CN214741780U - Novel transmission part for high-pressure common rail - Google Patents

Abstract

The utility model discloses a high pressure is rail with novel transmission part altogether for marine low-speed machine rail formula heavy oil high-pressure oil pump altogether, including lower spring holder, hard piece, rand, direction piston assembly. The hard block is in interference fit with a circular boss middle hole of the guide piston and is integrated with the guide piston assembly, and the lower spring seat is limited by the retainer ring and is connected with the guide piston assembly. The guide piston assembly consists of a guide piston, an elastic retainer ring for a shaft, a piston pin, a roller bushing and a thrust bearing. This novel transmission part compact structure, oil duct, oil groove are arranged rationally, and existing sufficient intensity is guaranteed, also can effectively promote the anti-bite ability of moving part to satisfy the abominable operational environment demand of marine low-speed machine common rail formula heavy oil high-pressure oil pump, guarantee the reliability of system.

Description

Novel transmission part for high-pressure common rail

Technical Field

The utility model relates to a high pressure is rail-low speed diesel engine fuel oil system technical field altogether, concretely relates to marine low speed machine is rail formula heavy oil high-pressure oil pump altogether.

Background

Along with the stricter emission regulations at home and abroad, the marine low-speed diesel engine puts higher requirements on a fuel injection system, and the electronic control high-pressure common rail fuel system can realize the accurate control of the timing and the circulating fuel injection quantity of fuel injection, and is one of effective means for realizing high fuel economy and reducing harmful substance emission of the high-power marine diesel engine. However, the continuous increase of the density and power of the diesel engine means that the transmission part needs to bear larger load, and the working environment of the transmission part is increasingly severe due to the influence of factors such as poor flowability of heavy oil and the like. Therefore, a novel transmission part needs to be invented to meet the working environment requirement of the common-rail heavy oil high-pressure oil pump of the marine low-speed engine, reduce the risk of driving part seizure and improve the system reliability.

Disclosure of Invention

The utility model aims at providing a high pressure is rail with novel transmission parts altogether to adapt to the marine low-speed machine and rail formula heavy oil high-pressure oil pump operational environment demand altogether, reduce the driving medium and sting the card risk, improve system reliability.

The technical scheme of the utility model as follows:

a novel transmission part for a high-pressure common rail comprises a lower spring seat, a hard block, a clamping ring and a guide piston assembly; the guide piston assembly comprises a guide piston and a roller transmission assembly matched with the lower part of the guide piston. The guide piston is a concave shape with a circular boss at the center, the lower spring seat is connected with the circular boss of the guide piston through the limiting of the clamping ring, the hard block is arranged on the circular boss of the guide piston and is in interference fit with the middle hole of the lower spring seat, the hard block and the guide piston are combined into a whole, and the upper end face of the hard block is contacted with the tail end of the plunger penetrating into the middle hole of the lower spring seat.

Furthermore, the circular boss is coaxial with the large excircle of the guide piston, the circular boss and the middle hole of the lower spring seat are designed in a matching mode of H8/f7, and H8 and f7 are size tolerance zones of the middle hole of the spring seat and the circular boss respectively, so that the coaxiality of the lower spring seat and the guide piston is guaranteed.

Further, the depth H of the effective working section of the circular boss is 40-45 mm.

Furthermore, the hard block is made of high-carbon chromium bearing steel, the heat treatment hardness is not lower than 60HRC, the guide piston is provided with a soft nitriding or salt bath nitriding treatment layer, and the layer depth is 10-15 mu m.

Furthermore, the guide piston is provided with an upper cavity and a lower cavity, wherein the upper cavity is provided with a lower spring seat, the lower cavity is provided with a roller transmission assembly, and an axial oil hole is arranged between the upper cavity and the lower cavity for conduction.

Furthermore, an air hole which is axially communicated is formed in the center of the guide piston, and the upper end face of the circular boss for assembling the hard block is communicated with the lower cavity of the guide piston.

Further, the roller transmission assembly comprises a piston pin, a thrust bearing, a roller bushing and a roller; the roller bush is embedded into the roller in a clearance fit mode, the thrust bearings are assembled on two sides of the roller bush in an interference fit mode, the piston pin penetrates through the transverse hole in the lower portion of the guide piston and the middle hole of the roller bush to be connected into a whole, and the piston pin is installed in the piston pin clamping groove through the elastic check ring for the shaft to clamp the piston pin.

An annular oil groove is further arranged on the periphery of the guide piston, and an annular oil chamber is formed between the guide piston and the pump body.

