Air pump structure

Abstract

An air pump structure comprises a cylinder body, a cylinder cover, a piston and a motor, the piston is a connecting rod piston, the piston can be installed in the cylinder body in a front-back moving mode, and a connecting rod of the piston is in transmission connection with an output gear of the motor through an eccentric gear, and is characterized in that the eccentric gear is a large inner gear, and the output gear of the motor is a small outer gear; the eccentric gear is in transmission connection with an output gear of the motor in an internal meshing mode. The eccentric gear is changed into the inner meshing gear from a traditional outer meshing gear, the air pump has the advantages of being good in transmission stability, high in bearing capacity and low in noise, and due to the fact that the output gear is arranged in the eccentric gear, the length and the size of the air pump are reduced, and assembly and transportation are convenient.

Description

Technical Field

[0001] The utility model belongs to the technical field of inflation equipment and relates to an air pump structure with stable transmission and low noise. Background Art

[0002] An air pump is a device that removes or adds air from a closed space. The working principle of an air pump is as follows: When the motor runs and air is pumped out, the valve of the connecting valve is pushed open by atmospheric pressure, allowing air to enter the cylinder. When air is pumped into a tire, the valve is closed by the air pressure inside the cylinder, allowing air to enter the tire. Traditional air pumps generally consist of a cylinder, a valve seat with inlet and outlet valves, and a cylinder head. When the piston moves upward, the inlet valve closes, the outlet valve opens, and air is discharged through the outlet valve. When the piston moves downward, the inlet valve opens, allowing air to enter the cylinder, and the outlet valve closes. The up and down movement of the piston within the cylinder is driven by a motor. An eccentric gear meshes with the motor's output gear. The eccentric shaft of the eccentric gear is rotatably connected to the lower end of the piston connecting rod. The rotation of the eccentric gear drives the connecting rod up and down, thereby enabling the piston to move up and down within the cylinder. Existing structures use external meshing between the eccentric gear and the output gear, resulting in insufficient load-bearing capacity, unstable transmission, and high noise levels.

[0003] Upon investigation, the existing Chinese patent number CN201920950843.6, "A Plastic Cylinder Air Pump Structure", includes a cylinder body, a cylinder head, and a piston component installed in the cylinder body. Its eccentric gear and the output gear of the motor are also externally meshed, and the above-mentioned defects also exist.

[0004] Therefore, it is necessary to develop a new air pump structure to improve the transmission stability and load-bearing strength and reduce noise. Summary of the Invention

[0005] The technical problem to be solved by the utility model is to provide an air pump structure with stable transmission and low noise in response to the above technical status quo.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: an air pump structure, including a cylinder body, a cylinder head, a piston and a motor, the piston is a connecting rod piston, the piston is installed in the cylinder body and can move back and forth, the connecting rod of the piston is connected to the output gear of the motor through an eccentric gear, and is characterized in that: the eccentric gear is an internal meshing gear, the output gear of the motor is a small external gear, and the eccentric gear and the output gear of the motor are connected through internal meshing.

[0007] As an improvement, the motor is mounted on the outer side of the bracket, the eccentric gear is mounted on the inner side of the bracket, the output gear of the motor passes through the bracket and engages with the eccentric gear, an eccentric cover is formed on the upper end face of the eccentric gear, a center hole and an eccentric hole are provided on the eccentric cover, a bearing is installed in the center hole, and a convex shaft that cooperates with the bearing is provided on the inner side of the bracket, a screw passes through the bearing and is screwed into the convex shaft to connect the eccentric gear with the convex shaft, and the eccentric gear is driven by the motor to rotate with the convex shaft as the center axis.

[0008] Furthermore, a connecting hole is provided at the rear end of the connecting rod of the piston, and the eccentric gear is rotatably connected to the connecting rod by an eccentric shaft passing through the connecting hole and the eccentric hole.

[0009] Finally, an annular groove is formed at the front end of the piston, and a sealing ring is embedded in the annular groove and abuts against the inner wall of the cylinder.

