| 摘要 |
A method and apparatus for pumping fluids from a well using a walking beam (10) which is connected to the pump rod (17) at one end (11) located above the well and which carries a counterweight (Wc) at the opposite balancing end (12), the walking beam (10) being pivotally supported on a fulcrum (F) disposed between the ends of the beam. The fulcrum (F) and walking beam (10) are associated in a manner to permit relative shifting in the longitudinal direction of the walking beam (10). An actuating mechanism is provided to cause the shifting alternately in opposite directions. As the shifting of the walking beam (10) relative to the fulcrum (F) takes place in a first direction towards the balancing end, the walking beam (10) moved past a loaded balanced condition, i.e. a position in which the turning force caused by the balancing end is equal to the turning force of the pumping rod (17) and head of liquid in the well, and having passed the loaded balance condition, the balancing end thus swings downwardly so as to provide the lifting stroke of the pump. The actuating mechanism then shifts the walking beam (10) relative to the fulcrum (F) in the opposite direction past an unloaded balanced condition, i.e. a position in which the turning force caused by the weight of the pumping rod (17) is equal to the turning force caused by the balancing end of the walking beam (10), and having passed the unloaded balanced condition, the pump rod (17) moves to its lowered position and thereby effects raising of the balancing end to its raised position. The shifting of the balanced beam (10) relative to the fulcrum (F) in the first direction as described above is then repeated as the first complete pumping cycle has been completed. The pumping cycle makes efficient use of the energy input which may be manual or some other conventional power source such as an electric motor. Even when a manual input is used, the pump can be utilized in a deep well situation. High peak loading is avoided which allows the use of lighter structural and driving parts normally used in pump jacks of the walking beam type. Moreover, the operating parts may be of a simple nature so as to be serviceable in geographical areas where skilled technicians and precision tools are not available. |