And furthermore, a plurality of annular oil grooves are formed in the surface of the piston pin, and two oil grooves are communicated with each other through two inclined oil holes.

Furthermore, the roller bush is provided with radial oil holes, so that lubricating oil in the annular oil groove enters the roller bush and the roller through the radial oil holes.

The novel transmission part for the high-pressure common rail is additionally provided with a hard block between the guide piston assembly and the lower spring seat, and because the guide piston is a nodular iron casting, the surface hardness and the strength can not meet the requirements of working conditions, and if the guide piston is in direct contact with the tail part of the plunger, the guide piston is easy to deform; the matching surface in contact with the tail of the plunger piston is required to have higher flatness and smoothness, and if no hard block is designed, the matching surface has the limitation of a processing technology; therefore, the design of the hard block is increased, the manufacturability of the transmission part can be improved, the reliability is improved, and the risk of seizure is reduced.

The utility model discloses in, the special type technology that the guide piston adopted tufftride or salt bath nitrogenize is handled, and the layer depth is 10-15um, can improve the intensity, the hardness of product, improves the anti-bite ability of product. The guide piston is designed to be a circular boss, the circular boss and the large excircle of the guide piston have high coaxiality requirements, and the circular boss and the large excircle of the guide piston are designed in a matching mode of H8/f7 with a middle hole of a lower spring seat. In addition, the circular boss and the lower spring seat are respectively provided with a limiting clamping groove, the limiting through the clamping ring ensures that the circular boss and the lower spring seat are integrated without falling all the time in the movement process, and the clamping risk is reduced. The depth H of the effective working section of the circular boss is 40-45mm, and the circular boss has enough depth to ensure that the spring seat does not generate side sway in the operation of the oil pump, so that the stability of the spring is ensured, the risk of rubbing the spring against the piston is reduced, and the reliability of the whole oil pump is improved.

The utility model also arranges the oil duct, the oil groove and the oil chamber reasonably, and the annular oil chamber is formed by the pump body and the large annular groove of the guide piston; the inclined oil hole conveys lubricating oil in the annular oil chamber to an annular oil groove on the piston pin, and then the lubricating oil enters the roller bush through the radial oil hole; the axial oil hole is communicated with the upper cavity and the lower cavity of the guide piston; the vent hole is communicated with the lower cavity of the guide piston. The annular oil grooves of the piston pin are communicated with each other in pairs through the two inclined oil holes, so that lubricating oil supply and the formation of an oil film on an outer cylindrical surface are ensured.

The utility model discloses produced beneficial effect:

1. the hard block is made of high-carbon chromium bearing steel, the heat treatment hardness is not lower than 60HRC, and the hard block is high in strength, wear-resistant and impact-resistant; the hard block design is added between the guide piston and the lower spring seat, so that the processing manufacturability of a product can be improved, the reliability of the transmission part can be improved, and the risk of seizing is reduced.

2. The guide piston is treated by a soft nitriding or salt bath nitriding special process, the layer depth is 10-15um, the strength and the hardness of the product can be improved, and the anti-seizure capacity of the outer cylindrical surface of the guide piston is improved.

3. The guide piston is designed by adopting a circular boss, the circular boss has high coaxiality requirement with the large excircle of the guide piston, and the circular boss and the large excircle of the guide piston are designed by adopting the matching of H8/f7 with the middle hole of the lower spring seat, and the design characteristics are favorable for ensuring the coaxiality of the lower spring seat and the guide piston and further ensuring the coaxiality of the plunger and a transmission part, so that the risk of seizure of the plunger is reduced, and the reliability of the oil pump is improved; in addition, the circular boss and the lower spring seat are respectively provided with a limiting groove, and the circular boss and the lower spring seat are ensured to be integrated into a whole without falling off all the time in the movement process through the limiting of the clamping ring, so that the clamping risk is reduced; the depth H of the effective working section of the circular boss is 40-45mm, and the circular boss has enough depth to ensure that the spring seat does not generate side sway in the operation of the oil pump, ensure the stability of the spring, reduce the risk of rubbing the spring and the piston and improve the reliability of the oil pump; the design of the lug boss and the clamping groove can avoid screw holes on the guide piston and the lower spring seat, and the structure is simplified.

4. The annular oil chamber can reduce the contact surface between the guide piston and the pump body, is favorable for forming an oil film between the guide piston and the pump body, reduces friction pairs in the up-and-down reciprocating motion process of the guide piston, and can provide stable and abundant lubricating oil for the whole transmission component.

