APPLICATIONS Gianandrea Mazzola

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SPECIALIZED IN THE DESIGN AND MANUFACTURING OF INNOVATIVE SOLUTIONS FOR INDUSTRIAL POWER TRANSMISSIONS. THE GROUP OF BOLOGNA, STM, USES A NEW BTB TRANSFER MACHINE FOR THE PRODUCTION OF CASES FOR THEIR NEW RANGE OF WORM GEARBOXES. THE MAIN STRENGTH OF THIS MACHINE IS QUALITY WITHOUT COMPROMISE, SILENCE, MAXIMUM ENERGY EFFICIENCY AND RELIABILITY. THIS ALLOWS TO MEET ALL PRODUCTION NEEDS EVEN WITHOUT THE PRESENCE OF THE OPERATOR

AFROM RAW TO FINISHED PART RAPIDLYAND WITH QUALITY

mechanical company that studies, designs, and produces transmission organs. STM is specialized in the production of gearboxes, such as worm gearboxes, planetary gearboxes, coaxial and helicoidal

bevel helical, and parallel gearboxes.Strongly oriente d towards product customization.

This tailor made concept has been able to evolve and accommodate the request of an increasingly demanding market, where integrated solutions are a plus value. In this context, technological innovation, R&D and continuous update of manufacturing equipment assumes great importance. «Even though gearboxes are a technologically mature product – comments Mr.Doriano Gambini, plant manager for Stm - there are still several fields of application that require new technologies from our sector.

BB776, the Btb Transfer rotary

table multi-center machine with

horizontal axis 6 stations, 6 working units purchased by

Stm.

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Many customers request higher performance systems which consequently require a performing gearbox». In order to satisfy the increasingly stringent requirements, appropriate processes are necessary in terms of product performance and quality. Such as those that characterize the new transfer machine model BB776 recently purchased from BTB Transfer of Brescia. A multi-center rotary table machine with horizontal axis, 6 stations and 6 integrated machining centers.

Maximum precision, high productivity The gearbox is a transmission organ composed of gears that rotate in cascade within a crate , body or box. The gearboxes are continuously more precise, performing, and silent thanks to continuous investments in state of the art technology made by the STM team.

This aspect is absolutely important and essential in order to obtain a very precise gearbox. «However precision is not a synonymous of fast production –Gambini adds – therefore it was necessary for Stm to find a partner that could put its own experience towards this issue»

40 years of innovative solutions for industrial power transmissionStm was founded in 1976 (celebrating the 40th anniversary this year) by Tiziano Girotti, Altero Vignoli e Giuseppe Lucchini , and thanks to their entrepreneurial skills, initiative and belief the company now represents an important point of reference in the field of mechanical transmissions.«Currently Stm is a group of 4

manufacturing facilities plus 15 companies worldwide for assembly and sales – explains one of the current owners Lorenzo Vignoli ».The headquarters in Lippo di Calderara di Reno (Bologna), is developed on a surface of 50.000 sq meters of which 25.000 covered. Part of the 350 group employees work here, reaching a consolidated balance of 85 million. euro.

company's success is reached only through the capacity to endure and support the balance between important factors such as product innovative technology and internal systems such as machines, procedures, software. And the dynamics of all the company environments and a strong sharing of company goals. These ingredients are essential to obtain high quality products and satisfy the needs of demanding customers. And compete with competitors of less industrialized countries that often offer at a low price dzǎƛƴƎ this as a weapon to conquer market areas of Italian and European fabricated products»Φ The markets are constantly changing being more sensitive towards the political and financial instability of the nations and the international political uncertainties including all factors that influence the economical stability. The group of Bologna responds to these issues by making important investments to guarantee a presence in areas where Stm is still not strongly present and also to improve the internal company efficiency. One of the latest improvements is the construction of a new logistic center, which began last year. This will strengthen and increase the market position nationally and also internationally.

«Our main market is without a doubt the European market where Stm develops 65% of the sales, while the remaining 35% is divided between South America, Africa and Far East - Mr. Vignoli adds».However Stm is not only a mechanical company with a wide range of products, but given the continuous request for integrated solutions, it has been able to offer for years a series of motoinverter Esv.«Actually Stm differs from others for the targeted customer service. For example the online "configurator" for our products that gives the technician a wide choice of drawings and catalogues in numerous formats. Also the "interactive" program that gives customers the possibility to trace their orders and view its status». «Its no longer a secret on how the

Lorenzo Vignoli, associate owner of Stm of Lippo di Calderara di Reno (Bologna)

Stm machines 9 different cases for worm gearboxes on the Btb Transfer with maximum working cube of 220 mm with centesimal tolerances

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The need was to replace a machining plant that no longer met the requirements requested with a more powerful and updated one. Btb Transfer has thus provided the technology to achieve the accuracy remaining within the production time required.« A joint development – comments Gambini – which also involved directly Mr. Altero Vignoli, one of the founders and current owner, one who always follows the Group's technological field and the development of machinery in collaboration with manufacturers». The mutual synergistic activity and co-design and co-engineering has thus resulted in a machine whose job is also to work together with a parts washer, a vertical automatic warehouse and an anthropomorphic robot, thus forming an automatic work cell.

