Electric compressor

#The present disclosure relates to an electric compressor. An electric compressor includes a compression mechanism, an electric motor for driving the compression mechanism, and a drive circuit for controlling the electric motor.

#The drive circuit of this type of electric compressor is accommodated in a metal housing. The drive circuit has an external connector to be electrically connected to a vehicle battery, which is an external power source. Electrical components on the circuit board receive electric power via the external connector. An inverter circuit for driving the electric motor and a switching element for performing switching control of the inverter circuit are mounted on the circuit board. Also, a filter coil and filter capacitors are mounted on the circuit board. The filter coil and the filter capacitors are filter elements, which protect switching elements from instantaneous and excessive currents and reduce noise.

#As described above, a great number of electric circuits and electrical components are mounted on the circuit board of a drive circuit. Since the sizes of filter coils and filter capacitors are large, the circuit board has adhesive applied thereon to reduce vibration and parts having auxiliary functions for fixing the board with bolts. As a result, circuit boards tend to be large.

#The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

#FIG. 1(a) is a partial cross-sectional view, with a part cut away, illustrating an electric compressor according to a first embodiment;

#FIG. 1(b) is an enlarged view illustrating the inverter unit shown in FIG. 1(a);

#FIGS. 1(a) and 1(b) show a first embodiment. In these drawings, the axial direction of an electric compressor 10, that is, the direction along which the axis L of a rotary shaft 17 of the electric compressor 10 extends, is the left-right direction.

#As shown in FIG. 1(a), the electric compressor 10 includes a first housing 11 and a second housing 12. The second housing 12 has a cylindrical shape with a closed end, and the first housing 11 closes the open end, or the left end as viewed in FIG. 1(a) of the second housing 12. The first housing 11 also has a cylindrical shape with a closed end. The second housing 12 accommodates an electric motor 16, which is arranged at a position close to a bottom wall 12a, and a compression mechanism 15, which is arranged at a position close to the first housing 11. That is, the second housing 12 is a motor housing for accommodating the electric motor 16. The interior of the second housing 12 is a motor accommodating space 13 for accommodating the electric motor 16. In the present embodiment, the electric compressor 10 is a scroll compressor.

#A stator 18 of the electric motor 16 is fixed to the inner circumferential surface of the second housing 12. The stator 18 has a stator core 18a and a motor coil 18b wound about the stator core 18a. The rotary shaft 17 is rotatably supported by the second housing 12 via bearings (not shown). A rotor 19 of the electric motor 16 is fixed to the rotary shaft 17 to rotate integrally with the rotary shaft 17. When the electric motor 16 is driven to rotate the rotary shaft 17, the compression mechanism 15 is activated to compress, for example, refrigerant of a vehicle air conditioner.