5. The annular oil groove on the piston pin is carried to the lubricating oil of oblique oilhole in the annular oil chamber, and then gets into roller bush, gyro wheel through radial oilhole, and the design of this oil circuit does benefit to between piston pin and the roller bush, when forming the oil film between roller bush and the gyro wheel, also can better cooling roller bush, and then reduces this drive disk assembly's the risk of stinging the card, improves the reliability of oil pump.

6. The axial oil hole can be communicated with the upper cavity and the lower cavity of the guide piston, so that the resistance of the guide piston in the up-and-down reciprocating motion is reduced, the lubricating oil can be splashed through the disturbance generated by the hole, the transmission part can be lubricated and cooled better, and the seizure risk is reduced.

7. The vent hole is communicated with the lower cavity of the guide piston, so that the influence of air pressure on the hard block during interference assembly can be eliminated, the hard block is ensured to be in full contact with the circular boss of the guide piston, and the quality accident that the oil pump is clamped due to the fact that the hard block is not assembled in place can be avoided.

8. The surface of the piston pin is carburized and coated, so that the piston pin is wear-resistant and corrosion-resistant; clamping grooves are formed in the two sides of the piston rod, and the piston rod can be prevented from moving left and right by utilizing the limiting of a clamping ring; and the three annular oil grooves are communicated with each other in pairs through two inclined oil holes, so that lubricating oil supply and the formation of an oil film on a large outer cylindrical surface are ensured. The design characteristics can effectively reduce the risk of oil pump seizure and improve the reliability of the whole system.

Drawings

Fig. 1 is a schematic view of the patent structure of the present invention;

FIG. 2 is a schematic view of a pilot piston assembly;

FIG. 3 is a schematic diagram of the distribution of oil chambers, oil ducts and oil grooves in the present invention;

FIG. 4 is a hard block diagram;

FIG. 5 is a schematic view of a pilot piston;

FIG. 5A is a bottom view of the pilot piston;

FIG. 6 is a schematic view of a lower spring seat;

FIG. 7 is a schematic view of a roller bushing;

FIG. 8 is a schematic view of a piston pin.

Detailed Description

The structure of the present invention is further explained with the following drawings:

referring to fig. 1, the high-pressure oil pump includes plunger (5), pump body (7) and spring (6), and the high pressure is installed in pump (7) with novel drive disk assembly common rail, and it includes spring holder (1), hard piece (2), rand (3), direction piston assembly (4) down. The hard block (2) is made of high-carbon chromium bearing steel, has heat treatment hardness not lower than 60HRC, high strength, wear resistance and impact resistance, and is in interference fit with a middle hole on a circular boss (4-1-1) of the guide piston (4-1) to be integrated with the guide piston (4); the lower spring seat (1) is limited by a clamping ring (3) and is connected with a guide piston (4-1); the guide piston assembly comprises a guide piston (4-1), a shaft elastic retainer ring (4-2), a piston pin (4-3), a thrust bearing (4-4), a roller bushing (4-5) and a roller (4-6); in the assembly, a roller bushing (4-5) is embedded into a roller (4-6) in a clearance fit mode, a thrust bearing (4-4, 1 piece of each of the left side and the right side is assembled on the two sides of the roller bushing (4-5) in an interference fit mode, a piston pin (4-3) penetrates through a transverse hole of a guide piston (4-1) and a middle hole of the roller bushing (4-5) to connect the guide piston (4-1) and the roller bushing into a whole, an elastic check ring (4-2) for a shaft is arranged in a clamping groove (4-3-1) of the piston pin to clamp the piston pin (4-3) so as to prevent the piston pin from moving left and right, and the connection of each oil way needs to be noticed in the assembling process.

Referring to fig. 4 in combination, in the present invention, a hard block (2) is added between the guide piston assembly (4) and the lower spring seat (1). Because the guide piston (4-1) is a nodular iron casting, the surface hardness and the strength can not meet the requirements of working conditions, and if the guide piston is in direct contact with the tail of the plunger, the guide piston is easy to deform; the matching surface contacted with the tail part of the plunger piston is required to have higher flatness and smoothness, and if no hard block (2) is designed, the matching surface has the limitation of a processing technology; therefore, the design of the hard block is increased, the manufacturability of the transmission part can be improved, the reliability is improved, and the risk of seizure is reduced.

