Bearing lubricating structure and reciprocating pump crank connecting rod

Abstract

Provided is a bearing lubrication structure, which comprises a connecting rod head, a bearing and a connecting rod cover, the bearing lubrication structure comprising a first position and a second position, the first position being arranged to be able to be immersed in an oil pool when the connecting rod of a reciprocating pump is at one stroke, and the second position being arranged to be always unimmersed in the oil pool; wherein the connecting rod cover is provided with a first external through hole, and the bearing comprises a first internal through hole, a second internal through hole, a turned-up edge and a communication groove; the first internal through hole is in communication with the first external through hole and is arranged at the first position, the communication groove is arranged on the turned-up edge, extends from the edge of the turned-up edge to the inner circumferential surface of the bearing and is arranged to be in communication with the inner side aperture of the second internal through hole, and the second internal through hole and the communication groove are arranged at the second position. The bearing lubrication structure has good lubrication performance. A reciprocating pump crankshaft connecting rod is also provided.

Description

Technical Field

[0001] This invention relates to the field of reciprocating pump connecting rods, and more specifically to the field of connecting rod bearing lubrication. Background Technology

[0002] The connecting rod of a reciprocating pump is the component that connects the crankshaft and the crosshead; its motion is a combination of reciprocating and rotary motion. The connecting rod big end bearing is a sliding bearing. Numerous tests have shown that the service life of sliding bearings is largely related to lubrication. In addition to the type of lubricant, the structural design of the bearing lubrication system is also quite important.

[0003] Currently, the most common lubrication structures for connecting rod big end bearings employ a scraper plate structure and an oil collection groove structure. The scraper plate scrapes oil from the outer circumference of the crankshaft crank and collects the oil in an oil collection groove inside the machine body. Near the big end of the connecting rod, a short, inclined pipe is installed on the side of the oil collection groove, which is in the same plane as the center of the connecting rod. The oil in the oil collection groove flows through the short pipe into a groove on the upper back of the connecting rod body, and then flows into the connecting rod bearing through an oil hole in the groove, thus achieving lubrication.

[0004] This structure has several drawbacks. First, a groove needs to be cast on the upper part of the connecting rod body, and an oblique hole needs to be machined inside the groove to facilitate the flow of oil from the groove into the bearing bush. This structure is quite complex, and correspondingly, the casting process also becomes more complex. Second, because the groove on the upper part of the connecting rod body has a larger cross-sectional dimension under the same force, it not only makes the structure bulky but also increases the reciprocating inertial force of the crankshaft. Third, when the rod body undergoes the combined reciprocating and rotational motion, the oil in the groove may be in a state of no oil or little oil at certain positions. This means that when the bearing bush is under the greatest stress, there is no lubricating oil to immediately replenish the bearing bush surface. At this time, the oil film in the contact area between the shaft diameter and the bearing bush is at its thinnest. Under pressure, instantaneous dry friction may occur between the shaft diameter surface and the bearing bush surface, causing premature wear of the bearing bush. Summary of the Invention

[0005] One object of the present invention is to provide a bearing lubrication structure with better lubrication performance.

[0006] To achieve the above objectives, a bearing lubrication structure is provided on the connecting rod of a reciprocating pump. This lubrication structure includes a connecting rod head, a bearing, and a connecting rod cap. The connecting rod cap and the connecting rod head are joined to form an annular structure, with the bearing located on the inner circumference of the annular structure. The bearing lubrication structure includes a first position and a second position. The first position is configured to be submerged in an oil sump when the reciprocating pump connecting rod is in one stroke, while the second position is configured to never be submerged in the oil sump. The connecting rod cap has a first external through-hole, and the bearing includes a first internal through-hole, a second internal through-hole, a flange, and a connecting groove. The first internal through-hole communicates with the first external through-hole and is located at the first position. The connecting groove is located on the flange, extending from the edge of the flange to the inner circumferential surface of the bearing, and is configured to communicate with the inner opening of the second internal through-hole. The second internal through-hole and the connecting groove are located at the second position.

[0007] In one or more embodiments, the first external through hole is inclined so that the outer opening of the first external through hole is higher than the inner opening.

[0008] In one or more embodiments, the acute angle between the axis of the first external through hole and the horizontal plane ranges from 8 to 12°, preferably 10°.

[0009] In one or more embodiments, the acute angle formed by the axes of the first internal through hole and the second internal through hole with the horizontal plane is 45°.

[0010] In one or more embodiments, the connecting groove is inclined such that the outer opening of the connecting groove is higher than the inner opening.

