Patent ID: 7584917

Claim:
A mill for pulverizing a solid fuel, the mill comprising: a substantially closed separator body; a grinding table rotatably mounted on a shaft in the separator body; a grinding roll rotable via a journal assembly disposed in the separator body, the journal assembly being supported so as to be pivotable and move the grinding roll into and out of engagement with solid fuel disposed on the grinding table; a coil spring assembly connected to the separator body and in communication with the journal assembly to apply a spring force to the grinding roll, the coil spring assembly including: a preload stud having a first end in communication with the journal assembly and an opposite second end extending from the coil spring assembly and exposed outside of the separator body; a spring adjustment bolt and bearing assembly being fixed relative to the preload stud extending therethrough; and a seal being substantially cylindrical shaped and flexible at least along a central axis thereof, the seal having a first end operably secured to the spring adjustment bolt and bearing assembly and an opposite second end operably secured to the second end of the preload stud thereby sealing a bushing area corresponding to a portion of the preload stud surrounded by the spring adjustment bolt and bearing assembly from ground solid fuel dust and allowing movement of the preload stud at least along the central axis thereof to apply the spring force from the coil spring assembly to the grinding roll.