Abstract: A high-vacuum pump comprises a plurality of pumping stages, each comprising a plurality of mutually cooperating elements, including at least one rotating rotor element and one stationary stator element. At least one of the elements of at least one of the pumping stages is made of a plastic material reinforced with short fibres, dispersed in chaotic and substantially random manner inside the matrix of plastic material. Use of a plastic material reinforced with short fibres allows making the at least one element by injection molding and allows manufacturing the vacuum pump with considerably reduced production costs if compared to the conventional vacuum pumps.

Abstract: System and method for testing a pump. The testing of the pump includes determining a Mechanical Power Index (MPI) for the pump. The MPI is determined by operating the pump at operating speed for a minimum operating interval. When the pump is stopped under normal operation by the application, the pump speed is continuously monitored. The time when the pump speed decreases to an initial speed close to the operating speed is read as an initial time. When the pump speed decreases to a final pump speed close to the critical speed, the end time is read and the elapsed time is determined as ?t=end time?initial time. The MPI is calculated to be the initial pump speed minus the final pump speed divided by ?t. The MPI can be used during the lifetime of the pump to determine when the pump is deteriorating.

Abstract: System and method for testing a pump. The testing of the pump includes determining a Mechanical Power Index (MPI) for the pump. The MPI is determined by operating the pump at operating speed for a minimum operating interval. When the pump is stopped under normal operation by the application, the pump speed is continuously monitored. The time when the pump speed decreases to an initial speed close to the operating speed is read as an initial time. When the pump speed decreases to a final pump speed close to the critical speed, the end time is read and the elapsed time is determined as ?t=end time?initial time. The MPI is calculated to be the initial pump speed minus the final pump speed divided by ?t. The MPI can be used during the lifetime of the pump to determine when the pump is deteriorating.

Abstract: A high-vacuum pump comprises a plurality of pumping stages, each comprising a plurality of mutually cooperating elements, including at least one rotating rotor element and one stationary stator element. At least one of the elements of at least one of the pumping stages is made of a plastic material reinforced with short fibres, dispersed in chaotic and substantially random manner inside the matrix of plastic material. Use of a plastic material reinforced with short fibres allows making the at least one element by injection molding and allows manufacturing the vacuum pump with considerably reduced production costs if compared to the conventional vacuum pumps.

Abstract: A rotor assembly for rotary vacuum pumps has improved mechanical characteristics and low manufacturing cost due to a one-step thermal coupling of a rotor having a male axial projection and its supporting shaft having an end portion comprising a female cavity with a shape and size for receiving the male projection with interference at an ambient temperature. The rotor and the shaft are made of different materials. Heating of the end portion of the shaft provides expansion of the female cavity and allows for inserting the mail projection of the rotor into the female cavity of the shaft. By cooling the end portion to the ambient temperature the contraction of the cavity is obtained forming fixed interference coupling between the shaft and the rotor, where the end portion of the shaft contracts and compresses about the male axis projection of the rotor.

Abstract: A rotor assembly for rotary vacuum pumps has improved mechanical characteristics and low manufacturing cost due to a one-step thermal coupling of a rotor having a male axial projection and its supporting shaft having an end portion comprising a female cavity with a shape and size for receiving the male projection with interference at an ambient temperature. The rotor and the shaft are made of different materials. Heating of the end portion of the shaft provides expansion of the female cavity and allows for inserting the mail projection of the rotor into the female cavity of the shaft. By cooling the end portion to the ambient temperature the contraction of the cavity is obtained forming fixed interference coupling between the shaft and the rotor, where the end portion of the shaft contracts and compresses about the male axis projection of the rotor.