  We construct helium (He) star models with optically thick winds and compare
them with the properties of Galactic Wolf-Rayet (WR) stars. Hydrostatic He-core
solutions are connected smoothly to trans-sonic wind solutions that satisfy the
regularity conditions at the sonic point. Velocity structures in the supersonic
parts are assumed by a simple beta-type law. By constructing a
center-to-surface structure, a mass-loss rate can be obtained as an eigenvalue
of the equations. Sonic points appear at temperatures ~ 1.8e5 - 2.8e5 K below
the Fe-group opacity peak, where the radiation force becomes comparable to the
local gravity. Photospheres are located at radii 3-10 times larger than sonic
points. The obtained mass-loss rates are comparable to those of WR stars. Our
mass-loss rate - luminosity relation agrees well with the relation recently
obtained by Graefener et al. (2017). Photospheric temperatures of WR stars tend
to be cooler than our predictions. We discuss the effects of stellar evolution,
detailed radiation transfer, and wind clumping, which are ignored in this
paper.
