Vane-type pump and heat recovery device

Abstract

A vane-type pump includes a housing and a rotatable rotor having a plurality of slots within which displaceable vanes are disposed. The rotor is disposed in a pump chamber formed in the housing such that delivery cells of variable volume are formed between adjacent vanes. The pump chamber defined by a pair of side walls laterally adjoining the rotor and the vanes, a stroke contour formed between the side walls and having an inner face against which the vanes bear during rotation of the rotor, and a pair of openings one of which serves for charging the delivery cells with a liquid medium and the other of which serves for discharging the pressurized medium.

1 . A vane-type pump, with
 a housing,   a rotationally drivable rotor,   which has a number of slots,   which in each case receive a displaceable vane,   conveying cells of variable volume being formed between successive vanes, with   a pump space receiving the rotor having the vanes, with side faces bearing laterally against the rotor and against the vanes and with a stroke contour which is arranged between the side faces and against which the outer ends of the vanes bear when the vane-type pump is in operation, and with   ports which are provided in the side faces and at least one of which serves for filling the conveying cells and at least one of which serves for discharging a pressurized medium conveyed by the conveying cells,   the medium containing water, alcohols, such as ethanol, ammonia or other organic liquids or a mixture of said substances, and also a lubricant, the specific weight and/or the viscosity of which are/is higher than those of the remaining constituents of the medium,   
       wherein
 an outer margin of the ports which faces the stroke contour is arranged at a distance (x) from the stroke contour. 
 
     
     
         2 . The vane-type pump as claimed in  claim 1 , wherein the outer contour of the rotor is arranged at a distance (y) from the stroke contour. 
     
     
         3 . The vane-type pump as claimed in  claim 2 , wherein the distance (y) of the rotor from the stroke contour corresponds to, is preferably identical to, the distance of (x) of the margin of the ports from the stroke contour. 
     
     
         4 . The vane-type pump as claimed in  claim 1 , wherein the distance (x 1 y) is selected in the range of 0.1 mm to 2 mm and is preferably 0.7 mm to 1.3 mm, in particular 1 mm. 
     
     
         5 . A heat recovery device having an evaporation circuit which comprises a vane-type pump having a housing, a rotationally drivable rotor which has a number of slots, which in each case receive a displaceable vane, conveying cells of variable volume being formed between successive vanes, a pump space receiving the rotor having the vanes with side faces bearing laterally against the rotor and against the vanes and with a stroke contour which is arranged between the side faces and against which the outer ends of the vanes bear when the vane-type pump is in operation, and ports which are provided in the side faces and at least one of which serves for filling the conveying cells and at least one of which serves for discharging a pressurized medium conveyed by the conveying cells, the medium containing water, alcohols, such as ethanol, ammonia or other organic liquids or a mixture of said substances, and also a lubricant, the specific weight and/or the viscosity of which are/is higher than those of the remaining constituents of the medium, wherein an outer margin of the ports which face the stroke contour is arranged at a distance from the stroke contour, which contains a medium to be evaporated, the medium containing a lubricant, the specific weight of which is higher than that of the remaining constituents of the medium and/or the viscosity of which is higher than that of the remaining constituents of the medium. 
     
     
         6 . A vane-type pump, comprising:
 a housing defining a pump space and first and second ports; and   a rotor operably disposed for rotation within said pump space, said rotor having a plurality of slots each having a displaceable vane disposed therein such that conveying cells are formed in said pump space between adjacent vanes;   wherein said pump space includes a pair of side faces bearing laterally against opposite sides of said rotor and said vanes, and a stroke contour arranged between said pair of side surfaces and having an inner face against which the outer ends of said vanes bear when said vane-type pump is in operation, said first and second ports being formed in said side faces with said first port configured to fill said conveying cells with a medium and said second port configured to discharge the pressurized medium conveyed by said conveying cells, said medium including a lubricant mixed with one or more other liquid constituents including water, alcohols, ammonia or other organic liquids, said lubricant having a specific weight and/or viscosity which is greater than the other liquid constituents of said medium;   wherein an outer margin of said first and second ports which faces said stroke contour is arranged at a distance (x) from said inner face of said stroke contour, whereby rotation of said rotor in said pump chamber causes said lubricant to be centrifugally displaced into engagement with said stroke contour and define a lubrication ring on said inner face.   
     
     
         7 . The vane-type pump as claimed in  claim 6 , wherein a thickness of said lubrication ring corresponds to said distance (x) between said inner face of said stroke contour and said outer margin of said first and second ports. 
     
     
         8 . The vane-type pump as claimed in  claim 6 , wherein due to the higher specific weight of said lubricant, said lubrication ring only includes small fractions of said other liquid constituents of said medium. 
     
     
         9 . The vane-type pump as claimed in  claim 6 , wherein said rotor includes an outer contour defining an outer face, and wherein said outer face of said rotor is maintained at a minimum distance (y) from said stroke contour.