With the combination of fig. 2 and 5, the utility model discloses in, guide piston (4-1) adopts the special technology of tufftride or salt bath nitrogenize to handle, and the layer depth is 10-15um, can improve the intensity, the hardness of product, improves the anti-bite ability of product. The guide piston (4-1) is designed by adopting a circular boss (4-1-1), the circular boss has high coaxiality requirement with the large excircle of the guide piston, and the circular boss and the middle hole of the lower spring seat (1) are designed by adopting the matching of H8/f7, and the design characteristics are favorable for ensuring the coaxiality of the lower spring seat (1) and the guide piston (4-1) and further ensuring the coaxiality of a plunger and a transmission part, so that the risk of the plunger being seized is reduced, and the reliability of the common rail high-pressure oil pump is improved; in addition, the round boss (4-1-1) and the lower spring seat (1) are respectively provided with a limiting clamping groove (4-1-2 and 1-0-1), the limiting of the clamping ring (3) ensures that the round boss and the lower spring seat are integrated without falling off all the time in the movement process, the clamping risk is reduced, and the clamping ring adopts a standard part (GB 895.1-86); the depth H of the effective working section of the circular boss (4-1-1) is 40-45mm, and the circular boss has enough depth to ensure that the spring seat does not generate side swing in the operation of the oil pump, so that the stability of the spring is ensured, the risk of rubbing the spring and the piston is reduced, and the reliability of the whole oil pump is improved.

The utility model discloses an oil duct, oil groove, oil chamber put see fig. 3, and annular oil chamber (10) are formed by the first annular oil groove (4-1-3) of the pump body and guide piston (4-1), and this oil chamber can not only reduce the contact surface of guide piston (4-1) and the pump body, also is favorable to forming the oil film between guide piston and the pump body, reduces the friction of guide piston (4-1) up-and-down motion in-process, more can provide stable, abundant lubricating oil for whole drive disk assembly. The first oblique oil hole (20) and the second oblique oil hole (30) are respectively arranged on the lower portion of the guide piston and the piston pin, lubricating oil in the annular oil chamber (10) is conveyed to the second annular oil groove (40) on the piston pin, and then enters the roller bush (4-5) and the roller (4-6) through the radial oil hole (50), and due to the design of the oil way, oil films are formed between the piston pin (4-3) and the roller bush (4-5) and between the roller bush and the roller, the roller bush can be well cooled, the clamping risk of the transmission part is reduced, and the reliability of the oil pump is improved. The axial oil hole (60) is provided with 4 parts and is arranged on the guide piston (4-1), so that the upper cavity and the lower cavity of the guide piston (4-1) can be communicated, the resistance of the guide piston (4-1) in the up-and-down reciprocating motion is reduced, the lubricating oil can be splashed through the disturbance generated by the hole, the transmission part can be lubricated and cooled better, and the seizure risk is reduced. An axially through air vent (70) is arranged in the center of the guide piston (4-1), and the upper end face of the circular boss of the assembled hard block (2) is communicated with the lower cavity of the guide piston (4-1), so that the influence of air pressure on the hard block (2) during interference assembly can be eliminated, and the hard block is ensured to be fully contacted with the circular boss (4-1-1) of the guide piston (4-1).

In addition, referring to fig. 8, the surface of the piston pin (4-3) is carburized and coated, and is wear-resistant and corrosion-resistant. The two sides are provided with a clamping groove (4-3-1) which is limited by a clamping ring. The surface has three second annular oil grooves (40), realizes two liang of intercommunications through two oblique oilholes (30) of second between them, guarantees that the lubricating oil supplies and the formation of oil film on the outer cylinder face, and then reduces the oil pump and stings the card risk, improves entire system's reliability.

The lubricating oil lubrication mechanism and the distribution principle of the lubricating oil paths are specifically described below with reference to fig. 1 to 7:

forced lubrication: forced lubrication is respectively carried out between the large outer cylindrical surface of the guide piston (4-1) and the pump body, between the large outer cylindrical surface of the piston pin (4-3) and the guide piston (4-1), between the large outer cylindrical surface of the piston pin (4-3) and the middle hole of the roller bush (4-5), and between the large outer cylindrical surface of the roller bush (4-5) and the middle hole of the roller (4-6); the lubricating mechanism takes the pressure of lubricating oil as kinetic energy, and an oil film with a certain thickness is formed on a small clearance fit surface, so that the lubricating condition is improved, the friction is reduced, the deformation resistance is reduced, and the meshing risk among transmission parts is reduced.

Splash lubrication: splash lubrication is respectively carried out between the excircle of the roller (4-6) and the cam, and between the thrust bearing (4-4) and the guide piston (4-1); the lubricating mechanism takes the rotation of a roller as kinetic energy, and the lubricating oil is splashed and atomized from oil drops into small drops to be carried to a friction pair to form automatic lubrication.

