Aircraft Torque Tube Assembly With Sliding Spline U-Joint
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Solution Overview
Problem
Existing torque tube assemblies for aircraft high lift devices face issues with large rotational envelopes, bolt loosening, and structural integrity due to wing flexing, which affects torque transmission and alignment.
Innovation Solution
The use of spline connections and U-joints in torque tube assemblies, where one end is fixedly coupled to a drive shaft and the other end is slidably inserted into a channel, allowing axial and angular movement to accommodate wing flexing while maintaining rotational energy transfer, eliminates the need for bolted flanges and reduces dynamic imbalance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If bolted flanges or plates are used to couple torque tube to pinion gear or GRA, then structural connection is achieved, but rotational envelope becomes large and space requirement increases
Solution Approach 1:
The coupling mechanism is divided into a flange portion with bolts and a hub portion with splines, allowing the torque tube to connect to the pinion gear through separate functional segments that reduce overall rotational envelope while maintaining structural strength
Solution Approach 2:
The hub portion is nested within the flange portion, with the splined hub inserted into the bolted flange assembly, creating a compact nested structure that reduces the rotational envelope while maintaining both bolted connection strength and spline engagement
2Strength
If bolted flanges are used to couple torque tube, then structural connection is achieved, but bolts can loosen and structural integrity is reduced
Solution Approach 1:
The splines are pre-formed on the hub portion and the corresponding spline receptacles are pre-formed in the flange portion, creating a predetermined engagement geometry that prevents bolt loosening by distributing loads through the spline teeth rather than relying solely on bolt clamping force
Solution Approach 2:
The coupling assembly combines two connection methods (bolted flange connection and splined connection) into a composite structure, where the bolts provide positional stability and the splines provide torque transmission, creating a more reliable overall connection that prevents bolt loosening
3Power
If rigid torque tube assembly is used, then torque transmission is efficient, but wing flexing causes additional forces and strain on the assembly
Solution Approach 1:
The torque tube assembly is made dynamic by allowing relative movement between the flange portion and hub portion through the spline engagement, enabling the assembly to flex and accommodate wing flexing while maintaining efficient torque transmission through the splined connection
Data Source
Figure 1
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Figure 3~4
AI summary
Example torque tube assemblies for use with aircraft high lift devices are described herein. An example torque tube assembly (200) includes a torque tube (304) having a first end (302) and a second end (308) opposite the first end. A first fitting is coupled to the first end and a second fitting is coupled to the second end. The first fitting is to be coupled to a first high lift device of an aircraft. The second fitting (800) has a spline section (910). The torque tube assembly also includes a sliding spline shaft (804) having a channel (902) and a first yoke (810). The second fitting (800) is slidably received within the channel (902). The torque tube assembly further includes a spline coupling (808) having a second yoke (812), which is coupled to the first yoke (810) of the sliding spline shaft (804) to form a U-joint (806). The spline coupling (808) is to be coupled to a second high lift device of the aircraft.