Single-phase household screw air compressor
By employing meshing zone ribs and staggered nested ribs in a household screw air compressor, the problem of heat dissipation difficulties under single-phase power supply is solved, achieving efficient heat conduction and centralized heat dissipation, thereby improving the reliability and lifespan of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG SUNHI-MACH CO LTD
- Filing Date
- 2026-03-16
- Publication Date
- 2026-05-12
Smart Images
Figure CN122014608A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of air compressor technology, specifically a single-phase household screw air compressor. Background Technology
[0002] A household air compressor, also known as a home air compressor, is a small mechanical device that provides compressed air power for home environments and personal part-time work. Its core function is to use a motor to drive a piston or screw compressor to draw in atmospheric pressure air, compress it forcefully, and store it in a built-in air tank. This continuously converts electrical energy into readily available high-pressure air kinetic energy. A typical household air compressor mainly consists of a power unit (motor), a compressor unit, an air tank, a pressure regulator, a safety valve, and an output interface. It operates with low noise, is compact, and is typically portable or small stationary. Its power and displacement are much smaller than industrial models, sufficient to meet intermittent low- to medium-pressure air needs. Its most crucial feature is its automatic start-stop function: it automatically stops when the pressure inside the tank reaches a preset upper limit (e.g., 8 atmospheres); and automatically restarts when the pressure drops to the lower limit due to use, thus ensuring a stable air supply. In a home setting, it is a multi-functional "miniature power station." Whether it's inflating car and bicycle tires, powering a nail gun for woodworking and furniture making, painting vehicles and graffiti walls with a spray gun, cleaning dust from crevices, inflating balls, or even powering pneumatic tools for models and aquariums, it can handle it all with ease. It overcomes the limitations of power tools in terms of continuous power, torque, and explosion-proof capabilities, making professional compressed air power safe, convenient, and economical—a powerful assistant for home DIY, car repair and maintenance, and hobbies.
[0003] Household screw air compressors are limited by single-phase 220V power supplies, and motor power is typically restricted to 3kW or slightly higher. At this power, the volumetric efficiency of the screw compressor is not optimal at low speeds. To achieve sufficient discharge volume in a small size, the compressor speed often needs to be increased, but this increases wear and heat generation. Its actual discharge volume may only be comparable to a high-end piston compressor of the same power, but the cost is much higher. Household users require lightweight and compact machines, which means the physical dimensions of the screw compressor head (rotor and housing) must be very small. The theoretical discharge volume formula is: rotor diameter... 2×rotor length × rotational speed. From the formula, it can be seen that when the rotor diameter and length are severely limited, the only adjustable variable to obtain usable exhaust volume is to significantly increase the rotational speed (n). As the rotational speed increases, the compression cycle time becomes shorter and the time window for gas leakage narrows. Although the leakage amount in each cycle may not change much, the number of cycles completed per unit time increases significantly. Therefore, at high speed, the absolute value of the actual exhaust volume will rise rapidly. Although its volumetric efficiency may still not be the highest (because there is still leakage in each cycle), it is sufficient to reach or exceed the gas production capacity of a small piston compressor. The friction of all moving parts is positively correlated with the rotational speed, or even exponentially correlated. Doubling the rotational speed may double the frictional work and wear rate. At the same time, at high speed, it is more difficult to maintain a stable oil film between the rotor gaps, and oil film rupture is more likely to occur, leading to metal micro-contact and abrasive wear. Due to the limitations of the overall size of the equipment, a large amount of heat will accumulate inside, which is also the reason why household air compressors cannot work continuously. Therefore, a device that can help the screw conduct heat quickly is needed. Summary of the Invention
[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a single-phase household screw air compressor with the advantages of efficient heat conduction and centralized heat dissipation, thus solving the problem of heat dissipation difficulties in household air compressors.
[0005] (II) Technical Solution To achieve the aforementioned goals of efficient heat conduction and centralized heat dissipation, this invention provides the following technical solution: A single-phase household screw air compressor, comprising a housing, wherein a screw casing and a cooling fan are disposed within the housing, and a male rotor within the screw casing is connected to a motor via a male rotor connecting shaft extending from the screw casing, wherein a male rotor housing and a female rotor housing are disposed in the middle portion of the screw casing, the male rotor housing and the female rotor housing being cavities for housing the screw male rotor and female rotor and compressing gas, and the diameter of the male rotor housing being larger than that of the female rotor housing, wherein a meshing area rib is provided on the surface of the male rotor housing, the meshing area rib being positioned corresponding to the meshing position of the male rotor and female rotor, and the curvature of the meshing area rib being the curvature of the male rotor tooth tip plus the wall thickness of the male rotor housing, wherein main ribs are provided on both sides of the screw casing, and fishbone-shaped branch ribs are provided on the upper and lower sides of the main ribs, and the branch ribs are staggered with the meshing area ribs.
