Piston Pump Regulator Adjusting Auxiliary Spring Bias
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Solution Overview
Problem
Machining errors in the control spool of fluid pressure rotating machines lead to inaccuracies in the biasing force exerted by control springs, affecting the control characteristic of the horsepower control regulator, resulting in insufficient accuracy for fluid pressure control.
Innovation Solution
A fluid pressure rotating machine with a regulator that includes a biasing member, a control spool, an auxiliary biasing member, and an adjusting mechanism to adjust the biasing force, allowing for precise control of the control pressure and tilting angle of the swash plate, thereby improving the accuracy of horsepower control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the biasing force of the outer and inner control springs is set to achieve desired control characteristic, then the horsepower control regulator exhibits the desired control characteristic, but machining errors in the control spool cause errors in the compressed amount of the springs and the biasing force, resulting in insufficient accuracy
Solution Approach 1:
The patent introduces an auxiliary spring whose biasing force can be adjusted by changing its compression amount through the adjusting mechanism. This allows compensation for errors in the control spring biasing force, enabling the system to maintain accurate control characteristics despite machining errors in the control spool dimensions.
Solution Approach 2:
The patent employs a feedback mechanism where the control spool position, which reflects the actual compression state of the control springs, is used to adjust the auxiliary spring biasing force through the adjusting mechanism. This feedback loop compensates for deviations caused by machining errors and maintains the desired control characteristic.
2Measurement precision
If the control spool is moved according to the biasing force from the outer and inner control springs, then the control pressure is adjusted, but machining errors cause inaccuracies in the control pressure adjustment
Solution Approach 1:
The auxiliary spring acts as an intermediary element that compensates for the inaccuracies introduced by the control spool's dimensional errors. By adjusting the auxiliary spring's biasing force independently, the system can correct the control pressure deviations caused by imperfect control spool dimensions.
Solution Approach 2:
The patent allows dynamic adjustment of the auxiliary spring's compression amount and biasing force through the adjusting mechanism. This parameter change capability enables compensation for control spool dimensional errors, ensuring accurate control pressure adjustment despite manufacturing tolerances.
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
The solution enables precise control of the discharge capacity of the piston pump, maintaining constant discharge pressure and adjusting it according to load changes, enhancing the accuracy and reliability of the fluid pressure control.
Implementation Method 1
a first biasing mechanism configured to bias the swash plate in accordance with control pressure supplied; a second biasing mechanism configured to bias the swash plate against the first biasing mechanism
Implementation Method 2
a plurality of cylinders formed in the cylinder block, the cylinders being arranged at predetermined intervals in a circumferential direction of the driving shaft; pistons respectively slidably inserted into the cylinders, the pistons each configured to define a capacity chamber in an interior of the cylinder
Data Source
AI summary
A piston pump includes: a first biasing mechanism configured to bias a swash plate in accordance with control pressure supplied; a second biasing mechanism configured to bias the swash plate against the first biasing mechanism; and a regulator configured to control the control pressure in accordance with self-pressure of the piston pump. The regulator has: an outer spring and an inner spring configured to be extended and compressed by following tilting of the swash plate; a control spool configured to be moved in accordance with biasing forces exerted by the outer spring and the inner spring, the control spool being configured to adjust the control pressure; an auxiliary spring configured to exert biasing force to the control spool against the biasing forces exerted by the outer spring and the inner spring; and an adjusting mechanism configured to adjust the biasing force exerted by the auxiliary spring.