US2201525A - Lubrication of internal-combustion engines - Google Patents

Description

y 21, 1 A. H. R. FEDD'EN El Al. 2,201,525

LUBRICATION OF INTERNAL COMBUSTION ENGINE;

Filed April 7, 19:59 a Sheets-Sheet 1 Iarve 6: Jamaal! y 1940. A. H. R. FEDDEN ET AL 2, 0 ,5

LUBRICATION OF INTERNAL COMBUSTION ENGINES 3 Sheets- Sheet 2 Filed April 7, 1939 frwnZm Edda) w J/f'rai 172mg 6. Jewel! 5, v 9L May 21, 1940.

A. H. R. FEDDEN EI'AL 2,201,525 LUBRICATION OF INTERNAL COMBUSTION "ENGINES Filed April 7, 1939 s Sheets-Sheet s Patented May 21, 1940 Ema 01,5 25

or INTERNAL-COMBUSTION ENGINES f memorials 1 OFFICE 2 (ilaims. (Cris a-c) This invention 'relates to the lubrication of internal-combustion engines and has for its object to provide a copious and accurately predetermined supply of lubricating oil to the pistons andassociated'partsL The invention is therefore of particular value 'as'applied to an engine of the sleeve-valve type.

According to the invention, an internal-combustion engine, of the kind in which the crankshaft is formed with a crank-web having a balance-weight on the side of the crank-shaft axis opposite'the crank-pin, comprises a conduit leading from the hollow interior of the crankshaft to a discharge orifice at or near the outer,

end of the balance-weight and means for supplying lubricant to the interior of the crank-shaft. The said orifice is preferably disposed near to the inside of the balance-weight, i. e., near to the transverse plane containing the adjacent connecting-rodor rods.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings of which- Figure 1 shows, in sectional elevation, part of.

a two-bank sleeve-valve internal-combustion engine of the radial cylinder type,

Figure 2 is an end elevation on the line 2-2 of Figure 1 to an enlarged scale, showing one crank-web and balance-weight,

Figure 3 is a section, to a greatly enlarged scale, on the line 3-3 of Figure 2, and

Figure 4 is a section on the line 4-4 of Figure 3.

i As shown first "in Figure 1, the crank-case IU of the engine supports cylinders ll of which one, only, is shown, there being seven or nine such cylinders radially arranged with respect to the crank-shaft axis l2. A similar bank of cylinders (not shown) is arranged to the left of the plane containing the cylinders H.

The crank-case carries bearings 13 for a fabricated two-throw crank-shaft comprising crankpins l4, 15, an intermediate crank-web iii, an end crank-web l1, and a shaft portion In. It will be understood that, at the left-hand end of the engine, an end web similar to I! and a shaft portion similar to I 8 are provided. The crankweb I! is clamped to the crank-pin l4 by means of a bolt 34, an arrangement which, however, forms no part of the present invention. The chamber 25 within the crank-pin l4 communicates by an oil-way 35 with an oil chamber 28 within the crank-web l1.

1 The'crank-pin I4 is engaged by a connectingrod'l9 pivoted at the top,'in' the usual way, to a piston which reciprocates inside a sleeve 20 slidable in the cylinder ll. The sleeve 23 is driven with a combined reciprocating and rotary mo-- tion by means of a sleeve-driving crank 2| which is drivenfrom' the shaft portion l8 by a gear train 22, 23, 24. It will be understood that conmeeting-rods for the other cylinders H in the bank-are articulated to the big-end of the connecting 'rod l9.

Thefabricated crank-shaft is hollow throughout and oil is supplied to it by means of an engine-driven pump. Oil from the chambers 25 and 26 passes through suitable parts of the crankpins l4 and I respectively to lubricate the bigends in the respective banks of cylinders.

A conduit 29 leads from the oil chamber 28 obliquely through the balance-weight portion 30.

