BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an air pump, and more particularly to a direct drive air pump that can solve the problems that the conventional air pump has many portions to seal, and the noise is loud.

Description of Related Art

With reference toFIGS. 9 and 10, a conventional air pump has a motor90, a cylinder91, a cylindrical body92, a cylindrical cover95, a piston assembly94, and a non-return member93. The cylinder91is disposed on an end of the motor90. The cylinder90has a seat911and a soundproof plate912. The seat911is disposed on the motor90. The soundproof plate912is fastened on the seat911by multiple screws. The seat911is located between the motor90and the soundproof plate912. The cylindrical body92is mounted on a top portion of the cylinder91. The cylindrical cover95is mounted on a top portion of the cylindrical body92. The piston assembly94is connected to a driving shaft of the motor90and is able to move upwardly and downwardly.

The non-return member93is disposed between the top portion of the cylindrical body92and a bottom portion of the cylindrical cover95and has a non-return valve sheet931. The non-return valve sheet931is located on a top surface of a non-return plate930of the non-return member93for controlling an air hole of the non-return plate930to open or close. Air in the cylindrical body92can be compressed by the piston assembly94. The compressed air can push the non-return valve sheet931of the non-return member93for flowing into the cylindrical cover95and then flowing through an outlet951of the cylindrical cover95.

However, the cylindrical body92has a top opening formed on a top end of the cylindrical body92and a bottom opening formed on a bottom end of the cylindrical body92. The non-return member93has to be disposed between the cylindrical body92and the cylindrical cover95for sealing. The non-return member93has two O-rings932. One of the two O-rings932is located between a bottom surface of the non-return plate930of the non-return member93and the top end of the cylindrical body92. The other one of the two O-rings932is located between a top surface of the non-return plate930of the non-return member93and the cylindrical cover95. Sealing structure used between the cylindrical body92and the cylindrical cover95has many components, thereby increasing the cost of the sealing structure. The two O-rings932are co-used. The conventional air pump has many portions to seal. The compressed air in the cylindrical body92is prone to leakage.

Moreover, the non-return valve sheet931is made of metal. In use, the rigid non-return valve sheet931repeatedly beats the non-return plate930of the non-return member93and generates loud noise. The non-return valve sheet931is a thin slice and is easy to deform after repeated beating. The air hole of the non-return plate930can not be closed completely by the non-return valve sheet93. The compressed air in the cylindrical body92is prone to leakage.

In addition, the soundproof plate912is fastened on the seat911by the screws to close an opening of the seat911for insulating the noise generated in use. The soundproof plate912is screwed on a side of the seat911. The assembly of the soundproof plate912is inconvenient. Vibrations are generated by the piston assembly94driven by the motor90. The screws fixed on the soundproof plate912may be loosened and generate noise.

To overcome the shortcomings, the present invention provides a direct drive air pump to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The objective of the invention is to provide a direct drive air pump that can solve the problems that the conventional air pump has many portions to seal, and the noise is loud.

The direct drive air pump has a motor and a pumping mechanism. The motor has an end and a driving shaft. The driving shaft is rotatably disposed on the motor and has an end.

The pumping mechanism is connected to the end of the driving shaft of the motor, and has a cylinder, a cylindrical body, a piston assembly, a cylindrical cover, and a non-return valve.

The cylinder is disposed on the end of the motor and has a top end and a space formed in the cylinder. The driving shaft of the motor is inserted into the space of the cylinder.

The cylindrical body is disposed on the top end of the cylinder, and has a cylindrical chamber, a cylindrical wall, a cylindrical opening, and a top plate. The cylindrical chamber is formed in the cylindrical body. The cylindrical wall is formed on the cylindrical body, surrounds the cylindrical chamber, and has a top end and a bottom end. The cylindrical opening is formed through the bottom end of the cylindrical wall and communicates with the cylindrical chamber. The top plate is integratedly formed on the top end of the cylindrical wall, is located above the cylindrical chamber, and has an exhaust hole. The exhaust hole is formed through the top plate and communicates with the cylindrical chamber.

The piston assembly is connected to the driving shaft of the motor, and is located in the space of the cylinder and the cylindrical chamber of the cylindrical body. The piston assembly is driven by the motor to move upwardly and downwardly in the space of the cylinder and the cylindrical chamber of the cylindrical body.

The cylindrical cover covers the cylindrical body, is fixedly disposed on the cylinder, and has a bottom surface, an insertion recess, an air room, an abutting wall, an O-ring, and a connector. The insertion recess is formed on the bottom surface of the cylindrical cover. The air room is formed in the cylindrical cover, and is located above and communicates with the insertion recess of the cylindrical cover and the exhaust hole of the top plate. The abutting wall is formed in the cylindrical cover adjacent to the insertion recess of the cylindrical cover, is located above the insertion recess of the cylindrical cover, is disposed around the air room of the cylindrical cover, and faces the top plate. The O-ring is disposed on the abutting wall and abuts against the top plate. The connector is disposed on the cylindrical cover and has an outlet. The outlet of the connector is formed through the connector and communicates with the air room of the cylindrical cover.

The non-return valve is disposed in the air room of the cylindrical cover for controlling the exhaust hole of the top plate of the cylindrical body to open and close, and has a valve block and a spring. The valve block is a soft component and is movably disposed on the top plate of the cylindrical body. The spring is connected between the valve block and the cylindrical cover.

