Ring generator

Abstract

A ring generator of a wind power installation is provided comprising a stator having a peripherally extending stator ring for receiving stator windings and a rotor mounted rotatably about an axis of rotation relative to the stator, wherein the stator ring has cooling passages for cooling the stator by an air flow. A ring generator of a wind power installation is also provided having a stator, a peripherally extending stator ring for receiving stator windings, a rotor mounted rotatably relative to the stator and a stator bell connected to the stator ring for providing a pressure chamber with an increased or reduced pressure for providing an air flow through and/or along the stator and/or rotor for cooling the ring generator, wherein the stator bell has at least one fan opening provided with a fan.

1 . A ring generator of a wind power installation comprising:
 a stator having a peripherally extending stator ring for receiving a laminated core with stator windings; and   a rotor mounted rotatably about an axis of rotation relative to the stator, wherein the ring generator is in the form of an internal rotor and the stator ring has cooling passages for cooling the stator by an air flow.   
     
     
         2 . A ring generator according to  claim 1  wherein at least some cooling passages are provided for active cooling by a forced air flow and/or some cooling passages are provided for passive cooling in particular by the wind. 
     
     
         3 . A ring generator according to  claim 1 , further comprising:
 a stator bell connected to the stator, in particular the stator ring, for providing a pressure chamber with an increased or a reduced pressure for providing an active air flow through and/or along the stator and/or rotor for cooling the ring generator.   
     
     
         4 . A ring generator according to  claim 3  wherein with respect to the axis of rotation the stator ring has an inner ring portion for active cooling and an outer ring portion for passive cooling and the stator bell is so fixed to the stator ring that only the inner ring portion receives an afflux flow of the active cooling air flow. 
     
     
         5 . A ring generator according to  claim 3  wherein the stator bell is adapted to carry the stator ring. 
     
     
         6 . A ring generator according to  claim 3  wherein at least one fan opening having a fan is provided in the stator bell. 
     
     
         7 . A ring generator according to  claim 1  wherein some or all cooling passages extend axially with respect to the axis of rotation. 
     
     
         8 . A ring generator according to  claim 1  wherein a plurality of cooling passages are arranged concentrically around the axis of rotation and form at least one ring-shaped cooling region. 
     
     
         9 . A ring generator according to  claim 1  wherein in the radial direction with respect to the axis of rotation, the stator ring has an inner and an outer and optionally a central stabilizing carrier ring, wherein a ring-shaped cooling region is provided at least between two carrier rings. 
     
     
         10 . A ring generator according to  claim 9  wherein the central stabilizing carrier ring is provided and further comprising:
 a stator bell fixed to the central stabilizing carrier ring such that the stator ring and hence the stator is carried by the stator bell. 
 
     
     
         11 . A ring generator according to  claim 9  wherein adjacent cooling passages of a cooling region are delimited from each other by boundary walls and the boundary walls form connecting limbs between two adjacent stabilizing carrier rings and/or two adjacent carrier rings are connected together by cooling ribs. 
     
     
         12 . A ring generator according to  claim 1  wherein at least one the cooling passages of at least one cooling region are of a triangular shape in axial cross-section and/or two respective adjacent cooling passages together in axial cross-section form the shape of a parallelogram and/or the cooling passages have at least one cooling rib facing towards the inside of the cooling passage. 
     
     
         13 . A ring generator according to  claim 1  wherein the stator ring is segmented, in particular being composed of two, three, four or more substantially symmetrical segments. 
     
     
         14 . A ring generator according to  claim 1  wherein the stator ring at least in the region of the cooling passages is made from aluminum or an aluminum alloy. 
     
     
         15 . A ring generator according to  claim 1  further including passive cooling passages each having an intake flow opening facing in the axial direction and an at least partially radially outwardly facing outlet flow opening. 
     
     
         16 . A ring generator according to  claim 15  wherein the outlet flow opening is in the form of a suction opening so that a wind providing an axial afflux flow to the stator ring from the exterior produces a suction action at the outlet flow opening and/or has a curved surface to promote a suction action on the outlet flow opening of the stator ring in the axial direction in the region of the outlet flow opening. 
     
     
         17 . A ring generator of a wind power installation comprising:
 a stator having a peripherally extending stator ring for receiving stator windings;   a rotor mounted rotatably relative to the stator; and   a stator bell connected to the stator ring for providing a pressure chamber with an increased or reduced pressure for providing an air flow through and/or along the stator and/or rotor for cooling the ring generator, the stator bell having at least one fan opening provided with a fan mounted movably thereto to enable selective opening of the fan opening for maintenance purposes.   
     
     
         18 . A ring generator according to  claim 17  wherein the fan is mounted to the stator bell by a motion mechanism. 
     
     
         19 . A ring generator according to  claim 17  wherein the stator bell has a first fixing portion for fixing to a machine carrier of a wind power installation and a plurality of carrier portions, in particular carrier arms, which extend therefrom in a star-shaped arrangement outwardly to a second fixing portion for fixing to the stator ring, so that the stator ring can be carried by way of the carrier portions on the machine carrier. 
     
     
         20 . A ring generator according to  claim 19  wherein the at least one fan opening is respectively arranged between two carrier portions. 
     
     
         21 . A ring generator according to  claim 17  wherein the stator bell substantially comprises metal, in particular cast iron, preferably spheroidal cast iron, and/or is cast in one piece. 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . A ring generator according to  claim 1  wherein the ring generator has a nominal power of at least 30 kW. 
     
     
         25 . A method of controlling a wind power installation, wherein the wind power installation has a ring generator having a rotor and a stator, including the steps:
 detecting the electric power generated by the ring generator; and   switching on at least one fan installed in a stator bell to produce an air flow through and/or along the stator and/or rotor for cooling the ring generator if the detected electric power reaches or exceeds a predetermined value.   
     
     
         26 . A method according to  claim 25  wherein nominal power is established as the predetermined value. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled) 
     
     
         29 . A wind power installation, comprising:
 a pod, and   a ring generator, the ring generator including a stator having a peripherally extending stator ring for receiving a laminated core with stator windings, and a rotor mounted rotatably about an axis of rotation relative to the stator, wherein the ring generator is in the form of an internal rotor, wherein, except for an outer portion of the stator ring, the ring generator is arranged within the pod and wherein the outer portion of the stator ring is arranged outside the pod to receive an afflux flow of wind for cooling purposes.   
     
     
         30 . A wind power installation according to  claim 29  wherein the outer portion of the stator ring has cooling passages for passive cooling, which are directly exposed to the wind. 
     
     
         31 . A wind power installation according to  claim 29  wherein the pod is so shaped aerodynamically that the wind can flow substantially laminarly along the pod to the outer portion of the stator ring to promote a cooling action at the outer portion of the stator ring. 
     
     
         32 . A wind power installation according to  claim 29  wherein flow means are provided outside the pod in the region of the outer portions of the stator ring for promoting a flow of wind along the outer portion of the stator ring. 
     
     
         33 . A ring generator according to  claim 1  wherein the stator ring at least in the region of the cooling passages is cast from a material. 
     
     
         34 . A ring generator according to  claim 17  wherein the fan is mounted to the stator bell by a motion mechanism in the form of a pivotal mechanism.