Patents by Inventor Seppo Hokkanen

Seppo Hokkanen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5531564
    Abstract: A multi-stage centrifugal pump has a shorter shaft length compared to conventional multi-stage pump with the same number of impellers on the drive shaft (e.g. about 17-28% shorter length). The shorter length is obtained by utilizing first and second annular slide bearings. Adjacent at least one end (and preferably both) of a rotatable elongated shaft of the pump (which mounts the impellers) within a casing the first slide bearing is mounted to a stationary end structure while the second slide bearing is mounted to the shaft for rotation with it. A plurality of O-rings may be provided to mount the second slide bearing to the shaft. A sleeve with shoulder engaging opposite ends of the second slide bearing may be provided, and the slide bearings may have a clearance of about 0.04-0.1 mm between them, with a lubricant in the clearance. A labyrinth seal is typically provided in the most remote shoulder.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: July 2, 1996
    Assignee: A. Ahlstrom Corporation
    Inventors: Kari Anttonen, Seppo Hokkanen, Jukka Timperi