Engine with speed responsive multi-ratio turbocharger drive

• US 4,445,337 A
• Filed: 09/24/1982
• Issued: 05/01/1984
• Est. Priority Date: 09/24/1982
• Status: Expired due to Term

• Current Assignee: General Motors Auto OOO (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: McCreary, Charles H.
• Primary Examiner(s): KOCZO JR, MICHAEL
• Application Number:
  US06/422,545
• Time in Patent Office: 585 Days
• Field of Search: 60/607, 60/608, 123/561, 74/664, 74/665 B, 192/48.6, 192/48.92, 192/20
• US Class Current: 60/608
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02B 37/105 exhaust drive and pump being both connected through gearing to engine-driven shaft
• CPC Class Codes: F02B 39/12 Drives characterised by use of couplings or clutches therein using fluid slip couplings for varying gear ratio F02B39/08
• CPC Class Codes: F02C 7/36 Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user F02C3/107 - F02C3/13 and F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y10T 74/19019 Plural power paths from prime mover
• CPC Class Codes: Y10T 74/19056 Parallel

Abstract

An internal combustion engine, especially of the two stroke cycle diesel type, has a turbocharger with a supplemental mechanical drive for maintaining a minimum speed ratio relative to engine speed, when exhaust energy is insufficient to provide a higher speed, so as to maintain adequate charging air for engine operation throughout the engine speed range. In order to provide more efficient operation during engine operation at idle and in a lower portion of the operating range where a reduced amount of charging air is adequate, a secondary lower speed ratio is provided by the mechanical drive system. A speed responsive clutch is included to disconnect the higher speed primary drive during engine operation in the lower speed range and permit operation at the more efficient secondary speed ratio.

Claims

1. In combination, an internal combustion engine having a turbocharger,

supplemental primary mechanical drive means in the engine for maintaining a minimum primary operating speed ratio of the turbocharger relative to engine speed when exhaust energy is insufficient to provide a higher turbocharger speed, said primary speed ratio providing charging air adequate for engine operation throughout its speed range, and the improvements comprising

secondary mechanical drive means in the engine for maintaining a minimum secondary operating speed ratio of the turbocharger relative to engine speed lower than the primary speed ratio and requiring reduced energy but capable of providing sufficient charging air for engine operation in a lower portion of its operating speed range, and

speed responsive means in the primary drive means and operative to maintain driving operation of the primary drive means at engine speeds above said lower portion of the engine speed range and to disengage the primary drive means to allow lower speed driving of the turbocharger by the secondary drive means during engine operation within said lower portions of its operating speed range,

whereby an energy efficient two speed supplemental turbocharger drive system is provided.

2. In an internal combustion engine, the combination comprising an exhaust driven turbocharger connected to supply charging air to the engine,

a supplemental drive system interconnecting the engine and turbocharger including primary drive means operative when engaged to drive the turbocharger at a primary speed ratio relative to engine speed when exhaust energy is insufficient to maintain a higher turbocharger speed, said primary speed ratio being adequate to provide sufficient air for engine operation at all speeds,

overrunning means in the drive system operative to permit exhaust driven operation of the turbocharger at speeds above that provided by the supplemental drive system when adequate exhaust energy is available, and the improvement comprising

secondary drive means in the drive system operative to drive the turbocharger at a secondary speed ratio relative to engine speed when exhaust energy is insufficient to maintain a higher turbocharger speed, said secondary speed ratio being lower than said primary speed ratio but adequate to provide sufficient air for engine operation in a lower portion of the engine speed range with a reduction of drive energy from that required for operation at the primary speed ratio,

overrunning means in said secondary drive means and operative to permit operation of the drive system at the primary speed ratio when the primary drive means is engaged, and

speed responsive engaging means in the primary drive means and operative to disengage the primary drive means when the engine speed remains within said lower portion of the engine speed range and to engage said primary drive means when the engine speed rises above said lower portion of the engine speed range,

whereby, during conditions of insufficient exhaust gas energy for higher speed operation, the turbocharger is driven at the higher primary speed ratio at engine speeds above said lower portion of the engine speed range and at the reduced energy lower secondary speed ratio at engine speeds within said engine speed range lower portion.

3. In an internal combustion engine, the combination comprising an exhaust driven turbocharger connected to supply charging air to the engine,

a supplemental mechanical drive system interconnecting the engine and turbocharger including primary drive means operative when engaged to drive the turbocharger at a primary speed ratio relative to engine speed when exhaust energy is insufficient to maintain a higher turbocharger speed, said primary speed ratio being adequate to provide sufficient air for engine operation at all speeds,

an overrunning clutch in the drive system operative to permit exhaust driven operation of the turbocharger at speeds above that provided by the mechanical drive system when adequate exhaust energy is available, and the improvement comprising

secondary drive means in the drive system operative when exhaust energy is otherwise insufficient to drive the turbocharger at a secondary speed ratio relative to engine speed lower than said primary speed ratio but adequate to provide sufficient air for engine operation in a lower portion of the engine speed range with a reduction of drive energy from that required for operation at the primary speed ratio,

an overrunning clutch in said secondary drive means and operative to permit operation of the drive system at the primary speed ratio when the primary drive means is engaged, and

a speed responsive clutch in the primary drive means and operative to disengage the primary drive means when the engine speed remains within said lower portion of the engine speed range and to engage said primary drive means when the engine speed rises above said lower portion of the engine speed range,

whereby during conditions of insufficient exhaust gas energy for higher speed operation, the turbocharger is driven at the higher primary speed ratio at engine speeds above said lower portion of the engine speed range and at the reduced energy lower secondary speed ratio at engine speeds within said speed range lower portion.

4. In an internal combustion engine, the combination comprising

a crankshaft and a camshaft mounted for rotation on spaced parallel axes,

an exhaust driven turbocharger connected to supply charging air to the engine when in operation and

a mechanical drive system interconnecting the engine crankshaft and the turbocharger to drive the turbocharger at predetermined minimum drive ratios with respect to engine speed when exhaust energy is inadequate to maintain the turbocharger speed above said drive ratios, said drive system including

a crankshaft gear carried by the crankshaft

an idler gear operatively connected with and driven by the crankshaft gear,

a camshaft gear drivingly connected with the camshaft and operatively connected with and driven by the idler gear to drive the camshaft at a fixed speed ratio relative to the crankshaft,

a primary turbo drive gear rotatably mounted for rotation in substantially coaxial spaced relation with said idler gear,

speed responsive clutch means between said idler and primary turbo drive gears and operative to drivingly interconnect said gears above a predetermined rotational speed of the crankshaft and to otherwise disconnect said gears,

a secondary turbo drive gear rotatably mounted in substantially coaxial spaced relation with said camshaft gear,

overrunning clutch means between said camshaft and secondary turbo drive gears and operative to drive said secondary turbo drive gear from said camshaft gear or permit overrunning of the secondary turbo drive gear above the speed of the camshaft gear,

turbo drive means connected to drive said turbocharger and operatively connected with both said primary and secondary turbo drive gears to be selectively driven thereby as determined by the conditions of crankshaft rotational speed and available exhaust energy supplied to the turbocharger.