Rotary vane pump vane wear detection

Abstract

An assembly for detecting wear of a vane of a rotary vane pump, the assembly comprising: a vane configured to be mounted in a radial slot of a rotor of a rotary vane pump, the vane having a vane body of non-electrically conductive material, the vane body configured to, in use, extend from the slot to contact an electrically earthed housing of the rotor; the vane being provided with a marking having at least one characteristic that varies in the radial direction; the assembly further comprising a sensing device fixed relative to the housing and arranged to read the marking at a predetermined radial distance from the housing, whereby the characteristic of the marking that is read by the sensing device is indicative of wear of the vane.

1 . An assembly for detecting wear of a vane of a rotary vane pump, the assembly comprising: a vane configured to be mounted in a radial slot of a rotor of a rotary vane pump, the vane having a vane body of non-electrically conductive material, the vane body configured to, in use, extend from the slot to contact an electrically earthed housing of the rotor; the vane being provided with a marking having at least one characteristic that varies in the radial direction; the assembly further comprising a sensing device fixed relative to the housing and arranged to read the marking at a predetermined radial distance from the housing, whereby the characteristic of the marking that is read by the sensing device is indicative of wear of the vane. 
     
     
         2 . The assembly of  claim 1 , wherein the vane has a first end being the end that contacts the housing in use, and a second, opposite end that is located in the slot in use, and wherein the characteristic of the marking varies in the direction from the first end to the second end. 
     
     
         3 . The assembly of  claim 1 , wherein the sensing device is a laser sensor that emits a laser beam onto the vane to read the marking. 
     
     
         4 . The assembly of  claim 1 , wherein the marking comprises a series of bar codes that vary in the radial direction. 
     
     
         5 . The assembly of  claim 4 , comprising three different bar codes each indicative of a different degree of wear of the vane when read by the sensing device. 
     
     
         6 . The assembly of  claim 1 , wherein the marking is printed onto the vane. 
     
     
         7 . The assembly of  claim 1 , wherein the marking is etched onto the vane. 
     
     
         8 . The assembly of  claim 1 , wherein the marking is adhered to the vane. 
     
     
         9 . The assembly of  claim 1 , wherein the sensing device is a reflection sensor. 
     
     
         10 . The assembly of  claim 9 , wherein the sensing device has varying characteristics to indicate if the degree of wear of the vane is one of ‘good’ or ‘bad’ depending on reception of a signal reflected from the vane. 
     
     
         11 . The assembly of  claim 1 , wherein the sensing device is secured in a holder mounted to or integrally formed with the housing. 
     
     
         12 . A rotary vane pump comprising:
 a rotor;   a rotor housing within which the rotor rotates;   the rotor having a plurality of radial slots;