US 12,234,831 B2
Pump shaft for a multi-stage pump
Gerhard Gross, Frankenthal (DE); Kai Molitor, Frankenthal (DE); and Sophia Sergi, Frankenthal (DE)
Assigned to KSB SE & Co. KGaA, Frankenthal (DE)
Appl. No. 17/597,268
Filed by KSB SE & Co. KGaA, Frankenthal (DE)
PCT Filed Jun. 22, 2020, PCT No. PCT/EP2020/067302
§ 371(c)(1), (2) Date Dec. 30, 2021,
PCT Pub. No. WO2021/001191, PCT Pub. Date Jan. 7, 2021.
Claims priority of application No. 10 2019 004 539.4 (DE), filed on Jul. 1, 2019.
Prior Publication US 2022/0316490 A1, Oct. 6, 2022
Int. Cl. F04D 29/043 (2006.01); F04D 1/06 (2006.01); F04D 13/02 (2006.01); F04D 13/10 (2006.01); F04D 17/12 (2006.01); F04D 29/041 (2006.01); F04D 29/044 (2006.01); F04D 29/62 (2006.01); F16D 1/033 (2006.01); F16D 1/04 (2006.01); F16D 1/05 (2006.01); F16D 1/08 (2006.01); F16D 1/09 (2006.01); F16D 1/096 (2006.01)
CPC F04D 29/043 (2013.01) [F04D 1/06 (2013.01); F04D 13/021 (2013.01); F04D 13/10 (2013.01); F04D 17/12 (2013.01); F04D 29/041 (2013.01); F04D 29/044 (2013.01); F04D 29/628 (2013.01); F16D 1/033 (2013.01); F16D 1/04 (2013.01); F16D 1/05 (2013.01); F16D 1/0829 (2013.01); F16D 1/0864 (2013.01); F16D 1/09 (2013.01); F16D 1/096 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A pump shaft for a multi-stage pump, comprising:
a pump shaft having a circumferential groove region configured to receive and cooperate with a load-relieving device to impart a force acting in the axial direction of the pump shaft to the pump shaft,
wherein
the groove region in an axial direction of the pump shaft includes a plurality of grooves spaced apart from one another in the axial direction,
the plurality of grooves are circumferential grooves separated from one another or are portions of a single-start or multi-start closed screwthread,
a respective groove base of each of the plurality of grooves, viewed in the axial direction, has a shape of a segment of a circle, and
radii of the groove bases of the plurality of grooves relative to an axis of rotation of the pump shaft are different, and
the groove region is not tapered.