Maschinenbau Kitz relies on distance-maintaining torque ball bushings

tretter10318 Maschinenbau Kitz has a new chain circulation system in its portfolio that clocks workpieces and feeds and removes them from the machining center based on their position. In order to be able to transport components of different sizes, the distance between the two profile strands on which the components lie can be changed via an adjustment unit. In addition built-in torque ball bushings and shafts from Dr. Steps enable an absolutely parallel and smooth run.

tretter20318 Maschinenbau Kitz GmbH in Troisdorf is one of the leading suppliers of mechanical modules and components for factory automation - including belt conveyors for internal transport. "What makes us so competitive?" Sabine Eßer, group leader in mechanical engineering Kitz, does not think long: "With the modules and components of the profile and conveyor technology, we fulfill almost all requirements of our customers. In conveyor technology, for example, we supply the complete chaining to the processing machine from a single source, and in a high quality - despite the price pressure that prevails in the industry. "

The company in Troisdorf in North Rhine-Westphalia operates as the parent company of the MK Technology Group, which also has branches in Gera near Leipzig, in Spain, the Netherlands, Austria, Switzerland and the USA. Of the 460 employees in the group, only 264 are employed in Troisdorf. The conveyor systems are used, for example, for in-house transport in the automotive industry, mechanical engineering, electrical engineering and the food, pharmaceutical or packaging industries.

The systems are assembled and commissioned at the Troisdorf site. In addition to their own production, suppliers play an important role for the mechanical engineering company. "With our partners, we attach great importance to reliability, price, adherence to deadlines and fast delivery," describes Sabine Eßer. One of the selected providers is Dr. Tretter GmbH & Co from Rechberghausen in Swabia. “We are particularly impressed by the high quality of the components. This includes the powerful torque ball bushings and shafts, ”says the group leader.

Custom made from the kit

tretter30318 "With our proven and extensive modular system of profile and conveyor technology we can adapt our standard solutions to customer-specific requirements," explains Sabine Eßer. The machine manufacturer manufactures 4000 to 6000 function modules a year, and the export quota is just under 20%. One of the latest developments is the TKU 2040 chain circulating system: the chain conveyor is predestined for the machine tool and plastics industries as well as for the automotive sector.

In use, for example, a handling unit, a robot or an employee supplies the chain circulating system with the workpieces. The conveyor feeds it to and from the machining center in a defined and location-oriented manner. "The clocking takes place after a fixed cycle, which the user can configure individually," explains Esser. "For this solution, we also supply the fixed linkage to the various processing stations."

Promote workpieces of different sizes

tretter40318 The belt body consists of two chain conveyors - the profile strands. In addition there are sliding guides for the double roller chain as transport medium. As workpiece holders prisms made of plastic, brass or workpiece carriers are attached to the transport chain. About wheels in the deflection this is guided safely. "The important thing about this system is that the user can feed workpieces of different sizes," says Ms. Eßer. For this purpose, the designers have screwed the band body on an adjustment.

If a component change is present, an employee can move the profile strand both manually and automatically and change the distance accordingly with a handwheel. The design challenge here: Because both profile strands are coupled together, the engine drives not only one strand, but also the other. "So a parallel adjustment on the shaft is absolutely necessary," explains the group leader. "If the strand to be displaced jams, a smooth process can no longer be ensured, and there is also considerable wear."

For the adjustment movement in comparable plants in the past, splined shafts or shafts with long keyways were used. "Prior to delivery, of course, we had adjusted each system accordingly and checked their function," says Sabine Eßer. "However, the transport on the loading areas of the trucks could solve attitudes, in use at the customer, the adjustment units then often no longer work. There were always complaints. "

High quality machine elements for compact construction

tretter50318 In search of a solution for the new chain circulating systems, the mechanical engineers came across the torque ball bushings of Dr. Ing. Tretter. They are installed in the pulleys and transmit the drive torque to the profile strand. "These high-precision longitudinal transmission systems for torque transmission enable a smooth, parallel adjustment of the profile strands in every position - without tilting them. This is ensured by the ball rolling element, "explains Detlef Stracke, field sales representative for Dr. Ing. Tretter. He also supervised mechanical engineering Kitz in this project.

The torque ball bushing experiences only a lateral force. During transmission, the bushes fulfill the function of a splined shaft. The special feature is that no stick-slip effect occurs due to the rolling element. The translation movement is almost jerk-free. In the case of the torque ball bushings, the ball runs in ground grooves. This means that these machine elements are significantly more wear-free than splined shafts. This is due to the geometry of the touching bodies: the concave circular arc groove snugly fits the convex ball. The engineers at Maschinenbau Kitz also have the advantage of being able to realize very compact designs with the torque ball bushings.

"Even if the machine elements are slightly more expensive, in the end we will get the cheaper solution," sums up Sabine Esser. "If we need components such as the torque ball bushings, we simply send the drawing with the respective dimensions to Dr. med. Tretter. We then get the complete component with the right shaft and only have to install it. "