# US 8,770,934 B2 · Teeter mechanism for a multiple-bladed wind turbine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,934 B2 - Document ID: US8770934B2 - Status: Granted - Kind: B2 - Application number: 12/639,027 - Filed: 2009-12-16 - Published: 2011-06-16 - Granted: 2014-07-08 - Earliest claimed: 2009-12-16 - Assignees: Hamilton Sundstrand Corporation - Applicants: Robert H. Perkinson - Inventors: Robert H. Perkinson - Web page: https://patentgrep.com/patent/US8770934B2 ## CPC - F03D 1/0658: {Arrangements for fixing wind-engaging parts to a hub} - F03D 13/20: Arrangements for mounting or supporting wind motors; Masts or towers for wind motors - F03D 80/00: Details, components or accessories not provided for in groups F03D1/00 - F03D17/00 - F03D 80/70: Bearing or lubricating arrangements - Y02E 10/72: Wind turbines with rotation axis in wind direction - Y02E 10/728: Onshore wind turbines - F03D: WIND MOTORS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A teeter mechanism for a multiple-bladed wind turbine includes a rotor shaft operable to rotate about a first axis. A spherical member is rotatable about the first axis along with the rotor shaft. A plurality of turbine blades is mounted to a rotor hub. The rotor hub rotationally drives the rotor shaft, and is operable to teeter about the spherical member such that the rotor hub rotates about the first axis in a first position and rotates about a second axis offset from the first axis in a second, teeter position. ## Claims ### Claim 1 A teeter mechanism for a multiple-bladed wind turbine, comprising: a rotor shaft operable to rotate about a first axis; a spherical member rotatable about the first axis along with the rotor shaft; a rotor hub for mounting a plurality of turbine blades to rotationally drive the rotor shaft, wherein the rotor hub is operable to teeter about the spherical member such that the rotor hub rotates about the first axis in a first position and rotates about a second axis offset from the first axis in a second, teeter position; and a pin roller fastened to the spherical member and received into a slot within the rotor hub, the pin roller being operable to translate rotation of the rotor hub to rotation of the rotor shaft. ### Claim 2 (depends on 1) The mechanism of claim 1, further comprising: an annular damper lining a circular opening at a front of the rotor hub; and a center post coaxially aligned with the rotor shaft, wherein in the second, teeter position the center post compresses a portion of the damper such that the damper limits an amount of teeter experienced by the rotor hub. ### Claim 3 (depends on 2) The mechanism as recited in claim 2, wherein the annular damper is attached at one axial end thereof to a first washer that extends from the rotor hub and at an opposed axial end thereof to a second washer that extends from the center post. ### Claim 4 (depends on 1) The mechanism of claim 1, further comprising: a plurality of base plates, each base plate corresponding to one of the plurality of turbine blades and being operable to rotate about an axis formed by its corresponding turbine blade to adjust a pitch of the corresponding turbine blade; and a plurality of pins, each pin corresponding to one of the base plates, and extending from its corresponding base plate into an opening of a yoke plate, such that the corresponding base plate is operable to add or subtract pitch angle to its corresponding turbine blade as function of teeter angle. ### Claim 5 (depends on 4) The mechanism of claim 4, wherein each pin extends from its corresponding base plate at a location offset from a center point of its corresponding base plate. ### Claim 6 (depends on 4) The mechanism of claim 4, wherein each pin includes: a first portion that extends from its corresponding base plate and has a spherical end; a second portion that extends from the yoke plate and has a spherical end; and a third, turnbuckle portion that links the spherical ends of the first and second portions. ### Claim 7 (depends on 1) The mechanism of claim 1, further comprising: a gear portion on each of the plurality of turbine blades; and pitch change motor operable to engage the gear portion of each of the plurality of turbine blades to adjust a pitch of each of the plurality of turbine blades, wherein the pitch change motor is operable to permit independent changes in pitch due to teeter base plate rotation within a predefined range. ### Claim 8 (depends on 1) The mechanism of claim 1, further comprising an expandable/contractible environmental shield around the spherical member. ### Claim 9 (depends on 8) The mechanism as recited in claim 8, wherein the environmental shield is made of an elastomeric material. ### Claim 10 (depends on 1) The mechanism as recited in claim 1, wherein the spherical member is mounted at an end of the rotor shaft and is coaxial therewith. ### Claim 11 (depends on 1) The mechanism of claim 1, further