Abstract: A vane air pump has a vane holder which includes a main body. A vane extends outward from one side of the main body and a balance weight extends outward from the other side of the main body in a direction opposite to the vane. The balance weight is cast integrally with the main body. The method discloses integrally forming a balance weight with the main body of the vane holder.

Abstract: A fiber reinforced plastic drive shaft comprising a pair of metal joint members, an inner plastic layer extending over the entire length of the drive shaft and holding the metal joint members in both end portions thereof, and an outer plastic layer formed on the inner layer. The inner layer comprises continuous carbon fibers helically wound at 45-75 degrees to the axis of the drive shaft, while the outer layer comprises continuous fibers such as carbon fibers, glass fibers, polyester fibers and aramide fibers helically wound at 5-40 degrees to the axis of the drive shaft. The drive shaft has a greatly increased torsional strength and damping effect. The maximum damping effect is provided when the outer layer is formed only over the joint members.

Abstract: A vane type air pump having vanes with an edge that slidably engages the inside of a cylindrical casing and sides that slidably engage carbon sealing elements. The vanes are constructed of pre-impregnated glass cloth with the warp and weft positioned at acute angles to the sealing element to provide less and smoother wear on the sealing element and inhibit air leakage. A heavy density weave of glass cloth also reduces the wear.