An air compressor housing and an air compressor with such a housing

Abstract

The present invention discloses an air compressor housing and an air compressor with such a housing. The housing includes a main body portion and a cylinder seat portion. The inner cavities of the main body portion and the cylinder seat portion communicate with each other. The main body portion is cylindrical. A necking portion is provided between the inner end and the outer end of the main body portion. The inner diameter of the necking portion is smaller than the inner diameters of the inner end and the outer end of the main body portion. Between the outer end of the main body portion and the necking portion is a reduced-diameter section with a gradually decreasing inner diameter, and between the necking portion and the inner end of the main body portion is a flared section. For this housing, the structural design is more reasonable, which can guide the cooling air flow generated by the blower to better dissipate heat from the motor. At the same time, it can increase the proportion of the cooling air flow entering the cylinder seat portion, enabling the cylinder assembly to be better cooled.

Description

Technical Field

[0001] The present invention relates to an air compressor, and particularly to an air compressor housing and an air compressor with such a housing. Background Art

[0002] An air compressor is a gas source device for compressing air. An air compressor generally includes a housing, a motor, and a cylinder assembly. The housing includes a main body portion and a cylinder base portion that communicate with each other. The motor is installed at the inner end of the main body portion. The motor shaft extends into the interior of the main body portion and is provided with a crank and a wind blade. The cylinder assembly includes a cylinder liner, a piston, a valve plate, and a cylinder head. The piston is installed in a piston cavity within the cylinder liner and is connected to the crank through a connecting rod. When the motor rotates, it drives the piston to reciprocate, compresses the air inhaled into the cylinder liner, and provides high-pressure gas outward.

[0003] When the air compressor is working, the motor generates heat, and as the temperature of the motor itself rises, the working efficiency decreases. At the same time, when compressing the air in the cylinder liner, the compressed gas also generates heat, causing the temperatures of the piston, cylinder liner, valve plate, and cylinder head to rise. The increase in the temperatures of the piston, cylinder liner, valve plate, and cylinder head will, on the one hand, lead to a reduction in the service life of the seal between the piston and the cylinder liner. On the other hand, the physical properties of the gas itself determine that the higher the gas temperature, the larger the volume, the higher the self-pressure, and the more difficult it is to compress. When the outside air enters the intake cavity and the piston cavity, the heat of the cylinder head, valve plate, and cylinder liner will be transferred to the air. The higher the temperatures of the cylinder liner, valve plate, and cylinder head, the higher the temperature of the air in the piston cavity, and the lower the working efficiency of the air compressor. At the same time, the higher the temperature in the piston cavity, the lower the service life of the seal in the piston cavity, resulting in a reduction in the overall service life of the air compressor. Therefore, the heat dissipation performance of the motor and the cylinder assembly has a greater impact on the working efficiency of the air compressor.

[0004] A Chinese patent with the patent number 201811471190.X and the name of a multi-cylinder air compressor discloses an air compressor heat dissipation structure. A heat dissipation flow channel is opened on the cylinder head. The heat dissipation flow channel communicates with the inner cavity of the housing. At the same time, a heat dissipation hole is opened on the inner end face of the housing. A part of the cooling air flow generated when the wind blade rotates dissipates heat from the cylinder liner, valve plate, and cylinder head through the heat dissipation flow channel. Another part of the cooling air flow generated by the wind blade can be discharged through the heat dissipation hole on the inner end face of the housing, and during this process, the end of the motor is dissipated.

[0005] Most of the main bodies of the existing boxes are in a straight cylinder shape. When the fan blades rotate, the air at the outer end of the main body is sucked in to form an axially flowing cooling air current. The cooling air current flows axially. On the one hand, due to the obstruction of the crank, connecting rod and the end face of the electrode, a large eddy current will be generated between the inner side of the connecting rod and the end face of the motor, resulting in a large wind resistance. At the same time, since the eddy current swirls between the connecting rod and the end face of the motor, the temperature of the cooling air current forming the eddy current will rise. The existence of the eddy current will also prevent other cooler cooling air currents from contacting the end of the motor and taking out the heat of the motor, so that the motor cannot be cooled well. On the other hand, the cylinder block part is arranged outside the straight cylinder-shaped main body part. When the cooling air current flows axially, it is not easy for the cooling air current to enter the cylinder block part, and the flow rate of the cooling air current entering the cylinder block part is small, resulting in the cylinder assembly not being sufficiently cooled by the cooling air current. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an air compressor box body, with a more reasonable structural design, which can guide the cooling air current generated by the fan blades to better dissipate heat from the motor, and at the same time can increase the proportion of the cooling air current entering the cylinder block part, so that the cylinder assembly can be better cooled.

[0007] The above technical purpose of the present invention is achieved through the following technical solutions: An air compressor box body includes a main body part and a cylinder block part. The main body part is in a cylindrical shape. There is a cavity in the cylinder block part. The inner cavity of the main body part and the inner cavity of the cylinder block part are interconnected. A necking part is arranged between the inner end and the outer end of the main body part. The inner diameter of the necking part is smaller than the inner diameter of the inner end of the main body part and the inner diameter of the outer end of the main body part. Between the outer end of the main body part and the necking part is a reduced-diameter section with a gradually decreasing inner diameter. Between the necking part and the inner end of the main body part is a flared section.

[0008] Through the above technical solutions, the inner diameter of the reduced-diameter section gradually decreases, so that the cooling air current generated by the fan blades installed at the outer end of the main body part can be guided by the inner wall of the reduced-diameter section, so that part of the cooling air current can flow towards the outer surface of the motor stator coil under the action of the inner wall of the reduced-diameter section to cool the end of the motor stator. At the same time, since the cylinder block part and the inner cavity of the main body part are interconnected, after the necking part is arranged, relatively speaking, the lower end of the cylinder block part extends more into the main body part, so that the through-flow area where the cylinder block part and the main body part communicate is increased, so that the axially flowing cooling air current can more easily enter the cylinder block part, increasing the proportion of the cooling flow rate of the cylinder block part, and effectively improving the cooling effect of the cylinder assembly.

