US3144095A

US3144095A - Oiling system

Info

Publication number: US3144095A
Application number: US190661A
Authority: US
Inventors: Robert L Trapp; Haft Gerald
Original assignee: Outboard Marine Corp
Current assignee: Outboard Marine Corp
Priority date: 1962-04-27
Filing date: 1962-04-27
Publication date: 1964-08-11
Anticipated expiration: 1981-08-11

Description

g- ,1 R. L. TRAPP ETAL 3,144,095

OILING SYSTEM Filed April 27, 1962 INVENTORS. iamser 1. 72 4 65:41 4 4" BY United States Patent 3,144,095 OILING SYSTEM Robert L. Trapp and Gerald Haft, Milwaukee, Wis., as-

signors to Outboard Marine Corporation, Waukegan, 11]., a corporation of Delaware Filed Apr. 27, 1962, Ser. No. 190,661 6 Claims. (Cl. 184-6) The invention relates to internal combustion engines and especially to arrangements for oiling such engines. Still more particularly, the invention relates to arrangements for oiling machines, such as internal combustion engines, having two or more pistons and associated separate crankcases.

The invention has for its principal object the provision of an improved arrangement for lubricating the crankshaft, connecting rod bearings, Wrist pin bearings, and piston of an internal combustion engine. In its preferred form, the invention provides an oiling arrangement for a multi-cylinder engine wherein lubricating oil is supplied directly from an oil source through an oil pump to separate, substantially closed crankcases which are respectively associated with at least one pair of oppositely acting pistons and which are subject to cyclical pressure variation in response to piston movement. In addition, the invention provides for controlling the flow of oil to the several separate crankcases of a multicylinder engine by the pressures created in the crankcases as an incident to piston movement in the cylinders.

The invention also provides for an arrangement for shutting down the engine in the event that the oil supply for the pump reaches a predetermined minimum level, Other objects and advantages of the invention will be apparent by reference to the following description and the accompanying drawings of one embodiment.

In the drawings:

FIGURE 1 is a partially sectioned and broken away,

diagrammatic view illustrating a lubrication arrangement embodying various features of the invention;

FIGURE 2 is a fragmentary, enlarged sectional view of a portion of the cylinder block shown in FIGURE 1;

FIGURE 3 is a fragmentary, enlarged sectional view of the pump incorporated in the arrangement shown in FIGURE 1;

FGURE 4 is a sectional View taken generally along line 44 of FIGURE 3; and

FIGURE 5 is a sectional view taken generally along line 55 of FIGURE 3 and showing a slightly modified form of piston.

The oiling arrangement illustrated in FIGURE 1 is shown in association with a conventional twostroke.

engine 9 having

separate crankcases

10 and 12 for a pair of parallel cylinders 11 and 13 formed in a cylinder block 15 including a common wall 17 separating the

crankcases

10 and 12. Extending through both

crankcases

10 and 12 adjacent one end of the block 15 is a crankshaft 19. Oppositely operable in the usual manner in each of the cylinders 11 and 13 are pistone 21 and 22 which are respectively connected to the crankshaft 19 by connecting rods 23 and 24. Each cylinder is provided with a spark plug 25 which is electrically connected to an ignition system 26 (partially shown in diagrammatic form). Also associated with each of the pistons 21 and 22 are usual intake, transfer and exhaust ports (not shown). All of the foregoing elements are of Well known construction and need not be further described.

Lubricating oil is supplied to the crankshaft 19, to the wrist pin and connecting rod bearings, and to the pistons by an arrangement comprising an oil pump 27 which is desirably driven by the crankshaft 19 and by conduit means 29, including a first portion connected to the oil pump 27 and two branch portions which are 3,144,095 Patented Aug. 11., 1964 connected to the first portion and to the respective crankcases. The oil pump 27 is constructed so as to deliver generally uniform quantities of oil through the conduit means 29 in timed relation to the rotation of the crankshaft 19. In the disclosed construction, entry of oil into the crankcases is controlled or governed by the movement of the pistons 21 and 22.

