Stepper Motor Vent Valve for High Pressure Lubrication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric vent valves in lubrication systems face challenges in maintaining high pressure closure due to high lubricant pressures, leading to rapid erosion and clogging, especially with high viscosity greases, and are inefficient in the bleed-off phase, particularly in cold climates.
Innovation Solution
A vent valve design featuring a motor-driven closure element with a threaded engagement, allowing for precise control between open and closed positions, using a stepper motor and large orifices to manage high pressures and prevent clogging, with a control system to manage the valve's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a solenoid is used to maintain the spool in the closed position against high pressure, then the valve can maintain closure, but the solenoid requires excessive force that is difficult to achieve with typical low voltage power supplies
Solution Approach 1:
The patent replaces the solenoid (electromagnetic actuator) with a stepper motor-driven lead screw mechanism. The stepper motor converts rotational motion into linear motion of the spool through the lead screw, providing precise positional control with reduced force requirements compared to the solenoid that must continuously counteract high pressure.
Solution Approach 2:
The system transitions from a static holding force requirement (solenoid must continuously maintain closed position against pressure) to a dynamic positioning system (stepper motor moves spool to desired position and holds it through positional control). This reduces the continuous force requirement to intermittent motor torque during positioning and lower holding torque at the positioned state.
2Length of moving object
If the valve orifices are made relatively small to accommodate short solenoid stroke, then the valve can achieve closure, but the small orifices lead to rapid erosion of metal parts particularly when handling high pressure grease
Solution Approach 1:
The lead screw mechanism provides extended stroke capability compared to a solenoid, allowing the use of larger orifices in the valve body. The larger orifices reduce flow velocity and erosive forces on the valve components, significantly improving reliability when handling high pressure grease.
3Length of moving object
If the valve orifices are made relatively small, then the valve can achieve closure with short stroke actuator, but the small orifices restrict the flow of grease during the bleed off phase particularly in cold temperature climates
Solution Approach 1:
The stepper motor provides controllable, extended stroke capability that allows the valve to fully open for high-flow bleed-off operations. The larger orifices enabled by the extended stroke mechanism allow grease to flow freely during the bleed-off phase, even in cold temperatures where grease viscosity increases.
4Length of moving object
If the valve orifices are made relatively small, then the valve can achieve closure, but the small orifices subject the valve to clogging if even small amounts of contaminants are present in the grease
Solution Approach 1:
The lead screw mechanism enables larger orifice dimensions that are less susceptible to clogging by contaminants. The larger flow passages provide tolerance for particulate matter in the grease without blocking flow, significantly improving reliability in contaminated lubrication environments.
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 effectively maintains high pressure closure without requiring excessive torque, reduces wear and clogging, and ensures complete bleed-off even with high viscosity greases, enhancing the reliability and functionality of lubrication systems in various conditions.
Implementation Method 1
A closure element is disposed at least partially within the vent passage, has a threaded portion and is linearly displaceable between an open position... A motor has a shaft rotatable about a central axis, the shaft having a threaded portion threadedly engaged with the closure element threaded portion
Data Source
AI summary
A lubrication system vent valve includes a valve body having a flow passage with an inlet fluidly coupled with a supply and an outlet fluidly coupled with a dispenser, and a vent passage with an inlet port fluidly coupled with the flow passage and an outlet port. A closure element disposed within the vent passage has a threaded portion and is linearly displaceable between an open position where the vent ports are fluidly coupled to permit lubricant flow from the primary passage and out of the body through the vent outlet port, and a closed position at which fluid flow between the vent ports is substantially prevented. A motor has a shaft with a threaded portion engaged with the closure element such that shaft rotation in one direction displaces the closure element toward the closed position and shaft rotation in an opposing direction displaces the element toward the open position.