[0009] There is a flared section between the necking part and the inner end of the main body. The inner diameter of the flared section is small at the end close to the necking part and large at the end close to the motor. The space formed between the inner wall of the flared end and the outer surface of the motor stator coil increases axially. After the cooling air flow enters this space, its flow velocity decreases and the static pressure increases. The decrease in flow velocity enables more sufficient heat exchange between the cooling air flow and the outer surface of the motor stator coil, taking away the heat on the electronic coil. The decrease in flow velocity can also reduce the generation and intensity of eddy currents. The increase in static pressure enables the cooling air flow at this place to be discharged from the main body more smoothly.

[0010] In addition, the main body part has a variable diameter setting, which can better improve the longitudinal compressive capacity of the main body part. When the air compressor is working, the piston is always in a reciprocating swinging motion state. Although it is balanced by a crank, there is still a small part of the longitudinal impact force transmitted to the main body part. The two ends of the main body part are large and the middle is small, presenting an hourglass shape as a whole. Compared with a straight tube shape, when the main body part is subjected to longitudinal (perpendicular to the axis of the main body part) pressure, the main body part is less likely to deform, avoiding the cross-section changing from circular to elliptical and improving the stability during operation.

[0011] Preferably, the inner diameter of the outer end of the main body part is larger than the inner diameter of the inner end of the main body part. The ratio of the inner diameter of the necking part to the inner diameter of the outer end of the main body part is between 1:1.15 and 1.30, and the ratio of the inner diameter of the diameter-reducing section to the inner diameter of the inner end of the main body part is between 1:1.03 and 1.20.

[0012] Through the above technical solution, increasing the outer single inner diameter of the main body part can install a wind leaf with a larger outer diameter at the outer end of the main body part, thereby increasing the total flow rate of the cooling air flow generated when the wind leaf rotates. After the total flow rate of the cooling air flow is increased, the corresponding flow rate for cooling the motor will increase, and the flow rate for cooling the cylinder assembly will also increase, thus achieving a better heat dissipation effect.

[0013] The ratio of the diameter-reducing section to the inner diameter of the outer end of the main body part is between 1:1.15 and 1.30, which can ensure a certain compression ratio when the cooling air flow generated by the wind leaf flows axially, thereby ensuring the wind pressure. On the one hand, it enables the cooling air flow to flow more smoothly towards the cylinder seat part, increasing the flow rate distribution ratio of the cylinder seat part. On the other hand, as the wind pressure increases, the corresponding flow velocity of the cooling air flow will also increase, enabling the cooling air to accurately spray between the outer surface of the stator coil and the inner wall of the flared section, thereby achieving a better heat dissipation effect on the outer surface of the stator coil. And this ratio within this range can ensure better wind pressure and will not make the overall wind resistance too large, affecting the intake at the outer end of the main body part, and the actual heat dissipation effect is better.

[0014] The ratio of the diameter-reducing section to the inner diameter of the inner end of the main body part is between 1:1.03 and 1.20, which makes the space between the flared section and the stator coil gradually increase, thereby reducing the wind speed and enabling the cooling air flow to fully contact and exchange heat with the outer surface of the stator coil, improving the cooling efficiency.

[0015] Preferably, the necking-down part is close to the inner end of the main body part, and the center of the cylinder seat part is between the necking-down part and the outer end of the main body part.

[0016] Through the above technical solution, most of the cylinder seat part is located at the outer end of the necking-down part, so that the cooling air flow generated by the wind leaf can be discharged through the heat dissipation channels on the cylinder head and the valve plate as much as possible. The heat dissipation effect of the cylinder assembly is improved. Relatively speaking, the working efficiency of the air compressor increased by reducing the temperature of the cylinder assembly is greater than that increased by reducing the temperature of the motor.

[0017] Preferably, a motor shaft seat is arranged in the box body, and the motor shaft seat is connected to the inner wall at the necking-down part through spokes.

[0018] Through the above technical solution, the setting of the motor shaft seat can fix and support the motor shaft. When the motor shaft drives the piston to reciprocate, the vibration and swing generated by the piston will act on the motor shaft seat through the motor shaft. The inner diameter near the necking-down part is smaller. On the one hand, setting the spokes here can reduce the length of the spokes and save materials. On the other hand, after the spokes are stressed, they can transmit the impact force to the outer wall of the box body on both sides of the necking-down part, so as to achieve the purpose of dispersing the force and improve the overall structural strength of the box body.

[0019] Preferably, the cross-section of the cylinder seat part is a polygon with more than five sides or a circle.

[0020] Through the above technical solution, since the cross-section of the piston chamber is generally circular and the cylinder seat part is located outside the cylinder liner, the cylinder seat part being a polygon with more than five sides or a circle forms an annular air flow channel between the inner wall of the cylinder seat part and the outer wall of the cylinder liner, making the distance between the outer wall of the cylinder liner and the inner wall of the cylinder seat part basically the same. When the cooling air flow enters between the two, the cooling air flow can cool the surface of the cylinder liner more evenly, thus achieving a better cooling effect.

[0021] Preferably, the inner wall of the reduced-diameter section is a first conical surface, and the half vertex angle α of the first conical surface is between 5° and 20°.

[0022] Through the above technical solution, the inner wall of the reduced-diameter section is a first conical surface. When guiding the cooling air flow, the inner wall of the reduced-diameter section will not cause a large obstruction to the cooling air flow, and the flow is relatively smooth. The half vertex angle of the first conical surface is small, the cross-sectional area of the reduced-diameter section changes little, and the cooling air flow flows relatively smoothly and regularly.

