drive shaft (7). A double-direction skeleton oil seal (22) is installed in the pump body. The double-direction skeleton oil seal divides the pump body into an independent working chamber (22-1) and a lubricating oil chamber (22-2). Several oil pumping systems (9) arranged along the circumferential direction of the pump body and an oil transfer pump (19) installed on the pump body; both ends of the drive shaft are installed in the pump body through bearings. A cam (6-1) is arranged on the drive shaft between the two bearings. The cam abuts against several tappet bodies (6-2). The upper end of each tappet body corresponds to an oil pumping system. The oil pumping system is installed on the pump body through fasteners; the above-mentioned bearings, cam and tappet bodies are located in the lubricating oil chamber; a pressure balance oil passage is arranged on the pump body in the radial direction; a lubricating oil joint seat (10) is installed at the inlet for the forced lubrication pressure of the lubricating oil on the pump body. An oil transfer pump (19) is installed on the working chamber of the pump body. In the pump body, the drive shaft (7) is connected to the transmission shaft (20) of the oil transfer pump through a coupling (21); an oil inlet (11) and an oil outlet (15) are arranged on the pump body. A proportional valve (16) for controlling the oil volume entering the oil pumping system is also installed on the pump body; a relief valve (12) is installed on the pump body, and the relief valve is communicated with the oil outlet. The oil transfer pump (19) includes an oil transfer pump body (51), a driving gear (56) installed on the oil transfer pump body. The driving gear (56) is installed on the transmission shaft (20). The driving gear meshes with a driven gear (55). The pump cover (53) is installed on the oil transfer pump body through fastening bolts (54). A pressure limiting valve (57) for preventing oil pressure overload and a plug (52) for sealing the processing oil passage are installed on the oil transfer pump body.

2. The radially distributed high-pressure variable fuel injection pump lubricated with engine oil according to claim 1, characterized in that: An exhaust valve (13) communicated with the exhaust oil passage of the pump body is installed on the pump body.

3. The radially distributed high-pressure variable fuel injection pump lubricated with engine oil according to claim 1, characterized in that: The transmission shaft of the oil transfer pump adopts an integral structure, including a gear driving part (62) and a coupling claw (61) connected to the coupling (21).

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