US2688316A

US2688316A - Crankcase ventilation

Info

Publication number: US2688316A
Application number: US707076A
Authority: US
Inventors: William E Brill
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1946-11-01
Filing date: 1946-11-01
Publication date: 1954-09-07
Anticipated expiration: 1971-09-07

Description

Sept. 7, 1954 w. E. BRILL 2,683,316

CRANKCASE VENTILATION Filed Nov. 1, 1946 3nventor Gttornegs Patented Sept. 7, i954 2,688,316 CRANKCASE VENTILATION William E. Brill, Cleveland, Ohio, assignor to I General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application November 1, 1946, Serial No. 707,076

4 Claims.

The present invention relates to crankcase ventilating and oil separating systems for engines.

In conventional systems of this type in order to prevent pickup of the oil separated in the separator when crankcase vapors are, drawn therethrough by connection with an engine suction source-la U-shaped oil return line is connected between the separator and crankcase of sufficient height to act as a U-tube seal for maximum values of engine suction.

In installations on submarines where a telescopic engine air intake pipe is required to permit operation of the engines at different submerged depths it has been found that the resistance to air now through the intake pipe and numerous bends in the connections to the engine that there is not suflicient height in the hull of the submarine for a U-tube seal for this purpose.

The principal object of the invention is to provide a crankcase ventilating system including means connected between the crankcase and a variable lower pressure or suction source for separating the lubricant from the vapor drawn from the crankcase and insuring that all of the lubricant separated is returned to the crankcase irrespective of wide variations in suction of the source.

The means by which this object is accomplished is described in detail in the following specification and one modification is illustrated in the accompanying drawing.

Figure 1 is a partial side elevation view of one end of an internal combustion engine incorporating my crankcase ventilating system with parts broken away. 1

Figure 2 is an enlarged end elevation view of details shown in Figure 1 with parts shown broken away and in section.

As best shown in Figure l the engine comprises a crankcase l and cylinders 3 in which pistons therein are connected by connecting rods to the crankshaft, not shown, in conventional manner to cause rotation thereof in conventional manner. The engine illustrated is provided with a scavenging blower operatively connected to the engine crankshaft and located in a blower housing 5 secured on one end of the engine crankcase. A telescopic engine air inlet pipe is shown generally at 1 connected to the inlet side of the blower housing 5 and the suction therein is proportional to the resistance to air flow therethrough depending on its length and number of bends therein and also proportional to the speed of the engine driven blower. The outlet of the blower housing 5 is connected by suitable passages, not shown, in the engine crankcase l to well known type is secured to the blower housing and connected by a suction outlet pipe 13 to the suction side of the blower and a vapor inlet pipe 15 is connected between the crankcase I and the separator. The oil separated by the separator is led by an oil return line including pipe I! between the separator l I and the inlet of an oil scavenging pump IQ of the constant displacement gear type secured to the crankcase and driven by the engine. The outlet of the oil scavenging pump I9 is connected by oil delivery return pipe 2| of U-shape to the crankcase I. One end of the U-shaped pipe 2| is shown in Figures 1 and 2 connected to the crankcase at a point slightly above the level of the other end of the pipe 2|, shown connected to the pump outlet, so that some oil is always retained in the housing of the pump l9 whereby an oil film seal is continuously maintained between the pump housing and gears to prevent oil from the tube 2! and in the separator entering the separator suction pipe I3 and the engine blower and cylinders and thus insuring that all the oil from the separator is returned by the pump I9 through the return pipes I! and 2| to the crankcase, irrespective of the degree of suction in the separator and air inlet pipe of the engine connected to the inlet or suction side of the blowers. This operation makes the above described crankcase ventilating and oil separating system suitable for use in engines where wide and sudden changes in suction are applied to the separator due to changes in the engine speed or variations in the restriction to air flow in the suction passages.

I claim:

1. In a crankcase ventilating and oil separating system, a crankcase, a source of variable suction, an oil separator connected between said crankcase and variable suction source for separating oil from the vapor drawn from said crankcase and through said separator, an oil return connection connected between said separator and said crankcase and including a positive displacement oil scavenging pump, the outlet of said pump being positioned in said oil return connection at a level below the point of connection to said crankcase so that some oil is retained in the pump at all times.

2. In combination, an engine having a cylinder, a crankcase and an air inlet pipe for said cylinder, an oil separator connected between the in serve as an oil seal against the suction-in said air intake pipe.

3. In combination, an engine-having a crankcase, a blower driven by said engine 'forsupply ing air to said engine, an air inlet pipe connected to the inlet of said blower, an .oilscavenging pump driven by said engine, an oil separator connected between said inlet pipe and said-crankcase for separating oil from the vapor from said crankcase, and an oil-returnzconnection including. said; scavenging, pump connected between said separator and crankcase to return separated oil to saidcrankcase, the pump outlet being-lo cated at a lowerlevel in said oil return 00111160- tion than its pointofconnection tosaidcrank- 4 case in order to retain some oil in said pump at all times to seal said return connection against the suction in said inlet pipe.

4. In combination, an engine, a blower driven by said engine and supplying air under pressure to said engine, a telescopic air inlet pipe connected to the inlet of said blower, an oil separator connected between said blower inlet and said crankcase, and a combined oil return line and suction seal connected between said separator and said engine crankcase and including a positive. displacement engine driven oil scavenging pump, said oil return line between the outlet of said pump and said crankcase being of U -shape and having one end connected to said crankcase at a higher level than the other end connected tothe .outletof said pump to retain some separated oil in the pump outlet at all times.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,236,187 hemp Aug. 7, 1917 1,484,607 Hunt Feb. 19, 1924 1,623,242 Gruber Apr. 5, 1927