Swash Plate Pump Actuator Guide Surface Design
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Solution Overview
Problem
Swash plate-type axial piston pumps require complex and costly adjustment devices with significant constructional effort, leading to high production costs and inefficiencies due to the need for ball joints that increase friction and hysteresis.
Innovation Solution
The axial piston pump incorporates a compensation means with guide surfaces and a spring arrangement to eliminate the need for ball joints, allowing for a simpler structure and reduced friction, where the actuating piston and piston rod are formed as a single, integral part, and a single-acting actuating cylinder suffices for adjusting the swash plate position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ball joint is used between the actuating piston and piston rod to keep the piston free from constraining forces, then the piston can move freely during adjustment movements, but the device complexity and friction forces increase
Solution Approach 1:
The invention extracts and eliminates the ball joint from the system by redesigning the guide surfaces. Instead of using a separate ball joint component to accommodate movement, the guide surfaces are shaped to directly permit the necessary movement of the actuating piston within the actuating cylinder, thereby removing the complex ball joint while maintaining operational freedom.
Solution Approach 2:
The invention applies curved or spherical guide surfaces within the actuating cylinder that allow the actuating piston to move in an arc-like path during swash plate adjustment. This curvature enables the piston to follow the necessary motion trajectory without requiring a ball joint, reducing friction and hysteresis while maintaining operational freedom.
2Adaptability or versatility
If a complex gearing connection is used to convert linear motion of the actuating piston into swivel motion of the swash plate, then the adjustment function is achieved, but the constructional effort and production costs increase
Solution Approach 1:
The invention removes the complex gearing connection from the system by directly coupling the actuating piston's linear motion to the swash plate's angular adjustment through strategically positioned guide surfaces. This eliminates the intermediate conversion mechanism, simplifying the construction and reducing production costs while maintaining the adjustment function.
Solution Approach 2:
The invention changes the dimension of motion transmission by using guide surfaces that directly translate linear piston movement into angular swash plate adjustment in a single mechanical linkage. This eliminates the need for separate conversion stages, reducing constructional complexity and manufacturing effort.
3Reliability
If multiple articulation points are used between the swivel lever and actuating piston, then the adjustment mechanism is more robust, but the friction forces and hysteresis increase
Solution Approach 1:
The invention eliminates multiple articulation points by using a direct guide surface connection between the actuating piston and swivel lever. This single, optimized connection point reduces the number of moving joints, thereby reducing cumulative friction and hysteresis while maintaining sufficient mechanical robustness for the adjustment function.
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 design enhances operational reliability, reduces production costs, and minimizes friction and hysteresis, enabling efficient adjustment of the swash plate position while maintaining maximum pump delivery settings without additional mechanical complexity.
Implementation Method 1
a compression spring arrangement and/or a lubricant supply
Implementation Method 2
The compensating device, provided according to the invention, effects a mutual positional alignment of piston-sided guide surfaces and cylinder-sided guide surfaces. The compensation means can be formed at least partially by a spherical outer contour of at least one of the guide surfaces
Implementation Method 3
The compensation means can be formed at least partially by a spherical outer contour of at least one of the guide surfaces and/or a resiliently flexible sealing arrangement at the free end of at least one respective actuating piston and/or a compression spring arrangement and/or a lubricant supply
Data Source
AI summary
A swash plate-type axial piston pump, in particular for hydraulic systems, has a cylinder drum (3) rotatable about an axis of rotation (7) in a pump housing (1) and in which pistons (9) are arranged axially movable. The actuating ends of the pistons are accessible from outside of the cylinder drum (3) and are supported at least indirectly on a swash plate (15). In order to set the stroke of the pistons (9) and the fluid system pressure generated, the swash plate can be swiveled to the desired angle of inclination relative to the axis of rotation (7) by an adjustment device (21), which has at least one swiveling lever (23) that can be deflected and returned in at least one direction by an actuator and that each has in at least one hydraulically actuated actuating cylinder (31, 43) one actuating piston (35) acting on one end on an articulation point (29) of the swivel lever (23). One actuating piston (35, 47) has at its end, facing away from the articulation point (29), a guide surface (73), which is an integral part of the actuating piston (35, 47) and is in contact with an assigned guide surface (33, 45) of the actuating cylinder (31, 43). At least one compensator (75, 70, 59) is orients the guide surfaces (73; 33, 45) in their respective positions relative to each other.