A work cell capable of transforming a piece from raw to finished in reduced times, with a high accuracy and ready to be stored without the need for any operator to touch in any way the component.« When defining how to design this machine - said Gambini - the initial period of study was essential in order to exchange ideas that would lead to a machine capable of responding to our needs ».The work of analysis carried out by both STM and Btb Transfer technicians was crucial in order to understand each need and avoid any conceptual error. Especially the technical and commercial manager of Btb Transfer and the Production manager of the Group from Bologna played an important role in exchanging information, which, led to a high performance solution, thanks to the great experience of both.

Serving the worm gearbox and cubic shape worm gearbox More in detail the new machine supplied (rotary table with horizontal axis, configured with 6 stations and 6 operating units) is able to produce an average of 75-90 pieces/hour of highly complex parts. For the way the machine is designed and developed it is able to complete in a single cycle the machining of 4 sides without penalizing the productivity through the use of units mounted on machining centers. Thanks to the possibility of being able to process parts in different materials such as brass, steel, and aluminum, it is a valid alternative to traditional production machines represented by the classic machining centers.«We currently machine 9 types of cases for worm gearsboxes of maximum diameter 220mm with centesimal tolerances. Tolerances that have to be repeated on production batches of 10.000 parts –comments Mr. Gambini ». Such gearboxes are part of the series called R and U.The first worm gearboxes are available in a reduction ratio from 1/7 to 1/100, torque from 10 to 2.103 Nm, power between 0,01 and 31,16 kW. For these models the ZI teething profile has been adopted (section and involute) to improve efficiency and silence. A modular attachable output flange has been adopted to increase flexibility. The U series identifies a cubic form with reduction ratio from 1/7 to 1/100, torque from 26 to 638 Nm, power between 0,04 and 10,01 kW. The cubic form allows adaptability in fixing and extreme modularity in stocking the finished product.

DORIANO GAMBINI Plant Manager at Stm

Machining detail of a gearbox case on the Btb Transfer multi-center.

Top view of the automatic machining system composed of the Btb Transfer machine, the part washing machine, automatic vertical warehouse and robot

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With the adoption of a coupling it can be combined with all Brushless, Iec and Nema motors. Stm guarantees versatility in the possible configurations and eliminates the fretting phenomenon. The case that is machined on the new transfer is designed to optimize the heat dissipation and simplify cleaning, even in the harshest environments .

An additional value to win the market challenges«Many of the points we appreciate in this machine are the fast setting through an individual

operating system, the support of tools without the use of a special stock, the stability of the structure that gives a high degree of precision, and the repeatability of the production cycle. This also includes the interlocking by the articulated robot system, all which have contributed towards choosing BTB Transfer as a reliable partner in creating a system with a high level of automation and quality able to produce an important part of our production, for which these qualities are fundamental for an increasingly demanding market». Emphasis is also on the tool change concept adopted (patented by Btb Transfer) which, directly applied on the machining center, allows to quadruple the number of operations to be performed on the transfer without compromising the stiffness and precision of machining units. The robustness of the system allows to easily pass from aluminum machining to steel and cast iron machining. The fast manufacturing and quality make BB776 an additional value that Stm was looking for among the transfer machine builders. This machine will assist the group in appreciating the new market challenges. «Mr. Gambini concludes with stating–the future years will be dictated by the ability of companies to meet, comprehend, and solve all needs of the customer, by creating products with increasingly high returns for energy savings. And also inserting electronic components within mechanical ones such as sensors, able to make the reducer a remotely controllable machine able to supply status information».

«CUSTOMER-ORIENTED» MACHINESThe company of Brescia, BTB transfer was founded in 1987 and is now a world reference point for the design and manufacturing of transfer machines. Over 850 machines installed in over 30 different countries with more than 150 customers. Highly productive and precise machines with a rotary table for metal cutting and chip removal of various materials such as steel, aluminum, brass, copper, cast iron. The machines are created by a team of 130 employees, 40% of which are mechanical and electronic engineers. The industrial fields served are various and diversified, such as automotive industries, petrochemical, high pressure hydraulic, fitting and valves, heating and refrigeration, household appliance, and more. Common and unique is the commitment aimed to meet both the needs of large industries and the small and medium businesses, through the development of suitable and customized solutions for individual specifications. By choosing BTB Transfer you are able to count on full technical support where the best technological solutions can be found to make production efficient , fast and competitive.

Cubic worm gearboxes series U

Round worm gearboxes series R

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