More specifically, as is well known, the pistons 21 and 22, in a two-stroke engine aligned in the manner shown in FIGURE 1, are connected to the crankshaft 19 so that they travel, at all times, in directions opposite to each other. Accordingly, at any particular time, one piston is advancing toward top dead center and is thereby creating a negative pressure in its crankcase and in the connected branch portion in the conduit means 29. At the same time, the other piston is moving from top dead center, thereby creating a positive pressure in its crankcase and in the connected branch portion of the conduit means 29. As a result, the pressure differential between the

respective crankcases

10 and 12, acting in the branch portions of the conduit means 29, directs the oil to that one of the crankcases which is at the lower pressure.

In the specifically disclosed construction, in which the crankcases 1t) and 12 are separated from each other by a common wall 17, the branch portions of the conduit means 29 are provided by the opposite ends of a transverse bore 31 (see especially FIGURE 2) which may be located at any convenient spot in the common wall 17. The first portion of the conduit means is provided by a second bore 33 which connects with the transverse bore 31 at a distribution point intermediate its ends, and by a flexible hose or conduit 35 connected to the oil pump 27 and to the second bore 33 by a nipple 37.

Various oil pumps can be used to deliver oil to the conduit means 29. The disclosed oil pump 27 is especially suited to this function and comprises, as best seen in FIGURES 3 through 5, a generally closed housing 39 having, therein a cylindrical bore 41, and a cylindrical Valve member 43 located in the bore 41. The housing 39 and the valve member 43 are rotated relative to each other to provide the desired pumping action. In the disclosed construction, the valve member 43 includes a stub shaft 45 which extends through one wall 47 of the housing and has mounted thereon a pulley or sheave 49 connected by a belt 51 to a co-operating pulley or sheave 53 on the crankshaft 19. Of course, various arrangements can be used to drivingly connect the crankshaft 19 to the oil pump 27. In addition, the ratio between the rate of relative rotation between the housing 39 and the valve member 43 can be adjusted as desired in order to regulate the quantity of oil being delivered to the

crankcases

10 and 12.

Formed in the valve member 43 is a cavity 55 having therein a piston 57 which is movable relative to one end 59 of the cavity 55 so as to define therewith a pumping chamber 61 of variable volume. More specifically, in the disclosed construction, the cavity 55 is. of cylindrical form and is disposed in radial relation to the axis of the valve member 43.

The valve piston 57 is also a cylindrical member, having, at one end, a stud 63 which extends into a guide bore extending from the end 59 of the cavity and has a rounded end for camming engagement with the wall of the bore 41. The other end of the valve piston can also be rounded off for camming engagement with the wall of the housing bore 41. More specifically, the bore 41 also includes an annular recess 65 which is in tangential eccentric relation to the remainder of the bore and cooperates with the rounded ends of the valve piston 57 to provide means for effecting movement of the valve piston toward and away from the end 59 of the cavity in response to relative rotation between the valve member 43 and the housing 39. The recess 65 is disposed in spaced relation, axially of the housing bore 41, to an intake port 67 and a discharge port 69 so as to prevent communication therebetween.

More specifically, the intake and

discharge ports

67 and 69 are respectively connected to conduit means 68 leading to an oil source or storage tank 73 and to the conduit 35. The

discharge ports

67 and 69 are arranged in angularly spaced, diametrically opposed relation to each other and are alternately connected to the pumping chamber 61 incident to relative rotation between the housing 39 and the valve member 43 by a conduit or passageway 71 in the valve member 43. In order to provide a time interval for oil flow into and from the pumping chamber 61, each of the intake and

discharge ports

67 and 69 is enlarged circumferentially around the bore 41 within a radial angle of about 90.

As shown in FIGURE 5, the annular recess 65 is tangent to the bore 41 at a point spaced approximately midway between the intake and

discharge ports

67 and 69 so that the valve piston 57 moves away from the cavity end 59 when the passageway 71 is connected to the intake port 67, thereby effecting filling of the pumping chamber 61 with oil. When the passageway 71 is connected to the discharge port 69, the piston 57 is forced toward said one end 59 of said cavity to deliver oil from the pumping chamber 61. Thus, the disclosed pump functions both to suck oil into the chamber 61 from the storage tank 73 and to subsequently force the oil out of the chamber.

