Patent ID: 9010872
Filing Date: 2015-04-21
Classification: E21D,Y10T

Abstract:
1. A tunnel boring machine comprising: a cutterhead assembly; a forward shield assembly; a cutterhead support assembly for rotatably attaching the cutterhead assembly to the forward shield assembly, the cutterhead support assembly comprising (i) a cutterhead support structure comprising a housing portion with a plurality of drive mount stations spaced about a periphery of the housing portion, wherein each drive mount station includes an entry port and a pinion support cradle; (ii) a main bearing assembly; (iii) a plurality of pinion housings, each pinion housing attached to the support structure at one of the plurality of drive mount stations; and (iv) one or more cradle covers attached to the support structure at one of the plurality of drive mount stations, and wherein either (a) one of the plurality of pinion housings, or (b) one of the one or more cradle covers, are attached to the cutterhead support structure at each of the plurality of drive mount stations; a ring gear attached to the main bearing assembly; an attachment structure that attaches the cutterhead assembly to the ring gear; and a plurality of drive assemblies, each drive assembly comprising a pinion assembly disposed in one of the plurality of pinion housings and configured to drivably engage the ring gear, and wherein the one or more cradle covers are attached at drive mount stations that do not receive one of the plurality of drive assemblies; wherein the cutterhead support assembly is configured to engage a variable number of drive assemblies.