[0023] Preferably, the inner wall of the flared section is a second conical surface, and the half vertex angle β of the second conical surface is between 5 and 15°.

[0024] With the above technical solution, the inner wall of the flaring section is a conical surface. Accordingly, when the cooling air flow flows from the necking section to the inner end of the main body section, its flow velocity gradually decreases and the pressure gradually increases, and the flow becomes more regular, capable of generating a better heat dissipation effect.

[0025] Preferably, support feet are provided on the outer wall of the lower side of the diameter-reducing section.

[0026] With the above technical solution, the support feet are provided at this position, which is roughly at the lower part of the outer end of the cylinder seat section, so that the impact force generated during the operation of the piston can be directly transmitted to the support feet, making the overall structural rigidity of the box better and the vibration generated during operation smaller.

[0027] With the above technical solution, by improving the box structure, the effect of changing the cooling air flow distribution ratio is achieved, increasing the proportion of the cooling air flow flowing to the cylinder block section and correspondingly reducing the proportion of the cooling air flow flowing to the motor end. At the same time, by guiding the air flow axially flowing in the main body section, the cooling air flow is directly directed to the end face of the linear motor stator coil, thereby making full use of the cooling air flow and ensuring the cooling effect on the motor.

[0028] Another object of the present invention is to provide an air compressor, which has good heat dissipation performance, the cylinder assembly and the motor have relatively low temperatures during operation, high working efficiency, and good service life.

[0029] The above technical object of the present invention is achieved through the following technical solution: an air compressor, including a motor and a cylinder assembly. The cylinder assembly includes a cylinder liner, a piston, a valve plate and a cylinder head. Heat dissipation flow channels communicating with the inner cavity of the cylinder seat section are provided on the cylinder head and the valve plate. The air compressor box body as described above is further included. The inner end of the main body section is connected to the end of the motor. The motor includes a stator and a rotor. A stator coil is wound on the stator. A motor shaft is passed through the rotor. The motor shaft extends into the box body and is provided with a crank and a wind blade. The crank and the piston are connected by a connecting rod. The end of the stator coil extends into the inner end of the main body section. The inner wall of the diameter-reducing section points to the outer surface of the end of the stator coil. Heat dissipation holes are provided on the inner end of the main body section or on the motor.

[0030] With the above technical solution, the arrangement of the diameter-reducing section and the necking section can guide the cooling air flow. On the one hand, the axially flowing cooling air flow is directed to blow against the outer surface of the motor stator coil, and then flows along the outer surface of the stator coil and the inner wall of the inner end of the main body section to dissipate heat from the electronic coil, and finally is discharged from the heat dissipation holes at the end of the main body section or on the motor housing, taking out the heat generated by the motor.

[0031] The main body is arranged in such a way that it has a better heat dissipation effect compared to a straight cylindrical main body. Since the stator and rotor of the motor are solid, the cooling air flow cannot pass through, and the heat dissipation holes can only be opened on the electrode housing or the inner end face of the main body. When using a straight cylindrical main body, the cooling air flow flows axially. The cooling air flow in the central part of the main body directly impacts the end face of the motor stator or rotor, and then flows outward from the stator and rotor. This will generate eddy currents between the connecting rod and the motor end face, and eddy currents will also be generated at the rear end outside the stator end face, that is, the outer surface of the stator coil. After the eddy currents are generated on the outer surface of the stator coil, it will also affect the contact between the axially flowing cooling air flow near the inner wall of the main body and the outer surface of the stator coil, thus affecting the heat dissipation of the motor.

[0032] Using a main body with a necking part and a contraction section can guide the axially flowing cooling air flow, and guide the cooling air flow through the lower part of the contraction section, so that the cooling air flow at the lower part of the main body flows upward and towards the middle part of the main body, pointing to the outer surface of the motor stator coil. At the same time, by guiding the axially flowing air flow, more axial air flow can enter the cylinder base part, increasing the proportion of the cooling air flow entering the cylinder base part, and improving the cooling effect of the cylinder assembly without affecting the heat dissipation performance of the motor.

[0033] The heat dissipation holes can be set on the inner end face of the main body or on the motor housing. When the heat dissipation holes are set on the end face of the main body, the cooling air flow can flow out axially and the flow is smoother. When the heat dissipation holes are set on the motor housing, the cooling air flow flows along the outer wall of the electronic coil for a longer distance and the heat exchange is more sufficient, but relatively the wind resistance is larger during the flow.

[0034] Preferably, the inner diameter of the outer end of the main body is larger than the inner diameter of the inner end, and the outer diameter of the wind leaf is larger than the outer diameter of the motor.

[0035] Through the above technical solution, by increasing the inner diameter of the outer end and using a wind leaf with a larger outer diameter, at the same motor speed, the wind leaf can suck in more cooling air flow for cooling, thereby improving the cooling effect on the motor and the cylinder assembly.

[0036] Preferably, an air intake cavity and an air outlet cavity are opened on the cylinder head. The air intake cavity is located on the side of the cylinder head close to the motor, and the air outlet cavity is located on the side of the cylinder head far from the motor.

[0037] With the above technical solution, due to the presence of the crank and connecting rod, the flow of the cooling air flow will be obstructed. The flow rate of the cooling air flow in the cylinder head part at the outer end of the connecting rod will be greater than that on the other side of the cylinder head part, so that the cylinder block, valve plate and cylinder head on the outer end side of the necking part have better cooling effects. At the same time, when the air compressor works, the compressed high-temperature gas will enter the air outlet cavity, making the temperature of the cylinder head on the air outlet cavity side higher than that on the other side of the cylinder head. The air outlet cavity side of the cylinder head is above the cylinder seat part at the outer end of the necking part, so that more cooling air flow can be used to fully cool the higher-temperature side of the cylinder head, improving the utilization rate of the cooling air flow and the heat dissipation capacity.

