Electric Hydraulic Floor Jack With Load-Adaptive Plunger Pump
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Solution Overview
Problem
Conventional hydraulic jacks face issues with slow lifting speeds due to manual operation, high labor intensity, or complex and costly structures, and fail to achieve efficient lifting under varying load conditions.
Innovation Solution
An electric hydraulic floor jack with a variable plunger structure that automatically adjusts lifting speed based on load conditions, using a motor-driven speed reducer and eccentric wheel to control oil flow, combined with a spring mechanism for efficient oil pumping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a gear pump structure is used in the electric pump, then more oil is output, but the maximum output pressure is low, causing the jack not operable at high pressure
Solution Approach 1:
The patent employs a variable displacement pump mechanism where the plunger diameter can be dynamically adjusted based on operating conditions. This allows the pump to switch between large-diameter plungers for high flow at low pressure and small-diameter plungers for low flow at high pressure, resolving the contradiction between oil output quantity and maximum output pressure capability
Solution Approach 2:
The invention changes the physical parameter of plunger diameter to adapt to different operating requirements. By providing multiple plungers with different diameters and selecting the appropriate plunger based on load conditions, the system achieves both high oil output when needed and high pressure capability when required
2Stress or pressure
If a single-diameter plunger structure is used in the electric pump, then high output pressure is achieved, but less oil is output, such that the jack cannot realize fast lifting at low pressure
Solution Approach 1:
The variable displacement pump mechanism allows dynamic adjustment of plunger diameter based on real-time operating conditions. When low pressure and fast lifting are required, a larger diameter plunger is selected to increase oil flow rate. When high pressure is needed, a smaller diameter plunger is used, resolving the contradiction between pressure output and lifting speed
3Productivity
If a plurality of single-diameter plunger structures are combined to achieve faster lifting speed at low pressure, then lifting speed is improved, but cost increases, structure becomes complicated, and reliability deteriorates
Solution Approach 1:
Instead of combining multiple complete pump units, the invention segments the pumping function into multiple plungers of different diameters within a single pump body. Only one plunger is active at a time, selected based on operating conditions. This achieves variable displacement functionality without the complexity and reliability issues of combining multiple pump units
4Productivity
If two or more pump bodies and pump core structures are provided in the manual pump to accelerate lifting speed with no load, then lifting speed with no load is improved, but operation becomes troublesome, cost increases, size increases, and labor intensity is not reduced
Solution Approach 1:
The electric pump with variable displacement capability automatically selects the appropriate plunger diameter based on load conditions without requiring manual intervention. The system self-adjusts between high-speed low-pressure mode and low-speed high-pressure mode, eliminating the need for operators to manually switch between different pump configurations while maintaining optimal performance across all operating conditions
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 electric hydraulic floor jack achieves fast lifting speeds in no load conditions and stable lifting in heavy loads with reduced labor intensity, featuring a simple structure and low cost.
Implementation Method 1
a motor connected to the speed reducer
Implementation Method 2
an eccentric wheel provided on an output shaft of the speed reducer
Implementation Method 3
a spring provided in the piston hole and sleeved on the valve trim
Implementation Method 4
an oil chamber formed between the housing and the cylinder; an oil inlet passage and an oil return passage that communicate with the cylinder
Data Source
AI summary
An electric hydraulic floor jack includes a variable plunger structure provided on a motor base and an oil pump base. The variable plunger structure includes a piston hole formed in the oil pump base and communicating with an oil chamber and an oil inlet passage, a plunger sleeve provided at a port of the piston hole, a plunger slidably provided in the plunger sleeve, a U-shaped piston slidably provided in the piston hole, a valve trim slidably provided on the piston, a spring provided in the piston hole and sleeved on the valve trim, and an eccentric wheel provided on an output shaft of a speed reducer. The plunger is driven by the eccentric wheel in cooperation with the spring to continuously make a linear reciprocating motion, thereby continuously opening and closing the check valve, and pumping oil into the cylinder to push the piston rod for lifting work.