Vacuum Pump Clutch Assembly for On-Demand Vehicle Vacuum
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Solution Overview
Problem
Existing mechanical clutches for vacuum pumps are inefficient in terms of energy consumption and require electronic controls for demand-based operation, leading to increased costs and energy losses.
Innovation Solution
A clutched vacuum pump assembly that uses a wrap spring clutch and vacuum actuator to automatically activate and deactivate the vacuum pump based on vacuum conduit pressure, eliminating the need for electronic controls by connecting and disconnecting the camshaft and rotor using a wrap spring clutch and vacuum actuator, which is biased to the engaged position and controlled by a brake mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electrical pumps are used to implement demand-based vacuum generation, then the ability to switch vacuum pump on/off based on demand is achieved, but the system becomes more costly and suffers energy losses during mechanical-electrical-mechanical power conversion
Solution Approach 1:
The patent replaces electrical pumps and electronic controls with a mechanically operated clutch system. The clutch is engaged or disengaged by vacuum pressure differential acting on a diaphragm, which mechanically connects or disconnects the vacuum pump from the camshaft. This eliminates electrical power conversion losses and provides demand-based operation through pure mechanical means.
2Adaptability or versatility
If mechanical clutches with electronic controls are used for demand-based operation, then the vacuum pump can be switched on/off based on demand, but electronic controls and sensors increase device complexity and cost
Solution Approach 1:
The clutch system is self-regulating through vacuum pressure feedback. The diaphragm responds automatically to vacuum pressure differential, engaging or disengaging the clutch without external electronic control. The system serves itself by using the vacuum pressure it generates to control its own operation, eliminating the need for sensors, controllers, and electronic wiring.
Solution Approach 2:
The vacuum pressure differential acts as an intermediary between the vacuum pump output and the clutch control mechanism. Instead of using electronic sensors to detect vacuum levels, the system uses the vacuum pressure itself to directly actuate the clutch through the diaphragm, creating a direct mechanical feedback loop.
3Reliability
If the vacuum pump operates continuously to ensure continuous vacuum supply, then vacuum availability is maximized, but energy consumption increases
Solution Approach 1:
The clutch system dynamically adjusts the vacuum pump operation based on real-time vacuum demand. The clutch engages when vacuum pressure drops below a threshold and disengages when sufficient vacuum is achieved, creating an on-demand operation mode that reduces energy consumption while maintaining adequate vacuum supply through mechanical responsiveness to pressure differential.
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 solution reduces energy consumption by only generating vacuum when needed, automatically activating and deactivating the pump based on pressure, and ensures continuous vacuum supply even in failures, with optional features like torque limiting and oil flow control to enhance efficiency and reliability.
Implementation Method 1
a wrap spring clutch (24) operatively connecting the camshaft (14) to the rotor (28)
Implementation Method 2
a vacuum actuator (26) biased to the engaged position and controlled by a brake mechanism
Data Source
Figure 1
Figure 2
Figure 3~3A
AI summary
In an aspect a system is provided for generating vacuum in a vehicle. The system includes a vacuum pump, an engagement clutch, an actuator, and a torque limiting clutch. The e engagement clutch operatively connects a camshaft to the rotor. The actuator controls the clutch. The actuator is movable, based on air pressure in a vacuum conduit, between a low-pressure position in which the actuator causes the clutch to operatively disconnect the camshaft from the rotor, and a high-pressure position in which the actuator causes the clutch to operatively connect the camshaft to the rotor. The torque limiting clutch limits torque transfer to the rotor when the engagement clutch operatively connects the camshaft to the rotor. The system also provides control hysteresis.