Piston Pump Eccentric Bush Arrangement for Low-Wear Linear Motion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piston type pumps require close manufacturing tolerances, leading to increased assembly time and cost, and suffer from non-rectilinear piston movements causing wear and noise issues.
Innovation Solution
A first sliding bush is arranged between the eccentric and the sliding block guide, allowing translational movement along the main axis and restricting movement along the minor axis, with a tapered design to minimize friction and wear, and a biasing member to ensure continuous contact and compensate for manufacturing deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If close manufacturing tolerances are used for the drive assembly, then the pump achieves acceptable vibrational and noise levels, but assembly time and manufacturing cost increase
Solution Approach 1:
The drive assembly is divided into modular components: the drive shaft with integrated first eccentric, the sliding block guide with slot, and the first sliding bush as a separate intermediate element. This segmentation allows each component to be manufactured with relaxed tolerances while the assembled mechanism maintains low vibration and noise through the geometric relationship of the components rather than relying on tight machining tolerances of individual parts.
Solution Approach 2:
The first sliding bush acts as an intermediary element between the first eccentric and the first sliding block guide. It facilitates the conversion of orbital motion to rectilinear motion while accommodating manufacturing variations. The sliding bush absorbs tolerances and ensures smooth operation, reducing vibration and noise without requiring extremely precise manufacturing of the adjacent components.
2Object-affected harmful factors
If close manufacturing tolerances are used for the drive assembly, then the pump achieves acceptable vibrational and noise levels, but manufacturing cost increases
Solution Approach 1:
The drive assembly is divided into modular components: the drive shaft with integrated first eccentric, the sliding block guide with slot, and the first sliding bush as a separate intermediate element. This segmentation allows each component to be manufactured with relaxed tolerances while the assembled mechanism maintains low vibration and noise through the geometric relationship of the components rather than relying on tight machining tolerances of individual parts.
Solution Approach 2:
The first sliding bush acts as an intermediary element between the first eccentric and the first sliding block guide. It facilitates the conversion of orbital motion to rectilinear motion while accommodating manufacturing variations. The sliding bush absorbs tolerances and ensures smooth operation, reducing vibration and noise without requiring extremely precise manufacturing of the adjacent components.
3Device complexity
If non-rectilinear movement is allowed for the pistons, then the drive assembly has fewer components, but wear on piston and cylinder increases
Solution Approach 1:
The first sliding bush serves as a mediator that guides the first eccentric's orbital motion and converts it to rectilinear motion of the first sliding block guide. This ensures the first primary stage piston moves in a straight line, reducing wear on the piston and cylinder while maintaining a relatively simple drive assembly structure with integrated components.
Solution Approach 2:
The first eccentric is designed with a specific geometric profile that converts rotational orbital motion into linear reciprocating motion. The curved surface of the eccentric working in conjunction with the slot geometry of the sliding block guide ensures rectilinear piston movement, minimizing wear while maintaining mechanical simplicity.
4Device complexity
If the piston movement is not fixed to a rotational axis, then the drive assembly is simpler, but irregular wear on piston seals occurs
Solution Approach 1:
The first sliding bush serves as a mediator that guides the first eccentric's orbital motion and converts it to rectilinear motion of the first sliding block guide. This ensures the first primary stage piston moves in a straight line, reducing wear on the piston and cylinder while maintaining a relatively simple drive assembly structure with integrated components.
Solution Approach 2:
The first eccentric is designed with a specific geometric profile that converts rotational orbital motion into linear reciprocating motion. The curved surface of the eccentric working in conjunction with the slot geometry of the sliding block guide ensures rectilinear piston movement, minimizing wear while maintaining mechanical simplicity.
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 reduces manufacturing costs, improves wear characteristics, and lowers noise emissions while maintaining stable operation.
Implementation Method 1
The sliding bush allows for minimum friction between the first sliding block guide and the first sliding bush and/or between the first sliding bush and the first eccentric
Implementation Method 2
A first sliding bush is arranged between the fist eccentric and the first sliding block guide, such that an outer surface of said first sliding bush corresponds to said inner surface of the first sliding block guide
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a piston type pump (1), comprising a pump housing (2) having a pump inlet (4) and outlet (6) and a piston arrangement (8) connected to a drive shaft (10) comprising a first eccentric (20) driving the piston arrangement (8), wherein the piston arrangement (8) comprises a first primary stage piston (12) connected to a first sliding block guide (62), having a main axis (C1), a minor axis (C2) and an inner surface (114) and being slidably seated on the first eccentric (20). According to the invention, a wear reduction member is arranged between the first eccentric (20) and the first sliding block guide (62), such that movement of said wear reduction member relative to said first sliding block guide (62) is allowed along the main axis (C1) and restricted along the minor axis (C2). The invention further relates to a vehicle.