Machine room-less elevators, usually known as MRL, are either hydraulic or traction elevators that do not require a machine space for the elevator. Let's explore the brief information regarding this below: Types Of Machine Room Fewer Elevators
1. Traction elevators Machine room less elevators do not possess a fixed machine room above the hoistway; instead, the traction hoisting machine is lodged either on the bottom of the hoistway or the top sidewall of the hoistway. The electric motor is installed utilizing a permanent magnet that sticks the motor indelibly and operates with VVVF (Variable Voltage Variable Frequency) drive. Some of the hoisting machines are utilizing gearless coincide motors instead of traditional induction motors. This structure removes the requirement of a fixed machine room and further saves more building space. Overall, all the MRL traction elevators are gearless traction. Though the hoisting motor is lodged on the hoistway sidewall, the central controller is installed on the top floor following the landing doors. This controller is located behind a locked cabinet which has to be unbolted utilizing a key for repair, maintenance, or emergency purposes. Most elevators have their controllers lodged on the top floor, but only the lesser elevators have their controllers lodged on the bottom floor. Some elevators may have the hoisting motor placed below the elevator shaft put; thus, it is known as the bottom drive MRL elevator. Some elevators have the controller cabinet longed within the door frame rather than on the wall to save space. Like standard traction elevators, machine room less elevators use traditional steel cord ropes as hoisting cables. Therefore, some elevator brands use flat steel rope belts instead of conventional ropes. It is stated by the manufactures using this technology said that using flat steel belt ropes ultimately saves more space in the hoistway and enables a minimum size of the hoisting sheave. However, the flat steel belts also permit 30 percent lighter compared to the traditional steel ropes. Most mid-rise buildings use the MRL elevators as the mid-rise buildings cater up to 20 floors. 2. Hydraulic elevators Like the traction version, machine room less hydraulic elevators do not possess a fixed space to store the hydraulic machinery. The machinery, which consists of a pump, is installed on the elevator pit. The controller is placed on a wall close by the elevator and generally on the bottom floor. The merit of machine room less hydraulic elevators saves the construction space, cost, and time. How Do MRL Elevators Work Machine room less elevators use a gearless traction machine placed in the hoistway. The utilization of a counterweight helps the Machine turn the elevator sheave, which moves the cab from the hoistway. It is generally seen in apartments, mixed-use buildings, commercial offices, hotels, MRL elevators exclusively can withstand upto 2-25 stops (with a standard capacity of 2100 to 5000 lbs) and feature feasible design. And massive capacities (4000 lbs and above that) can lodge heavier can finishes. MRL Advanced Features Ultra-modern door controls: Variable Voltage Variable Frequency (VVVF) inverter control ensures quiet, smooth door operation. It enhances the product reliability and passenger's safety. This advanced door operation system utilizes a one-chip RISC microcomputer to recognize differences in the door load, the firmness of the debris in the sill grooves, and the firmness of the wind. It adjusts the door closing and opening speeds and the door motor torque at every floor utilizing the auto-tuning function. Additionally, the door system is structurally secluded to the car frame instead of mounted straightforwardly to the car top. Thereby, it reduces the vibration and noise transmission from the elevator cab. Extra architectural freedom: Builders, interior designers, and architects will admire the architectural freedom that a machine room less elevator system offers. Now, all the machinery successfully into the hoistway; in this case, an overhead elevator machine room is no longer required. Exceptionally, the control panel has to be located within a 100foot distance from the gearless traction machine. Also, a traditional machine room elevator appertains load stress in a building's construction, but comparatively, guide rails withstand as much as 75 percent of the load for additional building affability. Effective use of power: When machine room less elevators move down with a light carload (regenerative operation) or heavy carload, the gearless traction machine performs as a power generator. Though the power produced during machine traction operation is typically dissolute as heat, the regenerative converter transfers the power back to the distribution transformer and next to the electrical network in the building with electricity through the power supply. This system offers an energy-saving impact of up to 35 percent. Machine room detached for space-saving: The traction machine's condensation, which leads to the development of the gearless traction machine and the PM motor, allows a hoistway to contain driving instruments typically installed in a machine room. Furthermore, the space of the hoistway is almost precisely like our standard elevator for extra space-saving. So the only thing you have to think about is hoistway in your planning. The benefit of machine room less elevators:
Disadvantages:
Conclusion: Comprehensive information and benefits of using the machine room less elevators (MRL) are explained in the above post. It can be understood from the above information that it does not possess a different space for housing the elevator's motor. Instead, an exclusively constructed motor is logged directly in the hoistway at the bottom or top of the shaft. Therefore, the lift may be a hydraulic or traction machine though a machine room less elevator appears as a regular elevator in multiple ways.
