A crankshaft for a plunger pump

Abstract

This utility model relates to the technical field of crankshafts for plunger pumps, solving the technical problem that existing crankshafts for plunger pumps require extensive drilling, and the drilling process is cumbersome and lengthy. Specifically, it relates to a crankshaft for plunger pumps, comprising two symmetrically aligned connecting shafts serving as supporting bases. Several journals are equidistantly distributed between the two connecting shafts, and crank pins are fixedly connected between the journals. Each journal has a rotating bore, and radial oil holes are formed inside the rotating bore. The radial oil holes on the same journal are interconnected. Due to the crank pin configuration, the phase angle difference Δθ = 360°*(N-1) / 2N between adjacent crank pins ensures uniform force distribution on the crankshaft, reduces the time adjacent crank pins are simultaneously stressed, and reduces hydraulic pulsation. The oblique oil hole, oil outlet hole, and corresponding radial oil hole on each crank pin are all located within the phase angle plane of that crank pin, and the size, position, and angle of the corresponding holes are consistent, facilitating batch drilling and tooling manufacturing.

Description

Technical Field

[0001] This utility model relates to the technical field of crankshafts for plunger pumps, and more particularly to a crankshaft for plunger pumps. Background Technology

[0002] Piston pumps are a common power source in hydraulic systems, and horizontal piston pumps are the preferred power source for high-pressure, high-flow hydraulic systems. The crankshaft is a crucial component of a horizontal piston pump. The crankshaft, connecting rod, and slider work together to convert the rotary motion of the motor (there is usually a speed reducer between the motor and crankshaft) into linear motion, driving the pistons to pressurize the hydraulic medium and achieve the output of high-pressure media.

[0003] Traditional straight-line center oil holes can no longer meet the requirements. Designers have adopted various methods to address the problem of blocked lubrication holes. Some designers have used spatial oblique holes to directly connect the midpoint of the outermost generatrix of adjacent crankpins. This method is intuitive and simple, but the spatial positioning and machining of the oblique holes are difficult. The axial direction of the ellipse formed by the intersection of two oblique holes and the crankpins is relatively large, which is very detrimental to the life of the mating bearings. Other designers have designed the traditional straight-line center oil hole of the crankshaft as multiple sets of parallel oil holes, which, together with radial oil holes, achieve the connection of the lubrication oil passage. However, this method involves a large amount of machining, requires the sealing of a large number of open oil holes, and the parts in the middle of the crankshaft that cannot be connected by parallel oil holes still need to be drilled with oblique holes. To address the above problems, this application provides a crankshaft for a plunger pump. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a crankshaft for a plunger pump, which solves the technical problem that existing crankshafts for plunger pumps require a large number of holes and the drilling process is cumbersome and lengthy, thereby improving the drilling efficiency of the crankshaft.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a crankshaft for a plunger pump, comprising two symmetrically aligned docking shafts serving as supporting bases, a plurality of journals equidistantly distributed between the two docking shafts, a crank pin fixedly connected between the plurality of journals, a rotating hole opening on each of the plurality of journals, a radial oil hole opening inside the rotating hole opening, the radial oil holes on the same crankshaft being interconnected, and two V-shaped oblique oil holes opening inside the crank pin.

[0006] Preferably, each of the crank pins is provided with an oil outlet hole, and the oil outlet hole is connected to the corner of a nearby oblique oil hole.

[0007] Preferably, the two mating shafts are provided with oil inlets, which are connected to adjacent radial oil holes.

[0008] Preferably, the phase angles of the crank pins can be arranged either left-handed or right-handed, and the phase angle difference between adjacent crank pins is Δθ = 360°*(N-1) / 2N.

[0009] Preferably, the oblique oil holes and oil outlet holes on the crank pins are all in the same position and at the same angle relative to the crank pins.

[0010] Preferably, the lubricating oil enters from the oil inlets at both ends of the crankshaft, and the oil inlets are coaxial with the rotation center line of the crankshaft.

[0011] By means of the above technical solution, this utility model provides a crankshaft for a plunger pump, which has at least the following beneficial effects:

[0012] 1. Due to the setting of the crank pin, the phase angle difference Δθ=360°*(N-1) / 2N between adjacent crank pins in this utility model ensures uniform force on the crankshaft, reduces the time when adjacent crank pins are simultaneously stressed, and reduces hydraulic pulsation. The inclined oil hole, oil outlet hole and corresponding radial oil hole on each crank pin are all set in the phase angle plane of the crank pin, and the size, position and angle of the corresponding holes are consistent, which facilitates batch drilling and tooling manufacturing.

[0013] 2. Due to the radial oil hole design, this utility model is designed with the radial oil hole located at the mounting position of the journal bearing or gear. The radial oil hole is covered by the inner ring of the bearing or the inner hole of the gear, eliminating the need to consider the problem of blocking the open oil hole, which makes the opening process of the oil hole smoother and more convenient. Attached Figure Description

[0014] The accompanying drawings, which are provided to further illustrate this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application.

