A seal-less head apparatus for retaining and re-circulating lubrication oil within a mill head assembly, comprising:
- (a) the mill head assembly having a front end of the mill head assembly and a rear end of the mill head assembly, and a set of stationary components comprising a trunnion, an oil ring, a bearing-retainer, and a collector ring, and a set of rotating components, comprising a housing, a pump ring, and a baffle-ring;
- (b) said front end having a forward rotating interface defining a forward labyrinth passage between the set of stationary components and the set of rotating components, and said rear end having a rear rotating interface defining a rear labyrinth passage between the set of stationary components and the set of rotating components;
- (c) the oil ring being cooperatively engaged against a front bearing means opposite the housing at the front rotating interface and against a rear bearing means at the rear rotating interface, both said bearing means being located opposite the housing;
- (d) the housing having a rotating means for rotating the set of rotating components when a power is supplied to the rotating means;
- (e) the rotating means creating a centrifugal hydrodynamic force to circulate the lubrication oil within the mill head assembly when the power is supplied to the rotating means;
- (f) the trunnion having a supply port with an open end engagingly cooperative with an external oil lubricating means for supplying the lubrication oil under pressure to the mill head assembly, and an opposite supply port end;
- (g) the supply port cooperatively connected by the supply port end to a supply passage disposed within the trunnion, the supply passage having an opposite oil ring end connected to the oil ring cooperatively engaged with the trunnion between the trunnion and the housing;
- (h) the oil ring defining an inner annulus for receiving the lubrication oil via the supply passage and a ring front end and a ring back end;
- (i) a plurality of spray holes being disposed within each of the ring front end and the ring back end;
- (j) the lubrication oil circulating through the plurality of spray holes in each of the ring front end and ring back end to the respective front bearing means and the back bearing means, to the front end of the mill head assembly and rear end of the mill head assembly, respectively;
- cooling and lubricating both of said bearing means;
- (k) the housing having a plurality of housing passages disposed through the housing from the front end of the mill head assembly to the rear end of the mill head assembly for re-circulating the lubrication oil from the front bearing means to the rear of the mill head assembly;
- (l) lubrication oil exiting the front bearing means being retained between the housing and the trunnion prior to exiting the front end of the mill head assembly through the plurality of housing passages by a labyrinth-type sealing means for containing the lubrication oil exiting the front bearing means located in the forward rotating interface disposed between the bearing-retainer and the baffle-ring;
- (m) the lubrication oil exiting the front bearing means re-circulating through the plurality of housing passages to the rear of the mill head assembly;
- (n) lubrication oil circulating through the rear bearing means combining with the lubrication oil exiting the front bearing means and re-circulating through the plurality of housing passages, at the rear of the mill head assembly between the housing and the trunnion, creating a stream of lubrication oil;
- (o) the pump ring attached to the outer surface of the housing, said pump ring being located cooperatively between the trunnion and the collector ring at the rear of the mill head assembly;
- (p) the pump ring containing a forward surface, a rear surface, and an outer perimeter of the front surface;
- (q) the pump ring containing a plurality of pump ring slots disposed within the pump ring, directing the stream of lubrication oil at the rear surface to a collector ring annulus defined within the collector ring located at the rear of the mill head assembly;
- (r) the collector ring containing a return port cooperatively connected to the collector ring annulus having a collector ring end located at the collector ring annulus and an opposite free port end;
- (s) the stream of lubrication oil being retained within the collector ring annulus prior to exiting the rear end of the mill head assembly by a series of close-tolerance labyrinth seal means in communication with the collector ring annulus and located in the rear rotating interface, said series comprising a close-tolerance labyrinth seal means disposed between the trunnion and the pump ring and a close-tolerance labyrinth seal means disposed between the collector ring and the pump ring;
- (t) the stream of lubrication oil exiting the collector ring annulus at the collector ring end and the mill head assembly through the return port by the port end;
- (u) any lubrication oil leakage through the rear labyrinth passage between the trunnion and the pump ring being retained and re-circulated back to the collector ring annulus by the close-tolerance labyrinth seal means disposed between the trunnion and the pump ring and located on said forward surface;
- (v) any lubrication oil leakage through the rear labyrinth passage between the collector ring and the pump ring being retained and re-circulated back to the collector ring annulus by the close-tolerance labyrinth seal means disposed between the collector ring and the pump ring through a drain groove disposed within the collector ring in cooperation with the forward surface of the pump ring;
- (w) the drain groove being cooperatively connected to a drain passage having a drain end connected to the drain groove and an opposite drain ring end cooperatively connected to the collector ring annulus;
- (x) said lubrication oil leakages collectively exiting the collector ring annulus at the collector ring end the mill head assembly through the return port by the port end;
- and
- (z) whereby the lubrication oil is retained and re-circulated in the mill head assembly.