[0006] The branch ribs provided on one side of the male rotor housing are male rotor ribs, and the branch ribs provided on one side of the female rotor housing are female rotor ribs. The height of the male rotor ribs is greater than that of the female rotor ribs, and the male rotor ribs extend toward the direction of the female rotor housing. The ends of the male rotor ribs are provided on the surface of the female rotor housing and are staggered with the female rotor ribs to form nested fin groups.
[0007] The angle between the male rotor rib and the female rotor rib and the airflow direction is 15°-25°, and they are inclined towards the airflow direction.
[0008] The male rotor rib and the female rotor rib have trapezoidal cross-sections.
[0009] The top and rearward tilted edges of the male rotor rib and female rotor rib are rounded.
[0010] The surfaces of the male rotor rib and the female rotor rib are machined with parallel microgrooves.
[0011] The screw housing has a connecting end face at one end of the male rotor connecting shaft. The connecting end face is located on the side of the screw housing away from the cooling fan, and the connecting end face facing the cooling fan has an inclined surface with the inclination angle consistent with the male rotor rib and the female rotor rib.
[0012] The screw housing and cooling fan are set at the same horizontal height, and the gas tank and motor connected to the screw housing are fixed to the housing by brackets.
[0013] The screw housing is integrally cast and the meshing area ribs are machined by milling.
[0014] (III) Beneficial Effects Compared with the prior art, the present invention provides a single-phase household screw air compressor, which has the following beneficial effects: 1. This single-phase household screw air compressor features a meshing rib on the surface of the male rotor housing that perfectly corresponds to the rotor tooth tip movement trajectory. Through precise curvature matching design, this rib allows the high heat generated by rotor tooth friction to be transferred to the outside of the housing via the shortest path and lowest thermal resistance. The heat first diffuses rapidly through the large contact area between the tooth tip and the inner wall of the housing, then penetrates the housing wall almost in a straight line to reach the raised, arc-shaped rib on the outside. This linear heat conduction path—tooth tip-inner wall-housing-rib—significantly improves heat transfer efficiency, resulting in targeted and enhanced heat dissipation in the meshing area where heat generation is most concentrated. Simultaneously, the arc-shaped rib significantly increases the contact area with the cooling airflow inside the housing and guides the airflow to flow closely along the rib surface, thereby efficiently carrying away heat. This design not only significantly reduces the temperature rise of the male and female rotors during high-speed meshing, effectively preventing rotor expansion and jamming or lubricant deterioration caused by overheating, but also ensures compression efficiency and output stability during long-term operation by maintaining a stable fit clearance between the rotor and the housing. It also helps to improve the reliability and service life of the whole machine. The ribs are arranged in accordance with the meshing area, concentrating heat dissipation resources on the key parts with the highest temperature, avoiding heat dissipation redundancy, and improving the overall energy efficiency ratio of the heat dissipation system. The arc-shaped ribs themselves can act as a flow guide structure, guiding the airflow generated by the cooling fan to pass over the high-heat area more orderly and tightly, reducing airflow eddies and dead zones, and enhancing the forced convection heat transfer effect. Good heat dissipation keeps the rotor and housing in a more uniform thermal state, reducing imbalance or gap changes caused by local overheating deformation, thereby helping to reduce mechanical vibration and aerodynamic noise, and improving the quiet experience in the home environment. As a reinforcing rib on the outside of the housing, the ribs not only assist in heat dissipation, but also locally enhance the rigidity of the housing structure, which can better withstand the periodic stress generated by rotor meshing and improve the fatigue resistance of the housing.
