An air pump

Abstract

The present invention discloses an air pump. By changing the structure of the connection between the air pump housing and the motor and the design of the motor shaft, an integrated design of the motor and pump body is achieved. This eliminates the existing front end cover of the motor, shortens the cantilever length of the crankshaft, improves the stress conditions of the shaft, and increases the rigidity of the shaft. Furthermore, the temperature fields generated by the respective heat sources of the motor and the air pump are largely integrated, facilitating unified cooling and heat dissipation, and reducing component loosening caused by thermal expansion and contraction due to temperature differences. Furthermore, because the front end cover of the motor is eliminated, the number of parts and fasteners in the pump assembly is reduced, thereby correspondingly saving manufacturing and assembly costs.

Description

Technical Field

[0001] The invention belongs to the field of piston air pumps, and in particular relates to a DC brushless motor air pump with a compact structure. Background Art

[0002] In nuclear physics experiments, as well as chemical, energy, transportation, food and medical fields, the collection, transportation and storage of various gases are inseparable from electric air pumps or gas compressors with various pressure, flow and other requirements. Other requirements include corrosion resistance, oil-free, gas working temperature, etc. The structure of the air pump is also diverse.

[0003] This patent only relates to an air pump with an electric crankshaft connecting rod piston structure. Most traditional electric crankshaft connecting rod piston structure air pumps are composed of an independent motor connected to an air pump. A more compact way of transmitting rotational power is to extend the motor output shaft into the crankshaft of the air pump through a coupling or a motor. The latter structure is relatively small in size and light in weight, but because the front bearing of the motor shaft also serves as a cantilever structure supporting the crankshaft, the motor shaft is simultaneously subjected to the combined stress of the concentrated periodic radial load at the cylinder centerline position perpendicular to the rotating axis and the bending moment formed by the distance from the motor front bearing and the torque of the motor during the operation of the air pump. This causes the motor shaft to deform significantly during rotational motion, and the corresponding shaft fatigue stress is relatively large, which is prone to fatigue fracture. Therefore, the design rated working pressure of most such pumps does not exceed 1MPa, and most are around 0.7MPa. Summary of the Invention

[0004] The present invention is the design of this patent, which is to specially design a structure for connecting the pump body and the motor stator under the same weight and volume, cancel the front cover of the motor, and adopt a stepped shaft form for the motor rotor, thereby greatly improving the stress conditions of the motor shaft, thereby improving the structural rigidity of the transmission shaft composed of the crankshaft and the motor shaft and the pump body. The rated pressure of the air pump using this design can reach more than 2Mpa after experimental verification.

[0005] In order to solve the above problems, the technical solution provided by the present invention is:

[0006] An air pump housing, comprising:

[0007] A motor connection surface, wherein the motor connection surface is provided with an annular protrusion section that transitionally fits with the inner hole of the motor stator; the motor connection surface is provided with an annular groove in the outer ring area of the annular protrusion section, and the annular groove is used to accommodate the motor winding coil; the major diameter of the annular groove is smaller than the major diameter of the motor stator;

[0008] crankshaft chamber;

[0009] A bearing mounting cavity at the front end of the motor, wherein the crankshaft cavity is in communication with the bearing mounting cavity at the front end of the motor;

[0010] A transition chamber is communicated with the crankshaft chamber.

[0011] Furthermore, it also includes a groove for installing the cylinder, and the groove is connected to the transition chamber.

[0012] An air pump comprising

[0013] A motor, comprising a motor stator and a motor rotor shaft;

[0014] An air pump housing is provided with a motor connection surface, wherein the motor connection surface is provided with an annular protrusion segment that transitionally matches the inner hole of the motor stator; the motor connection surface is provided with an annular groove in the outer ring area of the annular protrusion segment, and the annular groove is used to accommodate the motor winding coil; the major diameter of the annular groove is smaller than the major diameter of the motor stator; the air pump housing also includes a crankshaft cavity;

[0015] A crankshaft having a through hole adapted to the small shaft section of the motor and sleeved on the motor rotor shaft, wherein the crankshaft rotates in the crankshaft cavity; the crankshaft is provided with an eccentric balance block;

[0016] A connecting rod, wherein the connecting rod is sleeved on the crankshaft through a bearing;

[0017] A piston assembly, wherein the connecting rod is connected to the piston assembly body;

[0018] A cylinder in which the piston group performs axial and torsional motion;

[0019] A film one-way valve group is used to control the inlet and outlet directions of the air in the cylinder.

