GB625966A - Tool-carrying or work-carrying spindle, in particular a grinding wheel-carrying spindle for internal and endwise grinding purposes - Google Patents

Abstract

625,966. Bearings. ETABLISSEMENTS PIAT. Oct. 22, 1945, No. 27786. Convention date, June 30, 1942. [Class 12 (i)] A spindle, such as an internal-grinding wheel spindle 6, is mounted in a cylindrical housing 1, adapted to be clamped on a machine part or other support, by self-adjusting front and rear ball-bearings 2-3, 4-5, the outer races of which have raceways of cylindro-conical cup form with the larger diameter facing towards the respective ends of the cylindrical housing and the inner races of the front and rear bearings being spaced by a sleeve 24 closely encircling the spindle shaft 6. The self-adjustment is effected by a circular coiled spring 37 acting in a contractile manner on a circumferential bevelled groove 36 of a sleeve 34 slidable inside the housing 1, whereby the sleeve 34 butts on the outer race of the rear bearing 4-5 slidable along the cylindrical housing 1, thereby to move the associated inner race, the shaft, and the front-end inner race which thus moves into closer axial proximity to the fixed outer race of the front bearing. The front end of the shaft is enlarged to provide a rotary end shield 13 to the housing 1 and at the rear end a similar rotary end shield 27 is provided by a member which in conjunction with a nut 28 and a spherically-seated washer 29 serves to secure the inner races and sleeve 24 in position by forcing them against a shoulder at the front end of the shaft. The shaft is hollow and a tie-rod 16 passes therethrough to screw into a coned-shank of an adaptor piece 7 on which the internal grinding wheel 8 is mounted, which adaptor is thus secured in a corresponding seating on the enlarged front end of the shaft. The tie rod at the rear end has a coned piece 22 which expands a split end 19 of the shaft into clamping engagement with the drive pulley 9. Lubrication is effected by lubricant forced in at a nipple 30 in the end shield 27 and passing to the bearings by a groove in the shaft. Distortion of the bearings which might arise on clamping the housing in position is avoided by forming grooves 10-11, 12 around the housing 1 at the region between the clamped middle portion and the end portions where the bearings are situated ; these grooves give an elastic connection. Closure of the housing is effected by pairs of split rings 31, 32 of annulus shape with the slits staggered. The Specification as open to inspection under Sect. 91 comprises also an arrangement, Fig. 3 (Cancelled), in which the cylindrical casing 1 has a uniform bore through which is inserted a shaft assembly of uniform diameter for retention by a set-screw and stud 45. The shaft assembly comprises front and rear pairs of bearings 2-3, 4-5, with the inner races spaced by a sleeve 24 closely fitting round the shaft 6 which has shielding discs 13, 27 shrunk thereon, that 27 at the rear end being of the uniform diameter of the shaft assembly which includes a jacket 43 fixed by the set-screw stud 45 and carrying the sliding sleeve 34 with its circular controlling spring 37 by which the self-adjusting movement is applied to the outer races of the rear end bearings 4-5. The flow of lubricant to the bearings from a reservoir space 44 is regulated by the radial expansion of the jacket 43 (of higher expansion coefficient material) reducing the clearance with the bore of the casing 1 when excess lubricant in the bearings has caused heating. This subject-matter does not appear in the Speci. fication as accepted.