Electromagnetic Wrap Spring Clutch for A/C Compressor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air conditioning compressor clutches, particularly friction clutches, are inefficient in terms of energy usage and unable to handle high torque loads effectively, necessitating a more energy-efficient and durable alternative.
Innovation Solution
A rotary clutch system incorporating a pulley, hub, wrap spring clutch, carrier, and actuator with an electromagnet and armature plate, where the electromagnet generates a magnetic field to engage helical coils for torque transfer, reducing power consumption while maintaining high torque handling capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a friction clutch is used for the A/C compressor, then the clutch can handle high torque loads and provide reliable engagement, but the power consumption is high and energy efficiency is poor
Solution Approach 1:
The patent replaces the traditional friction-based mechanical clutch system with an electromagnetic clutch system. The electromagnetic clutch uses magnetic fields generated by an electromagnet to engage and disengage the clutch, eliminating the need for friction surfaces. This substitution dramatically reduces power consumption while maintaining the ability to handle high torque loads through magnetic attraction forces between the electromagnet and armature plate.
Solution Approach 2:
The patent changes the fundamental operating parameter of the clutch from friction-based mechanical contact to magnetic field-based engagement. By using electromagnetic fields instead of friction, the system achieves lower power consumption during both engagement and maintenance of the engaged state, while the magnetic force provides sufficient torque handling capability for A/C compressor applications.
2Device complexity
If a wrap spring clutch is used as an alternative to friction clutch, then the structure may be simpler, but the clutch cannot handle the high forces required of an A/C clutch and is not sufficiently efficient
Solution Approach 1:
The patent replaces the mechanical spring-based wrap clutch system with an electromagnetic clutch system. Instead of relying on spring tension and friction surfaces, the electromagnetic clutch uses magnetic fields to provide the necessary engagement force. This substitution enables the clutch to handle the high forces required by A/C compressors while maintaining a relatively simple structure with fewer moving parts.
3Volume of moving object
If an electromagnetic clutch is designed with a small pulley diameter of 85 mm, then the space requirement is reduced and efficiency is improved, but the clutch must still generate sufficient magnetic field strength to engage the armature plate reliably
Solution Approach 1:
The patent optimizes the electromagnetic clutch parameters to achieve reliable engagement with a compact 85 mm pulley diameter. This involves carefully selecting the electromagnet coil specifications, magnetic circuit geometry, and air gap dimensions to generate sufficient magnetic field strength within the constrained space. The design balances the reduced volume with the required power output by optimizing the magnetic circuit efficiency and using high-permeability magnetic materials.
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 rotary clutch system uses significantly less power than traditional friction clutches, efficiently handling engine accessory drive and high inertia loads, with the ability to operate with a 85 mm pulley diameter requiring less than 15 Watts to engage, offering improved efficiency and durability.
Implementation Method 1
Activating the electromagnet generates a magnetic field that urges the armature plate to the engaged position
Implementation Method 2
The rotation of the armature plate causes the helical coils to expand into gripping engagement with the torque transfer surface
Data Source
AI summary
An automotive air conditioning assembly including a scroll compressor and a wrap spring clutch. The wrap spring clutch enables the use of a comparatively smaller pulley (a diameter of at most 85 mm) which comparatively increases the compressor speed and hence cooling capacity at a given engine speed. The clutch requires low power (e.g. less than 5 Watts) for continuous operation.