[0015] 2. This single-phase household screw air compressor uses the main ribs on both sides of the screw casing as a heat dissipation framework. The branch ribs extending vertically are biomimetic to a fishbone shape to increase surface area and optimize airflow turbulence. For the male rotor side, which generates more heat, the ribs are not only taller but also actively extend towards the surface of the female rotor casing, where the heat generation is lower. This allows the ends of the male rotor ribs to cover the outer side of the meshing area ribs on the female rotor surface. This design creates a precise heat flow relay. First, the concentrated high temperature generated in the meshing area is quickly dissipated by the curvature-matched meshing area ribs. Then, this heat is rapidly captured and diffused by the efficient branch ribs flowing through it (especially the male rotor ribs extending from the high-temperature area). Finally, through the staggered nesting of the male and female rotor ribs, heat is forcibly transferred from the high-temperature male rotor region to the low-temperature female rotor region, forming a secondary enhanced heat dissipation zone on the female rotor surface. This active heat transfer not only significantly accelerates overall heat dissipation but also establishes a dynamic temperature balance cycle between the male and female rotor casings, effectively eliminating local hot spots and ensuring that the rotor and casing maintain a stable and precise working clearance. The entire system achieves superior heat dissipation with less material, striking a delicate balance between performance and cost. The staggered, fishbone-like branch fins effectively disperse and guide the cooling airflow, creating strong turbulence between the fins, breaking down stagnant air boundary layers, and greatly improving the heat exchange efficiency between the airflow and the metal surface. This achieves thorough airflow without dead zones. While enhancing heat dissipation, the branch fins also serve as a reinforcing network for the casing, significantly improving the overall structural rigidity and deformation resistance of the casing. This allows it to better withstand the combined loads of internal gas pressure and rotor vibration, improving reliability. The gaps formed by the staggered fins constitute directional airflow channels, which helps guide the fan airflow to concentrate through high-heat areas. At the same time, this structure can also block the direct deposition of large dust particles to a certain extent, keeping the heat dissipation surface relatively clean. The biomimetic fishbone and nested design can usually be integrally molded, resulting in good manufacturability. While achieving the same heat dissipation performance, this design can achieve the goal with less material usage, which helps to reduce the overall weight and production costs. By actively guiding the heat from the male rotor area to the female rotor side for dissipation, it helps to reduce the asymmetric thermal expansion caused by the temperature difference between the male and female rotor housings, thereby maintaining better rotor meshing accuracy. This is of positive significance for ensuring energy efficiency and lifespan. The staggered fins have a sorting and straightening effect on airflow, which can smooth the airflow in the housing and reduce the howling and turbulent noise caused by airflow vortices and sudden acceleration and deceleration, thus improving the user experience.
[0016] 3. This single-phase household screw air compressor features branch fins angled at 15°-25° to meet the airflow. This ensures smooth airflow into the fin array, avoiding energy loss and backflow vortices caused by head-on impact, minimizing airflow resistance and maximizing cooling medium coverage efficiency. Secondly, the trapezoidal profile of the fins naturally guides the airflow, causing it to flow close to the fin surface and effectively suppressing airflow separation. This not only stabilizes the efficient heat exchange flow field and significantly reduces wind noise, but also greatly enhances the structural rigidity of the fins themselves due to the widened root. Even more ingeniously, the parallel microgrooves machined on the fin surface precisely disrupt the stable boundary layer attached to the metal surface, continuously inducing micro-turbulence, resulting in a significant increase in direct contact and heat exchange intensity between the cooling air and the hot metal surface. Furthermore, all fins have rounded top and side edges, completely eliminating the risk of scratches from sharp edges and improving safety and maintenance convenience in a household environment. These details, complementing the macroscopic interlocking and nested structure, together construct a comprehensive high-performance heat dissipation system encompassing airflow introduction, flow field optimization, microscopic transduction, and safety protection. The tilt angle and trapezoidal profile ensure smoother and more uniform airflow as it passes through the interlocking and nested fins, avoiding localized low-speed zones and ensuring that each fin is effectively "sweeped" by high-speed airflow. This achieves optimal matching between the macroscopic structure and the microscopic flow field. The parallel microgrooves and rounded corners on the surface provide a smooth transition, preventing the accumulation of dust and oil, reducing the insulation effect caused by dirt adhesion, and helping to maintain long-term stable heat dissipation performance. The trapezoidal profile and rounded corner design improve material flowability and stress distribution during metal casting or injection molding, reducing the risk of manufacturing defects. At the same time, the rounded corners effectively reduce stress concentration and improve the fatigue resistance of the fin root under thermal cycling and vibration. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the internal structure of the housing of the present invention; Figure 2 This is a front view of the housing of the present invention; Figure 3 This is a schematic diagram of the screw housing structure of the present invention; Figure 4 This is a schematic diagram of the male rotor housing and female rotor housing structure of the present invention; Figure 5 This is a schematic diagram showing the arrangement of the ribs in the meshing area of the present invention; Figure 6 This is a schematic diagram of the rib structure of the present invention.
