Issue 6/2005
11/02/05
Spirit – The New MRL with Optimized Well Dimensions
Jochen Müller (ThyssenKrupp Aufzugswerke Germany)
For several years, passengers have already been comfortably transported by longestablished elevator systems without machine rooms. Planners and architects use the compact systems for more freedom and flexibility in designing buildings. And, thanks to the manifold economic advantages offered by an elevator without a machine room, the operators themselves get their money’s worth.
Category: Issue 6/2005
Posted by: Editor
A considerable potential with regard to the continuous advancement of these systems lies in the field of system construction. Approaches to reduce the shaft dimensions have already been implemented with some solutions, where reduced headroom or pit dimensions can be found. This applies, for example, to the “Evolution® compact” elevator system, which was presented by ThyssenKrupp Aufzugswerke several years ago. With a shaft pit depth of only 300 millimetres, this elevator was the first on the market featuring a respectable dimensional reduction.
Initially, the solution was either a reduced headroom or a reduced pit. There was no elevator system available which neither exceeded the height of the top floor nor the depth of the foundation. Although such solutions were known, they only complied with the Machinery Directive and not with the required safety provisions of the 95/16/EC Elevator Directive. For this reason, these systems can, on the one hand, only be deployed for privately used areas with considerably reduced speed and, on the other hand, the safety spaces for the maintenance and repair personnel are only temporarily available here. These temporary safety spaces are provided by, for example, stopping the car. A supplementary or alternative feature of the system is a sensor technology for person detection. However, the used sensors have to be designed as a safety circuit, for example in accordance with SIL 3, which is regarded as a disadvantage. It involves extensive reporting and documentation, being hardly comprehensible for the maintenance personnel.
Objective
At ThyssenKrupp Aufzugswerke, the development and manufacture of elevators without machine room is specifically oriented towards the demand for high-quality, flexibly adjustable systems without pits. A core competence based on a comprehensibly quality- and future-oriented corporate philosophy.
This means: The development of a further innovation in the sector of elevators without machine room did not imply that we virtually worked on a “face lifting level” in terms of technical or costspecific factors. To us, the development of a further innovation in this sector meant the creation of an elevator which combines convincing and unique characteristics.
First and foremost, the following characteristics are in the focus of attention:
• Minimized shaft dimensions
• Minimum headroom
• Minimum shaft pit
• Drive unit positioned in the area of the lowest landing
• Deployment of a permanent magnet synchronous machine
• Compact car with fixed dimensions
• Floorvariable operating box
• Installation of landing door in shaft or recess
• One product for the standard volume market
Manufacture of an elevator with minimum headroom and minimized pit, featuring a reduced shaft crosssection for the standard volume market. An objective which simply meant to design the most compact elevator system available now and to set a new benchmark for elevators. And it also meant to tread many new paths.
Customer Benefits
• Optimum utilization of construction volume
• All vertical loads are only transferred via the pit into the building base
• Low costs
• Short delivery times
• Easy installation
• High quality
• Easy maintenance
• Modernization: Basement and attic can easily be made accessible
• Ideal for building grounds with a high groundwater level
Pre-requisites for the shortest shaft with a simultaneously reduced shaft cross-section
General prerequisites for the shortest shaft when using a 2:1 rope guide
• A technically mature safety concept documented within the scope of a risk analysis
• Development of new or extended safety concepts
• Compact systems for the provision of temporary safety space
• Miniaturization of basic components
• Optimally matched components
Pre-requisites for a minimum headroom
The basic pre-requisites:
• No components above the car path
• One suspension rope diversion below the car floor
• A highly compact car construction
• A car door drive which does not considerably protrude over the car
• Flat elements for the detection and protection of persons on the car roof
• Flat elements for the provision of a temporary safety space on the top of the car
Pre-requisites for a minimized pit
The basic pre-requisites:
• A highly compact flat bottom beam integrated in the car floor, with suspension rope diversion
• Only few components below the car path
• Flat safety gear which can be integrated into the car floor
• Compact tripping mechanism for the safety gear integrated in the car floor
• Safety concept for the protection of persons entering the pit
• System for the provision of a temporary safety space at the bottom
• System for the provision of a temporary safety space at the bottom
Pre-requisites for the reduced shaft cross-section with the shortest shaft
As, for the “shortest shaft” objective, all components should be positioned next to the drive path, their design should be as flat as possible or as required.
The basic pre-requisites:
• Flat drive
• Compact rope diversion
• Flat and short counterweight
• Flat overspeed governor
Technical Details
Project planning data/layout
Two figures to start with: SK = 2600 mm, SG = 400.
Safety concept
Shaft safety is ensured. A basic pre-requisite for the completion of the system is a technically mature safety concept for the operation and maintenance of the highly compact MRL elevator system, which is able to meet the requirements of practical applications. Diverse electrical and mechanical safety devices are responsible for the safety in the shaft. The entire safety concept accounts for the lack of permanently access-ible safety spaces in the pit and the headroom and has been tested and approved within the scope of type approval in accordance with the Elevator Directive (95/16/EC) by the TÜV Süd (German technical inspection agency).