[0020] Furthermore, the motor rotor shaft is a stepped shaft, comprising

[0021] A large shaft section, the large shaft section being used for supporting the front end bearing of the motor;

[0022] A small shaft segment, the small shaft segment is used to install the crankshaft and the connecting rod, and the small shaft segment is provided with a plane at a distance;

[0023] The stepped shaft reducing section is used for transition from the large shaft section to the small shaft section.

[0024] Furthermore, the crankshaft and the eccentric balance block are designed as one piece, and the eccentric balance block is provided with a fixing hole for fixing the crankshaft on the motor rotor shaft.

[0025] Furthermore, the stepped shaft diameter-changing section is a conical transition or an R transition.

[0026] Furthermore, the piston assembly includes:

[0027] A piston is provided on the piston body with a flexible bowl-shaped piston.

[0028] Furthermore, a motor front end bearing mounting rib is designed at the intersection of the motor front end bearing mounting cavity and the crankshaft cavity.

[0029] The present invention achieves a beneficial effect by changing the structure of the motor connection surface of the air pump housing to achieve an integrated design of the motor and pump body, thereby eliminating the existing front cover of the motor, shortening the cantilever length of the crankshaft, improving the stress conditions of the shaft, and increasing the rigidity of the shaft. Furthermore, the temperature fields generated by the respective heat sources of the motor and the air pump are largely integrated, facilitating unified cooling and heat dissipation, and reducing component loosening caused by thermal expansion and contraction due to temperature differences. Furthermore, the elimination of the front cover of the motor reduces the number of parts and fasteners in the pump assembly, thereby saving corresponding manufacturing and assembly costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a cross-sectional structural diagram of an embodiment of the present invention;

[0031] Figure 2 This is a cross-sectional structural diagram of an embodiment of the present invention with some parts removed;

[0032] Figure 3 This is a schematic diagram of the explosion structure of an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the explosion structure of an embodiment of the present invention from another perspective

[0034] Among them, 1 motor rotor shaft, 1.1 small shaft section, 1.2 stepped shaft diameter reducing section, 1.3 front bearing support section, 1.4 crankshaft mounting surface, 2 motor stator, 2.5 motor mounting hole, 3 motor front bearing, 4 motor rear bearing, 5 stator winding coil, 6 rotor magnet, 7 motor rear cover, 8 crankshaft, 8.1 crankshaft hole, 8.2 eccentric outer circle, 8.3 screw hole, 8.4 eccentric balance block, 9 crankshaft fixing screw, 10 air pump housing, 10.1 bearing seat protrusion section, 10.2 motor connection surface, 10.3 crankshaft cavity, 10. 4 Cylindrical groove, 10.5 Conical transition cavity, 10.6 Annular groove, 10.7 Motor front end bearing mounting cavity, 10.8 Motor front end bearing mounting rib, 10.11 Cylinder head screw hole, 11 Crankshaft bearing, 12 Connecting rod, 12.2 Piston connecting rod hole, 13 Piston and connecting rod connecting screw, 14 Piston body, 15 Piston leather cup, 16 Leather cup pressure plate, 17 Cylinder, 18 Diaphragm one-way valve group, 19 Cylinder head, 20 Air pump box cover, 25 Air pump box body connecting screw, 26 Air pump box cover mounting screw, 27 Cylinder head mounting screw. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] like Figure 1-3 As shown,

[0039] An air pump,

[0040] The motor comprises a motor rotor shaft 1 and a motor stator 2. The motor rotor shaft 1 is designed as a stepped shaft, which includes a small shaft section 1.1, a stepped shaft diameter reducing section 1.2, a front end bearing support section 1.3 and a crankshaft mounting surface 1.4.

[0041] The air pump housing 10 is further comprised. The connection point between the air pump housing 10 and the motor is the motor connection surface 10.2. This surface is provided with a motor front end bearing mounting cavity 10.7 for mounting the motor front end bearing 3. The motor connection surface 10.2 includes an annular protrusion 10.1 that transitionally fits within the inner bore of the motor stator 2. An annular groove 10.6 is formed on the outer periphery of the annular protrusion 10.1 to accommodate the motor winding coil 5. The major diameter of the annular groove 10.6 is smaller than the major diameter of the motor stator 2.

