Pump shaft with fastening bolts

Abstract

A retaining device for an impeller of a centrifugal pump, including: a pump shaft with a recess formed substantially parallel to the axis of rotation of the pump shaft; a fastening bolt, which is insertable into the recess such that a first channel is defined between the inserted fastening bolt and the pump shaft and which is connected to the pump shaft on one end thereof and provides a retainer for fixing the impeller on the other end thereof; wherein the pump shaft includes at least one further channel extending from the circumferential surface of the pump shaft up to and into the recess and allowing the first channel to be emptied.

1 . A retaining device for an impeller of a centrifugal pump, comprising:
 a pump shaft with an opening formed substantially parallel to an axis of rotation of the pump shaft;   a fastening bolt insertable into the opening such that a channel is defined between the inserted fastening bolt and the opening of the pump shaft,   wherein the fastening bolt is connected to the pump shaft on one end thereof and provides a retainer for fixing the impeller on an other end thereof,   wherein the pump shaft comprises at least one further channel extending from a circumferential surface of the pump shaft up to and into a recess and allowing the channel defined between the inserted fastening bolt and the opening of the pump shaft to be emptied.   
     
     
         2 . The retaining device according to  claim 1 , wherein the fastening bolt is a threaded bolt having a thread on at least one of its ends. 
     
     
         3 . The retaining device according to  claim 1 , wherein the retainer is provided with a thread and bracing is accomplished by screwing. 
     
     
         4 . The retaining device according to  claim 1 , wherein the fastening bolt is insertable into and removable from a bore from at least one end of the pump shaft. 
     
     
         5 . The retaining device according to  claim 1 , wherein the opening formed substantially parallel to the axis of rotation of the pump shaft extends through a length of the pump shaft. 
     
     
         6 . The retaining device according to  claim 1 , wherein the opening formed substantially parallel to the axis of rotation of the pump shaft does not extend through a length of the pump shaft. 
     
     
         7 . A centrifugal pump for use in plants for producing foodstuff, cosmetics and pharmaceutical products, comprising:
 a pump casing;   an impeller with impeller blades for feeding a medium in the pump casing; and   a retaining device comprising:
 a pump shaft with an opening formed substantially parallel to an axis of rotation of the pump shaft; 
 a fastening bolt insertable into the opening such that a channel is defined between the inserted fastening bolt and the opening of the pump shaft, 
   wherein the fastening bolt is connected to the pump shaft on one end thereof and provides a retainer for fixing the impeller on an other end thereof, and   wherein the pump shaft comprises at least one further channel extending from a circumferential surface of the pump shaft up to and into a recess and allowing the channel defined between the inserted fastening bolt and the opening of the pump shaft to be emptied.   
     
     
         8 . The centrifugal pump according to  claim 7 , wherein, measured along the axis of rotation of the pump shaft, the channel in the pump shaft is longer than a thickness of the impeller and of an area which one or a plurality of mechanical seals on the pump shaft overlap. 
     
     
         9 . The centrifugal pump according to  claim 7 , further comprising one or a plurality of mechanical seals for sealing the pump shaft against the pump casing. 
     
     
         10 . The centrifugal pump according to  claim 9 , wherein an area between the plurality of mechanical seals is configured to be rinsed. 
     
     
         11 . The centrifugal pump according to  claim 7 , wherein the pump shaft is provided with one or a plurality of channels in an area in which the pump casing overlaps the pump shaft, the channels extending from the circumferential surface of the pump shaft up to the opening, which is formed substantially parallel to the axis of rotation of the pump shaft, and allowing access to the channel defined between the inserted fastening bolt and the opening of the pump shaft. 
     
     
         12 . The centrifugal pump according to  claim 11 , wherein the plurality of channels in the area in which the pump casing overlaps the pump shaft allow communication between the channel defined between the inserted fastening bolt and the opening of the pump shaft and an area behind the internal sealing elements. 
     
     
         13 . The centrifugal pump according to  claim 7 , wherein the pump casing and/or the impeller are replaceable. 
     
     
         14 . The centrifugal pump according  claim 7 , wherein the pump shaft is connectable to a motor shaft. 
     
     
         15 . The centrifugal pump according to  claim 7 , wherein the pump shaft is adapted to be braced onto a motor shaft via a clamping element.