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Designed for Heavy Usage and Heavy Loads
MagneMotion’s engineering and LSM design expertise enables the development of LSM-based elevator systems that eliminate the need for counterweights, cables, and pulley systems, requiring less space due to the direct drive design. MagneMotion’s elevator designs are fast, safe, and efficient, bearing loads over 20 tons, and achieve higher efficiency and throughput than conventional systems. Applications include freight elevators; high-rise people-movers; industrial, residential, and commercial elevators; and weapons and aircraft elevators developed for the US Navy.
- Military Applications
MagneMotion has developed an advanced weapons elevator with Federal Equipment Co. and Northrop Grumman Newport News for the U.S. Navy's new class aircraft carrier, the CVN 78. MagneMotion’s Advanced Weapons Elevator (AWE) proof of concept developed for the U.S. Navy demonstrates a 12,000-pound lift capacity and represents one of four motors that will be used together to lift a maximum load of 48,000 pounds. Designed to move at 148 feet per minute, it accelerates to full speed in 2 seconds. Features include motor thermal protection, emergency braking, and our "smart control system" that estimates the payload weight. Its features are typical of all MagneMotion LSM-based Elevator Systems, and the elevator design serves as a proof of concept for industrial elevator applications. LSM-based vertical platform lifts can be used for heavy machinery, munitions, or as a part of a vertical storage system. Click here to see the video of the advanced weapons elevator demonstration system.
- Industrial Elevators
MagneMotion's experience with the AWE project proves that its LSM-based elevators can be deployed as freight elevators and vertical platform lifts for applications in all industrial environments. Single path or multiple path stators can be used to facilitate transport of the heaviest loads, from cargo containers to loaded lift trucks, passenger vehicles, or bulk inventory. MagneMotion’s industrial elevator systems can be integrated with automated storage and retrieval systems (AS/RS), and existing warehouse logistic systems to optimize the vertical transport and overall material handling process. As an example, LSM-based vertical lifts can be designed for transporting vehicles to meet the needs of automated parking garages.
- Passenger / High-Rise Elevators
MagneMotion’s LSM Elevator technology serves as a cost-effective alternative to hydraulic or cable high-rise elevators. The stators used in the elevator shaft take up less space and are more reliable than either system. Maintenance requirements for LSM-based elevators are minimal due to the lack of moving parts and greatly reduced need for hydraulic maintenance or cable and counterweight space. Perhaps most important, LSM Elevators can have multiple cars in a shaft, thereby reducing the number of shafts in a building, and creating more rentable space.
Click the image below to see the video of the advanced weapons elevator demonstration system.
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MagneMotion uses a simple elevator design based on its Linear Synchronous Motor (LSM) technology. This primary LSM stator is mounted between steel rails that support guidance wheels and mechanical brakes. Current in the stator windings create a magnetic field which can move relative to the stator when powered by a microprocessor-controlled inverter. The field moves in synch with permanent magnets mounted on the elevator platform and produces a controllable thrust and speed based on precise knowledge of position and commands from a central control.
LSM propulsion allows for a dual-cab elevator with horizontal switching without sacrificing the simple elevator design. The cabs are propelled by one or more magnet array(s) mounted on the side(s) of each cab. A pair of steel rails is used by wheels to control motion and by mechanical brakes to hold the cab when stopped. The attractive force of the permanent magnets is more than enough to hold the suspension wheels against the steel rails and catch rails prevent any cab from falling. With MagneMotion’s propulsion system the cabs move independently, including the ability to occupy any pair of adjacent floors at the same time so virtually any scheduling algorithm could be used.
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For high-rise buildings with elevator speeds over 10 m/s (22 mph) the motor efficiency is over 85 percent and energy generated by a descending elevator can be used by an ascending elevator, stored in a battery, or returned to the mains. When there is more than one hoistway on the central controller, one can schedule movement to enhance the probability that regenerated power from a descending cab can be used to power an ascending cab, thereby mitigating much of the penalty of not using counterweights. Modern batteries used for hybrid automobiles offer the possibility of even greater smoothing of power requirements while simultaneously providing backup power in case of a utility power loss.
LSM propulsion systems are less costly when the cabs are operated at relatively high speeds because the stator duty cycle is low. The world’s tallest building (Tapei 101) has two elevators operating at 17 m/s, an amazing feat for a cable hoist system, but one that would be much easier with LSM propulsion.
The most important future role for LSM elevator propulsion is for designs that use horizontal switching between adjacent hoistways. This allows scheduling to be similar to those used by Automated People Movers (APM). The control options are almost unlimited, but very likely would involve switching at intermediate levels and several cabs for each hoistway. MagneMotion has constructed LSM propelled transport systems for horizontal travel and has perfected a magnetic switch allowing path change without the need for any mechanical motion of components on the guideway. This same idea can be implemented for commercial elevators, residential elevators, industrial elevators, and vertical storage systems while still providing the high level of safety which has been a hallmark of the elevator industry. With horizontal switching, the capacity of each hoistway can be increased by a significant factor with minimal added cost for the switching system.
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Brakes that prevent the platform from falling in an uncontrolled manner are the most important safety feature for an LSM elevator system. In order to achieve a high level of safety we have used redundancy and conservative design.
When the cab is stationary it is supported by mechanical brakes. When the cab is moving there are two independent brake mechanisms: As long as there is power available, the LSM can provide all required braking; When a platform stops, electrically operated wedge brakes on the platform act on the guide rails. Springs cause the brakes to engage when power is not applied. Solenoids are used to hold back the springs when the brakes are to be disengaged. In this manner, the brakes are “fail-safe” under power-loss conditions (the brakes engage in the event of power loss). These brakes are "self-energizing," which means that once they start to grip the stator rails, the braking force that they apply to the vehicle causes this grip to tighten, further increasing the brake force.
The brakes are designed so that the vehicle may be lifted a very short distance while the brakes are engaged. This feature is used to measure the load on the platform and make sure that the elevator is not overloaded before releasing the brakes.
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| Click on the link below to access a pdf of Dick Thornton's article published in the September, 2006 issue of Elevator World.
Elevator World: LSM-Based Vertical Lift Solutions
September, 2006 (1,834 KB pdf)
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