[0038] Preferably, the ratio of the volume of the air inlet cavity to the volume of the air outlet cavity is between 1:1.7 and 2.6; or the ratio of the inner wall area of the air inlet cavity to the inner wall area of the air outlet cavity is between 1:1.3 and 2.2.

[0039] With the above technical solution, due to the limited volume of the cylinder head itself, increasing the volume of the air outlet cavity will largely reduce the volume of the air inlet cavity. At the same time, for simple and regular chamber structures, such as chambers with circular arc or polygonal cross-sections, the larger the volume, the larger the corresponding inner wall area. The volume of the air outlet cavity being larger than that of the air inlet cavity can make the inner wall area of the air outlet cavity larger than that of the air inlet cavity, so that after the compressed high-temperature gas enters the air outlet cavity, more heat can be transferred to the cylinder head and then dissipated through the cylinder head, preventing the compressed gas with a higher temperature after compression from entering the air storage tank, causing the gas temperature and pressure in the air storage tank to increase and reducing the air supply efficiency of the air compressor.

[0040] Correspondingly, convex ribs, convex blocks, etc. protruding towards the center of the air outlet cavity can also be arranged in the air outlet cavity to increase the inner wall area of the air outlet cavity, thereby increasing the heat exchange area without increasing the volume of the air outlet cavity, making the volume of the air outlet cavity equal to or less than that of the air inlet cavity.

[0041] Preferably, fan blades are arranged on the end face of the rotor.

[0042] With the above technical solution, the heat dissipation conditions of the inner wall of the stator coil can be improved. Generally, the length of both ends of the stator coil is greater than the length of the rotor. After fan blades are arranged on the end face of the rotor, the fan blades will also be inside the stator coil. When the rotor rotates, the fan blades generate centrifugal air flow, which can cool the stator coil, thereby further improving the heat dissipation performance of the stator coil.

[0043] Preferably, a recessed part is arranged on the upper surface of the valve plate opposite to the air inlet cavity and the air outlet cavity.

[0044] Through the above technical solution, the overall height of the cylinder head can be reduced. Since the air compressor generally has certain requirements for the volumes of the air inlet cavity and the air outlet cavity, after the recessed part is arranged on the upper surface of the valve plate, the depths of the air inlet cavity and the air outlet cavity on the corresponding cylinder head can be reduced accordingly, thereby reducing the overall height of the cylinder head. At the same time, after the recessed part is arranged, the thickness of the cylinder head at this place is reduced, and the heat generated when the piston compresses the air can be transferred to the cylinder head more quickly, which is convenient for cooling.

[0045] Preferably, a valve piece limiting block is installed on the upper surface of the valve plate, and a plurality of heat dissipation inclined surfaces are arranged on the valve piece limiting block.

[0046] Through the above technical solution, the arrangement of the plurality of heat dissipation inclined surfaces can increase the surface area of the limiting block, thereby increasing the heat exchange area, facilitating the heat exchange between the limiting block and the compressed air in the air inlet cavity, and thus reducing the temperatures of the limiting block and the valve plate.

[0047] Preferably, boxes are installed at both ends of the motor.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows: By improving the internal structure of the box body, the cooling air flow flowing along the axis can act on the outer surface of the motor stator, improving the heat dissipation performance of the stator coil. At the same time, the flow distribution of the cooling air flow is adjusted, increasing the proportion of the cooling air flow flowing to the cylinder seat part, improving the heat dissipation capacity of the cylinder assembly, reducing the temperature of the cylinder assembly during operation, improving the working efficiency and the service life of the sealing parts, reducing the eddy current intensity at the end of the motor, and facilitating the heat dissipation of the motor. Description of the Drawings

[0049] Figure 1 It is a perspective view of the outer end of the main body part in the first embodiment;

[0050] Figure 2 It is a perspective view of the inner end of the main body part in the first embodiment;

[0051] Figure 3 It is a schematic three-dimensional cross-sectional view of the first embodiment;

[0052] Figure 4 It is a cross-sectional view of the first embodiment;

[0053] Figure 5 It is a schematic horizontal cross-sectional view after the boxes are connected in the first embodiment;

[0054] Figure 6 It is a three-dimensional view of the second embodiment;

[0055] Figure 7 It is a cross-sectional view of the second embodiment;

[0056] Figure 8 It is an exploded view of the second embodiment;

[0057] Figure 9 It is a three-dimensional view of the rotor in the second embodiment;

[0058] Figure 10 It is a three-dimensional view of the cylinder head in the second embodiment in the upward view state;

[0059] Figure 11 It is an exploded view of the valve plate limiting block in the second embodiment.

[0060] Reference numerals: 1, box body; 2, main body part; 3, cylinder seat part; 4, reduced neck part; 5, outer end of the main body part; 6, inner end of the main body part; 7, reduced diameter section; 8, flared section; 9, motor shaft seat; 10, spoke; 11, motor; 12, cylinder assembly; 13, cylinder liner; 14, piston; 15, valve plate; 16, cylinder head; 17, heat dissipation flow channel; 18, stator; 19, rotor; 20, stator coil; 21, motor shaft; 22, crank; 23, wind blade; 24, connecting rod; 25, heat dissipation hole; 26, intake cavity; 27, exhaust cavity; 28, fan blade; 29, piston cavity; 30, seal; 31, silencer; 32, first conical surface; 33, second conical surface; 34, support leg; 35, recessed part; 36, valve plate limiting block; 37, heat dissipation inclined surface; 38, valve plate. Detailed implementation manners

[0061] The present invention will be further described in detail below with reference to the accompanying drawings.

