Radial Piston Pump with Pivoting Piston Head for Compact Design
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Solution Overview
Problem
Conventional radial piston pumps with internal support have a large outer diameter due to transverse forces from the eccentric drive, limiting their compactness and efficiency.
Innovation Solution
The radial piston pump design features pistons with a short casing height that pivot about the longitudinal axis of the cylinder bore, supported by an inner eccentric or hydrostatic bearing, allowing for a compact design and efficient sealing, with optional star-shaped cylinder bores and articulated connections for enhanced performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional single-piece pistons with large casing height are used for guidance in cylinders, then rectilinear movement of pistons is ensured, but the outer diameter of the pump becomes comparatively large
Solution Approach 1:
The piston is divided into two separate components: a piston base that is supported on the eccentric and a piston head that moves in the cylinder bore. This segmentation allows the piston base to handle the eccentric drive forces while the piston head maintains sealing contact with the cylinder wall, eliminating the need for a long single-piece piston and reducing the pump's outer diameter.
Solution Approach 2:
A pivot connection is introduced as an intermediary element between the piston base and piston head. This pivot connection allows the piston head to pivot relative to the piston base, accommodating the transverse forces from the eccentric drive while maintaining effective sealing, thus resolving the contradiction between movement stability and compact size.
2Force
If transverse forces are accommodated by conventional piston construction, then the pistons can be supported on the eccentric, but a large outer diameter is required
Solution Approach 1:
By separating the piston into base and head components with different functions, the piston base can be optimized for force accommodation through pivot connection while the piston head is optimized for sealing with minimal radius, reducing the overall outer diameter while maintaining force handling capability.
Solution Approach 2:
The solution moves from a single-dimensional linear piston design to a two-dimensional design where the piston head can pivot through an angle range. This angular movement capability allows the system to accommodate transverse forces without increasing the radial dimension (outer diameter) of the pump.
3Area of stationary object
If the piston head pivots in a predetermined angle range, then the outer diameter is reduced, but sealing effectiveness must be maintained
Solution Approach 1:
The piston head is given a spherical or convex outer surface that changes its orientation through a predetermined angle range during operation. This parameter change in orientation allows compact design while the spherical geometry ensures continuous contact with the cylinder bore, maintaining sealing effectiveness despite the angular movement.
Solution Approach 2:
The piston head features a spherical or convex outer surface that enables pivoting motion while maintaining constant contact with the cylindrical bore. This curved geometry allows the piston head to accommodate angular movements without compromising the sealing interface, resolving the contradiction between compact size and sealing reliability.
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 significantly reduces the outer diameter of the pump while maintaining effective sealing and increasing swept volume, leading to improved economy and compactness.
Implementation Method 1
the piston head, during its longitudinal movement, pivots in a predetermined angle range Δα about the longitudinal central axis of the associated cylinder bore
Implementation Method 2
the displacement pistons are supported on the eccentric, or on a cylindrical roller bearing which surrounds the eccentric, by means of a hydrostatic plain bearing arrangement
Implementation Method 3
The piston heads of the displacement pistons are preferably of convex design and have, for sealing in the cylinder bores, at least in each case one piston ring per displacement piston
Implementation Method 4
the displacement pistons preferably have a corresponding inner bore which extends through the displacement piston lengthwise and permits a metered pressure medium supply
Data Source
AI summary
A radial piston pump having external loading. The radial piston pump has an inner eccentric which is attached to a rotatable driveshaft, a cylinder block which has positionally fixed cylinder bores aligned radially with respect to the driveshaft, and displacement pistons which are mounted in a longitudinally movable manner in the cylinder bores. The displacement pistons have a piston head with a short casing height, and are mounted with their piston base on the eccentric, in such a way that the piston head, during its longitudinal movement, pivots in a predetermined angle range (Δα) about the longitudinal central axis of the associated cylinder bore.