Air compressor having enlarged compartment for receiving pressurized air

An air compressor device comprising:

• a supporting base including a supporting plate,
• a cylinder housing defining therein a chamber and provided at said supporting base,
• a piston slidably received in said chamber of said cylinder housing and provided with a piston rod extended from said piston, and
• a motor attached to said supporting plate for moving said piston rod relative to said cylinder housing in a reciprocating action and for generating pressurized air, and
• said cylinder housing including a partition formed in a middle portion of said cylinder housing for defining an upper wall for said chamber of said cylinder housing, and including a compartment formed in an upper portion of said cylinder housing and separated from said chamber of said cylinder housing with said partition, and including a passage formed in said partition and communicating with said chamber and said compartment of said cylinder housing for allowing the pressurized air to flow from said chamber into said compartment of said cylinder housing, said compartment of said cylinder housing including an inner diameter (D) greater than an inner diameter (d) of said chamber of said cylinder housing for allowing the pressurized air in said chamber of said cylinder housing to easily flow into said compartment of said cylinder housing, said cylinder housing including a peripheral wall and an inner peripheral fence which is formed integrally with said peripheral wall at a bottom of said cylinder housing, at which said chamber of said cylinder housing opens into an ambient environment, for defining said chamber within said inner peripheral fence, said compartment within said peripheral wall and above said partition, and an annular channel between said peripheral wall and said inner peripheral fence, said annular channel extending upwardly from said bottom of said cylinder housing to communicate with said compartment of said cylinder housing, wherein said annular channel extends at a distance substantially equal to the distance between said partition of said cylinder housing and said bottom of said cylinder housing.