[0011] In one or more embodiments, the bearing bush includes an inner circumferential axial oil reservoir that covers the second internal through hole and communicates with the connecting groove.

[0012] In one or more embodiments, the depth of the inner circumferential axial oil reservoir ranges from 1.2 to 1.8 mm, preferably 1.5 mm.

[0013] In one or more embodiments, the diameters of the first external through hole and the first internal through hole are larger than the diameter of the second internal through hole.

[0014] In one or more embodiments, the diameter of the first external through hole is larger than the diameter of the first internal through hole.

[0015] Another object of the present invention is to provide a reciprocating pump crankshaft connecting rod, including a connecting rod body, a large end, a small end, a connecting rod cap, and a bearing bush, wherein the large end is used to mate with the crankshaft diameter, the small end is used to mate with a cross pin, and the bearing bush adopts the above-described bearing bush lubrication structure.

[0016] The aforementioned bearing lubrication structure uses splash lubrication to obtain lubricating oil from the oil sump through the rotation of the bearing and the connection between the first internal through hole and the first external through hole. With the dual functions of oil storage and venting of the connecting groove and the second internal through hole, the oil wedge between the crankshaft journal and the bearing can always be filled with lubricating oil during the discharge and suction strokes of the reciprocating pump, thus achieving better lubrication performance. Attached Figure Description

[0017] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0018] Figure 1 This is a structural schematic diagram of the connecting rod big-end bearing;

[0019] Figure 2 This is a schematic diagram of a common large-head bearing lubrication structure;

[0020] Figure 3 This is a schematic diagram of the bearing lubrication structure of this application;

[0021] Figure 4A This is a structural schematic diagram of one embodiment of the connecting rod cover;

[0022] Figure 4B This is a side view of one embodiment of the connecting rod cover;

[0023] Figure 5A This is a structural schematic diagram of one embodiment of the bearing bush;

[0024] Figure 5B This is a side view of one embodiment of the bearing bush;

[0025] Figure 6A This is a schematic diagram showing the first position of the bearing lubrication structure submerged in the oil bath;

[0026] Figure 6B This is a schematic diagram of the bearing lubrication structure leaving the oil sump.

[0027] Symbol marking explanation

[0028] 7 Babbitt

[0029] 8 Crankshaft

[0030] 9 crankshaft journals

[0031] 10. Ring structure

[0032] 11 Connecting rod cover

[0033] 12 bearings

[0034] 13 Connectors

[0035] 14. Linkage Body

[0036] 15. Oil scraper

[0037] 16 oil collection tanks

[0038] 17 Inclined Short Pipe

[0039] 18 grooves

[0040] 19 oil holes

[0041] 100 oil tank

[0042] 101 First Position

[0043] 102 Second position

[0044] 111 First external through hole

[0045] 115 Axial sidewall

[0046] 121 First internal through hole

[0047] 122 Second internal through hole

[0048] 123 Flip-over

[0049] 124 Connecting slots

[0050] 125 Inner circumferential axial oil reservoir Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0052] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0053] The connecting rod big end bearing structure of the reciprocating pump power end is as follows: Figure 1 As shown, the head of the connecting rod body 14 is a semi-circular arc-shaped large-end structure. The connecting rod cap 11 is connected to the large-end structure through the connector 13 to form a ring structure 10. The connecting rod bearing 12 is located on the inner circumference of the ring structure 10 and acts as a sliding bearing, cooperating with the crankshaft journal 9. Generally, an oil film of appropriate thickness is formed between the crankshaft journal 9 and the bearing 12, so that the bearing 12 is always in a liquid lubrication state. Good lubrication can reduce wear resistance, reduce wear, and extend the service life of the bearing.

[0054] A common large-head bearing lubrication structure reference Figure 2 As shown, the reciprocating pump connecting rod is located inside the housing. An oil sump 100 is located at the bottom of the housing, storing lubricating oil. The large end of the connecting rod mates with the crankshaft 8, and the small end mates with the crosshead. Under the reciprocating motion of the crankshaft 8, the connecting rod moves clockwise along the rotation direction A of the crankshaft 8, following the sequence I→II→III→IV. An oil scraper 15 is positioned above, scraping oil from the outer circumference of the crankshaft 8 and collecting it in an oil collection groove 16 inside the housing. An inclined short pipe 17 is located on the side of the oil collection groove 16 near the large end of the connecting rod. The connecting rod body 14 has a groove 18 and an oil hole 19 that mate with the groove. The oil in the oil collection groove 16 flows along the inclined short pipe 17 into the groove 18 above the connecting rod body 14, and then flows through the oil hole 19 into the bearing bush 12, forming an oil film for lubrication.

