Shot peening with more efficiency and safety

Advancements in the field of transmission manufacture

To increase capacity at locations in Germany and Asia an automotive company had to invest in new shot peening equipment. With the RDT 150-S5 and RSA 1400-S6 peening systems Rösler offered a solution that offers clear advantages with regard to performance, reliability and safety. 

Shot peening improves the surface characteristics of transmission components which are in high demand in the automotive industry:
Less wear and, subsequently, longer life with, at the same time reduced component weights. The customer specifications called for partial peening of the teeth of different gears to induce a residual compressive stress on the parts surface at a given production rate in the customer's Asian and German production facilities.

RDT 150-S5 - up to eight parts with 1200 MPa in 25 seconds
The planning engineers from the customer were impressed by the many features of the Rösler satellite turn table system: For example the turn table that is divided into 5 segments (chambers) by solid walls. These walls consist of manganese steel. In the direct blast area they are further protected with wear plates made from tool steel. Moreover, they are equipped with special magnetic seals. This ensures that the blast area is properly sealed, and the operator is not "shot" by stray media, when the turntable indexes. Each of the five chambers is equipped with a rotary satellite onto which the parts-specific fixtures - holding up to 8 gears -- are mounted. The parts are placed on the fixture manually.

The blast process itself takes place in 2 of the 5 chambers with high performance Hurricane® turbines, type H 32. These are single disk turbines allowing a quick change of the throwing blades from outside with having to dismount the impeller and control cage. The blades in one wheel can be replaced within 10 minutes. This reduces downtime to an absolute minimum. A significant feature of the Rösler system was its small footprint requiring a minimum of space. A decisive factor in the customer's decision for Rösler was the reduced space requirements that allow a decentralized  blast operation with a minimum of parts handling and the security that if one system in the production line was defective, the rest of the production line would still be running. A further advantage of the Rösler system was its competitive price and the excellent blast results: The RDT 150-S5 can produce residual, compressive stress values of 1,200 MPa, whereas with the existing equipment the customer could only reach 1,000 MPa. 

RSA 1400-S6 - shot blasting with automatic parts handling
For applications where residual stress values of 1,500 MPa are required Rösler developed a customer-specific peening system around the air blast system RSA 1400-S6. Here the parts are loaded automatically into the peening system with special handling systems which were also engineered by Rösler. However, if required, the system could also be loaded manually. The handling system removes one part (gear) at a time from a cleaning system and places it on the satellite fixture with an accuracy of +/- 1.0 mm. After the peening process the part is automatically removed and returned to the cleaning system.
The system is equipped with three blast guns which direct the blast precisely to the areas to be peened. Up to three peening positions can be selected. Based on customer requirements the blast machines are equipped with one and two peening positions. At a blast time of 40 seconds this allows processing of 1,500 parts per machine in a three-shift operation (expansion up to 4,500 parts per machine is possible).

Extremely important was that the RSA system produces absolutely repeatable results. After the acquisition of the peening specialists Baiker and Vapor Blast Rösler has become the leading supplier of high-tech air blast systems for the automotive and aerospace industries. This technological leadership could be achieved - among other reasons - with many patented solutions like, for example, special media dosing systems. A very important factor in achieving absolute repeatability of the peening results was the continuous media re-cycling and-cleaning system consisting of air wash separator, screen decks and spiral separator. The latter ensures that only spherically shaped media remains in the system. Random shaped, broken media is discarded.

For the plant in Asia the customer's project engineers decided to purchase four systems of the type RDT-S5 and one RSA 1400-S6 with manual parts loading/unloading. The German facility purchased seven RSA 1400-S6 systems. Commissioning of all machines took place within the required time period of 20 weeks after the purchase order had been placed.