In addition, the direct drive air pump has the motor, the pumping mechanism, an auxiliary pumping mechanism, and a tube.

The motor has two ends and the driving shaft. The driving shaft is rotatably disposed on the motor and has two ends. The pumping mechanism is connected to one of the two ends of the driving shaft of the motor. The auxiliary pumping mechanism is connected to the other one of the two ends of the driving shaft of the motor.

Each one of the pumping mechanism and the auxiliary pumping mechanism has the cylinder, the cylindrical body, the piston assembly, the cylindrical cover, and the non-return valve.

The cylinder is disposed on a corresponding one of the two ends of the motor and has the top end and the space formed in the cylinder. The driving shaft of the motor is inserted into the space of the cylinder.

The cylindrical body is disposed on the top end of the cylinder, and has the cylindrical chamber, the cylindrical wall, the cylindrical opening, and the top plate. The cylindrical chamber is formed in the cylindrical body. The cylindrical wall is formed on the cylindrical body, surrounds the cylindrical chamber, and has the top end and the bottom end. The cylindrical opening is formed through the bottom end of the cylindrical wall and communicates with the cylindrical chamber. The top plate is integratedly formed on the top end of the cylindrical wall, is located above the cylindrical chamber, and has the exhaust hole. The exhaust hole is formed through the top plate and communicates with the cylindrical chamber.

The piston assembly is connected to the driving shaft of the motor, and is located in the space of the cylinder and the cylindrical chamber of the cylindrical body. The piston assembly is driven by the motor to move upwardly and downwardly in the space of the cylinder and the cylindrical chamber of the cylindrical body.

The cylindrical cover covers the cylindrical body, is fixedly disposed on the cylinder, and has the bottom surface, the insertion recess, the air room, the abutting wall, the O-ring, a vent, and the connector. The insertion recess is formed on the bottom surface of the cylindrical cover. The air room is formed in the cylindrical cover, and is located above and communicates with the insertion recess of the cylindrical cover and the exhaust hole of the top plate. The abutting wall is formed in the cylindrical cover adjacent to the insertion recess of the cylindrical cover, is located above the insertion recess of the cylindrical cover, is disposed around the air room of the cylindrical cover, and faces the top plate. The O-ring is disposed on the abutting wall and abuts against the top plate. The vent is formed on the cylindrical cover and communicates with the air room of the cylindrical cover. The connector is disposed on the cylindrical cover and has an outlet. The outlet of the connector is formed through the connector and communicates with the air room of the cylindrical cover.

The non-return valve is disposed in the air room of the cylindrical cover for controlling the cylindrical opening of the cylindrical body to open and close, and has the valve block and the spring. The valve block is the soft component and is movably disposed on the top plate of the cylindrical body. The spring is connected between the valve block and the cylindrical cover.

The tube is disposed between and is connected to the vent of the pumping mechanism and the vent of the auxiliary pumping mechanism.

The direct drive air pump in accordance with the present invention has the following advantages.

Reducing the Sealing Portions

The top plate is integratedly formed on the top end of the cylindrical wall and has the exhaust hole formed through the top plate. The single O-ring is used to seal between the cylindrical body and the cylindrical cover. The sealing portions in the direct drive air pump are reduced for avoiding leaking.

Reducing the Noise

The top plate is integratedly formed on the top end of the cylindrical wall and has the exhaust hole formed through the top plate. The valve block of the non-return valve can co-work with the spring for opening and closing the exhaust hole. The valve block is the soft component and is connected to the rigid top plate of the cylindrical body for well closing the exhaust hole and reducing the noise of collision between the valve block and the top plate.

Furthermore, the cylindrical cover has multiple ribs. The ribs are axially formed in the cylindrical cover at spaced intervals, are located in the air room of the cylindrical cover, and are located around the valve block for guiding the valve block to move linearly and preventing the valve block from skewing. The exhaust hole can be opened and closed correctly. In addition, multiple channels are formed in the cylindrical cover. Each one of the channels is located between two adjacent ribs. In use, the air flow can be flowed through the channels smoothly.

Moreover, the cylinder has a seat and a soundproof plate. The soundproof plate engages with the seat and is located on a first side of the seat. The assembly between the seat and the soundproof plate is convenient for improving assembly of the cylinder and decreasing the cost of the cylinder. In addition, the soundproof plate can close the first side of the seat of the cylinder. The noise generated by the movement of the piston assembly driven by the motor is insulated by the soundproof plate. The soundproof plate engages with the first side of the seat of the cylinder for preventing the soundproof plate from loosening and reducing the noise.

Furthermore, the seat has multiple engaging holes, an engaging protrusion, and a slot. The engaging holes are formed on the first side of the seat. The engaging protrusion is formed on an outer-bottom surface of the first side of the seat. The slot is formed in the first side of the seat, is located above the engaging protrusion, and is located in the first opening of the seat. The soundproof plate has a back surface, multiple engaging arms, an engaging ring, and a plug. The back surface faces the first opening of the seat and has a bottom end. The engaging arms are formed on the back surface of the soundproof plate and respectively engage with the engaging holes of the seat, respectively. The engaging ring is formed on the bottom end of the back surface of the soundproof plate, and engages with the engaging protrusion of the seat. The plug is formed on the back surface of the soundproof plate above the engaging ring, and is inserted into the slot of the seat. The soundproof plate engages with the first side of the seat for increasing the assembly stability of the cylinder.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