[0015] In the attached diagram:

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a schematic diagram of the cross-sectional structure of the crankshaft of this utility model;

[0018] Figure 3 This is a schematic diagram of the radial oil hole opening structure of this utility model;

[0019] Figure 4 This is a schematic diagram of the radial oil hole cross-sectional structure of this utility model.

[0020] In the diagram: 1. Connecting shaft; 2. Journal; 3. Rotary bore; 31. Radial oil hole; 32. Angled oil hole; 4. Crank pin; 5. Oil outlet; 6. Oil inlet. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Example 1

[0023] Traditional straight-line center oil holes are no longer sufficient for operational requirements. Designers have employed various methods to address the issue of blocked lubrication channels. Some designers have used spatial oblique holes, directly connecting the midpoint of the outermost generatrix of adjacent crankpins. This method is intuitive and simple, but the spatial positioning and machining of these oblique holes present certain difficulties. The ellipse formed by the intersection of two oblique holes and the crankpins has a large axial direction, which is detrimental to the lifespan of the mating bearings. Other designers have redesigned the traditional straight-line center oil hole of the crankshaft into multiple sets of parallel oil holes, which, together with radial oil holes, achieve the connection of the lubrication channels. However, this method involves a large amount of machining, requiring the sealing of numerous open oil holes, and oblique holes are still needed to connect areas in the middle of the crankshaft where parallel oil holes cannot be used. Please refer to [reference needed]. Figures 1-4 This embodiment provides a crankshaft for a plunger pump, which solves the technical problem that existing crankshafts for plunger pumps require a large number of holes and the drilling process is cumbersome and lengthy. The device includes two symmetrical docking shafts 1 that serve as supporting bases. Several journals 2 are equidistantly distributed between the two docking shafts 1. Crank pins 4 are fixedly connected between the journals 2. Each journal 2 has a rotating hole 3. Radial oil holes 31 are opened inside the rotating hole 3. The radial oil holes on the same journal are interconnected. Two V-shaped oblique oil holes 32 are opened inside the crank pin 4. Each crank pin 4 has an oil outlet 5. The oil outlet 5 is connected to the corner of the adjacent oblique oil hole 32. An oil inlet 6 is opened on the two docking shafts 1. The oil inlet 6 is connected to the adjacent radial oil hole 31.

[0024] Several crank pins 4 can be arranged in either left-hand or right-hand rotation. In order to ensure uniform force on the crankshaft, reduce the time when adjacent crank pins 4 are simultaneously stressed, and reduce hydraulic pulsation, the phase angle difference between adjacent crank pins 4 is Δθ = 360°*(N-1) / 2N (N is the number of crank pins, which is usually an odd number). For a crankshaft with 5 crank pins 4, Δθ = 360°*2 / 5 = 144°.

[0025] To facilitate batch drilling and tooling manufacturing, the oblique oil holes 32 and oil outlet holes 5 on several crank pins 4 are positioned and angled in the same way relative to the crank pins 4. Lubricating oil enters from the oil inlets 6 at both ends of the crankshaft, and the oil inlets 6 are coaxial with the rotation center line of the crankshaft.

[0026] The angled oil hole 32 is used to connect the two radial oil holes 31 on both sides of the same crankpin 4. The angle of the angled oil hole 32 is determined according to factors such as the crankshaft eccentricity and crank neck size, and an angle that is easy to machine is selected without drilling through the crankpin 4. The oil outlet hole 5 is used to supply lubricating oil to the mating surface between the crankpin 4 and the bearing shell. The stress is relatively small near the crankshaft rotation center line, so setting the oil hole here is more conducive to force transmission and crankshaft life.

[0027] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A crankshaft for a plunger pump comprising two counter-rotating shafts (1) symmetrical with respect to a support base, characterized in that: A number of journals (2) are equidistantly distributed between the two docking shafts (1), and a crank pin (4) is fixedly connected between the journals (2). A rotating hole (3) is opened on each of the journals (2), and a radial oil hole (31) is opened inside the rotating hole (3). The radial oil holes on the same journal are interconnected. Two V-shaped oblique oil holes (32) are opened inside the crank pin (4).

2. A crankshaft for a piston pump according to claim 1, characterized in that: Several of the crank pins (4) are provided with oil outlet holes (5), and the oil outlet holes (5) are connected to the corners of the nearby oblique oil holes (32).

3. A crankshaft for a piston pump as defined in claim 1, characterized in that: Oil inlets (6) are provided on the two docking shafts (1), and the oil inlets (6) are connected to the adjacent radial oil holes (31).

4. The crankshaft for a piston pump of claim 1, wherein: The phase angles of the crank pins (4) can be arranged either left-handed or right-handed, and the phase angle difference between adjacent crank pins (4) is Δθ = 360°*(N-1) / 2N.

5. A crankshaft for a plunger pump according to claim 2, characterized in that: The oblique oil holes (32) and oil outlet holes (5) on several of the crank pins (4) are in the same position and angle relative to the crank pins (4).

6. A crankshaft for a plunger pump according to claim 3, characterized in that: Lubricating oil enters from the oil inlets (6) at both ends of the crankshaft, and the oil inlets (6) are coaxial with the rotation center line of the crankshaft.

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