[0010] Compared with the prior art, the advantages of the present invention are that the eccentric gear is replaced by an internal gear instead of a traditional external gear. Since the tooth surface strength of the internal gear is significantly greater than that of the external gear, and the slip rate of the internal gear is less than that of the external gear, the transmission stability and load-bearing capacity are improved, and noise is reduced. The present invention has a reasonable structure and is characterized by good transmission stability, strong load-bearing capacity, and low noise. Since the output gear is disposed within the eccentric gear, the length and volume of the air pump are reduced, making it easier to assemble and transport. The main advantages of the present invention are its small size and high pressure capability, making it particularly suitable for bicycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an exploded view of the structure of Example 1 of the present utility model;

[0012] Figure 2 This is a cross-sectional view of Example 1 of the present utility model;

[0013] Figure 3 for Figure 1 Exploded view of

[0014] Figure 4 This is an exploded view from another angle of Example 1 of the present invention. DETAILED DESCRIPTION

[0015] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0016] like Figures 1 to 4As shown, an air pump structure includes a cylinder body 1, a cylinder head 2, a piston 3, a motor 4, a bracket 5 and an eccentric gear 6. The piston 3 is a connecting rod piston, and the piston 3 is installed in the cylinder body 1 so as to be movable forward and backward. The connecting rod 31 of the piston 3 is connected to the output gear 41 of the motor 4 through the eccentric gear 6. The eccentric gear 6 is an internal meshing gear, and the output gear 41 of the motor 4 is a small external gear. The eccentric gear 6 and the output gear 41 of the motor 4 are connected to each other through internal meshing.

[0017] The specific structure is as follows: a bracket 5 is provided at the rear end of the cylinder body 1. The rear end of the cylinder body 1 is mounted on the bracket 5. The motor 4 is mounted on the outer side of the bracket 5. The eccentric gear 6 is mounted on the inner side of the bracket 5. The output gear 41 of the motor 4 passes through the bracket 5 and meshes with the eccentric gear 6. The eccentric gear 6 is equivalent to a transmission sleeve with an internal gear ring. An eccentric cover plate 61 is formed on the upper end surface of the eccentric gear 6. The eccentric cover plate 61 is provided with a center hole 62 and an eccentric hole 63. A bearing 8 is installed in the center hole 62. A protruding shaft 7 is provided on the inner side of the bracket 5 to cooperate with the bearing 8. A screw 9 passes through the bearing 8 and is screwed into the protruding shaft 7 to connect the eccentric gear 6 to the protruding shaft 7, so that the eccentric gear 6 rotates around the protruding shaft 7 when driven by the motor 4. A connecting hole 33 is provided at the rear end of the connecting rod 31 of the piston 3. The eccentric shaft 10 passes through the connecting hole 33 and the eccentric hole 63 to connect the eccentric gear 6 to the connecting rod 31. The front end of the piston 3 is formed with an annular groove 32, in which a sealing ring 30 is embedded, which abuts against the inner wall of the cylinder body 1. The cylinder body 1 and the cylinder head 2 are fixed together by bolts, and a one-way valve 21 is installed in the cylinder head 2. The structure of the cylinder body 1 and the cylinder head 2 is consistent with the existing technology and will not be further described here.

[0018] The working principle is: the motor 4 rotates to drive the eccentric gear 6 to rotate, and the eccentric gear 6 drives the piston 3 to move back and forth in the cylinder 1 to achieve air intake and exhaust.

[0019] Since the eccentric gear 6 of this embodiment is an internal meshing gear, the meshing mode between the eccentric gear 6 and the output gear 41 of the motor 4 is internal meshing. The tooth surface strength of the internal meshing gear is significantly greater than that of the external meshing gear, and the slip rate of the internal meshing is less than the slip rate of the external meshing. Therefore, the transmission stability and load-bearing capacity are greatly improved, and the noise is effectively reduced.

[0020] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An air pump structure comprising a cylinder, a cylinder head, a piston, and a motor, wherein the piston is a connecting rod piston, which is mounted in the cylinder body so as to be movable forward and backward, and the connecting rod of the piston is connected to the output gear of the motor via an eccentric gear, characterized in that: The eccentric gear is an internal meshing gear, the output gear of the motor is a small external gear, and the eccentric gear and the output gear of the motor are connected to each other through internal meshing.

2. The air pump structure according to claim 1, characterized in that: The motor is mounted on the outer side of the bracket, the eccentric gear is mounted on the inner side of the bracket, the output gear of the motor passes through the bracket and engages with the eccentric gear, an eccentric cover is formed on the upper end face of the eccentric gear, a center hole and an eccentric hole are opened on the eccentric cover, a bearing is installed in the center hole, a convex shaft matching the bearing is provided on the inner side of the bracket, a screw passes through the bearing and is screwed into the convex shaft to connect the eccentric gear with the convex shaft, and the eccentric gear is driven by the motor to rotate with the convex shaft as the center axis.

3. The air pump structure according to claim 2, characterized in that: A connecting hole is provided at the rear end of the connecting rod of the piston, and the eccentric gear is rotatably connected to the connecting rod by an eccentric shaft passing through the connecting hole and the eccentric hole.

4. The air pump structure according to claim 3, characterized in that: An annular groove is formed at the front end of the piston, and a sealing ring is embedded in the annular groove and abuts against the inner wall of the cylinder.

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