Three-Position Power Cylinder With Rod-Bushing Alignment
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Solution Overview
Problem
Existing three-position pneumatic and hydraulic cylinders face issues with large dimensions, inability to implement additional rod outlets, and alignment problems due to complex designs and increased energy requirements for neutral position, leading to potential rod run-out and reduced operational reliability.
Innovation Solution
A three-position pneumatic or hydraulic cylinder design featuring a housing with two pistons and a rod, where the rod has peripheral and central protuberances forming a hermetic coupling with an annular protuberance, allowing for simplified movement and fluid supply channels that communicate with each chamber, enabling efficient and accurate positioning without the need for additional end caps or complex sealing systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional upper end cap is used to ensure rod alignment, then rod alignment is improved, but device dimensions, weight and material consumption increase
Solution Approach 1:
The invention extracts the alignment function from the traditional end cap structure and transfers it to the rod-bushing interface. The bushing is directly attached to the rod and provides alignment through its fit with the rod, eliminating the need for a separate upper end cap dedicated to alignment purposes.
Solution Approach 2:
The invention merges the alignment function with the rod-bushing connection structure. The bushing serves dual purposes: guiding the rod and providing structural support, thereby combining multiple functions into a single integrated component rather than using separate parts.
2Device complexity
If the end surface of the protuberance on the rod acts as a piston, then sealing is simplified, but additional energy (pressure) is required to set the rod to medium or neutral position
Solution Approach 1:
The invention introduces a dedicated stop element as an intermediary component between the rod and the chamber. This stop element provides a defined stopping surface that prevents the rod from overshooting the neutral position, eliminating the need for the rod's protuberance end surface to act as a piston and reducing the energy required for positioning.
3Productivity
If the potential pressure difference causes rod run-out beyond the middle position, then positioning accuracy is reduced, but device operation may be interrupted
Solution Approach 1:
The invention applies preliminary anti-action by positioning stop elements in advance to prevent rod run-out beyond the middle position. These stop elements are pre-positioned to counteract the potential pressure differences that would cause overshooting, thereby maintaining positioning accuracy and preventing operational interruptions.
4Reliability
If piston fitting dimensions are increased to ensure rod alignment, then alignment reliability is improved, but device dimensions and manufacturing complexity increase
Solution Approach 1:
The invention extracts the alignment function from the piston fitting dimensions and relocates it to the rod-bushing interface. By making the rod the primary alignment element through its fit with the bushing, the design avoids increasing piston dimensions while maintaining alignment 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
The design simplifies manufacturing, reduces energy requirements, enhances alignment reliability, and maintains consistent driving force across all positions, ensuring uninterrupted operation and improved accuracy and speed.
Implementation Method 1
The central protuberance is configured in a form of a cylindrical bushing, and sleeved in the annular protuberance to form, with the annular protuberance, a hermetic moveable coupling of the shaft/opening type
Implementation Method 2
A three-position pneumatic or hydraulic cylinder that consists of a housing two pistons, a rod, and working fluid supply channels
Implementation Method 3
A three-position pneumatic or hydraulic cylinder that consists of a housing two pistons, a rod, and working fluid supply channels
Data Source
AI summary
The invention relates to hydraulic cylinder devices and can be used in vehicle transmissions. A three-position pneumatic or hydraulic cylinder consists of a housing having end caps, two pistons, a rod, and supply channels for a working fluid, each piston being configured for limited movement along the rod as a result of a central protuberance, which separates the pistons, and peripheral protuberances on the rod, and being configured for limited movement inside the housing. The central protuberance is configured in the form of a bushing, and an annular protuberance is configured on the inside surface of the housing. Said bushing and said protuberance form a hermetic moveable coupling of the shaft/opening type. Separate channels are provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing; or, separate channels are provided for supplying working fluid to the chambers formed by each piston and the central protuberance and bushing, and a shared channel is provided for supplying working fluid to the chambers formed by each piston and the corresponding end of the housing.