[0055] During the movement of the connecting rod big end from position III to IV to I, i.e., when the crankshaft journal 9 is in the discharge stroke with the connecting rod, as the connecting rod big end gradually rises from a horizontal position, the oil level in the groove 18 of the connecting rod body 14 quickly falls below the position of the oil hole 19 in the groove 18 that flows into the bearing shell 12. Therefore, during the movement of the connecting rod big end from position IV to I, the oil hole 19 of the connecting rod body 14 is in an oil-free state, which interrupts the oil supply to the oil wedge of the bearing shell, disrupts the continuity of the oil film pressure, and greatly reduces the load-bearing capacity. Only when the connecting rod rotates from position I to II to III, i.e., when the crankshaft journal 9 is pulling the connecting rod in the suction stroke, can the oil in the groove 18 of the connecting rod body 14 flow into the bearing shell 12.

[0056] For a single-acting reciprocating pump, the bearing experiences the greatest stress when the plunger is in the discharge stroke; during the suction stroke, the bearing experiences very little stress due to the lower inlet pressure. With the aforementioned lubrication system, when the bearing experiences maximum stress, no lubricating oil can immediately replenish the bearing surface. At this time, the oil film in the contact area between the crankshaft journal and the bearing is at its thinnest. Under pressure, momentary dry friction may occur between the crankshaft journal and bearing surfaces, leading to premature wear of the bearing.

[0057] Based on this, the bearing lubrication structure described in this disclosure can ensure that the oil wedge between the crankshaft journal and the bearing surface is always filled with lubricating oil, regardless of whether the reciprocating pump is in the discharge or suction stroke, and maintain the oil film with sufficient thickness.

[0058] Reference Figure 3 As shown, the bearing lubrication structure includes a connecting rod head, a bearing 12, and a connecting rod cap 11. The connecting rod cap 11 is connected to the head of the connecting rod body 14 via a connector 13 to form an annular structure 10. The bearing 12 is located on the inner circumference of the annular structure 10.

[0059] The bearing lubrication structure includes a first position 101 and a second position 102, as follows: Figures 6A-6BAs shown, the first position 101 is configured to be submerged in the oil sump 100 when the reciprocating pump connecting rod is in one stroke, and the second position 102 is configured to never be submerged in the oil sump 100.

[0060] exist Figure 3 In the embodiment shown, the first position 101 is generally located at the connecting rod big end bearing. Figure 3 The second quadrant position, roughly located at the connecting rod big end bearing... Figure 3 The position in the third quadrant.

[0061] Those skilled in the art will understand that the first position 101 and the second position 102 shown in the accompanying drawings are merely examples, and the first position 101 and the second position 102 may vary accordingly under different operating conditions, such as different oil tank liquid levels and different pump specifications.

[0062] Continue to refer to Figures 3 to 5B It is understood that the connecting rod cap 11 has a first external through hole 111, and the bearing bush 12 includes a first internal through hole 121, a second internal through hole 122, a flange 123, and a connecting groove 124. The first internal through hole 121 communicates with the first external through hole 111 and is located at the first position 101 of the bearing bush lubrication structure. Located at the first position 101, when the connecting rod big end performs rotational and reciprocating compound motion, the pressure generated during rotation forces the lubricating oil in the oil sump 100 into the first external through hole 111 and the first internal through hole 121, thereby forcing the oil into the inner circumferential axial oil reservoir 125 of the crankshaft journal 9 and the bearing bush 12, i.e., the oil wedge gap, and forming a certain pressure. During the plunger discharge stroke, a sufficiently thick oil film is formed on the working surface between the bearing bush 12 and the crankshaft journal 9 for lubrication.

[0063] Preferably, the first external through hole 111 is inclined so that the outer opening of the first external through hole 111 is higher than the inner opening. For example... Figure 4A As shown, the acute angle between the axis N of the first external through hole 111 and the horizontal plane P is in the range of 8 to 12°, preferably 10°. This design is to keep the pressed-in lubricating oil at a high level as much as possible, so as to achieve the oil storage effect and prevent the lubricating oil from flowing out during the rotation of the connecting rod big end.

[0064] The flange 123 is a flange that is turned up on both sides of the bearing bush 12 along the axial direction. The flange 123 is embedded in both sides of the connecting rod and fits against the side wall 115 of the connecting rod.

[0065] The two sides of the flange of the bearing can be embedded in the crankshaft, and a small gap is set between them to limit the movement of the connecting rod during the movement of the connecting rod.

