Method and apparatus for reducing backlash sound in gear mechanism
AssigneeToyota Jidosha Kabushiki Kaisha
InventorKatsuhiko Yamaguchi
Life of this patent
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Abstract
A backlash sound reducing method utilizes backlash sounds in a planetary gear unit in a hybrid vehicle that occur within predetermined operation ranges when the vehicle is stopped or running. If the output energy of an engine is within a predetermined range, the engine is controlled so that the output energy therefrom becomes a predetermined value. In the aforementioned case, it is also possible to increase the revolution speeds of the gears undergoing backlash. This operation avoids operating the engine within a range where the torque fluctuation is large, thereby reducing the backlash sound. Further, by setting relatively high revolution speeds, the force pressing the gears to each other is increased, so that the occurrence of backlash sounds is controlled.
Claims19
A method for reducing a backlash sound that occurs in a gear mechanism having at least a first shaft, a second shaft and a third shaft, the first shaft being connected to an output shaft of an internal combustion engine provided as a power source, the second shaft being connected to a drive shaft as a load, the third shaft being connected to an electric motor, the method comprising:
- detecting presence of a condition indicating occurrence of a backlash sound between gears of the gear mechanism;
- and
- setting torque transmitted between the gears to at least a predetermined value if the presence of the condition is detected.
A power output apparatus comprising:
- an internal combustion engine provided as a power source and having an output shaft;
- a gear mechanism having at least a first shaft, a second shaft and a third shaft, the first shaft being connected to the output shaft of the internal combustion engine;
- a drive shaft connected to the second shaft;
- an electric motor connected to the third shaft;
- a backlash sound condition detector that detects a condition indicating occurrence of a backlash sound between gears of the gear mechanism;
- and
- an internal combustion engine revolution speed controller that controls a revolution speed of the internal combustion engine so that the revolution speed becomes equal to or greater than a predetermined value if the condition indicating occurrence of a backlash sound is detected.
A power output apparatus comprising:
- an internal combustion engine provided as a power source and having an output shaft;
- a gear mechanism having at least a first shaft, a second shaft and a third shaft, the first shaft being connected to the output shaft of the internal combustion engine;
- a drive shaft connected to the second shaft;
- an electric motor connected to the third shaft;
- a backlash sound condition detector that detects a condition indicating occurrence of a backlash sound between gears of the gear mechanism;
- and
- an internal combustion engine torque controller that controls an output torque of the internal combustion engine so that the output torque becomes equal to or less than a predetermined value if the condition indicating occurrence of a backlash sound is detected.
Dependencies are inferred from the claim text.