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With the day-to-day updating technology, there are multiple and new types of elevators that keep emerging. Though the most common ones are gearless elevator machine manufacturers producing gearless and the other popular one is geared elevators. Therefore, some main comparisons need to be made while concluding the decision.21n this article, some crucial comparisons about these two types are explained, helping you make your desired choice. The Standing Of The Wheel
Both gearless and geared elevators are traction elevators. The most typical ones on which the support of rolling steel ropes the cabins are pulled up a pass over a wheel attached to a motor on top of the elevator shaft. The standing of the wheel is the main difference among both the elevators. In the gearless traction elevators, the wheels are above the cabin and moves with the cabin. On the geared traction elevators, the wheels are located in the machine room above the elevator shaft. The Requirement For The Machine Room One of the critical differences between the gearless and geared elevator is the machine room. There is no need for the machine in the gearless elevators as the wheel is directly attached to the cabin and the motor. But in the geared elevators, electric motor and wheel have to be placed in a machine room located on top of the elevator shaft. It is why gearless elevators are also known as MRL (Machine Room Less) elevators. Machine rooms are typically located on top of the elevator shaft and must be considered during the construction of the building. The machine room is required to be air-conditioned and well-lightened. In addition, the machine rooms have a significant size and need to the planned adequately at the architectural design of the building. So machine rooms can be termed as a waste of place and a massive demerit of geared elevators. Energy Consumption Gearless elevator machine manufacturers produced a comparatively smaller motor than geared elevator motors because they do not have gears, making the gearless motors shape smaller up to half of a geared motor. Furthermore, as the size of the motor is smaller, the other remaining components will also be relatively smaller, making resolve the efficiency issue and making the gearless motors more advantageous. Also, it makes the gearless motor more systematic on electricity usage. Comfort Comfort is another benefit that the gearless elevators possess compared to the geared ones during the decelerating, moving, and accelerating. Gearless traction elevators have a significant ability to level with the floors. In addition, gearless motors generate less noise, smoother on stopping and moving, and make lesser vibrations on the cabin while in motion. Automatically, it makes gearless elevators more comfortable compared to geared traction elevators. Capacity Issues Gearless traction elevators can speed upto 610 meters per minute with a maximum 600 meters travel distance. In contrast, geared traction elevators can travel up to 152 meters per minute speed and a maxi of nearly 75 meters height. Both the geared and gearless elevator machine manufactures are built to load the same efficient enough for passenger travel. Although the necessities may vary depending on the projects, it is evident that gearless elevators have more merits than geared ones about travel distance and speed capabilities. Maintenance In the case of both motors, maintenance is the main issue. However, geared traction elevators have more significant engines than gearless ones, which demand more prominent combined equipment making the maintenance harder. Also, the geared motors demand grease, which must be changed regularly, making the maintenance more expensive and more challenging. Because of the maintenance issues, gearless traction elevators top the most with their ideal advantages ( the instruments are small, and there is no oil usage in gearless ones), which the geared elevators lack. The unique quality of both elevators: Geared traction elevators These geared traction elevators have a gearbox attached to the motor, turns the hoisting sheave, and moves the rope. The geared traction elevators are driven either by alternating current (AC) or direct current (DC), and their max speed is up to 500 ft. per minute. The speed limit of this is comparatively lower compared to gearless traction elevators but higher than other types of elevators. Geared traction elevators have low energy consumption and proper maintenance and installation costs. While their speed is slower than gearless elevators, geared elevators offer benefits of energy efficiency as they consume less power to turn the sheave (pulley). Furthermore, these elevators are competent for traveling to a maximum distance of 250 ft. However, these elevators can lift loads upto 13600 kg. Gearless Traction Elevators The gearless elevators machine manufactures has built it where the wheels are directly attached to the motor. As a result, it has a considerably high travel speed that is upto 2000 ft. per minute and can travel significant distances making it an optimal choice for high-rise buildings. These elevators can be employed in all types of buildings of any height and a much greater speed than any other hydraulic motors. These elevators operate using hoisting ropes that are attached to the elevator above and packed around the sheave on one end. The other end of the cable is joined with a balance that lowers and arises in the hoistway. Together, the counterweight and cab weight press the cable, turning the sheave, and the elevator starts moving. The counterweight is matched with the elevator cab weight and half-load of the passengers to maintain the minimum load on the electric motor. Therefore it ultimately minimizes the energy consumption as the electric motor only bears the half cab weight load. Conclusion: With the above-discussed comparisons, it is proven that gearless elevator machine manufacturers produce the most advantageous traction elevator than the geared ones. But the real issues come with the money and needs. No doubt, gearless elevator motors are more expensive compared to geared ones. Therefore, when the geared elevators are estimated for the calculated requirements, it would be ideal to select geared elevator motors to save expenses and compatible with the projected budget. So, at last, money is the thing that matters in our decisions. |