US-12617527-B1 - Scissoring mechanisms deploying at low speed

US12617527B1US 12617527 B1US12617527 B1US 12617527B1US-12617527-B1

Abstract

Embodiments provide scissoring mechanisms for a vertical lift fan of an electric aircraft (e.g., a vertical take-off-landing eVTOL aircraft) where the blades of the vertical lift fan can be opened at almost zero speed. Exemplary scissoring mechanisms have position locking features that keep the collapsed blades in the low drag orientation once closed (e.g., in the stowed position). As a result, the scissoring mechanisms do not cause large impulses during opening and closing that cause large stresses and noise. In addition, the scissoring mechanisms provide an opportunity to check that the fans are opened properly prior to spinning them to the full operating speed. The scissoring mechanisms may not require an extra actuator, and rely on the propulsion motor.

Inventors

Geoffrey Alan LONG
Chase Nichols
Patrick Kelly

Assignees

WISK AERO LLC

Dates

Publication Date: 20260505
Application Date: 20240820

Claims (15)

1 . A system comprising: a motor, a driven blade coupled to a driven rotor rotating around a first shaft coupled to the motor, a following blade coupled to a following rotor rotating around a second shaft concentric with the first shaft, and a scissoring mechanism configured to move the following blade and the driven blade between a stowed configuration and a deployed configuration, the scissoring mechanism comprising: a positioning mechanism configured to keep the following blade and the driven blade in the stowed configuration, wherein disengaging the positioning mechanism moves the driven blade to a predetermined angle with respect to the following blade in the deployed configuration while the motor is operating at zero or near-zero speed; and a latch mechanism configured to keep the following blade and the driven blade in the deployed configuration, wherein engaging the latch mechanism locks the following blade at the predetermined angle with respect to the driven blade in the deployed configuration allowing the following blade and the driven blade to rotate together, wherein: the positioning mechanism includes a first arm and a second arm coupled to each other via a pair of scissoring links and a pair of springs, wherein the first arm is coupled to the second shaft and the second arm is coupled to the first shaft, in the stowed configuration, the pair of springs keep the pair of scissoring links in a closed configuration, wherein in the deployed configuration, the pair of springs keep the pair of scissoring links in an open and extended configuration, the latch mechanism includes a pawl provided on at least one of the first arm or the second arm, and a detent, and in the stowed configuration, a portion of the pawl is caught in the detent.
2 . The system of claim 1 , wherein the driven blade and the following blade are provided on a first side of the motor, and the scissoring mechanism is provided on a second side of the motor, opposite to the first side.
3 . The system of claim 1 , wherein the pawl of the latch mechanism is coupled only to the first arm.
4 . The system of claim 1 , wherein a pair of opposite polarity magnets are coupled to the pawl and the detent of the latch mechanism, respectively, such that in the stowed configuration, the pawl is held on the detent by a magnetic force.
5 . The system of claim 1 , further comprising: a plurality of sensors including at least a first sensor positioned on the motor and having a corresponding first magnet located on the first arm, and a second sensor positioned on the motor and having a corresponding second magnet located on the second arm, wherein the first magnet and the second magnet trigger the first sensor and the second sensor, respectively, at a preset voltage threshold.
6 . The system of claim 1 , wherein the near-zero speed is less than or equal to about 5 rpm.
7 . The system of claim 1 , comprising a lift fan including the motor, the driven blade, the following blade, and the scissoring mechanism.
8 . The system of claim 1 , wherein in case of system failure, the driven blade and the following blade remain locked in the deployed configuration.
9 . A system comprising: a motor, a driven blade coupled to a driven rotor rotating around a first shaft coupled to the motor, a following blade coupled to a following rotor rotating around a second shaft concentric with the first shaft, and a scissoring mechanism configured to move the following blade and the driven blade between a stowed configuration and a deployed configuration, the scissoring mechanism comprising: a positioning mechanism configured to keep the following blade and the driven blade in the stowed configuration, wherein disengaging the positioning mechanism moves the driven blade to a predetermined angle with respect to the following blade in the deployed configuration while the motor is operating at zero or near-zero speed; and a latch mechanism configured to keep the following blade and the driven blade in the deployed configuration, wherein engaging the latch mechanism locks the following blade at the predetermined angle with respect to the driven blade in the deployed configuration allowing the following blade and the driven blade to rotate together, wherein: the positioning mechanism includes: a disengageable coupler having a fixed portion coupled to the first shaft and a sliding portion coupled to the second shaft, a solenoid configured to disengage and engage the sliding portion with the fixed portion, and a spring configured to re-engage the sliding portion and the fixed portion, and the latch mechanism is incorporated in the positioning mechanism through the solenoid.
10 . The system of claim 9 , wherein while moving the following blade and the driven blade from the stowed configuration to the deployed configuration, the solenoid disengages the sliding portion from the fixed portion when the solenoid is energized allowing the driven blade to move with respect to the following blade, and engages the sliding portion from the fixed portion when the solenoid is deenergized allowing the driven blade to remain at a predetermined angle with respect to the following blade.
11 . The system of claim 9 , wherein the near-zero speed is less than or equal to about 5 rpm.
12 . The system of claim 9 , comprising a lift fan including the motor, the driven blade, the following blade, and the scissoring mechanism.
13 . The system of claim 9 , wherein in case of system failure, the driven blade and the following blade remain locked in the deployed configuration.
14 . An aircraft comprising one or more lift fans each including the system of claim 1 .
15 . An aircraft comprising one or more lift fans each including the system of claim 9 .

