Nissan Motor Company Limited

Haruki Yashiro

Akira Sasaki

Kazushige Maeda

Takao Kubozuka

Hisaaki Toujima

Kazuhiro Ooki

A synchronous electric machine includes a stator and a rotor. The stator is provided with teeth, which are wound around to establish electromagnetic fields. The rotor is provided with permanent magnets to generate magnetic fields, so that the rotor can rotate by interaction of the magnetic fields of the windings and the permanent magnets of the magnets. At least one pair of the permanent magnets is dislocated by a predetermined angle from positions where the permanent magnets is arranged at even pitch, and the predetermined angle being set to reduce electromagnetic excitation force acting on said teeth.

Synchronous electric machine

An expansion chamber, and first and second volume chambers on either side of said expansion chamber, are formed inside a muffler housing. Engine exhaust is led by an inlet tube to the first volume chamber, and an opening facing the expansion chamber is formed in an intermediate part of the inlet tube. Exhaust in the second volume chamber is discharged outside by a tail tube, and an opening is formed facing the expansion chamber in an intermediate part of the tail tube. A valve is provided for leading exhaust from the first volume chamber to the second volume chamber according to a pressure difference between the chambers. This forms two exhaust flowpaths. A resonance system with two degrees of freedom is thereby formed with respect to exhaust discharged via the two openings and the expansion chamber, and a high noise silencing efficiency is obtained.

Automobile exhaust noise silencer

A first and second noise suppressing mechanism are provided inside the muffler. Each mechanism is provided with a discharge pipe for discharging exhaust gas to outside the muffler. The first noise suppressing mechanism reduces exhaust noise in the low engine speed region. The second noise suppressing mechanism reduces noise in the medium and high engine speed regions. A valve is provided that connects the first noise suppressing mechanism and second noise suppressing mechanism according to the engine exhaust pressure. In the low speed region, the valve is closed and exhaust gas is discharged via the first noise suppressing mechanism where mainly low frequency noise is eliminated. In the medium and high speed regions, the valve is opened and exhaust gas is also discharged via the second noise suppressing mechanism where high frequency noise specific in these regions is also eliminated. Further, by the increased exhaust cross-sectional area, power drop due to increase of back pressure in the muffler in the high speed region, is prevented.

Automobile exhaust noise suppressor

A plurality of chambers are partitioned in a muffler by a baffle board. The muffler is provided with an exhaust gas passage for discharging exhaust gas outside the muffler via these chambers and a valve that bypasses a part of the exhaust passage. This valve opens according to the exhaust gas pressure. Also provided are a mechanism for pushing the valve in a closing direction, and a mechanism for damping the shock when the valve closes. Thus, valve closing noise is suppressed, and exhaust gas noise is further suppressed.

Growing community of inventors

Fujisawa, Japan

Haruki Yashiro