Hydraulic Return-Line Jet Pump for Oil Venting in Loading Vehicles
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Solution Overview
Problem
Existing hydraulic systems in loading vehicles and other mobile work machines face issues with air or gas entrainment in hydraulic fluid, leading to cavitation, noise, heat buildup, and reduced component life, and current solutions for oil venting are structurally complex and costly.
Innovation Solution
A hydraulic system with a jet pump integrated into the return line between the hydraulic motor arrangement and reservoir, using negative pressure to effectively vent hydraulic fluid, independent of the motor's direction of rotation, and incorporating a check valve and inclined outlet pipe for efficient air separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a suction device is integrated into the hydraulic motor assembly to extract hydraulic fluid, then effective oil venting is achieved, but structural complexity and cost increase
Solution Approach 1:
The suction device is extracted from the hydraulic motor assembly and integrated into the return line instead. This separates the venting function from the motor assembly, reducing its structural complexity while maintaining effective oil extraction through the jet pump mechanism in the return line.
Solution Approach 2:
The jet pump acts as an intermediary device in the return line, using the hydraulic fluid flow itself to create vacuum pressure for extraction. This eliminates the need for a separate power source or complex mechanical suction device within the motor assembly, reducing complexity while maintaining effectiveness.
2Reliability
If the hydraulic system is completely filled with hydraulic fluid to prevent foaming, then cavitation is prevented, but air venting capability is reduced
Solution Approach 1:
The system maintains complete filling to prevent cavitation during normal operation, but the jet pump suction device is pre-positioned in the return line to actively extract air bubbles as they form. This preliminary extraction action allows the system to maintain full fluid filling while still providing air venting capability.
Solution Approach 2:
The jet pump creates a continuous vacuum effect in the return line, providing feedback control for air bubble extraction. As air bubbles form in the hydraulic fluid, the vacuum pressure actively draws them out, allowing the system to maintain complete filling for cavitation prevention while adapting to vent air when needed.
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 provides a simple, space-saving, and efficient oil suction system that adapts to any driving situation, effectively separating air bubbles from hydraulic fluid, enhancing system performance and reducing maintenance costs.
Implementation Method 1
the suction device draws hydraulic fluid from the hydraulic motor arrangement into the hydraulic fluid accumulator by means of a vacuum (Δp)
Implementation Method 2
the outlet pipe is arranged at a vertical angle within the hydraulic fluid reservoir
Data Source
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AI summary
The invention relates to a device for venting hydraulic fluid from a hydraulic system (58), wherein the hydraulic system (58) comprises at least one hydraulic motor assembly (30) and a hydraulic fluid accumulator (41) hydraulically coupled to this hydraulic motor assembly (30), and wherein a suction device (39) for suctioning the hydraulic fluid (52) is assigned to the at least one hydraulic motor assembly (30) in such a way that the suction device (39) draws hydraulic fluid (52) from the hydraulic motor assembly (30) into the hydraulic fluid accumulator (41) by means of a vacuum (Δp), wherein the suction device (39) is designed as a jet pump (42) and is integrated into the return line (54) between the hydraulic motor assembly (30) and the hydraulic fluid accumulator (41).