Description

CROSS-REFERENCES TO OTHER APPLICATIONS This application is a division of U.S. patent application Ser. No. 17/948,135 filed Sep. 19, 2022 and entitled “Scissoring Mechanisms Deploying At Low Speed”, which claims benefit under 35 USC § 119 (e) to U.S. Provisional Patent Application No. 63/245,788 filed Sep. 17, 2021 and entitled “Scissoring Mechanisms Deploying At Low Speed”, and U.S. Provisional Patent Application No. 63/279,613 filed Nov. 15, 2021 and entitled “Scissoring Mechanisms Deploying At Low Speed”, the disclosures of which are incorporated by reference herein in their entirety for all purposes. BACKGROUND Lift fans (e.g., for vertical flight) in an electric aircraft (e.g., a vertical take-off-landing eVTOL aircraft) have deployed and stowed configurations. The lift fans are in the deployed configuration during vertical flight to provide lift to the electric aircraft. The lift fans are in the stowed configuration during a forward flight of the electric aircraft to reduce drag. A scissoring mechanism for the lift fans (e.g., four-bladed fans) allow the fans to move between the deployed configuration where the fans are about 90 degrees apart, and the stowed (e.g., collapsed) configuration where the fans are on top of each other, aligned for a low drag configuration in forward flight. There may be one motor that drives both sets of blades. The scissoring mechanism allows that one motor to apply both positive and negative torque to both sets of blades without them collapsing. Existing scissoring mechanisms deploy at high speeds (e.g., speeds above 1000 rpm) and require a torque (e.g., an impact event) to be applied to the blades. Both of these requirements have negative impacts on an aircraft in flight. Embodiments address these and other problems, individually or collectively. SUMMARY Embodiments provide scissoring mechanisms for an electric aircraft (e.g., a vertical take-off-landing eVTOL aircraft) where the blades of the fan can be opened at almost zero speed. Exemplary scissoring mechanisms have position locking features that keep the collapsed blades in the low drag orientation once closed (e.g., in the stowed position). As a result, the scissoring mechanisms do not cause large impulses during opening and closing that cause large stresses and noise. In addition, the scissoring mechanisms provide an opportunity to check that the fans are opened properly prior to spinning them to the full operating speed. According to various embodiments, the scissoring mechanisms do not require an extra actuator, and rely on the propulsion motor. Some embodiments provide a system comprising a motor, a driven blade coupled to a driven rotor rotating around a first shaft coupled to the motor, a following blade coupled to a following rotor rotating around a second shaft concentric with the first shaft, and a scissoring mechanism configured to move the following blade and the driven blade between a stowed configuration and a deployed configuration. The scissoring mechanism comprises a positioning mechanism and a latch mechanism. The positioning mechanism is configured to keep the following blade and the driven blade in the stowed configuration. Disengaging the positioning mechanism moves the driven blade to a predetermined angle with respect to the following blade in the deployed configuration while the motor is operating at zero or near-zero speed. The latch mechanism is configured to keep the following blade and the driven blade in the deployed configuration. Engaging the latch mechanism locks the following blade at the predetermined angle with respect to the driven blade in the deployed configuration allowing the following blade and the driven blade to rotate together. According to various embodiments, the system comprises a lift fan including the motor, the driven blade, the following blade, and the scissoring mechanism. Embodiments may further provide an aircraft comprising one or more of lift fans each including the above-described system. In some embodiments, the scissoring mechanism further comprises a latch ring that is fixed to the second shaft, a following ring that is fixed to the following rotor, and a driven ring fixed to the first shaft. The latch ring, the driven ring and the following ring are stacked around the second shaft. The positioning mechanism includes a driven pawl coupled to the driven ring and a following detent formed on the following ring. The driven pawl is released from a closed configuration when the motor starts operating at near-zero speed and engages the following detent. The latch mechanism includes a following pawl provided on the following ring, and a driven detent formed on the driven ring. In the deployed configuration, at least a portion of the following pawl is caught in the driven detent. In some embodiments, the positioning mechanism includes a first arm and a second arm coupled to each other via a pair of scissoring links and a pair of springs. The first arm is coupled to t