Selectable Flow Divider Drive System for Aerial Work Platforms
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aerial work platforms (AWPs) face inefficiencies in hydraulic drive systems due to flow dividers being sized for high flow conditions, leading to excessive leakage and reduced performance in low flow conditions, particularly affecting traction and power requirements.
Innovation Solution
A selectable flow divider drive system that automatically or manually bypasses flow dividers during high flow conditions, using a hydraulic pump operable in both high and low flow conditions, with a bypass valve and solenoid valve to optimize fluid distribution to drive motors, and includes a control system to adjust pump output based on operating parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If flow dividers are sized for high flow conditions, then maximum drive speed is achieved, but leakage increases and low flow performance deteriorates
Solution Approach 1:
The system dynamically switches between two flow divider configurations based on operating conditions. A bypass valve selectively connects or disconnects parallel flow paths, allowing the system to transition from a high-flow configuration (bypass open) to a low-flow configuration (bypass closed), optimizing performance for the current operating regime rather than being fixed for one condition
Solution Approach 2:
The flow divider is segmented into multiple parallel paths with different flow capacities. The main flow divider handles low flow conditions efficiently, while the bypass path provides an additional high-capacity route when needed for maximum speed, allowing the system to segment the flow management function across different structural elements
2Quantity of substance
If flow dividers are sized for high flow conditions, then high flow rate performance is improved, but low flow condition efficiency decreases
Solution Approach 1:
The system dynamically reconfigures the hydraulic circuit by opening or closing the bypass valve based on the required flow rate. During high flow conditions, the bypass valve opens to allow maximum flow through both the main divider and bypass path. During low flow conditions, the bypass valve closes, directing flow only through the properly-sized main flow divider, thereby optimizing efficiency for the current operating regime
3Speed
If bypass valve is always open, then high flow conditions are satisfied, but flow division is compromised during low flow conditions
Solution Approach 1:
The bypass valve dynamically changes its state based on operating conditions. During high-speed operation, the valve remains open to maximize flow capacity. During low-flow conditions requiring precise flow division for traction control, the valve closes to ensure all flow passes through the main flow divider's precision orifices, guaranteeing accurate flow distribution
4Power
If engine horsepower is reduced, then cost and heat generation are reduced, but available power decreases
Solution Approach 1:
The system changes the hydraulic circuit configuration parameter by switching the bypass valve state. This allows a smaller engine to deliver adequate power during low-flow conditions through efficient flow division, while still achieving maximum speed during high-flow conditions by opening the bypass, thereby reducing overall engine size requirements and associated heat generation
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 solution enhances efficiency and cost-effectiveness by reducing engine horsepower and heat generation, improving traction control, and extending oil life, while allowing for smaller engine and hydraulic tank sizes, and reducing manufacturing costs.
Implementation Method 1
A bypass valve is disposed upstream of the flow divider that selectively bypasses the flow divider when the hydraulic pump is operated in the high flow condition
Implementation Method 2
The flow divider component selectively divides hydraulic fluid flow to each of the plurality of drive motors, where a flow divider of the flow divider component is sized for the low flow condition of the hydraulic pump
Data Source
Figure 1
Figure 2
AI summary
A selectable flow divider drive system includes a hydraulic fluid reservoir and a plurality of drive motors in fluid communication with the hydraulic fluid reservoir, A hydraulic pump is connected between the hydraulic fluid reservoir and the plurality of drive motors and directs hydraulic fluid from the hydraulic fluid reservoir to the plurality of motors. The hydraulic pump is operable in a high flow condition and a low flow condition. A flow divider component is interposed between the hydraulic pump and the plurality of motors. The flow divider component selectively divides hydraulic fluid flow to each of the plurality of drive motors, where a flow divider of the flow divider component is sized for the low flow condition of the hydraulic pump. A bypass valve is disposed upstream of the flow divider that selectively bypasses the flow divider when the hydraulic pump is operated in the high flow condition.