Oscillating Head Counterweight Layout for Smoother Pump Torque
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Solution Overview
Problem
Existing lifting and lowering systems for unbalanced loads, such as beam pumping units, face inefficiencies due to significant differences in counterweight requirements between the upstroke and downstroke, leading to unresolved net torque issues, which result in increased wear, energy consumption, and operational expenses.
Innovation Solution
The system employs a head contiguous with a counterweight having a fulcrum, connected to a load, where the counterweight is oscillated by linkages to maximize counterbalance during lifting and minimize it during lowering, using a combination of head weight and crank weight to achieve optimal counterbalance effects, reducing net torque and structural stress, and incorporating a four-bar linkage mechanism for efficient rod acceleration and velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional beam pumping units use fixed counterweight designs, then the structure is simple, but the net torque varies significantly between upstroke and downstroke causing increased wear and energy consumption
Solution Approach 1:
The patent applies dynamics by making the counterweight system adjustable and variable rather than fixed. The counterweight can be repositioned along the beam to change its leverage ratio, allowing the system to adapt to different load conditions and optimize torque distribution throughout the stroke cycle, thereby reducing energy consumption and wear.
Solution Approach 2:
The patent changes the parameter of counterweight position and leverage ratio to optimize performance. By adjusting the counterweight's location on the beam, the system can modify the mechanical advantage and torque characteristics to minimize energy loss and balance the forces during both upstroke and downstroke operations.
2Force
If larger counterweight is used to balance the load during upstroke, then lifting capability is improved, but the machine size and cost increase
Solution Approach 1:
The patent uses a dynamic counterweight positioning system that allows the counterweight to be adjusted along the beam. This enables the same counterweight to provide different leverage ratios depending on the operational phase, maximizing lifting force during upstroke while avoiding the need for excessively large counterweight mass that would increase overall machine weight and cost.
Solution Approach 2:
The patent segments the counterweight function by allowing it to be positioned at different locations on the beam. This segmentation of the leverage function enables optimized force distribution without requiring a single large fixed counterweight, thereby reducing the overall weight and cost of the machine while maintaining adequate lifting capability.
3Ease of operation
If fixed fulcrum position is used, then the structure is simple, but the torque balance between upstroke and downstroke cannot be optimized
Solution Approach 1:
The patent implements a movable fulcrum mechanism that can be repositioned along the beam to optimize torque balance. By dynamically adjusting the fulcrum position, the system can achieve better force distribution between upstroke and downstroke operations, improving operational efficiency without requiring overly complex mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for increased permissible loads, reduced structural stress, longer component life, smaller speed reducers, and longer stroke lengths, resulting in economic and performance benefits by smoothing speed reducer loading and reducing vibration and shock.
Implementation Method 1
Gravity is the natural force being countered with the machine's counterbalance force
Implementation Method 2
The system employs a head contiguous with a counterweight having a fulcrum, connected to a load, where the counterweight is oscillated by linkages to maximize counterbalance during lifting and minimize it during lowering
Data Source
AI summary
A prime example of an application for a head with contiguous counterweight is a sucker rod reciprocating pump whose circular arc head is contiguous with a counterweight and is pivotably connected to the pitman arm, crank arm weight, and speed reducer. The pitman arm is substantially horizontal and the crank arm to wrist pin phase angle is about 70-90 degrees. Auxiliary counter weight extends from the head weight on a stinger and the head weights are adjustable. The head weight diameter is either constrained within the circular arc head's outer diameter or can be larger. The upper pitman bearings are outboard on the equalizer which is integral with the head. The center bearing of the head is outboard on the rectangular sampson post. The head counterweight increases permissible load on a speed reducer. This example use of a head with contiguous counterweight has can be configured to utilize beneficial embodiments for adjusting sampson post height and pitman arm length; and for changing the stroke length without removing the wrist pin from the crank weight hole.