The newly devel­oped oven gener­a­tion of Swiss premium house­hold appli­ance manu­fac­turer V-ZUG is a combi­na­tion of reli­able appli­ances that are easy to operate and modern tech­nology. And it leaves room for major culi­nary triumphs, because the ovens that have been in the market since February 2019 have signif­i­cantly larger cooking spaces. Although the device of the Swiss market leader in the white goods market is as compact as its prede­cessor, even the largest turkey will fit inside.

Andreas Büeler, devel­op­ment engi­neer at V-ZUG (Photo | V-ZUG)

“To achieve this, we had to reduce the instal­la­tion space and the height of the device’s oper­ating panel,” said Andreas Büeler, a devel­op­ment engi­neer at V-ZUG. “This left less space for the stove jacket cooling – the height in partic­ular was much lower,” added his colleague, Pascal Bosshard, who helped develop the venti­lation system. The company was presented with a chal­lenge, because the air throughput had to remain the same despite the reduced space. Some models even required higher air throughput, and the venti­lation system had to cool as quietly as the previous model.

No simple solu­tion

Relying on a more powerful motor was not the solu­tion because stove jacket cooling systems have several func­tions. They ensure that the walls and door do not become too warm, cool the lamps inside the oven, and remove mois­ture from the cooking space in order to produce optimal baking results. Each area must receive suffi­cient air, but at the same time the motor must be designed specif­i­cally for the baking process to ensure the proper climate and temper­a­ture inside the oven. To satisfy all these require­ments simul­ta­ne­ously, the two engi­neers reached out for support from ebm-papst. Until that point, the venti­lation specialist had only supplied motors. V-ZUG devel­oped the fan impeller and assem­bled both compo­nents in-house. For the first time, the company planned to rely on a complete solu­tion.

The solu­tion consists of a customer-specific, back­wards-curved impeller and a slow-running shaded-pole motor with a motor power of 15 W and custom, flat bearing supports. (Photo | V-ZUG)

“Initially, many vari­ables – such as the impeller diam­eter and the fan’s blade geom­etry – were open,” said Bosshard. “ebm-papst helped us get down to the specifics.” After the product analysis, they ran simu­la­tions. V-ZUG devel­oped the impeller and housing in collab­o­ra­tion with ebm-papst’s Land­shut loca­tion. The Swiss engi­neers joined ebm-papst at the produc­tion site in Slovenia to select the motor and opti­mize the instal­la­tion height. It took the engi­neers two years of combined work and many trips back and forth to develop the solu­tion.

The team hits the right note

Pascal Bosshard, devel­op­ment engi­neer at V-ZUG (Photo | V-ZUG)

V-ZUG and ebm-papst worked in partic­u­larly close collab­o­ra­tion starting in spring 2018. “The stove jacket cooling system was basi­cally finished. ebm-papst had devel­oped a combi­na­tion impeller and motor that met our require­ments for size, air pres­sure, and noise level,” said Büeler. “But we were not happy with the way the venti­lation system sounded.” He and his colleague wondered if the high frequency would disturb the company’s sophis­ti­cated customers when they used the oven in the kitchen. “The ebm-papst team under­stood what we wanted and despite the tight dead­line, was imme­di­ately willing to go another round to opti­mize the solu­tion,” said Bosshard.

They tested and tested, and finally found the solu­tion. It consists of a customer-specific, back­wards-curved impeller and a slow-running shaded-pole motor with a motor power of 15 W and custom, flat bearing supports to mini­mize instal­la­tion height. Motor mounts with an aero­dy­nam­i­cally opti­mized inlet ring and snap connec­tors ensure that the motor can move suffi­cient air despite its compact size.

“The ebm-papst team under­stood what we wanted and despite the tight dead­line, was imme­di­ately willing to go another round to opti­mize the solu­tion”

Pascal Bosshard, devel­op­ment engi­neer at V-ZUG

“We are now using a shaded-pole motor that we could only use to suffi­ciently cool steamers in the past,” explained Büeler. “But the oven now gets up to 70 degrees warmer.” After ebm-papst’s opti­miza­tions, it was finally possible to use the motor for heat jacket cooling as well. “It really helped to have venti­lation special­ists at our side who supported us with their know-how,” said Bosshard in summary. “We had a team with whom we could make the right deci­sions quickly and arrive at an excel­lent result.”