Patent GB-562487-A (GB)
Title: Improvements in or relating to the lubrication of internal combustion engines
IPC: F01M1/08
Filed: 1943-01-09
Abstract: 562,487. Crank shafts. CENTURY MOTORS CORPORATION. Jan. 9, 1943, No. 454. Convention date, April 27, 1942. [Class 80 (ii)] [Also in Groups XXVII and XXXIV], An internal-combustion engine has two sources of lubricant associated with separate supply pumps, one exclusively for lubricating the crank-shaft and connecting-rods and the other for lubricating the cylinder - walls, cams and other parts exposed to the interior of the crank-case. The crank-shaft lubricant has no access to the air of the crank-case so that oxidation is reduced and contamination by carbon or other particles is avoided. In the form shown, Fig. 1, the cylinder-wall lubricant 76 is contained in the sump 16 but the invention is also applicable to engines having dry sump lubrication. The crankshaft has main bearing portions 22, throw portions 24, and crankpins 26. The crank-shaft may be of the built-up construction described in U.S.A. Specification 2,013,039 and the big-ends and main bearings are of roller type comprising three rows of rollers running in hardened sleeves 34. The rollers are separated by spacers 33 and the sleeves of the main bearings are secured by caps 38 and screwed studs. If hardenable connecting-rods are used the rollers 44, Fig. 3, of these bearings may run in the bores of the connecting rods, the sleeves 34 being dispensed with. The various parts of the crank-shaft are connected by curved serrations 46, Fig. 3. A bolt 48 secures the main journal 22 to the crank web and each crank pin, Fig. 3, is secured in position by a stud 52 and nuts 54, the latter fitting closely in the crank-pin bore and having circumferential lubricant grooves 56. The little ends 60 are also of roller-bearing. type. Two independent oil pumps 68, 70, Fig. 1, are both driven from the cam-shaft 64. The larger pump 70 which supplies the cylinder walls &c. is fed from the sump 16 through a filter 74 and line 72 and delivers through a line 78 to longitudinal pipes 82 whence oil is sprayed on to the cylinder walls and on to the cam-shaft surfaces. The smaller pump 68 is supplied through a pipe 86 from an auxiliary oil reservoir 84 and discharges through a pipe 90 to the left-hand main bearing Fig. 2. Thence the oil passes through passages such as 118, 124, Fig. 3, to all the main and big-end bearings and by passages 134 to the little ends. The right-hand main bearing is connected to a line 104 discharging into the auxiliary reservoir 84. All the bearings supplied by the pump 68 are sealed against leakage by felt rings or other suitable seals. Plugs 150, Fig. 3, and washers 152 are provided to prevent escape of lubricant from the little ends. In some cases the line 104 returning the crankshaft lubricant to the reservoir 84 is dispensed with and the pump 68 then serves to maintain pressure in the crank-shaft bearings which are .externally cooled by the splash of the oil 76. In this modification new lubricant is continupusly fed to the crank-shaft and connecting-rod bearings. Any leakage from the crank-shaft system may serve to maintain the level of oil 76 and make up lubricant is added to the reservoir 84. If desired the lubricant in reservoir 84 may be of different character from that in the sump 16. Thus. particularly when roller bearings are employed the reservoir 84 may contain a solid or semi-solid lubricant and the pump 68 is replaced by a cylinder 150, Fig. 8, containing a spring-pressed piston which forces lubricant 154 past a valve 166 into a cylinder 162 having a plunger 164 connected at 170 to a pedal of a motor vehicle. Depression of the pedal forces lubricant into a line 901 leading to the left hand main bearing whence the lubricant passes to the whole crank-shaft system. The pedal is returned by a spring and the cylinder 162 refilled by the action of spring 158.