- To the inside face of the crank-web I! the usual block 3| is fitted, by means of screws 33, to increase the mass of the balance-weight and according to the invention the said conduit 29 leads from the balance-weight.portion 30 through the block 3| and opens in an orifice 32 at or near the curved periphery of the block. as shown in Figure 2.

The conduit 29 is lined with a tube 36 (see Figures 3 and 4) to the inner end of which a tubular valve chest 31 is screw-threaded as shown. The valve chest 31 is engaged at its inner end by a bush 38 the outer end of which is formed as a conical valve seat 39 to engage a steel ball 4!! pressed on to its seat by a compression-spring 4|. The bush 33 is formed longitudinally with a bore 42 which opens at the inner end into a diametral passage 43 the external orifices of which are spaced away in a radial direction with respect to the end of the tubular member 31. The end of the member 31 is cut across with four wide notches 44 so as to leave four intervening tongues 45 to engage the flanged head 46 of the bush 38. Thus, when the bush is screwed home, the four notches 44 constitute inlet orifices immersed in the oil chamber 28 and leading by way of the passage 43, the bore 42, and a bore 41 in the stem portion of the member 31, to'the interior of the tube 36. 1

It is found that, unless a valve is provided in the oil-spray conduit, the resistance to the flow of oil offered by the conduit at very low engine speeds is proportionately so small as to reduce unduly the pressure of the oil in the circuit. I The spring 4| is so designed that, at very low engine speeds, the valve 40 closes the tube 36 and prevents oil from being discharged through it. At higher speeds, however, the increased pressure of the oil lifts the ball off its seat and oil is discharged along the tube 36 and escapes through the orifice 32. As the crank-web l1 rotates the oil so discharged forms a curtain of spray which lubricates the internal and external surfaces of the sleeves 20 and therefore also lubricates the pistons and cylinder walls.

It is desirable that the operation of the ball valve shall not be modified by centrifugal force acting on the ball 40. For this purpose, as shown in Figure 3, the ball is arranged so that its centre coincides with the axis I 2 about which the crankshaft rotates. Alternatively, the ball might be so arranged that the combined efiects of the spring and centrifugal force maintains its operation constant despite variations in the speed of the engine.

It will be seen that, by arranging the discharge orifice 32 near the inside face of the crank-web ll, that is to say as near as possible to the plane .of the connecting-rods, the curtain of oil-spray above referred to strikes the sleeves and other parts as nearly as possible along the plane containing the cylinder axes. The advantage of arranging the discharge orifice 32 at the periphery of the balance-weight block 3! is that, since this point is at a greater radius from the axis l2 than any other rotating part within the crank-case, the oil is discharged with maximum velocity.

The orifices formed by the notches 44 at the inner end of the tubular member 31 and the narrow annular space between the bush 38 and the member 31 through which the oil has to flow on its way to the passage 43 act to regulate the rate of flow of oil into the tube 36. Moreover, sludge or other foreign matter in the oil is excluded by these narrow passages, whereby the arrangement also constitutes a filter.

We claim: a

1. A hollow crank-shaft having a crank-pin, a balance-weight on the side of the crank-shaft axis opposite the crank-pin, a conduit leading from the interior of the crank-shaft to a discharge orifice near the outer end of the balanceweight, an automatic valve so disposed in said conduit as to be substantially unafiected by centrifugal force, and means for closing said conduit except for one or more narrow orifices.

2. A hollow crank-shaft having a crank-pin, a balance-weight on the side of the crank-shaft axis opposite the crank-pin, a conduit leading from the interior of the crank-shaft to a discharge orifice near the outer end of the balanceweight, a valve seating in said conduit, a ball disposed with its centre lying substantially on the axis of rotation of the crank-shaft, a spring tending to close the ball on to the valve seating, and means for closing said conduit except for one or more narrow orifices.

ALFRED HUBERT ROY FEDDEN. HARVEY CHARLES MANSELL.

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