Rodless Hydraulic Cylinder for Dynamic Exercise Resistance
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Solution Overview
Problem
Conventional hydraulic exercise machines using cylinders are limited by high friction, rigidity, and velocity sensitivity, making them unsuitable for dynamic and quick response training needed for athletic success or rehabilitation, as they primarily offer passive resistance and are restrictive in speed and direction.
Innovation Solution
A low friction hydraulic cylinder system with a rodless design, coupled to a cable and pulley system, utilizing water flow velocity to generate controllable forces, featuring a water control spool valve and controllable pressure relief valve to regulate movement speed and force, allowing for high acceleration/speed and low force resistance, or low acceleration/speed and high force resistance exercises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional hydraulic cylinders use restrictive orifices to generate exercise forces, then exercise forces are generated, but velocity sensitivity increases and speed range is limited
Solution Approach 1:
The patent employs a rodless hydraulic cylinder design where the piston is directly coupled to the rod without traditional seals, allowing the system to dynamically adapt to varying speeds and forces. The hydraulic circuit includes variable orifices and flow control valves that can be adjusted in real-time to maintain optimal performance across different velocity ranges, resolving the contradiction between force generation and speed range limitation.
Solution Approach 2:
The system allows dynamic changing of hydraulic parameters including orifice size, flow rate, and pressure to optimize performance for different exercise requirements. By varying these parameters, the system can provide high force at low speeds or high speed with reduced force resistance, eliminating the fixed velocity sensitivity of conventional cylinders with restrictive orifices.
2Reliability
If traditional passive exercise cylinders use multiple hydraulic shaft and piston seals, then structural integrity is maintained, but friction forces increase and quick response ability is reduced
Solution Approach 1:
The patent extracts and removes the traditional sealed piston and shaft seal assembly from the hydraulic cylinder, replacing it with a rodless design where the piston is directly coupled to the rod. This elimination of multiple seals dramatically reduces friction forces while maintaining structural integrity through alternative sealing arrangements at the cylinder ends, enabling quick response training and high-speed exercise movements.
3Force
If conventional hydraulic cylinders impose higher forces as velocity increases, then resistance is provided, but athletic quickness and agility training is penalized
Solution Approach 1:
The system dynamically adjusts the relationship between force and velocity through variable flow control and pressure regulation mechanisms. Unlike conventional cylinders that passively increase force with velocity, this system can be programmed to provide constant force, constant power, or customized force-velocity profiles that specifically target athletic quickness and agility development while maintaining appropriate resistance levels.
4Stability of the object's composition
If hydraulic cylinders generate substantial friction forces from seals, then structural stability is maintained, but kinetic inertia and impact are excessive for safe training
Solution Approach 1:
The patent converts the potential harm of excessive kinetic inertia and impact into a benefit by using the rodless hydraulic design to create a more compliant, controllable system. The reduced friction from eliminating seals allows for smoother acceleration and deceleration, while the hydraulic system's inherent compressibility and controllable resistance provide natural cushioning, transforming what could be dangerous inertial forces into controlled, safe training loads.
Data Source
AI summary
The invention is a hydraulic cylinder for use in exercise machines to deliver a controllable fast acting force. The invention uses a hydraulic cylinder with features that allow high acceleration rates, rapid changes of force level and direction, and positive force limitation. In the preferred embodiment, the hydraulic cylinder is composed of a rodless, hydraulic cylinder coupled to a cable and pulley system. A water source delivers water to generate a force against an inner bi-directionally moving piston to generate a regulated movement and force.The ends of the rodless hydraulic cylinder are sealed by both a water control spool valve and a controllable poppet style pressure relief valve. The water control spool valves adjustably permits water to enter and exit the hydraulic cylinder to regulate the direction and speed of movement of the piston. The pressure relief valve controls the desired maximum pressure and corresponding forces exerted on cylinder. Thus, both the internal speed and force of movement of the piston can be controlled. The invention can deliver high acceleration/speed, high force resistance; high acceleration/speed, low force resistance; low acceleration/speed, high force resistance; or low acceleration/speed, low force resistance exercise forces and movements depending on the water flow, internal pressure, and resulting generated forces.