The Selection of Reliable Safety Brakes
Everywhere where people are transported via elevators, the safety of the passengers has top priority. Safety-relevant components such as the elevator brakes must therefore accord with the highest quality requirements. However, due to the intensive global competition in the elevator branch, the price repeatedly plays a primary role, even for safety-relevant components. In spite of this market situation, a well-founded selection of reliable products must be made – as safety does not allow for compromises.
Yolcu asansörleri, hala en güvenli ulaşım araçlarından biridir. Kaza ve arıza istatistikleri, önceden güvenilir bir şekilde test edilmiş teknik olarak yüksek kaliteli ürünlerin kullanıldığını doğrulamaktadır; bu durum gelecekte de devam etmelidir. Özellikle asansör frenleri alanında, doğru ürünün seçimi gittikçe zorlaşmaktadır. On yıl önce, çok az fren üreticisi, genelde çok tecrübeli orta büyüklükteki şirketlerden sadece birkaçı piyasada aktifti. Yetkinlikleri, gerekli kalite ve güvenilirliği karşılıyordu. Asansör tahrikleri konusunda pazarın küreselleşmesi, rekabetin muazzam yoğunluğu ve imitasyonlarla ilgili problemler, son yıllarda asansör frenleri gibi emniyetle ilgili kritik bileşenler konusunda bile büyük bir rekabet baskısına yol açtı. Geçmişte, güvenilirlik ve optimum kaliteye açıkça bağlılık gösterilirken, bugünkü piyasa katılımcıları konuşmaları sırasında önce fiyatı defalarca belirtiyor. Bununla birlikte, hızlı gelişmeler büyük bir risk potansiyelini gizliyor. Düşük fiyatlarla ürün sunan ancak bu alanda çok az tecrübeye sahip olan genç piyasa katılımcıları, özellikle de Türkiye’deki asansör üreticileri ve tahrik üreticileri için bu durumu kökten değiştirmiştir: Bunlar gittikçe dişsiz teknolojiye odaklanıyor ve geleneksel frenlere kıyasla birçok teknik avantaj sunan yeni fren teknolojileri içeren sözde “fren şaftlarını” seçiyor. Tam olarak bu uygulamada, deneyimli üreticilerin güvenilir asansör frenleri çok önemlidir. Kullanılan materyalleri ve ürünlerin güvenliğini azaltmak zorunda kalan ucuz frenler, hesaplanması imkânsız bir riski gizlemektedir.
Passenger elevators are still one of the safest means of transportation. The accident and fault statistics verify that technically high-quality products are used which have been tested reliably in advance – and this must also remain the case in future. In particular in the field of elevator brakes, the selection of the correct product is becoming increasingly difficult. Ten years ago, only a few brake manufacturers, mainly medium-sized companies with a lot of experience, were active on the market. Their competence ensured the required quality and reliability. The globalisation of the market for elevator drives, the enormous intensity of the competition and the related problems with copies, however, have led to massive competitive pressure developing over the past decades, even regarding safety-critical components such as elevator brakes. Whereas in the past, clear commitment to reliability and optimum quality was shown, market participants today repeatedly state the price first during dialogues. However, the rapid developments conceal a huge risk potential. Young market participants offering products at low prices but holding little experience in the field have radically altered the situation – in particular also for elevator constructors and drive manufacturers in Turkey: these are currently increasingly focussed on gearless technology, and are selecting the so-called “shaft brakes” featuring new brake technologies which offer several technical advantages in comparison to the traditional drum brakes. And yet precisely in this application, reliable elevator brakes from manufacturers with experience are essential. Inexpensive brakes which have to make cuts on the materials used and on the safety of the products conceal an incalculable risk.
Specifying and testing brakes
The collaboration with globally-active elevator manufacturers shows that in Turkey these companies increasingly rely on quality components and orientate themselves on the European Elevator Standard EN 81. The leading large companies also make substantial efforts to specify the requirements on safety-relevant components as precisely as possible and to align them in complex testing procedures. In addition, these companies have an appropriate input from the market, which makes it easy to continuously provide more details for products or product requirements, and to incorporate critical points into the qualification process.
However, this cannot be completely transferred onto the supplier industry. Smaller elevator companies and motor manufacturers, for example, who themselves receive no feedback through field data and who do not possess the resources to employ a large engineering team, generally work using simpler methods of specifying a brake and testing it. They frequently lack the bandwidth, and supply only regional application areas in which certain issues may not occur very often. Therefore, if such a drive manufacturer requires reliable brakes, they will orientate themselves on the points hitherto known to them. Over the course of the business development in other markets, however, they may well be confronted with other conditions, which reveal new issues.
Which criteria can a manufacturer of elevator motors – in particular in gearless technology – apply in order to select a reliable brake?
Production competence and certified quality process
As is generally the case in the field of purchasing, the prospective supplier should first be looked at in detail. A company does not qualify itself simply through the fact that it can manufacture brakes. Appropriate production competence and a certified quality process are essential prerequisites, as is well-founded experience with brakes for elevator drives. For this purpose, the company must have had a large number of elevator brakes on the market for many years. Only in this way is it in a position to know the risks and to supply reliable products. Prototype tests in which elevators are tested once for their functionality say nothing about the quality of the brakes when large quantities are produced. “Every single brake must be supplied in the required quality. For this, an appropriate test routine is required”, explains Johann Eberle, Sales and Marketing Director at mayr® power transmission. “The risk often lies in the fact that manufacturers with less experience are, so to speak, unaware of what they don’t know. In order to guarantee the required safety, clear processes, comprehensive testing possibilities, years of experience and highly-qualified employees represent essential prerequisites. This costs money; but only in this way is safety achieved. In future, not the cheapest, but rather the most reliable provider will prevail in Turkey”.
Conscientiously designed to last its intended lifetime
When selecting a brake supplier, both the evaluation of the company with regard to quality and reliability, and of course also the product specifications and their adjustment to the required criteria are of the utmost importance. Here, it is especially important that the elevator brakes are also considered under critical conditions such as high outside temperatures or high air humidity, which can also occur in real applications. Furthermore, it is important that specified values are not only achieved in new condition, but that their characteristics are assessed over the entire service lifetime. “The years of experience and countless tests conducted by our Development and Research Department in the Mauerstetten Headquarters form the basis for a conscientious product designed to last its intended lifetime, taking into account realistic and verified braking torque tolerances”, explains Johann Eberle. “All the brake components are reliably dimensioned and are only produced from high-quality, known and proven materials. Our brakes are dimensioned so that they can reliably achieve the required nominal torque under all occurring operating conditions, independent for example of the ambient temperature or the air humidity”.
Safety does not allow for compromises
Turkish drive manufacturers are currently increasingly making use of quality products. However, unfortunately it cannot be ruled out that, in addition to the certified quality products copies are used, which do not provide the necessary reliability. For this reason, it is better to specify the appropriate brakes from renowned manufacturers and to ensure that these are also used, for example through the inspection of the type tags. This ensures that these important components provide the reliability we expect. The Turkish market, too, has in the meantime recognised that the appropriate production competence and maximum care are essential for the reliable transport of the passengers – as safety does not allow for compromises.
The author: Sebastian Steinert
Sebastian Steinert works at Mayr power transmission, a German based international manufacturer of safety brakes, torque limiters and shaft couplings. The company also serve worldwide with 3 factories and more than 1000 employees at the headquarters in Mauerstetten, in the Allgäu region. He is part of the task force Key Account Management elevator brakes and served as Programme Manager for leading international OEM projects and the Turkish elevator market. Mayr power transmission has a reputation as the leading manufacturer of elevator brakes and holds many patents in this field.