Patent GB-587312-A (GB)
Title: Multi-speed drive axle
IPC: F16H3/64
Filed: 1944-05-09
Abstract: 587,312. Motor-vehicle driving gear. TIMKEN-DETROIT AXLE CO. May 9, 1944, No. 8807. Convention date, April 29, 1943. [Classes 79 (ii) and 79 (iv)] [Also in Groups XXII and XXIV] Comprises d e t a i l improvements in a twospeed overdrive vehicleaxle, wherein a differential bevel planet-carrier 93 is driven by the integral ring-gear 92 of a spurplanet train, a sunwheel 107 of which can be positively clutched to the fixed casing at 109 for overdrive, or to the driving planet carrier 55 at 83 for direct-drive. The spur planet-carrier 55 is part of a cast structure formed in two bolted sections 55, 62, the section 62 having a twodiametered portion with a radial web 64 to which is riveted the main driving bevel (or hypoid) wheel 67 meshing with a driving pinion 41. The four planet-shafts 78 are supported at both ends in axially spaced carrier-parts 55, 75 connected integrally by T-sectioned bridges 73, the shafts 78 having a small axial freedom limited at one end by the bearing 82 and at the other by the clutchring 83. The sun-wheel 107 is integral with a. sliding clutch sleeve 106, provided with teeth.108 at its outer end to engage brake-teeth on the ring 109 in one end position for overdrive, whilst in the other end position for direct drive, its own gear-teeth clutch teeth in the clutch-ring 83. The ratio-changing clutch sleeve 106 is operated by a double-acting suction or fluid-pressure piston 135 through a lever 124, the fulcrum of which is carried by the cylinder-mounting 129, which is attached as a unit to the casing. The coacting end-faces of the clutch and brake teeth on the sleeve 106 and rings 83, 109 lie on parallel surfaces of revolution and are smooth with sharp unchamfered tooth-corners, so as to be able to slide freely over each other in frictional contact until synchronized. By this means preselected changes are possible without clutch-actuation, the suction power, although applied, being ineffective until the vehicle accelerator-pedal is released to unload the clutchteeth and allow the sleeve to move into a position in which the teeth are biassed into engagement with the required clutch or brake ring 83 or 109, which subsequently occurs on synchronism, i.e. when the accelerator pedal is depressed if the shift is to' direct-drive. The tooth-backlash and other dimensions, as well as the power of the piston 135, are correctly interrelated for functioning in this manner. Lubricant is circulated by a pump formed by a screwthread on the periphery of a disc 149 fixed to the rotating section 62. This picks up oil through casing-passages 147 and delivers it to all internal gear parts through passages 155, 156, 157, in the differential spider. Oil reaches bearings 26, 27 of the main driving bevel-pinion-41 through passages 37, 38 in cup-members 24, 25 carrying the bearings. Shims 29, 31 at the joint faces of these cup members provide adjustment for the bearings 26, 27 and the mesh of the bevelpinion respectively. The casing of the axle is provided with an inspection hole, Fig. 4 (not shown), with a snap-on cover. The clutch and brake-rings 83, 109 are force-fitted in their housings 75, 11 after being thermally'shrunk. The rings have peripheral grooves 112 to receive any chips or burrs formed during fitting. A snap-ring 86 may be provided to retain the ring 83 axially should it become loose in service. The clutch-ring 83 also locks the planet-shafts 78 against rotation. The Specification as open to inspection under Sect. 91 states that the coacting end-faces of the clutch and brake teeth may, as shown in Fig. 3 (Cancelled), be coned to exert a centralizing action on the sun-wheel sleeve 106 which has no bearing on the internal shaft but is supported only by toothed engagement with the planetpinions. This subject-matter does not appear in the Specification as accepted.