[0062] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

[0063] Embodiment 1, an air compressor box body

[0064] As Figures 1 - 5As shown in the figure, an air compressor box body includes a main body part 2 and a cylinder seat part 3. The main body part 2 is cylindrical, and its longitudinal section is circular. The cylinder seat part 3 is provided with a cavity inside, and the inner cavity of the cylinder seat part 3 communicates with the inner cavity of the main body part 2. The cylinder seat part 3 is integrally arranged outside the main body part 2, and the inner cavity of the cylinder seat part 3 communicates with the inner cavity of the main body part 2. The two ends of the main body part 2 are respectively the inner end 6 of the main body part and the outer end 5 of the main body part. The inner end 6 of the main body part faces the motor 11 and is matched and connected with the motor 11. A necking part 4 is arranged in the middle of the main body part 2. The inner diameter at the necking part 4 is smaller than the inner diameter of the inner end 6 of the main body part, and is also smaller than the inner diameter of the outer end 5 of the main body part. Between the outer end 5 of the main body part and the necking part 4 is a reduced diameter section 7. The inner wall of the reduced diameter section 7 is a first conical surface 32, and the inner diameter of the reduced diameter section 7 gradually decreases from outside to inside along the axis of the main body part 2. The ratio of the inner diameter of the necking part 4 to the outer end inner diameter of the main body part 2 is between 1:1.15 and 1.30, and the half vertex angle α of the first conical surface 32 is between 10° and 20°. Between the necking part 4 and the inner end 6 of the main body part is a flared section 8. The inner wall of the flared section 8 is a second conical surface 33. The inner diameter of the end of the flared section 8 close to the necking part 4 is smaller than the inner diameter of the end of the flared section 8 close to the inner end 6 of the main body part. The ratio of the inner diameter of the necking part 4 to the inner end inner diameter of the main body part 2 is between 1:1.03 and 1.20, and the half vertex angle β of the second conical surface 33 is between 5 and 15 degrees. The main body part 2 has a variable diameter, making the main body part 2 non-cylindrical. The overall structural strength of the main body part 2 is higher. When the main body part 2 is subjected to radial pressure, the deformation amplitude is smaller, making the air compressor work more stably. At the same time, in order to better support the box body 1, a support leg 34 is arranged on the outer wall of the lower side of the reduced diameter section 7. The support is arranged at this position, roughly at the lower part of the outer end of the cylinder seat part 3, so that the impact force generated during the operation of the piston 14 can be directly transmitted to the support leg 34, making the overall structural rigidity of the box body 1 better and the vibration generated during operation smaller.

[0065] The inner diameter of the outer end 5 of the main body part is larger than the inner diameter of the inner end 6 of the main body part. This setting enables a blower blade 23 with a larger outer diameter to be installed inside the outer end 5 of the main body part. Thus, when the motor 11 drives the blower blade 23 to rotate, more air can be inhaled to form a cooling air flow for cooling the motor 11 and the cylinder assembly, thereby improving the cooling effect and reducing the working temperature of the motor 11 and the cylinder assembly 12.

[0066] Inside the box body 1, there is a motor shaft seat 9. The motor shaft seat 9 is connected to the inner wall near the necking part 4 through the spokes 10. The spokes 10 are arranged here. On the one hand, since the inner diameter at the necking part 4 is the smallest, the length of the spokes 10 can be reduced, saving materials. On the other hand, the reduced diameter section 7 and the flared section 8 are on both sides of the necking part 4, and the spokes 10 are also connected here, making the connection part of the spokes 10 and the necking part 4 form a Y-shaped structure. When the spokes 10 are subjected to the impact transmitted from the motor shaft seat 9, the Y-shaped structure can disperse the impact force to the reduced diameter section 7 and the flared section 8 on both sides of the spokes 10, thereby improving the overall structural strength at this place and the seismic resistance of the box body 1 during operation, and reducing the vibration generated during the operation of the air compressor. The number of spokes 10 is 7, and the angles between adjacent two spokes 10 are approximately the same. Except for the angle between the two uppermost spokes 10 which needs to be determined according to the outer diameter of the cylinder liner 13, the angles between other adjacent two spokes 10 are approximately between 45 and 55 degrees, and the adjacent angles are basically the same.

[0067] The inner end 6 of the necking part 4 is close to the main body part 2, and the center of the cylinder seat part 3 is between the necking part 4 and the outer end 5 of the main body part, so that most of the cylinder seat part 3 is located outside the necking part 4. Due to the existence of the connecting rod 24, the crank 22, the spokes 10 and the motor shaft seat 9, it will cause a greater obstruction to the axially flowing cooling air flow. The flow field inside the necking part 4 is relatively complex, and the wind resistance is large when the cooling air flow flows. While the flow field at the outer end 5 of the necking part 4 is relatively regular. Due to the existence of the reduced diameter section 7, it will guide the cooling air flow at the lower part of the main body part 2 to the middle part of the main body part 2, facilitating the cooling air flow to enter the cylinder seat part 3, thereby increasing the proportion of the cooling air flow in the cylinder seat part 3.

[0068] The cross-section of the cylinder seat part 3 is octagonal. After the cylinder liner 13 is installed, it can make the cooling air flow entering the cylinder seat part 3 evenly surround the outer wall of the piston cavity 29 to cool the cylinder liner 13. Since the cross-section of the piston cavity 29 is generally circular and the inner wall cross-section of the cylinder seat part 3 is octagonal, it can better surround the outside of the piston cavity 29 and form an almost annular area between the outer surface of the outer wall of the piston cavity 29 and the cross-section of the cylinder seat part 3, so that the cooling air flow entering the cylinder seat part 3 can be evenly distributed in this annular area, thereby generating a better and more uniform cooling effect on the cylinder liner 13.

