Highly automated shot blasting solution for transmission components in E-vehicles

Drahtgurt-Durchlaufstrahlanlage
A blast pattern simulation allowed the precise placement of the turbines on the blast chamber, thus ensuring perfect deburring results for the entire work piece range.

For the expansion of its transmission production facility for electric vehicles a German automotive supplier purchased a new continuous feed blast machine from Rösler that includes fully automatic work piece handling. The customer chose the Rösler equipment, because it offered a high productivity, is easy to maintain and has a long service life. Excellent experience with a practically identical shot blast machine that has been running at the OEM since 2016 also played a role in the decision making process.

The work pieces in question consist of various toothed components for the transmission in electric vehicles. They must be deburred by shot blasting after undergoing a machining and subsequent heat treatment operation. For this manufacturing stage in its transmission production facility the large German manufacturer had to invest in a new shot blasting system. In 2016 the same OEM had already purchased a shot blast machine for a similar surface treatment task. In both cases the customer chose a continuous feed wire mesh belt blast machine with largely automated work piece handling from the Rösler Oberflächentechnik GmbH. The company preferred the Rösler equipment over competition because of its high productivity, the well-engineered, compact automation concept, the easy maintenance and sturdy equipment design.

Consistent, reliable deburring with short cycle times
At the start of the deburring operation the work pieces are manually placed on two storage units, which are part of the work piece transport system. After an integrated camera system has confirmed the correct transport position, the components are precisely positioned on the wire mesh belt in lots of three and continuously transported through the shot blast machine.
Upon completion of the shot blast process a powerful blow-off system is completely removing any residual blast media from the work pieces. In the next step the now deburred components are transferred onto a buffering station consisting of a conveyor belt. Here the work pieces are precisely repositioned so that a robot can pick up four pieces at a time and place them in layers into suitably staged work piece bins. Whenever a layer is complete, the robot picks up an intermediate cardboard sheet and places it in the bin. Completely filled or, in case of a work piece change, partially filled bins are automatically removed from the robot working area. This allows the operator to safely remove them from the manufacturing cell with a lift cart.
Whenever the work piece type changes, the operator selects the new type in the HMI. This causes the machine control to empty one of the two storage units of the work piece transport system so that new parts can be immediately placed on the now empty storage unit. At the same the machine control selects the respective shot blast parameters for the new work piece type. This ensures perfect deburring results and prevents any input errors by the operator.

The goal: Short cycle times in three-shift operation
The shot blasting machine was designed for three-shift operation allowing cycle times of less than eight (8) seconds per work piece. Equipped with four high performance blast turbines with an installed power of 11 kW each, the machine provides ample “fire power” to achieve the required deburring results. The precise placement of the turbines on the blast chamber was determined with a special software allowing the simulation of the blast pattern for the entire work piece range. This ensures that all work piece sections are reliably deburred within the required cycle time.

Easy maintenance and long equipment life
To guarantee long uptimes and very little work for maintenance, the turbines are completely made from carbide steel. The same material was utilized for those blast chamber sections exposed to a higher risk of wear. To facilitate maintenance and minimize non-productive idle times, these sections are lined with replaceable carbide steel plates. The turbine type and blast chamber design of the existing and new shot blast machines are practically identical. This greatly facilitates the maintenance and supply of spare parts by the internal maintenance department.