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CN-121997471-A - Method for optimizing and constructing profile of upper crank of single-cylinder crankshaft

CN121997471ACN 121997471 ACN121997471 ACN 121997471ACN-121997471-A

Abstract

The invention discloses a method for optimizing and constructing a crank profile on a single-cylinder crankshaft, which comprises the steps of analyzing the motion law of a crank, a connecting rod and a cross head in the single cylinder, finding out the corresponding relation between each motion parameter and the crank profile, and reversely rotating the whole crank, the connecting rod and the cross head Obtaining point location data of the rotation centers of the connecting rod and the cross head, setting a safe distance and a vertical line, obtaining point location data of the intersection point of the cross head movement line and the crank profile limiting line and tangent point data of the crank profile where the crank profile limiting line is located, and adjusting And performing fitting and combining treatment on the multiple sets of tangent point data to obtain a first set and a second set of crank limit profile curves, performing offset on the outer circle of the crank pin to obtain an auxiliary profile, and connecting the three to obtain the crank profile. The invention can maximize the design of the crank profile, effectively improve the balance performance of the crank and enhance the application applicability of the crankshaft.

Inventors

  • HAO JIANXU
  • CAO XIAOYU
  • LUAN SU
  • WANG YANGYANG
  • DU XIANGYANG
  • LI XIAOLONG
  • WANG YALI

Assignees

  • 中油国家油气钻井装备工程技术研究中心有限公司
  • 宝鸡石油机械有限责任公司
  • 中国石油天然气集团有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (8)

  1. 1. The method for optimizing the profile of the upper crank of the single-cylinder crankshaft is characterized by comprising the following steps of: step 1, analyzing a motion rule of a crank, a connecting rod and a cross head in a single cylinder, and finding out a corresponding relation between each motion parameter and a crank outline; Step 2, integrally reversely rotating the crank, the connecting rod and the cross head Obtaining point position data of the rotation centers of the connecting rod and the cross head when the crank is at the initial position; Step 3, setting a safety interval to obtain point location data of an intersection point of the crosshead motion line and the crank profile limit line; Step 4, setting a vertical line, finding a tangent point on the crank contour where the crank contour limiting line is located, and acquiring the tangent point data based on the point data in the step 2 and the step 3; Step 5, adjusting Repeating the step 2 to the step 4 to obtain a plurality of groups of tangent point data; And 6, fitting the multiple sets of tangent point data to obtain a first set of crank limit profile curve, obtaining a second set of crank limit profile curve based on the first set of crank limit profile curve, shifting the outer circle of the crank pin to obtain an auxiliary profile, and connecting the first set of crank limit profile curve, the second set of crank limit profile curve and the auxiliary profile to obtain the crank profile.
  2. 2. The method for optimizing the profile of a crank on a single-cylinder crankshaft according to claim 1, wherein the corresponding relation in the step 1 is that the crank rotates around a crankshaft center point O, the cross head is driven by the connecting rod to do reciprocating linear motion, a connecting point Q between the cross head and the connecting rod is located on a reciprocating motion line of the cross head, and during the rotation of the crank, the position of each Q corresponds to a profile point of the crank.
  3. 3. The method for optimizing the profile of a crank on a single cylinder crankshaft as recited in claim 1, wherein the initial position of the crank in step 2 is as follows When the crank is in the initial position.
  4. 4. The method for optimizing and constructing a crank profile on a single cylinder crankshaft according to claim 1, wherein the point location data of the rotation center of the connecting rod and the cross head in the step 2 is specifically that when the crank returns to the initial position, the point location data of the Q point of the rotation center of the connecting rod and the cross head is , And Calculated by the following expression: ; ; Wherein L is the length of the connecting rod, L is the length of the crank; is the included angle between the crank and the connecting rod, ; The cross head movement line and the X-axis clamp angle are formed; Is the included angle between the connecting rod and the movement line of the cross head, 。
  5. 5. The method for optimizing and constructing a crank profile on a single cylinder crankshaft according to claim 1, wherein the point data of the intersection point S of the crosshead motion line and the crank profile limit line in the step 3 Calculated by the following formula: ; ; wherein L1 is the vertical distance between the rotation center Q of the connecting rod and the cross head and the end face of the cross head; Is a safe interval; Is the angle between the movement line of the cross head and the X axis.
  6. 6. The method for optimizing and constructing a crank profile on a single cylinder crankshaft according to claim 1, wherein the step 4 is characterized in that the point data of the tangent point T on the crank profile where the crank profile limiting line is located Calculated by the following formula: ; ; Wherein l is the crank length; Is the angle between the movement line of the cross head and the X axis.
  7. 7. The method for optimizing the profile of a crank on a single cylinder crankshaft according to claim 1, wherein in the step 5 The range of the value of (2) is 0-90 degrees.
  8. 8. The method for optimizing and constructing a crank profile on a single cylinder crankshaft according to claim 1, wherein the fitting of the plurality of sets of tangent point data in the step 6 is specifically to change the plurality of sets of tangent point data And mirroring the first set of crank limit profile curves to obtain a second set of crank limit profile curves.

