Caterpillar Tractor Co.

Alexander Goloff

Frank E Keske

George B Grim

Paul J Staebler

Noble G Barker

Richard A Cemenska

William H Belke

Hiram A Brubaker

Ralph E Denning

Mark F Sommars

Roger O Bjerk

Michael K Stratton

Ervin E Mangus

James A Ritchie

Ziedonis I Krauja

Tsu Pin Shyu

Darrell E Stafford

Thomas M Albright

Charles E Ballard

A centrifugal compressor (10/110) or a centripetal turbine (76) having coaxially aligned, relatively rotatable rotors (12,112,212/14,114,214) mounting a plurality of blades (30,32,34,36,38/130/230) having variable radial extension from a central axis (15). The blades closer to the center of rotation of the rotors are operated at high speeds so to maximize their gas treating effect while rotating the larger diameter blades (40,42,44/132,232) at lower speeds commensurate with their stress capabilities.

Coaxial turbomachine

A varible rate spring for use in a combustion engine has a lower spring rate at high valve lifts than at low valve lifts to reduce contact stresses in the valve train assembly (24) at maximum valve lift. In one embodiment, the varible rate spring includes a cantilevered spring (70) having a free end (80) for engagement with a valve (12), a fixed end secured to a cylinder head (18) and an intermediate portion (88) which engages a pair of stops (90/92). As the valve moves between the seated position to an intermediate lift position only that portion of the spring (70), from its free end (80) to the intermediate portion (88) engaging the stops (90/92) is active. At the intermediate lift position the spring (70) disengages the stops (90/92) and the entire length of the spring (70) becomes active thereby decreasing the spring rate. In another embodiment two coil springs (94/96) are connected in series having a separator (110), which acts as a spring damper, disposed therebetween. The separator (110) engages a spring retainer (98) to preload the lower spring. Only the upper spring (96) is active as the valve (12) moves between the seated and intermediate lift position, the preload on the lower spring (96) being overcome at the intermediate lift position so that both springs (94/96) are active as the valve (12) moves to the maximum lift position.

Variable rate valve spring

Prior art roller followers have generally been relatively expensive to produce and provisions have had to be made to deliver pressurized lubricant to bushings which have been used as bearings for the roller. Such roller followers have also been made with partially open apertures for bearings, thus eliminating the need for pressurized lubrication, but in such roller followers there is a tendency for the rollers to fall out of the open apertures. These probelms are solved herein by forming the body (16) and bearing surfaces (26,28) of a roller follower (10) in two parts, an inner structure (20) which supports the bearing surfaces (26,28) and an outer structure (18) which surrounds the inner structure (20) and fastens the entire assembly (10) together. Preferably, the inner structure (20) comprises a pair of half tubular shells (22,24) which fit together and include flanges (40,41) for keeping the roller (12) in contact with the bearing surfaces (26,28). The principal use of such a roller follower (10) is in engines wherein the roller (12 ) contacts a camshaft and an end (44) of the roller follower removed from the roller (12) motivates a push rod against the force of a spring, thus causing the rod to reciprocate.

Cam roller follower

Tappet with wear resisting insert

Low stress heat exchanger and method of making the same

Low profile heat exchanger and method of making the same

Fuel injection apparatus often uses valves which rapidly move in a start and stop motion for the purpose of starting and stopping injection. Undesirable inertial forces result from such start-stop movement of the valves. To limit such undesirable forces, a pair of valves (72,92) are provided for continuous rotation for starting and stopping injection.

Rotary fuel injection apparatus

A rotating fluidized bed heat exchanger particularly adaptable as a heat exchange unit in the recuperator section of conventional gas turbine engines comprising an annular fluidized bed, defined by inner and outer spaced apart coaxial cylindrical, perforated walls, which rotates about the longitudinal axis of the cylinders. The bed is comprised of pulverulent inert particulate material and includes fluid-containing heat exchange tubes passing substantially longitudinally therethrough. Hot gases, such as turbine exhaust gases, enter the bed through the outer perforated wall, heat and fluidize the bed particles, heat the fluid, usually compressed air, in the tubes, and exit the bed through the inner perforated wall. The heat exchange tubes direct the fluid flowing therein from an inlet adjacent the inner perforated wall to an outlet adjacent the outer perforated wall such that the fluid flows substantially countercurrently to the hot fluidizing gas. In a preferred embodiment, the heat exchange tubes comprise an inlet tube extending longitudinally adjacent the inner perforated wall, an outlet tube extending longitudinally adjacent the outer perforated wall and a plurality of tubes interconnecting the inlet and outlet tubes.

