Coupling members that join first and second rotary members

A coupling member 300, for connecting first and second rotary members, comprises a unitary body having a first coupling element 302, a second coupling element 304, and a hub 306. The unitary body forms a single piece with the hub 306 extending between and connecting the first and second coupling elements 302, 304. The first and second coupling elements 302 define first and second parallel planes and the hub 306 defines a hub axis normal to the first and second planes. Each of the first and second coupling elements 302, 304 comprise a plurality of connection elements 308, 310 arranged about a respective circumference having a respective radius extending from the hub axis, wherein a material of the respective coupling element in a respective circle and in a respective plane is less than the area of the circle. The coupling elements 302, 305 may be formed as structural branches (408, 410, fig 4A) or other geometric shapes, e.g. triangular. To reduce weight material voids 312, 314 may be provided in the connection elements 308, 310. Also referenced is a method of forming a coupling member.