[0069] During actual use, the dimensions of a box body 11 with good actual use effects are roughly as follows: the inner diameter of the outer end of the main body part 22 is 136 mm, the inner diameter of the reduced neck part 44 is 110 mm, the inner diameter of the inner end of the main body part 22 is 124 mm, the half apex angle α of the first conical surface is 14.6°, and the half apex angle β of the second conical surface is 11.8°. The dimensions of another box body 11 with good actual use effects are as follows: the inner diameter of the outer end of the main body part 22 is 168 mm, the inner diameter of the reduced neck part 44 is 136 mm, the inner diameter of the inner end of the main body part 22 is 149 mm, the half apex angle α of the first conical surface is 17.4°, and the half apex angle β of the second conical surface is 10.6°.

[0070] Embodiment 2, an air compressor,

[0071] As Figures 6 - 11 shown, an air compressor includes a motor 11, the box body 1 in Embodiment 1, and a cylinder assembly 12. A box body 1 is installed at each end of the motor 11.

[0072] The motor 11 includes a stator 18 and a rotor 19. A stator coil 20 is wound around the stator 18, and the end of the stator coil 20 protrudes from the stator 18. The rotor 19 is installed inside the stator 18, and a motor shaft 21 passes through the rotor 19. Both ends of the motor shaft 21 pass through the rotor 19 and protrude from the ends of the stator 18 and the stator coil 20. A box body 1 is installed at each end of the stator 18, and the two box bodies 1 are fixed by bolts, thereby clamping the motor 11 between the two box bodies 1. The motor shaft 21 extends from the inner end 6 of the main body part into the main body part 2. A crank 22 and a wind blade 23 are installed on the motor shaft 21 from the inside to the outside. When the motor 11 rotates, it drives the crank 22 and the wind blade 23 to rotate. When the wind blade 23 rotates, it sucks the air at the outer end 5 of the main body part into the main body part 2 to form a cooling air flow for dissipating heat from the motor 11 and the cylinder assembly 12. The heat generation of the motor 11 mainly concentrates on the stator 18. The stator 18 is a solid structure, and a rotor 19 is installed inside it. The rotor is also a solid structure. Therefore, the motor 11 can only dissipate heat through the end face of the stator 18, the end of the stator coil 20, and the outer side face of the stator 18.

[0073] The cylinder assembly 12 includes a cylinder liner 13, a piston 14, a valve plate 15, and a cylinder head 16. A piston chamber 29 is provided inside the cylinder liner 13, and a piston 14 is installed in the piston chamber 29. A seal 30 is provided between the piston 14 and the cylinder liner 13 to seal between the cylinder liner 13 and the piston 14. Heat dissipation channels 17 are provided on the valve plate 15 and the cylinder head 16. The heat dissipation channels 17 are communicated with the inner cavity of the cylinder seat part 3 and the inner cavity of the box body 1, so that the cooling air flow generated by the wind blade 23 can pass through the valve plate 15 and the cylinder head 16, enabling the valve plate 15 and the cylinder head 16 to come into contact with the cooling air flow and obtain effective temperature reduction.

[0074] The cylinder assembly 12 is installed on the cylinder seat portion 3 of the box body 1. Among them, the cylinder liner 13 is installed inside the cylinder seat portion 3, and the valve plate 15 and the cylinder head 16 are installed at the upper ends of the cylinder seat portion 3 and the cylinder liner 13. The piston 14 is connected to the crank 22 through the connecting rod 24. When the motor 11 rotates, the connecting rod 24 drives the piston 14 to move up and down inside the cylinder liner 13, compressing the gas in the piston chamber 29.

[0075] The end of the stator coil 20 also extends into the inner end 6 of the main body portion. The end of the stator coil 20 is inside the flared section 8. At the same time, the inner wall of the reduced-diameter section 7 points to the outer surface of the end of the stator coil 20, guiding a part of the cooling air flow to the outer surface of the stator coil 20. There are heat dissipation holes 25 on the end face of the inner end 6 of the main body portion. The cooling air flow that enters between the outer surface of the end of the stator coil 20 and the inner wall of the flared section 8 finally discharges from the heat dissipation holes 25.

[0076] There is also a fan blade 28 on the end face of the rotor 19. The fan blade 28 is inside the stator coil 20. When the rotor 19 rotates, the fan blade 28 at this place rotates together, thus generating a centrifugal air flow inside the stator coil 20. The centrifugal air flow flows around the inner surface of the stator coil 20, taking away the heat on the inner surface of the end of the stator coil 20. The existence of the fan blade 28 can also continuously discharge the air flow inside the end of the stator coil 20, realizing the air flow circulation between the inside and the outside of the stator coil 20, and improving the heat dissipation efficiency of the stator 18 of the motor 11.

[0077] The setting of the reduced-diameter section 7 with a gradually decreasing inner diameter makes the cooling air flow in the lower half of the main body portion 2 tend to deviate towards the middle of the main body portion 2 when flowing. The cooling air flow in the lower half of the main body portion 2 deviates towards the middle of the main body portion 2, and correspondingly, the air flow in the middle and upper parts of the main body portion 2 will also deviate upwards, so that more cooling air flow can enter the cylinder seat portion 3, increasing the proportion of the cooling air flow entering the cylinder seat portion 3 and improving the cooling effect of the cylinder assembly 12.