FIGURE also shows a modified form of valve piston 57 in which the end of the stud 63 does not extend into engagement with the wall of the recess 65 in the bore 41. In this arrangement, relative rotation between the valve member 43 and the housing 39 serves to positively displace the valve piston 57 toward the end 59 of the cavity 55, thereby discharging oil from the cavity, and permits movement of the piston away from said one end 59 of said cavity 55 when the valve member 57 is disposed relative to the recess 65 as shown in FIGURE 5. In this instance, the oil in the intake port 67 is maintained under pressure so that the valve piston 57 will be displaced outwardly of the cavity 55 by fluid pressure when the passageway 71 is connected to the intake port 67. Fluid pressure can be maintained in the intake port 67 by locating the oil storage tank 73 in elevated relation to the oil pump 27.

The disclosed construction also provides means for automatic shorting out of the ignition system 26 in the event that the oil level in the storage tank 73 reaches a predetermined low level. This means includes a float 75 carried at one end of a pivotally mounted rod 77. I When the oil level reaches said predetermined low level, the float 75 positions the rod 77 so as to connect electrical leads which short out the primary circuit of the ignition system 26. The float arrangement also provides means for warning of the approach of said predetermined low level in the tank by positioning the rod 77 to electrically connect a warning light 81 to a battery 83 or other source of electrical energy.

While the disclosed dual cylinder engine has been described as an internal combustion engine, the oiling arrangement is also adapted for other types of machines having two or more pistons and separate crankcases. For instance, by omitting fuel supply, exhaust and spark arrangements, and by including appropriate air intake and discharge connections, the cylinder 11 could be employed as an air pump driven by the piston 22 acting in the cylinder 13.

Various of the features of the invention are set forth in the following claims.

What is claimed is:

1. In a device for lubricating the bearings of an internal combustion engine having cylinders, separate crank cases, a crankshaft in the crank cases provided with exposed cranks and pistons operatively connected with the cranks and reciprocable in the respective cylinders to develop alternating pressure differentials on gas in said crank cases, the improvement which consists of a duct communicating with each of said crank cases at a point in spaced relation to said crankshaft, an oil pressure line communicating with said duct and thereby with the respective crank cases, and means for supplying oil through said line to said duct for direct delivery alternately to the respective crank cases by reason of said pressure differentials.

2. An oiling device in accordance with claim 1 wherein said oil supplying means comprises an oil pump including a housing having a cylindrical bore therein with opposed intake and discharge ports, said discharge port being connected to said oil pressure line, a cylindrical valve member carried in said bore for rotation relative to said housing, means connected to said crankshaft for effecting relative rotation between said valve memher and said housing, a cavity in said valve member, a piston member movable in said cavity relative to one end thereof to define a pumping chamber of variable volume, conduit means in said valve member for selectively establishing communication, incident to relative rotation between said valve member and said housing, between said one end of said cavity and said intake port and between said one end of said cavity and said discharge port, and means operable, incident to relative rotation between said valve member and said housing, for effecting movement of said piston member in said cavity in co-ordination with the communication between said cavity and said intake and discharge ports.

3. An oiling device in accordance with claim 2 including a source of oil under pressure connected to said intake port to effect movement of said piston member away from said one end of said cavity when said conduit means in said valve member is connected to said intake port, so as to effect filling of said pumping cham- 4. An oiling device in accordance with claim 1 wherein said oil supplying means comprises an oil pump, an oil' tank connected to said oil pump, and means for rendering said engine inoperative when the oil in said tank reaches a predetermined low level. 5. An oiling device for a two-stroke engine comprislng the combination of a pair of parallel generally closed cylinders and crankcases separated by a common wall, a piston operative in each of said cylinders, a crankshaft connected by opposed cranks to said pistons and operable in said crankcase, a port in said common wall interconnecting said crankcases, said port being disposed in spaced relation to said crankshaft, an oil pump drivingly connected to said crank shaft, and conduit means connecting said oil pump with said port whereby oil is alternately delivered to said crankcases as an incident to the pressure differential created by respective movement of said pistons relative to said crankcases.

6. An oiling device in accordance with claim 5 including means drivingly connecting said oil pump with said crankshaft for operating said pump to deliver a predetermined quantity of oil for a given number of revolutions of said crankshaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,277,991 Leonard Mar. 31, 1942 2,651,999 Harrington Sept. 15, 1953 2,792,912 Kangas May 21, 1957 2,800,119 Schmidl July 23, 1957 2,903,091 Goehring Sept. 8, 1959 FOREIGN PATENTS 10,667 Great Britain of 1913