[0066] A connecting groove 124 is provided on the flange 123, extending from the radially outer edge of the flange 123 to the inner circumferential surface of the bearing bush 12, and is configured to communicate with the inner opening of the second internal through hole 122. In the embodiment shown in 5B, the inner circumferential surface of the bearing bush 12 is provided with an inner circumferential axial oil reservoir 125, which covers the area where the second internal through hole 122 is located and communicates with the connecting groove 124.

[0067] The inner wall of the bearing bush 12 is also cast with Babbitt alloy 7, with a thickness of approximately 0.5 to 0.9 mm.

[0068] The second internal through hole 122 and the connecting groove 124 are connected and set at the second position 102 because the second position 102 of the lubrication structure is never submerged in the oil sump. Therefore, the second internal through hole 122 and the connecting groove 124 can serve as an exhaust structure. When the first external through hole 111 and the first internal through hole 121 draw in lubricating oil, the air between the bearing 12 and the crankshaft journal 9 is discharged in time, so that the lubricating oil can fill the entire oil storage space more quickly and fully to form an oil film.

[0069] In addition, when lubricating oil is drawn into the first external through hole 111 and the first internal through hole 121, the inner circumferential axial oil reservoir 125 and the connecting groove 124 can store a portion of the lubricating oil. The lubricating oil stored in the connecting groove 124 can distribute oil on the working surface of the flange 123, reducing the friction between the flange 123 and the positioning end faces on both sides of the crankshaft. The oil stored in the inner circumferential axial oil reservoir 125 is suitable for continuously supplying oil to the oil storage space between the bearing 12 and the crankshaft journal 9 after the first external through hole 111 and the first internal through hole 121 are removed from the oil sump 100, maintaining the presence of an oil film.

[0070] In some embodiments, the depth of the inner circumferential axial oil reservoir 125 ranges from 1.2 to 1.8 mm, preferably 1.5 mm.

[0071] The terms "inner" and "outer" generally refer to the radial direction of a component. The part located on the inner side of the radial direction is called "inner," and the part located on the outer side of the radial direction is called "outer." For example, the inner opening of the second inner through hole 122 is the opening of the second inner through hole 122 located on the radial inner circumferential surface of the bearing bush 12. Similarly, the outer opening of the first outer through hole 111 refers to the opening of the first outer through hole 111 located on the radial outer side of the connecting rod cover 11.

[0072] In some embodiments, such as Figure 5B As shown, the connecting groove 124 is inclined so that the radial outer groove of the connecting groove 124 is higher than the radial inner groove, which is conducive to the discharge of air in the oil wedge.

[0073] Preferably, the diameters of the first external through hole 111 and the first internal through hole 121 are larger than the diameter of the second internal through hole 122, and / or the diameter of the first external through hole 111 is larger than the diameter of the first internal through hole 121, so that more lubricating oil can be obtained when immersed in the oil bath.

[0074] In the embodiment shown in the accompanying drawings, the first external through hole 111, the first internal through hole 121, and the second internal through hole 122 are all four parallel through holes arranged along the axial direction S of the connecting rod big end. The diameters of the first internal through holes 121 and 122 are 6 mm, and the diameter of the first external through hole 111 is 8 mm. Those skilled in the art will understand that the number and size of the first external through hole 111, the first internal through hole 121, and the second internal through hole 122 can be adaptively adjusted according to lubrication conditions.

[0075] In some embodiments, such as Figure 3 As shown in Figures 5A and 5A, the acute angle formed by the axis M of the first internal through hole 121 and the second internal through hole 122 and the horizontal plane P is preferably 45°. If the angle is set to be greater than 45°, the stroke of the connecting rod into the oil-scooping area is shorter than that at 45°; while if it is less than 45°, in Figure 4A In the process, the position of hole 111 on the connecting rod cap is too low, affecting machining. Therefore, considering the timing of lubrication, the acute angle formed by the axis M of the first internal through hole 121 and the second internal through hole 122 and the horizontal plane P is preferably set to 45°.

[0076] It should be noted that the first internal through hole 121 and the second internal through hole 122 need to be opened in the non-load-bearing area of ​​the bearing bush 12.

[0077] The following describes the operation of the bearing lubrication structure. Specifically, when the connecting rod enters... Figure 6A During the suction stroke shown, that is, by Figure 3 During the rotation from position I to II to III, under the action of centrifugal force, the oil in the oil sump is forced into the space of the inner circumferential axial oil reservoir 125 between the crankshaft journal 9 and the bearing 12 through the first external through hole 111 and the first internal through hole 121 that mate on the connecting rod cover 11 and the bearing 12, thus establishing a sufficiently thick oil film between the working surfaces of the crankshaft journal 9 and the bearing 12. At this time, the second internal through hole 122 and the connecting groove 124 serve the dual functions of venting and storing oil.

