Torsion damping mechanism for a supercharger
First Claim
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1. A rotary blower of the backflow-type comprising a housing;
- first and second meshed lobed rotors rotatably disposed in the housing for transferring relatively low pressure inlet port air to outlet port air controllable between relatively low and high pressures;
first and second meshed timing gears respectively fixed to the first and second rotors for preventing contact of the meshed lobes; and
an input drive adapted to be rotatably driven by a positive torque about an axis in one drive direction at speeds proportional to speeds of a periodic combustion, torque transmitting engine selectively controllable between idle and maximum speeds;
the improvement comprising;
a torsion damping mechanism for transmitting engine torque to the first timing gear, said damping mechanism including drive means and first and second spring means,said drive means driven by the input drive and mounted for limited to-and-fro rotation relative to the first timing gear,said first spring means having opposite ends reacting between the drive means and the first timing gear and resiliently transmitting torque in the positive direction, andsaid second spring means having opposite ends reacting between the drive means and the first timing gear and resiliently absorbing torque in a negative drive direction, and said second spring means having a spring rate greater than the spring rate of the first spring means.
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Abstract
An intake manifold (18) for an engine (10) includes a Roots-type supercharger (26) having a torsion damping mechanism (54) for reducing audible rattle of timing gears (72,74) which prevents contact of meshed lobes (28a,29a) of the supercharger rotors (28,29). The damping mechanism includes torsion springs (98,100) preloaded against each other. Torsion spring (98) has a low spring rate for attenuating torque fluctions or spikes during non-supercharging, low engine speed modes of operation. Spring (100) has a relatively high spring rate and functions as a shock absorber during engine shut down and during rough engine operation.
57 Citations
24 Claims
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1. A rotary blower of the backflow-type comprising a housing;
- first and second meshed lobed rotors rotatably disposed in the housing for transferring relatively low pressure inlet port air to outlet port air controllable between relatively low and high pressures;
first and second meshed timing gears respectively fixed to the first and second rotors for preventing contact of the meshed lobes; and
an input drive adapted to be rotatably driven by a positive torque about an axis in one drive direction at speeds proportional to speeds of a periodic combustion, torque transmitting engine selectively controllable between idle and maximum speeds;
the improvement comprising;a torsion damping mechanism for transmitting engine torque to the first timing gear, said damping mechanism including drive means and first and second spring means, said drive means driven by the input drive and mounted for limited to-and-fro rotation relative to the first timing gear, said first spring means having opposite ends reacting between the drive means and the first timing gear and resiliently transmitting torque in the positive direction, and said second spring means having opposite ends reacting between the drive means and the first timing gear and resiliently absorbing torque in a negative drive direction, and said second spring means having a spring rate greater than the spring rate of the first spring means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- first and second meshed lobed rotors rotatably disposed in the housing for transferring relatively low pressure inlet port air to outlet port air controllable between relatively low and high pressures;
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10. A rotary blower of the backflow-type comprising a housing;
- first and second meshed lobed rotors rotatably disposed in the housing for transferring relatively low pressure inlet port air to outlet port air controllable between relatively low and high pressures;
first and second meshed timing gears respectively fixed to the first and second rotors for preventing contact of the meshed lobes; and
an input drive adapted to be rotatably driven by a positive torque about an axis in one drive direction at speeds proportional to speeds of a periodic combustion, torque transmitting engine selectively controllable between idle and maximum speeds;
the improvement comprising;a torsion damping mechanism for transmitting engine torque to the first timing gear, said mechanism including drive and driven means and first and second spring means, said drive and driven means respectively secured for rotation with the input drive and the first timing gear and mounted for limited rotation relative to each other, said first spring means having opposite ends reacting between the drive and driven means in said one drive direction, said second spring means having opposite ends reacting between the drive and driven means in a direction opposite the one drive direction, and said second spring means having a spring rate greater than the spring rate of the first spring means. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
- first and second meshed lobed rotors rotatably disposed in the housing for transferring relatively low pressure inlet port air to outlet port air controllable between relatively low and high pressures;
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20. A torsion damping mechanism for reducing audible noise of at least first and second continuous mesh gears operating at low loading and rotatably driven by torque in one direction from a periodic combustion engine operating in a speed range near engine idle;
- said mechanism comprising;
drive and driven means driven in said one direction, mounted for limited relative rotation, respectively driven by the engine and driving the first gear; first spring means having opposite ends reacting between the drive and driven means for transmitting torque in said one drive direction for attenuating torsionals, said first spring means having a low torque transmitting capacity relative to full torque transmitting capacity of said gears and having relatively low spring rate for reducing gear tooth rattle of said gears; first stop means for contacting a portion of the drive means and arresting said relative rotation in said one drive direction in response to the engine speed being increased a predetermined amount above engine idle and for limiting stored energy in the first spring means; second stop means for contacting another portion of the drive means and arresting said relative rotation in a direction opposite said one drive direction, said second spring means having a spring rate greater than the spring rate of the first spring means; second spring means having opposite ends reacting between the drive and driven means for absorbing torque in said opposite drive direction, said second spring means being sized to normally prevent engagement of the second stop means. - View Dependent Claims (21, 22)
- said mechanism comprising;
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23. A torsion damping mechanism for reducing audible noise of at least first and second continuous mesh gears operating at low loading and rotatably driven by torque in one direction from a periodic combustion engine operating in a speed range near engine idle;
- said mechanism comprising;
drive and driven means driven in said one direction, mounted for limited relative rotation, respectively driven by the engine and driving the first gear; first spring means having opposite ends reacting between the drive and driven means for transmitting torque in said one drive direction for attenuating torsionals; first stop means for contacting a portion of the drive means and arresting said relative rotation in said one drive direction in response to the engine speed being increased a predetermined amount above engine idle and for limiting stored energy in the first spring means; second stop means for contacting another portion of the drive means and arresting said relative rotation in a direction opposite said one drive direction; second spring means having opposite ends reacting between the drive and driven means for absorbing torque in said opposite drive direction, said second spring means being sized to normally prevent engagement of the second stop means; and means for increasing the spring rate of said second spring means in response to torque in said opposite direction exceeding a predetermined amount. - View Dependent Claims (24)
- said mechanism comprising;
Specification