Abstract: A microphone assembly comprises a circuit board, a microphone element connected to the circuit board, an external connection interface connected to the circuit board, and hot melt that is formed to cover the circuit board, the microphone element, and the external connection interface and has a hole formed to expose a part of the back side of the circuit board or the sound receiving part of the microphone element.

Abstract: A piezoelectric element connection structure, a vehicle, and a piezoelectric element connection method are disclosed. This piezoelectric element connection structure includes: a body; a casing that include a bottom and is fixedly connected to the body so as to face the placing area for the board; a piezoelectric element that is placed on the bottom; and a coil wire that includes a winding shape, extends from the piezoelectric element toward the placing area for the board, and electrically connects between the piezoelectric element and the board.

Abstract: A driving mechanism for driving a gear pump of a dual drive type having two shafts comprises a reversing gear having a pair of output shafts which rotate respectively in opposite directions at the same rotating speed, and a pair of gear couplings connecting the gear pump to the reversing gear. One of the pair of gear couplings comprises: a shaft, a first coupling head disposed on one end of the shaft, and a second coupling head disposed on the other end of the shaft. The number z.sub.1 of teeth of the component external spur gears and internal spur gears of the first coupling head is not equal to the number z.sub.2 of teeth of the component external spur gears and internal spur gears of the second coupling head.