[0078] When the link is in Figure 6B During the discharge stroke shown, that is, by Figure 3When rotating from position III to IV to I, the first external through hole 111 and the first internal through hole 121 leave the oil sump. The lubricating oil in the inner circumferential axial oil reservoir 125 and the second internal through hole 122 of the bearing 12 is subjected to centrifugal force during the rotation from position III to IV. It flows from the contact surface between the crankshaft journal 9 and the bearing 12 to the wedge gap between the crankshaft journal 9 and the bearing 12, so that the working surfaces of the crankshaft journal 9 and the bearing 12 are kept isolated by a sufficiently thick oil film until the first external through hole 111 and the first internal through hole 121 re-draw in lubricating oil during the next intake stroke.

[0079] Therefore, in one cycle, whether it is the intake stroke or the discharge stroke, the pressure lubricating oil generated by the rotation of the connecting rod big end can ensure that the shaft diameter and the bearing are always in a state of liquid friction, thus achieving the purpose of liquid lubrication.

[0080] This structure eliminates the need for traditional scraper blades and oil collection grooves, effectively simplifying the lubrication system. It employs splash lubrication to maintain lubrication of the big-end bearing, simplifying the engineering manufacturing process and improving the overall service life of the connecting rod.

[0081] Based on the above description of the bearing lubrication structure, we can also understand a reciprocating pump crankshaft connecting rod. This connecting rod includes a connecting rod body, a large end, a small end, a connecting rod cap, and a bearing. The large end is used to mate with the crankshaft diameter, and the small end is used to mate with the cross pin. The bearing adopts the above-mentioned bearing lubrication structure, which gives the connecting rod better lubrication performance.

[0082] It should be noted that the use of terms such as "first" and "second" to define the components in the above content is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0083] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0084] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0085] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A bearing lubrication structure, disposed on a connecting rod of a reciprocating pump, the lubrication structure comprising a connecting rod head, a bearing bush, and a connecting rod cap, wherein the connecting rod cap and the connecting rod head are mated to form an annular structure, and the bearing bush is located on the inner circumference of the annular structure; characterized in that, The bearing lubrication structure includes a first position and a second position. The first position is configured to be submerged in the oil sump when the reciprocating pump connecting rod is in one stroke, and the second position is configured to never be submerged in the oil sump. The connecting rod cover has a first external through hole, and the bearing bush includes a first internal through hole, a second internal through hole, a flange, and a connecting groove. The first internal through hole communicates with the first external through hole and is located at the first position. The connecting groove is disposed on the flange, extends from the edge of the flange to the inner circumferential surface of the bearing, and is configured to communicate with the inner opening of the second internal through hole. The second internal through hole and the connecting groove are disposed at the second position. The connecting groove is inclined so that the outer groove opening is higher than the inner groove opening. The bearing bush includes an inner circumferential axial oil reservoir, which covers the second internal through hole and communicates with the connecting groove; the second internal through hole and the connecting groove serve the dual functions of venting and storing oil.

2. The bearing lubrication structure as described in claim 1, characterized in that, The first external through hole is inclined so that the outer opening of the first external through hole is higher than the inner opening.

3. The bearing lubrication structure as described in claim 2, characterized in that, The acute angle between the axis of the first external through hole and the horizontal plane is in the range of 8~12°.

4. The bearing lubrication structure as described in claim 3, characterized in that, The acute angle between the axis of the first external through hole and the horizontal plane is 10°.

5. The bearing lubrication structure as described in claim 3, characterized in that, The acute angle formed by the axes of the first internal through hole and the second internal through hole with the horizontal plane is 45°.

6. The bearing lubrication structure as described in claim 1, characterized in that, The depth of the inner circumferential axial oil storage tank ranges from 1.2 to 1.8 mm.

7. The bearing lubrication structure as described in claim 6, characterized in that, The depth of the inner circumferential axial oil storage tank is 1.5 mm.

8. The bearing lubrication structure as described in claim 1, characterized in that, The diameters of the first external through hole and the first internal through hole are larger than the diameter of the second internal through hole.

9. The bearing lubrication structure as described in claim 1, characterized in that, The diameter of the first external through hole is larger than the diameter of the first internal through hole.

10. A reciprocating pump crankshaft connecting rod, comprising a connecting rod body, a large end, a small end, a connecting rod cap, and a bearing bush, wherein the large end is used to mate with the crankshaft diameter, and the small end is used to mate with a cross pin, characterized in that... The bearing bush adopts the bearing bush lubrication structure as described in any one of claims 1-9.

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