A camshaft phaser for controllably varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine, said camshaft phaser comprising: a housing connectable to said crankshaft and having a housing bore extending along an axis and a plurality of lobes extending radially inward such that a space is formed between adjacent ones of said plurality of lobes; a stroke limiter connectable to said camshaft and disposed coaxially within said housing, said stroke limiter having a central hub with a plurality of vanes extending radially outward therefrom such that each one of said plurality of vanes extends into a respective said space formed between adjacent ones of said plurality of lobes; and a harmonic gear drive unit disposed operationally between said housing and said stroke limiter, said harmonic gear drive unit being connected to a rotational actuator for imparting rotation on said harmonic gear drive unit such that rotation of said harmonic gear drive unit by said rotational actuator causes relative rotation between said housing and said stroke limiter; whereby the amount of relative rotation between said housing and said stroke limiter is limited by at least one of said plurality of lobes and at least one of said plurality of vanes, wherein said plurality of vanes of a rotor form journal bearing interfaces with said housing bore, whereby said journal bearing interfaces substantially prevent radial movement and tipping of said stroke limiter within said housing, wherein at least one of said plurality of vanes includes an oil passage for communicating oil to at least one of said journal bearing interfaces, wherein the camshaft phaser further comprises a back cover attached to one axial end of said housing; and a front cover attached to the other axial end of said housing and, wherein said housing is clamped between said back cover and said front cover with a plurality of bolts which threadably engage one of said back cover and said front cover such that each one of said plurality of bolts extends through a respective one of said plurality of lobes of said housing. a housing connectable to said crankshaft and having a housing bore extending along an axis and a plurality of lobes extending radially inward such that a space is formed between adjacent ones of said plurality of lobes; a stroke limiter connectable to said camshaft and disposed coaxially within said housing, said stroke limiter having a central hub with a plurality of vanes extending radially outward therefrom such that each one of said plurality of vanes extends into a respective said space formed between adjacent ones of said plurality of lobes; and a harmonic gear drive unit disposed operationally between said housing and said stroke limiter, said harmonic gear drive unit being connected to a rotational actuator for imparting rotation on said harmonic gear drive unit such that rotation of said harmonic gear drive unit by said rotational actuator causes relative rotation between said housing and said stroke limiter; whereby the amount of relative rotation between said housing and said stroke limiter is limited by at least one of said plurality of lobes and at least one of said plurality of vanes, wherein said plurality of vanes of a rotor form journal bearing interfaces with said housing bore, whereby said journal bearing interfaces substantially prevent radial movement and tipping of said stroke limiter within said housing, wherein at least one of said plurality of vanes includes an oil passage for communicating oil to at least one of said journal bearing interfaces, wherein the camshaft phaser further comprises a back cover attached to one axial end of said housing; and a front cover attached to the other axial end of said housing and, wherein said housing is clamped between said back cover and said front cover with a plurality of bolts which threadably engage one of said back cover and said front cover such that each one of said plurality of bolts extends through a respective one of said plurality of lobes of said housing.