[0078] The inner diameter of the outer end 5 of the main body portion is larger than the inner diameter of the inner end 6 of the main body portion. At the same time, the outer diameter of the fan blade 23 is larger than the outer diameter of the motor 11. Increasing the inner diameter of the outer end 5 of the main body portion can install a fan blade 23 with a larger outer diameter. The larger the outer diameter of the fan blade 23, the more cooling air flow can be generated under the drive of the motor 11 with the same rotation speed. Correspondingly, the flow rate of the cooling air flow for dissipating heat from the motor 11 will increase, and at the same time, the cooling flow rate for dissipating heat from the cylinder assembly will also increase, thereby improving the heat dissipation effect of the motor 11 and the cylinder assembly 12, reducing the working temperature of the motor 11 and the cylinder assembly, improving the working efficiency, and increasing the service life of the seal 30 between the cylinder liner 13 and the piston 14.

[0079] An intake chamber 26 and an exhaust chamber 27 are formed in the cylinder head 16. An intake valve plate is mounted on the lower surface of the valve plate 15 facing the intake chamber 26, and an exhaust valve plate 38 is mounted on the upper surface of the valve plate 15 facing the exhaust chamber 27. When the piston chamber 29 sucks air, the intake valve plate opens, and outside air enters the piston chamber 29 through the intake chamber 26. When the piston chamber 29 exhausts air, the exhaust valve plate opens, and the compressed air in the piston chamber 29 enters the exhaust chamber 27 through the exhaust valve plate. Both the exhaust chamber 27 and the intake chamber 26 are located directly above the piston chamber 29. The intake chamber 26 is located on the side of the cylinder head 16 close to the motor 11, and the exhaust chamber 27 is located on the side of the cylinder head 16 away from the motor 11. The volume of the exhaust chamber 27 is larger than that of the intake chamber 26, so that the inner wall area of the exhaust chamber 27 is larger than that of the intake chamber 26. According to a large number of tests, when the volume ratio of the intake chamber 26 to the exhaust chamber 27 is between 1:1.7 and 2.6, or the inner wall area ratio of the intake chamber 26 to the exhaust chamber 27 is between 1:1.3 and 2.2, the heat dissipation performance of the cylinder head 16 is better, and the temperature of the cylinder head 16 is lower during operation. For example, the intake chamber 26 and the exhaust chamber 27 can be set in the following proportions: the inner wall area ratio of the intake chamber 26 to the exhaust chamber 27 is 1:1.64, and the volume ratio of the intake chamber 26 to the exhaust chamber 27 is 1:1.92; or the inner wall area ratio of the intake chamber 26 to the exhaust chamber 27 is 1:1.93, and the volume ratio of the intake chamber 26 to the exhaust chamber 27 is 1:2.48.

[0080] The intake chamber 26 and the exhaust chamber 27 are arranged in this way for two reasons. On the one hand, the cooling air flow rate is larger on the side of the cylinder head 16 close to the outer end 5 of the main body part, and the cooling air flow rate is smaller on the side of the cylinder head 16 close to the inner end 6 of the main body part. At the same time, during the actual operation of the air compressor, the temperature on the exhaust chamber 27 side of the cylinder head 16 is higher than that on the intake chamber 26 side. By arranging the side of the exhaust chamber 27 with a higher temperature of the cylinder head 16 above the cylinder block part 3 with a larger cooling air flow rate, the larger cooling air flow rate at this place can be fully utilized to cool the exhaust chamber 27 side of the cylinder head 16, making full use of the cooling air flow and reducing the overall temperature of the cylinder head 16. A muffler is also installed on the cylinder head 16. The muffler is installed inside the cylinder head 16 and most of it is located above the motor 11, so that the cylinder head 16 and the motor 11 shield and protect the muffler 31, preventing the muffler 31 from colliding with other objects during use and causing damage.

[0081] On the upper surface of the valve plate 15 facing the intake cavity 26 and the outlet cavity 27, there is a recessed portion 35. The setting of the recessed portion 35 can, on the one hand, reduce the depths of the intake cavity 26 and the outlet cavity 27 on the cylinder head 16 by providing the recessed portion 35 on the valve plate 15, so that the overall height of the cylinder head 16 can ensure the volumes of the intake cavity 26 and the outlet cavity 27 even when the overall height is correspondingly reduced. At the same time, after the valve plate 15 is provided with the recessed portion 35, the thickness of the valve plate 15 at the recessed portion 35 is reduced, so that the heat generated when the gas in the piston 14 cavity is compressed can be transferred more quickly to the air in the intake cavity 26 or the outlet cavity 27 of the cylinder, and then transferred to the cylinder head 16 through the air in the intake cavity 26 or the outlet cavity 27 for heat dissipation, obtaining a better heat dissipation effect. Correspondingly, a plurality of heat dissipation inclined surfaces 37 can also be provided on the valve piece limiting block 36 installed on the upper surface of the valve plate 15 to increase the heat exchange area, so as to accelerate the transfer of the temperature on the valve plate 15 to the compressed air in the outlet cavity 27, and finally transfer the heat to the cylinder head 16 for dissipation.

[0082] By changing the structure of the box body, compared with the air compressor with a straight cylindrical main body part in the first embodiment, when using the same model of motor and cylinder block assembly and under the same working conditions, the operating parameters when the two work continuously and stably are shown in the following table:

[0083] Straight - cylinder air compressor Example Two Performance improvement ratio Total cooling air flow rate 670.3 L / min 905.1 L / min Improved by 35.0% Cooling air flow rate of cylinder assembly 323.1 L / min 591.5 L / min Improved by 83.1% Proportion of cooling air flow rate of cylinder assembly 48.2% 65.4% Improved by 35.7% Cooling air flow rate of motor 347.2 L / min 313.6 L / min Decreased by 9.7% Proportion of cooling air flow rate of motor 51.8% 34.6% Decreased by 33.2% Working temperature rise of cylinder liner 80℃ 55℃ Decreased by 31.3% Working temperature rise of valve plate 130℃ 95℃ Decreased by 26.9% Working temperature rise of cylinder head 90℃ 70℃ Decreased by 22.2% Working temperature rise of motor 55℃ 50℃ Decreased by 10.0% Seal life 600 - 800 hours Over 1200 hours Greater than 50%

[0084] As can be seen from the above table, by providing a necking portion 4 on the main body part 2 and a reduced diameter section 7 between the outer end of the main body part 2 and the necking portion 4, the flow rate ratio of the cooling air flow flowing to the cylinder block part can be greatly improved. At the same time, due to the setting of the reduced diameter section 7, the temperature rise of the motor 11 will not increase significantly, and the heat loss is small. In addition, by increasing the inner diameter of the outer end of the main body part 2 and the inner diameter of the fan blade 23, the total cooling air flow rate is significantly increased, the working temperature rise of the improved cylinder block assembly is greatly reduced, and the service life of the seal 30 is greatly improved.