Description

Method for optimizing and constructing profile of upper crank of single-cylinder crankshaft Technical Field The invention belongs to the technical field of liquid hydrogen pressurizing equipment, and particularly relates to a method for optimizing and forming a crank profile on a single-cylinder crankshaft. Background The high-pressure liquid hydrogen pump is core equipment for the development of a liquid hydrogen industry chain, is widely applied to the aerospace field, the new energy field and the fuel cell field, and mainly aims to flow and pressurize liquid hydrogen from a storage tank to a vaporizer. The single-cylinder reciprocating liquid hydrogen pump supplies power to liquid hydrogen through mechanical reciprocating action, forces the liquid hydrogen to be pressurized, pushes the liquid hydrogen to flow, and promotes the liquid hydrogen from a low-pressure state to a high-pressure state. The crankshaft is a key part of the high-pressure liquid hydrogen reciprocating pump, and the crank is an important component structure of the crankshaft, and has the functions of structurally connecting a crank pin to form the whole crankshaft, adjusting the center of gravity of the crankshaft and balancing the crankshaft so as to ensure the stability of the crankshaft during rotation. The crankshaft for the high-pressure liquid hydrogen pump adopts a single-cylinder crankshaft, and mainly depends on a crank balance crank pin, the crank pin has large design diameter because of bearing a large connecting rod load, and meanwhile, the whole pump has smaller structural size, so that the size space of the balanced crank is limited, and the conventional crank is difficult to play a role of balancing the crank pin in the limited space. Therefore, the crank profile of the crankshaft is developed, so that the crank obtains larger mass in a limited space, and the balance of the crankshaft is ensured. Disclosure of Invention The invention aims to provide the method for optimizing the profile of the crank on the single-cylinder crankshaft, which can maximize the profile of the crank, effectively improve the balance performance of the crank and enhance the application applicability of the crankshaft. The technical scheme adopted by the invention is that the method for optimizing and forming the profile of the crank on the single-cylinder crankshaft specifically comprises the following steps: step 1, analyzing a motion rule of a crank, a connecting rod and a cross head in a single cylinder, and finding out a corresponding relation between each motion parameter and a crank outline; Step 2, integrally reversely rotating the crank, the connecting rod and the cross head Obtaining point position data of the rotation centers of the connecting rod and the cross head when the crank is at the initial position; Step 3, setting a safety interval to obtain point location data of an intersection point of the crosshead motion line and the crank profile limit line; Step 4, setting a vertical line, finding a tangent point on the crank contour where the crank contour limiting line is located, and acquiring the tangent point data based on the point data in the step 2 and the step 3; Step 5, adjusting Repeating the step 2 to the step 4 to obtain a plurality of groups of tangent point data; And 6, fitting the multiple sets of tangent point data to obtain a first set of crank limit profile curve, obtaining a second set of crank limit profile curve based on the first set of crank limit profile curve, shifting the outer circle of the crank pin to obtain an auxiliary profile, and connecting the first set of crank limit profile curve, the second set of crank limit profile curve and the auxiliary profile to obtain the crank profile. The present invention is also characterized in that, In the step 1, the corresponding relation is that the crank rotates around the center point O of the crankshaft, the connecting rod drives the cross head to do reciprocating linear motion, the point Q of the connecting point Q of the cross head and the connecting rod is positioned on the reciprocating motion line of the cross head, and in the process of crank rotation, the position of each point Q corresponds to the contour point of one crank. The initial position of the crank in the step 2 is as followsWhen the crank is in the initial position. In the step 2, the point location data of the rotation center of the connecting rod and the cross head is specifically that when the crank returns to the initial position, the point location data of the Q point of the rotation center of the connecting rod and the cross head is,AndCalculated by the following expression: ; ; Wherein L is the length of the connecting rod, L is the length of the crank; is the included angle between the crank and the connecting rod, ;The cross head movement line and the X-axis clamp angle are formed; Is the included angle between the connecting rod and the movement line of the cross head, 。 Point locat