Safety concept for safety space in headroom
The essential new feature is the temporary provision of safety spaces on the car roof.
The specifications of the multistage concept is as follows:
1 Electrical detection of persons on the car roof.
2 Electrically monitored, manually operated fixed stops for restricting all car movements in upward direction.
Safety concept for safety space in pit
The assurance of safety spaces in the reduced pit is based on the concept of the Evolution® Compact and has proven itself in practical applications for many years.
Also this safety concept has several stages:
1 Electrical monitoring of the lowest shaft door.
2 Anti-creep device.
3 Resting support.
Ropes
To attain the extremely small shaft dimensions, the diameter of diverter pulleys and sheaves had to be minimized. As a logical consequence of the required minimum dimensions, we selected respectively thin steel wire ropes. Despite the enormous minimizations, the Spirit® is actuated by means of the tried-and-tested D/d. The design of the rope configuration has successfully passed diverse long-term tests.
Drive
A very flat drive design is a basic pre-requisite for the achieved radical shaft minimization. Both in regards to the conceptual design of the construction and of the drive arrangement, new questions had to be raised and new paths treaded.
The result was a highly compact synchronous machine with permanent magnets, which was arranged and coupled below the traction sheave/brake unit.
The innovative drive engine has been developed at the Neuhausen elevator plant, where it is now manufactured, and convinces with a series of outstanding advantages, among others:
• the flat construction with a depth of only 200 mm, including traction sheave
• the oil-free operation
• very low starting currents
• the minimum self-locking for powerless emergency evacuation
Since the machine brake has been designed as a type-approved safety brake, an additional braking system on the car against uncontrolled upward movement can be dispensed with.
Car
The objective was the construction of a lightweight, yet stable, car without frame, which can be easily and quickly installed. The challenge we had to deal with was to design the car with the shortest possible external car height including:
• the integrated insulated rope diverter at the bottom;
• the integrated safety gear with tripping mechanism;
• and the devices for securing the temporary safety space for the headroom.
Car door
Special demands have also been placed on the car door. The main objective here was the realization of the low headroom. The door height must, for example, not considerably exceed the clear car height. Available door models, however, are usually equipped with a farprotruding door drive motor. For this reason, the door drive motor of the new K12 car door points laterally downwards and has thus been successfully integrated into the door concept. Also the interface between the car and the car door could be optimized for the Spirit.
Overspeed governor
The requirements placed upon the overspeed governor could also not be met by an available standard product. Both the comprehensively available product know-how and the modern production technologies formed, however, an optimum basis for the development of the required overspeed governor: The new device tailored to the special needs of the Spirit® is characterized by its very flat design, its remote control option and the diverse integrated sensors.
Type approval
The Spirit® has been typeapproved by a Notified Body the TÜV Süddeutschland (technical inspection agency for the south of Germany). At the primary stage, we intensively discussed the risk analysis with the TÜV experts and adjusted our solution details accordingly. While the final version of the system components was finished, the sample elevator was regularly inspected and examined in the Neuhausen plant.
Particularly short development Time
High vertical range of manufacture
Also, and particularly for the development of a completely new, highly compact elevator, optimally matched components constitute a central pre-requisite. This may sound like a rather general statement which goes without saying. It, however, contains a decisive challenge. Particularly three aspects are responsible for the fast and perfect integration and adaptation of all components into the new elevator system:
1 The fact that the development and production department of ThyssenKrupp Aufzugswerke work under one roof;
2 The high degree of vertical integration we can benefit from
3 Successful teamwork.
As a complete supplier, independently developing and manufacturing about 80 % of all its components, ThyssenKrupp Aufzugswerke follows a national unique concept at its corporate domicile in Neuhausen near Stuttgart and represents one of the largest plants in Europe. As has been proven by the result and the required time, we therefore provide ideal framework conditions for futureoriented plantengineering and consistently high system quality.
Against this background, a drive unit with frequency controller, overspeed governor, car door drive, floor selector, control and additional safety systems have been designed and developed by our development team in a way which reflects singular compactness in terms of system characteristics and short development times. Including the successfully passed type approval test, the Spirit® elevator system could be developed and launched within one year.
Future prospects
The market response to Spirit® forecasts a successful future for this innovative elevator system. Extensions of Spirit® will be consistently oriented towards the market requirements. In diverse European countries, it is foreseeable that systems such as Spirit® will also be approved for new buildings. Prospective national and international customers and representatives of notified bodies have already frequently seized the opportunity to personally get a detailed view of the new Spirit® elevator system in Neuhausen.
With the Spirit® elevator system without machine room, we have once again launched a groundbreaking development. It represents a self-contained solution which is focused on the volume segment and, as a high quality, future-oriented system, constitutes a reliable, strategically reasonable supplementation of our systems concentrated on the premium segment, the Evolution® series without machine room.
Lecture on the occasion of the European Lift Congress Heilbronn (ELCH), 28 and 29 June 2005
6/2005