After being conveyed to the pump body through an oil inlet pipe, lubricating oil is stored in an annular oil chamber (10) formed by the pump body and a first annular oil groove (4-1-3) of a guide piston (4-1), then reaches a second annular oil groove (40) and a second inclined oil hole (30) on a piston pin (4-3) through a first inclined oil hole (20) of the guide piston, further enters a gap between a roller bush (4-5) and a roller (4-6) through a radial oil hole (50), and flows out through the gap. Whole oil circuit design not only can satisfy this drive disk assembly's lubrication, cooling demand, also can make and form the oil film between the driving medium through the constantly supply of lubricating oil to reduce the risk of stinging of driving medium, improve the reliability of oil pump.

Claims (10)

1. A novel transmission part for a high-pressure common rail comprises a lower spring seat (1) and a guide piston assembly (4); the guide piston assembly (4) comprises a guide piston (4-1) and a roller transmission assembly matched with the lower part of the guide piston (4-1); the device is characterized by also comprising a hard block (2) and a clamping ring (3); the guide piston (4-1) is a concave shape with a circular boss (4-1-1) at the center, the lower spring seat (1) is limited by a clamping ring (3) and is connected with the circular boss (4-1-1) of the guide piston (4-1), the hard block (2) is arranged on the circular boss (4-1-1) of the guide piston (4-1) and is in interference fit with a middle hole of the lower spring seat (1) and is combined with the guide piston (4-1) into a whole, and the upper end face of the hard block (2) is contacted with the tail end of a plunger penetrating into the middle hole of the lower spring seat (1).

2. The novel transmission part for the high-pressure common rail as claimed in claim 1, wherein the circular boss (4-1-1) is coaxial with the large outer circle of the guide piston (4-1), and the circular boss and the central hole of the lower spring seat (1) are designed in a clearance fit manner of H8/f7, so that the coaxiality of the lower spring seat (1) and the guide piston (4-1) is ensured.

3. The new transmission part for the high pressure common rail according to claim 1 or 2, characterized in that the effective working section depth H of the circular boss (4-1-1) is 40-45 mm.

4. The novel transmission part for the high-pressure common rail according to claim 1 or 2, wherein the hard block (2) is made of high-carbon chromium bearing steel, the heat treatment hardness is not lower than 60HRC, and the surface of the guide piston (4-1) is provided with a soft nitriding or salt bath nitriding treatment layer with the depth of 10-15 μm.

5. The novel transmission part for the high-pressure common rail according to claim 1 or 2, wherein the guide piston (4-1) has an upper chamber with a lower spring seat mounted on the upper part and a lower chamber with a roller transmission assembly mounted on the lower part, and an axial oil hole (60) is arranged between the upper chamber and the lower chamber for conducting.

6. The novel transmission part for the high-pressure common rail as claimed in claim 1 or 2, wherein an axially through vent hole (70) is formed in the center of the guide piston (4-1) to communicate the upper end face of the circular boss of the assembling hard block (2) with the lower cavity of the guide piston (4-1).

7. The new transmission part for a high pressure common rail according to claim 1 or 2, characterized in that the roller transmission assembly comprises a piston pin (4-3), a thrust bearing (4-4), a roller bushing (4-5) and a roller (4-6); the roller bush (4-5) is embedded into the roller (4-6) in a clearance fit mode, the thrust bearings (4-4) are assembled on two sides of the roller bush (4-5) in an interference mode, the piston pin (4-3) penetrates through a transverse hole in the lower portion of the guide piston (4-1) and a middle hole of the roller bush (4-5) to be connected into a whole, and the piston pin (4-3) is installed into a piston pin clamping groove (4-3-1) through an elastic retaining ring (4-2) for a shaft to clamp the piston pin (4-3).

8. The novel transmission member for a high pressure common rail according to claim 1 or 2, characterized in that: a first annular oil groove (4-1-3) is arranged on the periphery of the guide piston (4-1) and forms an annular oil chamber (10) with the pump body.

9. The novel transmission member for a high pressure common rail according to claim 8, characterized in that: the lower part of the guide piston (4-1) is provided with a first oblique oil hole (20) for communicating the annular oil chamber (10) with the outer surface of the piston pin, the surface of the piston pin (4-3) is provided with a plurality of second annular oil grooves (40), and two-two intercommunication is realized through two second oblique oil holes (30).

10. The novel transmission member for a high pressure common rail according to claim 7, characterized in that: radial oil holes (50) are distributed on the roller bush (4-5), so that lubricating oil in the second annular oil groove (40) enters the roller bush (4-5) and the roller (4-6) through the radial oil holes (50).

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