# US 11,309,754 B2 · Generator with series stators, and series rotors separated by annular collars with cooling vents > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,754 B2 - Document ID: US11309754B2 - Status: Granted - Kind: B2 - Application number: 15/774,330 - Filed: 2016-11-09 - Published: 2020-08-20 - Granted: 2022-04-19 - Earliest claimed: 2015-11-09 - Assignees: Time To Act Limited - Applicants: Greenspur Renewables Limited - Inventors: Hugh-Peter Granville Kelly - Web page: https://patentgrep.com/patent/US11309754B2 ## CPC - H02K 1/2796: where both axial sides of the rotor face a stator - H02K 1/32: with channels or ducts for flow of cooling medium - H02K 7/1838: {Generators mounted in a nacelle or similar structure of a horizontal axis wind turbine} - H02K 9/04: having means for generating a flow of cooling medium - H02K 9/06: with fans or impellers driven by the machine shaft - H02K 9/12: wherein the cooling medium circulates freely within the casing - H02K 16/00: Machines with more than one rotor or stator {(machines for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts H02K51/00; permanent magnet machines with multiple rotors or stators relatively rotated for vectorially combining the excitation fields or the armature voltages H02K21/029)} - H02K 21/24: with magnets axially facing the armatures, e.g. hub-type cycle dynamos - Y02E 10/72: Wind turbines with rotation axis in wind direction - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A generator (10) comprising a series of spaced annular stators (15) sandwiched between a series of rotors (11), the rotors (11) each being separated by annular collars (16), the annular collars (16) defining a central cavity; at least one cooling gas source for supplying gas to the central cavity; vents (23,24,25,26,27,28,31,32,33,34,35) through the annular collars (16) for providing a means of egress for the cooling gas (20) from the central cavity radially outwards over the rotors (11) and the annular stators (15). ## Claims ### Claim 1 A generator comprising: a series of spaced annular stators sandwiched between a series of rotors, the rotors each being separated by annular collars, the annular collars defining a central cavity; at least one cooling gas source for supplying gas to the central cavity; vents through the annular collars for providing a means of egress for the cooling gas from the central cavity radially outwards over the rotors and the annular stators; and a central shaft on which the rotors and annular collars are carried, wherein: the cooling gas source comprises one or more fans caused to rotate by an ancillary electric motor, and the one or more fans are mounted on the central shaft, wherein the diameter and/or number of vents through at least one of the annular collars is gradually increased the further away the at least one annular collar is from the cooling gas source. ### Claim 2 (depends on 1) The generator of claim 1, wherein the number and/or aperture size of the vents is so selected as to ensure a substantially even dispersal of cooling gas over any given pair of rotors and the stator sandwiched between them regardless of the spacial separation of the said pair of rotors and their respective sandwiched stator from the at least one cooling gas source. ### Claim 3 (depends on 1) The generator according to claim 1, wherein the vents are angled relative to a true radius of the collars to assist dispersal of the cooling gas in a spiral direction opposite to the direction of rotation of the collars, in use. ### Claim 4 (depends on 1) The generator according to claim 1, wherein an outlet of each vent in a radially outer surface of the respective annular collar is axially aligned with one or both axial ends of a respective annular stator and/or an axial end of a respective rotor. ### Claim 5 (depends on 1) The generator of claim 1, wherein the cooling gas source comprises two fans, positioned at each end of the central cavity, and configured to feed equal amounts of gas into the central cavity. ### Claim 6 (depends on 1) The generator of claim 1, further comprising one or more radial support members affixed to the rotors and extending inwardly towards the central shaft. ### Claim 7 (depends on 6) The generator of claim 6, wherein the radial support members extend inwardly from the rotors towards housings carrying one or more central bearings mounted upon the central shaft, enabling the rotor assembly to rotate around the central shaft. ### Claim 8 (depends on 6) The generator of claim 6, wherein the radial support members are permanently affixed to the central shaft, such that the rotors and shaft rotate together. ### Claim 9 (depends on 1) The generator according to claim 1, wherein the generator is mounted substantially hermetically within a housing, there being one or more orifices in the housing specifically to permit the intake of cooling gas, and one or more further orifices in the housing for allowing cooling gas to escape. ### Claim 10 (depends on 9) The generator of claim 9, wherein the at least one cooling gas source comprises means for facilitating the forced extraction of the cooling gas through the one or more further orifices. ### Claim 11 (depends on 10) The generator of claim 10, wherein the means for facilitating the forced extraction of the cooling gas comprises one or more fans for sucking gas out of the housing.