[0085] The above description is only an exemplary embodiment of the present invention and is not used to limit the protection scope of the present invention. The protection scope of the present invention is determined by the appended claims.

Claims

1. An air compressor housing, comprising a main body portion (2) and a cylinder base portion (3). The main body portion (2) is cylindrical, and there is a cavity inside the cylinder base portion (3). The inner cavities of the main body portion (2) and the cylinder base portion (3) communicate with each other. It is characterized in that: A necking portion (4) is provided between the inner end (6) and the outer end (5) of the main body portion. The inner diameter of the necking portion (4) is smaller than the inner diameters of the inner end (6) and the outer end (5) of the main body portion. The ratio of the inner diameter of the necking portion (4) to the inner diameter of the outer end (5) of the main body portion is between 1:1.15 and 1.30, and the ratio of the inner diameter of the necking portion (4) to the inner diameter of the inner end of the main body portion (2) is between 1:1.03 and 1.

20. A reducing diameter section (7) with a gradually decreasing inner diameter is between the outer end (5) of the main body portion and the necking portion (4), and a flaring section (8) is between the necking portion (4) and the inner end (6) of the main body portion; The inner diameter of the outer end (5) of the main body portion is larger than the inner diameter of the inner end (6) of the main body portion. The necking portion (4) is close to the inner end (6) of the main body portion, and the center of the cylinder seat portion (3) is between the necking portion (4) and the outer end (5) of the main body portion.

2. The air compressor box according to claim 1, characterized in that: A motor shaft seat (9) is provided inside the air compressor housing (1), and the motor shaft seat (9) is connected to the inner wall at the necking portion (4) through spokes (10).

3. The air compressor box according to claim 2, characterized in that: The number of the spokes (10) is seven.

4. The air compressor box according to claim 1, characterized in that: The cross-section of the cylinder seat portion (3) is a polygon with more than five sides or a circle.

5. The air compressor box according to claim 1, characterized in that: The inner wall of the reducing diameter section (7) is a first conical surface (32), and the half vertex angle α of the first conical surface (32) is between 10° and 20°.

6. A compressor housing according to claim 1 or 5, characterized in that: The inner wall of the flaring section (8) is a second conical surface (33), and the half vertex angle β of the second conical surface (33) is between 5° and 15°.

7. The air compressor box according to claim 1, characterized in that: A support leg (34) is provided on the outer wall of the lower side of the reducing diameter section (7).

8. An air compressor, including a motor (11) and a cylinder assembly (12), further including the air compressor housing (1) according to any one of claims 1 to 7, the cylinder assembly (12) includes a cylinder liner (13), a piston (14), a valve plate (15) and a cylinder head (16), and heat dissipation flow channels (17) communicating with the inner cavity of the cylinder seat portion (3) are formed on the cylinder head (16) and the valve plate (15), and it is characterized in that: The inner end (6) of the main body portion is connected to the end of the motor (11). The motor (11) includes a stator (18) and a rotor (19). A stator coil (20) is wound around the stator (18). A motor shaft (21) passes through the rotor (19). The motor shaft (21) extends into the air compressor housing (1) and is provided with a crank (22) and a wind blade (23). The crank (22) and the piston (14) are connected through a connecting rod (24). The end of the stator coil (20) extends into the inner part of the inner end (6) of the main body portion. The inner wall of the reducing diameter section (7) points to the outer surface of the end of the stator coil (20). A heat dissipation hole (25) is provided on the inner end (6) of the main body portion or the motor (11).

9. The air compressor according to claim 8, characterized in that: The inner diameter of the outer end (5) of the main body portion is larger than the inner diameter of the inner end (6) of the main body portion, and the outer diameter of the wind blade (23) is larger than the outer diameter of the motor (11).

10. An air compressor according to claim 8, characterized in that: An air inlet cavity (26) and an air outlet cavity (27) are provided on the cylinder head (16). The air inlet cavity (26) is on the side of the cylinder head (16) close to the motor (11), and the air outlet cavity (27) is on the side of the cylinder head (16) far from the motor (11).

11. An air compressor according to claim 10, characterized in that: The ratio of the volume of the air inlet cavity (26) to the volume of the air outlet cavity (27) is between 1:1.7 and 2.6; or the ratio of the inner wall area of the air inlet cavity (26) to the inner wall area of the air outlet cavity (27) is between 1:1.3 and 2.

2.

12. The air compressor according to claim 8, wherein: A fan blade (28) is provided on the end face of the rotor (19).

13. A kind of air compressor according to claim 10, characterized in that: A recessed portion (35) is provided on the upper surface of the valve plate (15) facing the air inlet cavity (26) and the air outlet cavity (27).

14. An air compressor according to claim 8, characterized in that: A valve piece limiting block (36) is installed on the upper surface of the valve plate (15), and a plurality of heat dissipation inclined surfaces (37) are provided on the valve piece limiting block (36).

15. A kind of air compressor according to claim 8, characterized in that: Both ends of the motor (11) are installed with the air compressor housing (1).

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