US 12,228,133 B2
Rotary positive displacement pump with a guard
Simon Cargill, Eastbourne (GB)
Assigned to ALFA LAVAL CORPORATE AB, Lund (SE)
Appl. No. 18/260,493
Filed by ALFA LAVAL CORPORATE AB, Lund (SE)
PCT Filed Jan. 19, 2022, PCT No. PCT/EP2022/051071
§ 371(c)(1), (2) Date Jul. 6, 2023,
PCT Pub. No. WO2022/157168, PCT Pub. Date Jul. 28, 2022.
Claims priority of application No. 21152412 (EP), filed on Jan. 19, 2021; and application No. 21178353 (EP), filed on Jun. 8, 2021.
Prior Publication US 2024/0052831 A1, Feb. 15, 2024
Int. Cl. F04C 2/18 (2006.01); F01C 17/02 (2006.01); F04C 13/00 (2006.01); F04C 15/00 (2006.01)
CPC F04C 2/18 (2013.01) [F01C 17/02 (2013.01); F04C 13/00 (2013.01); F04C 15/0061 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A rotary positive displacement pump for pumping a fluid product, the pump having a front side and a rear side and comprising:
a transmission housing having an axial front wall and an axial rear wall and providing rotational support to first and second parallel and axially extending drive shafts having gears in constant mesh condition, such that the first and second drive shafts are arranged to rotate in opposite directions, and
a rotor casing connected to a front side of the transmission housing and having an axial rear wall, an axial front wall and a circumferential side wall jointly defining a stationary interior pumping cavity,
wherein the rotor casing houses a first rotor that is drivingly connected to the first drive shaft and a second rotor that is drivingly connected to the second drive shaft,
wherein the first and second rotors are configured for rotating in opposite directions and mutually interacting for providing a positive pumping effect on a fluid product that enters the pumping cavity via a rotor casing inlet and exits the pumping cavity via a rotor casing outlet,
wherein the axial front wall of the transmission housing and the axial rear wall of the rotor casing jointly define an intermediate space through which the first and second drive shafts extend, and
wherein the rotary positive displacement pump further comprises:
a first guard located in said intermediate space and surrounding the first and second drive shafts for protecting a person from contacting the first and second drive shafts, or
a first guard located in said intermediate space and surrounding the first drive shaft for protecting a person from contacting the first drive shaft, and a second guard located in said intermediate space and surrounding the second drive shaft for protecting a person from contacting the second drive shaft,
wherein a protective body of the first guard, or each of the first and second guards, is axially displaced from an abutment surface of a guard attachment device, such that a first axial gap is provided between the protective body and a front surface associated with the front wall of the transmission housing, and/or from a rear surface of the rear wall of the rotor casing, such that a second axial gap is provided between the protective body and the rear wall of the rotor casing, for enabling improved visibility of the first and second drive shafts, and for enabling improved detection of leakage of a fluid product and/or transmission oil at a drive shaft seal associated with the first guard, or any of the first and second guards.