Long stroke beam pumping unit

Abstract

A long stroke beam pumping unit includes a base and a driving mechanism fixedly mounted at one end of the base. A walking beam is provided at the other end of the base via a bracket mechanism to form a beam structure, a donkey head is mounted at the front end of the walking beam, and the rear end of the walking beam is connected to the driving mechanism via a connecting rod to form a crank-connecting rod structure. A middle seat is mounted on the walking beam, the bracket mechanism includes a front bracket and a rear bracket connected to each other at top ends, and the other ends of the front bracket and the rear bracket are mounted at both sides of the base. The long stroke beam pumping unit reduces stress concentration by adjusting the size of the component and optimizing the bracket mechanism.

What is claimed is: 
     
         1 . A long stroke beam pumping unit comprising a base and a driving mechanism fixedly mounted at a first end of the base, wherein a walking beam is provided at a second end of the base via a bracket mechanism, a donkey head is mounted at a front end of the walking beam, and a rear end of the walking beam is connected to the driving mechanism via a connecting rod; a middle seat is mounted on the walking beam; and the bracket mechanism comprises a front bracket and a rear bracket, wherein a top end of the front bracket and a top end of the rear bracket are connected, and a bottom end of the front bracket and a bottom end of the rear bracket are mounted on both sides of the base;
 setting: A is a distance from the donkey head to the middle seat; C is a distance from the middle seat to the rear end of the walking beam; and the A=5791-7395 mm and the C=3050-3611 mm.   
     
     
         2 . The long stroke beam pumping unit according to  claim 1 , wherein
 I is a distance between a rotation center of the driving mechanism and a projection of the middle seat on the base; P is a length of the connecting rod; H is a distance between the middle seat and the base; G is a distance from the rotation center of the driving mechanism to the base; R is a rotation radius of the driving mechanism; and   the I=3050-3569 mm, the P=5759-7386 mm, the H=8636-10838 mm, the G=2819-3643 mm, and the R=1524-2047 mm.   
     
     
         3 . The long stroke beam pumping unit according to  claim 2 , wherein the long stroke beam pumping unit adjusts the distance, the length and the rotation radius by a cut-and-trial, and a dynamic characteristic curve of the long stroke beam pumping unit is output by a dynamic simulation calculation; and the distance, the length and the rotation radius are adjusted again according to feedback of the dynamic characteristic curve until the dynamic characteristic curve is optimal. 
     
     
         4 . The long stroke beam pumping unit according to  claim 3 , wherein the walking beam is connected to a crank of the driving mechanism via the connecting rod to form a crank-connecting rod structure; the walking beam and the bracket mechanism form a long-stroke beam structure by adjusting the distance, the length and the rotation radius; the connecting rod comprises a bottom rod hinged to the walking beam and a transmission rod hinged to the driving mechanism, respectively; and the transmission rod is connected to the bottom rod via a telescopic rod built in the transmission rod, and the telescopic rod and the bottom rod are hinged. 
     
     
         5 . The long stroke beam pumping unit according to  claim 1 , wherein an extension column is provided on both sides of a hinge; the front bracket and the rear bracket are respectively sleeved on the extension column on both sides of the hinge;
 and the front bracket and the rear bracket are movably mounted on the base along a long axis direction of the walking beam to adjust a first included angle between the front bracket and the rear bracket.   
     
     
         6 . The long stroke beam pumping unit according to  claim 5 , wherein a vertical line of the middle seat is set as a center line, a second included angle between the front bracket and the center line is 0-10°, and a third angle between the rear bracket and the center line is 0-16°. 
     
     
         7 . The long stroke beam pumping unit according to  claim 1 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         8 . The long stroke beam pumping unit according to  claim 7 , wherein the stress arc patch extends arcuately along a long axis of the walking beam towards both ends. 
     
     
         9 . The long stroke beam pumping unit according to  claim 1 , wherein a stroke of the long stroke beam pumping unit is above 6.1 meters. 
     
     
         10 . The long stroke beam pumping unit according to  claim 4 , wherein the driving mechanism comprises an electric motor, wherein the electric motor is connected to a speed reducer via a belt, and the speed reducer is connected to a connecting rod via a crankshaft. 
     
     
         11 . The long stroke beam pumping unit according to  claim 1 , wherein the middle seat is slidably mounted on the walking beam; the top end of the front bracket and the top end of the rear bracket are connected to each other via a hinge; and the bottom end of the front bracket and the bottom end of the rear bracket are slidingly mounted on both sides of the base. 
     
     
         12 . The long stroke beam pumping unit according to  claim 2 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         13 . The long stroke beam pumping unit according to  claim 3 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         14 . The long stroke beam pumping unit according to  claim 4 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         15 . The long stroke beam pumping unit according to  claim 5 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         16 . The long stroke beam pumping unit according to  claim 6 , wherein the middle seat and the bracket mechanism is connected at a connection by a stress arc patch. 
     
     
         17 . The long stroke beam pumping unit according to  claim 2 , wherein the middle seat is slidably mounted on the walking beam; the top end of the front bracket and the top end of the rear bracket are connected to each other via a hinge; and the bottom end of the front bracket and the bottom end of the rear bracket are slidingly mounted on both sides of the base. 
     
     
         18 . The long stroke beam pumping unit according to  claim 3 , wherein the middle seat is slidably mounted on the walking beam; the top end of the front bracket and the top end of the rear bracket are connected to each other via a hinge; and the bottom end of the front bracket and the bottom end of the rear bracket are slidingly mounted on both sides of the base. 
     
     
         19 . The long stroke beam pumping unit according to  claim 4 , wherein the middle seat is slidably mounted on the walking beam; the top end of the front bracket and the top end of the rear bracket are connected to each other via a hinge; and the bottom end of the front bracket and the bottom end of the rear bracket are slidingly mounted on both sides of the base. 
     
     
         20 . The long stroke beam pumping unit according to  claim 5 , wherein the middle seat is slidably mounted on the walking beam; the top end of the front bracket and the top end of the rear bracket are connected to each other via a hinge; and the bottom end of the front bracket and the bottom end of the rear bracket are slidingly mounted on both sides of the base.