Rotating fluidized bed heat exchanger

Idler gears (14) which transmit power from crankshaft gears (12) to camshaft gears (16) may have helical teeth thus producing a tilting or cocking force on the idler gears (14). Past attempts to solve this problem have led to bulky and expensive structures, or to structures which are subject to failure. The problem is solved herein by a sleeve bushing (38, 54 or 54') having an axially extending bearing surface (42, 58 or 88') and being located between the bore (26,52) of an idler gear (14) or other rotary member and a stub shaft (30 or 56), the sleeve bushing (38,54 or 54') including construction (51 or 60) which maintains an extended area (44,46 or 58,88) of the bearing surface (42 or 58 or 88) in fitted mating relation against an extended area (49, 52 or 97) of a respective one of the shaft (30,56) and the bore (26,52) as the bearing surface (42,58,88') is worn down.

Stub shaft bearing

A rotating drive wheel which drives a pair of output shafts. The driving of each of the output shafts proceeds via a mechanical transmission which delivers rotary motion from the drive wheel to the output shafts. A drive ratio delivered by each of the transmissions can be selectively varied.

Transmission-differential combination

Power output of a compound engine is increased and fuel consumption per unit of output power is reduced by eliminating the blowdown losses heretofore associated with opening of exhaust valves or ports. Exhaust gases of a positive displacement engine stage drive a turbine or other gas-expansion stage, the two stages being mechanically coupled to jointly contribute to power output. The turbine stage may also drive a compressor to supercharge the positive displacement stage. Flow-regulating means in the exhaust gas passage between the two stages maintain exhaust gas passage pressure at a level corresponding to that which exists in the combustion chambers of the positive displacement stage at the time that exhaust valves or ports open. This avoids exhaust gas expansion between stages and reduces or eliminates the blowdown losses which would otherwise occur. Power losses at the positive displacement stage from the high back pressure are compensated for by the additional power recovered by the turbine stage as a result of the high expansion ratio at the turbine. Automatic control means may adjust the flow-regulating means in response to changes of engine operating conditions in order to maintain the optimum exhaust gas pressure.

Method and apparatus avoiding blowdown losses in compound engines

PCT No. PCT/US79/00929 Sec. 371 Date Nov. 1, 1979 Sec. 102(e) date Nov. 1, 1979 PCT Filed Nov. 1, 1979 PCT Pub. No. WO81/01295 PCT Pub. Date May 14, 1981 A rotating fluidized bed gasifier system especially useful in compound engines comprising an annular fluidization chamber containing a bed of carbon containing pulverulent solid materials. The chamber, which is defined by inner and outer spaced apart coaxial, cylindrical, perforated walls, rotates about the longitudinal axis of the cylinders. Steam enters the bed, which is maintained at about 1800.degree. F., through the outer perforated wall and fluidizes the particles. The steam reacts endothermically with the carbon to produce reaction product gas which exits the bed, together with unreacted steam, through the inner perforated wall. In a preferred form of the invention the bed is maintained at approximately 1800.degree. F. by combining a rotating fluidized bed combustor with the gasifier. In this embodiment compressed air and powdered coal enter the bed with the steam through the outer perforated wall. The air reacts exothermically with the fuel within the bed to generate heat for the endothermic steam-carbon reaction and to produce hot combustion gas which exit the bed, together with the reaction product gas, unreacted steam and compressed air, through the inner perforated wall.

Rotating fluidized bed gasifier system

PCT No. PCT/US79/00883 Sec. 371 Date Oct. 22, 1979 Sec. 102(e) Date Oct. 22, 1979 PCT Filed Oct. 22, 1979 Pilot injection of a high cetane fuel (16) and main injection of a relatively lower cetane fuel (16a) is accomplished by providing dual fuel, rotary controlled, pilot and main injection including a first rotating valve (32) for starting and stopping pilot injection of the high cetane fuel (16) through a first nozzle (46) and for starting main injection of the lower cetane fuel (16a) through a second nozzle (46a). A second rotating valve (32a) stops main injection of the lower cetane fuel (16a).

Dual fuel rotary controlled pilot and main injection

Flow of viscous molten metal (12) to thin sections (48) of mold cavities (14) is difficult to attain thus resulting in inferior molded products. This problem is solved herein by generating waves (20) in the molten metal (12), sensing the waves (20) in the molten metal (12) at a thin section (48) of the mold cavity (14) spaced from the generating position of the waves (20), and controlling the generating responsive to the waves (20) sensed. Basically, a control circuit (56) increases the amplitude, and/or changes the frequency, of the waves (20) generated, if the waves (20) sensed are not sufficiently strong. The invention is useful for flowing other liquids besides molten metal in other cavities than in molds, although this is its prime contemplated use.

Vibrator casting system with feedback

An engine valve comprises an elongated stem having a head secured on an end thereof. A tube is disposed in the stem to terminate at an outlet to communicate a liquid coolant, such as oil, to an annular chamber defined in the head. An agitator ring is loosely mounted in the chamber for moving therein during valve operation. A plurality of circumferentially disposed and radially extending ribs are preferably secured between the head and a cap secured thereon to define a plurality of inlet and outlet passageways therebetween.

Growing community of inventors

East Peoria, IL, United States of America

Alexander Goloff