[0042] The iron core length of the motor rotor 1 is shorter than that of the motor stator 2, so that the annular protrusion section 10.1 designed on the air pump housing 10 and transitionally matched with the inner hole of the motor stator can extend into the small section for centering assembly.

[0043] The air pump housing 10 is also provided with a crankshaft cavity 10.3, which is communicated with the above-mentioned motor front end bearing mounting cavity 10.7 and has a coaxial axis. A motor front end bearing mounting rib 10.8 is designed at the intersection of the motor front end bearing mounting cavity 10.7 and the crankshaft cavity 10.3 to prevent axial movement of the motor bearing and the motor rotor.

[0044] The small shaft section 1.1 enters the crankshaft cavity 10.3 through the bearing mounting cavity 10.7 at the front end of the motor. The crankshaft 8 is sleeved on the small shaft section 1.1 of the motor rotor shaft 1. The crankshaft 8 is provided with an eccentric balancing block 8.4. There is also a screw hole 8.3 on the eccentric balancing block 8.4. The screw hole 8.3 is used to fix the crankshaft 8 and the motor shaft 1 on the crankshaft mounting surface 1.4 with a set screw 9; a crankshaft bearing 11 is interference fitted on the eccentric outer circle 8.2 of the crankshaft 8, and a connecting rod 12 is interference sleeved on the outer ring of the crankshaft bearing 11. The connecting rod 12 is connected to the piston body 14 through a piston and connecting rod connecting screw 13. A piston leather cup 15 is provided on the piston body 14, and the piston leather cup 15 is tightly attached to the piston body 14 through a leather cup pressure plate 16; the piston body 14 performs reciprocating and torsional motion in the cylinder 17.

[0045] A cylindrical groove 10.4 for accommodating the cylinder 17 is provided on the upper portion of the air pump housing 10. The cylindrical groove 10.4 is connected to a conical transition chamber 10.5, and the transition chamber is connected to the crankshaft chamber 10.3 through a connecting hole 10.6.

[0046] A cylinder head 19 is provided on the upper part of the cylinder 17, and an air inlet and outlet are provided on the cylinder head 19. The cylinder head mounting screws 27 fix and compress the cylinder head 19, the diaphragm one-way valve group 18 and the cylinder 17 on the air pump housing 10 in sequence. The diaphragm one-way valve group 18 is used to control the inlet and outlet direction of the air in the cylinder.

[0047] The air pump case connecting screws 25 pass through the air pump case mounting holes and the motor mounting holes 2.5 to assemble the air pump case 10, the motor stator 2 and the motor back cover 7 into a whole, and the air pump case cover mounting screws 26 fix the air pump case cover 20 on the air pump case 10.

[0048] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. An air pump, characterized in that: include A motor, comprising a motor stator and a motor rotor shaft; An air pump housing is provided with a motor connection surface, wherein the motor connection surface is provided with an annular protrusion segment that transitionally matches the inner hole of the motor stator; the motor connection surface is provided with an annular groove in the outer ring area of the annular protrusion segment, and the annular groove is used to accommodate the motor winding coil; the major diameter of the annular groove is smaller than the major diameter of the motor stator; the air pump housing also includes a crankshaft cavity; A crankshaft having a through hole adapted to the small shaft section of the motor and sleeved on the motor rotor shaft, wherein the crankshaft rotates in the crankshaft cavity; the crankshaft is provided with an eccentric balance block; A connecting rod, wherein the connecting rod is sleeved on the crankshaft through a bearing; A piston assembly, wherein the connecting rod is connected to the piston assembly body; A cylinder in which the piston group performs axial and torsional motion; A diaphragm one-way valve assembly, the diaphragm one-way valve assembly is used to control the inlet and outlet directions of the air in the cylinder; The motor rotor shaft is a stepped shaft, comprising: A large shaft section, the large shaft section being used for supporting the front end bearing of the motor; A small shaft segment, the small shaft segment is used to install the crankshaft and the connecting rod, and the small shaft segment is provided with a plane at a distance; A stepped shaft reducing section, used for transition from the large shaft section to the small shaft section; The piston group includes a piston, and a flexible bowl-shaped piston is provided on the piston body.

2. An air pump according to claim 1, characterized in that: The crankshaft and the eccentric balance block are designed as one piece, and the eccentric balance block is provided with a fixing hole for fixing the crankshaft on the motor rotor shaft.

3. An air pump according to claim 1, characterized in that: The stepped shaft diameter reducing section is a conical transition or an R transition.

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