comprising a wear-resistant bearing upon which the spherical member is mounted, the wear-resistant bearing being located between the spherical member and the rotor hub. ### Claim 12 (depends on 1) The mechanism as recited in claim 1, wherein the turbine blades are mounted on respective ones of a plurality of ring bearings such that the turbine blades are rotatable upon their respective ring bearings to change pitch. ### Claim 13 A teeter mechanism for a multiple-bladed wind turbine, comprising: a rotor shaft operable to rotate about a first axis; a center post coaxially aligned with the rotor shaft; a yoke plate adjustably secured on the center post such that an axial position of the yoke plate on the center post is variable, the yoke plate being rotatable about the first axis along with the rotor shaft; a rotor hub rotatable about the first axis in a first position and rotatable about a second axis offset from the first axis in a second, teeter position; and at least three turbine blades extending radially outward from the rotor hub, each turbine blade having a pin and a base plate, each pin extending from its corresponding base plate into an opening in the yoke plate, such that each base plate is operable to add or subtract pitch angle to its corresponding turbine blade as function of teeter angle. ### Claim 14 (depends on 13) The mechanism of claim 13, further comprising: a spherical member rotatable about the first axis along with the rotor shaft, wherein the rotor hub teeters about the spherical member in the second, teeter position. ### Claim 15 (depends on 13) The mechanism of claim 13, further comprising: an annular damper lining a circular opening at a front of the rotor hub; and wherein in the second, teeter position the center post compresses a portion of the damper such that the damper limits an amount of teeter experienced by the rotor hub. ### Claim 16 (depends on 13) The mechanism of claim 13, wherein each pin extends from its corresponding base plate at a location offset from a center point of its corresponding base plate. ### Claim 17 (depends on 13) The mechanism of claim 13, wherein each pin includes: a first portion that extends from its corresponding base plate and has a spherical end; a second portion that extends from the yoke plate and has a spherical end; and a third, turnbuckle portion that links the spherical ends of the first and second portions. ### Claim 18 (depends on 13) The mechanism of claim 13, further comprising: a gear portion on each turbine blade; and pitch change motor operable to engage the gear portion of each turbine blade to adjust a pitch of each turbine blade, wherein the pitch change motor is operable to permit independent changes in pitch due to teeter base plate rotation within a predefined range. ### Claim 19 (depends on 13) The mechanism of claim 13, further comprising a plurality of adjustable fasteners mounted on the center post adjacent axial sides of the yoke plate, the plurality of adjustable fasteners being adjustable to vary the axial position of the yoke plate on the center post. ### Claim 20 (depends on 19) The mechanism of claim 19, wherein the plurality of adjustable fasteners are nuts. ### Claim 21 A teeter mechanism for a multiple-bladed wind turbine, comprising: a rotor shaft operable to rotate about a first axis; a yoke plate rotatable about the first axis along with the rotor shaft; a rotor hub rotatable about the first axis in a first position and rotatable about a second axis offset from the first axis in a second, teeter position; at least three turbine blades extending radially outward from the rotor hub, each turbine blade having a pin and a base plate, each pin extending from its corresponding base plate into an opening in the yoke plate, such that each base plate is operable to add or subtract pitch angle to its corresponding turbine blade as function of teeter angle; a spherical member rotatable about the first axis along with the rotor shaft, wherein the rotor hub teeters about the spherical member in the second, teeter position; and a pin roller fastened to the spherical member and received into a slot within the rotor hub, the pin roller being operable to translate rotation of the rotor hub to rotation of the rotor shaft. ### Claim 22 A method of facilitating teeter in a wind turbine, comprising: receiving a spherical member into a rotor hub, the rotor hub having at least three radially extending turbine blades; receiving a pin roller fastened to the spherical member into a slot within the rotor hub, the pin roller being operable to translate rotation of the rotor hub to rotation of a rotor shaft; rotating the rotor hub and plurality of turbine blades to rotationally drive the rotor shaft about a first axis; and teetering the rotor hub about the spherical member such that the rotor hub and plurality of turbine blades rotate about a second axis, offset from the first axis, in response to wind shear.