[0018] In the diagram: 1. Housing; 2. Screw housing; 21. Male rotor housing; 22. Female rotor housing; 23. Main rib; 24. Connecting end face; 25. Male rotor connecting shaft; 101. Cooling fan; 231. Male rotor rib; 232. Female rotor rib; 233. Meshing area rib. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] Please see Figures 1-6 A single-phase household screw air compressor includes a housing 1, within which a screw housing 2 and a cooling fan 101 are housed. The male rotor within the screw housing 2 is connected to a motor via a male rotor connecting shaft 25 extending from the screw housing 2. The middle portion of the screw housing 2 contains a male rotor housing 21 and a female rotor housing 22. These housings serve as cavities for housing the male and female screw rotors and for compressing gas. The diameter of the male rotor housing 21 is larger than that of the female rotor housing 22. The internal structure of the male and female rotors within the screw housing 2 is the same as that of a common twin-screw air compressor, and will not be described further here.
[0021] Because the inner walls of the male rotor housing 21 and the female rotor housing 22 need to be fitted with the corresponding rotors to ensure a seal, an effective heat-conducting structure cannot be set inside the cavity. The surface of the male rotor housing 21 is provided with a meshing area rib 233. The meshing area rib 233 is positioned corresponding to the meshing position of the male and female rotors, and the curvature of the meshing area rib 233 is the curvature of the male rotor tooth tip plus the wall thickness of the male rotor housing 21. The meshing area rib 233 does not directly contact the male rotor, but achieves indirect fitting through curvature matching through the housing wall surface. The heat conduction path is short and efficient. The curvature of the inner wall surface of the housing that mates with the rotor is consistent with the curvature of the male rotor tooth tip. When the male and female rotors mesh, the contact between the male rotor tooth tip and the inner wall surface of the housing is... With the largest contact area, this is a naturally efficient heat-conducting surface. The arc curvature of the meshing zone rib 233 equals the curvature of the male rotor tooth tip plus the shell wall thickness. This makes the protruding shape of the guide rib on the outside of the shell perfectly correspond to the movement trajectory of the inner rotor tooth tip. This design allows the heat conduction path from the rotor tooth tip to the inner wall of the shell, then to the shell body, and finally to the arc-shaped guide rib to be linear. The thermal resistance is reduced by 25%-30% compared to traditional flat ribs. When the male and female rotors mesh, the frictional heat generated by the tooth tip is directly transferred to the inner wall of the shell. Because the curvature of the wall surface matches that of the rotor tooth tip, the heat is concentrated in a point shape and diffused in a planar shape within the shell wall, quickly transferred to the outer meshing zone rib 233. The protruding structure of the meshing zone rib 233 increases the contact area with the airflow.
[0022] The screw housing 2 has main ribs 23 on both sides. The main ribs 23 have fishbone-shaped branch ribs on their upper and lower sides, and these branch ribs are staggered with the meshing area ribs 233. The branch ribs on one side of the male rotor housing 21 are male rotor ribs 231, and the branch ribs on one side of the female rotor housing 22 are female rotor ribs 232. The height of the male rotor rib 231 is greater than that of the female rotor rib 232, and the male rotor rib 231 extends towards the female rotor housing 22. The end of the male rotor rib 231 is located at the female rotor housing 22. The surface of the shell 22 is staggered with the female rotor ribs 232 to form a nested fin assembly. The ribs extending from the male side to the female side have their ends covering the outer area of the meshing zone ribs 233. The concentrated heat conducted by the meshing zone ribs 233 is directly carried away by the airflow flowing through the branch ribs, forming a relay heat dissipation of local high heat → heat accumulation in the meshing zone ribs 233 → heat diffusion in the branch ribs. This solves the problem of difficult dissipation of single-point high temperature in the meshing zone. The diameter of the male rotor shell 21 is larger than that of the female rotor shell 22 not only because the internal rotor diameter is larger, but also... There is a heat generation deviation. The male rotor is the active rotor, directly connected to the motor, and bears all the driving torque and power input. During compression, it needs to overcome air pressure to drive itself and the female rotor. Therefore, the male rotor shaft and tooth root bear greater torsional shear stress and bending stress. This mechanical work is directly converted into heat, making the heat generated by the male rotor housing 21 greater than that of the female rotor housing 22. By increasing the housing and branch rib height, not only is the heat exchange area effectively increased, but the end of the male rotor rib 231 also covers the outer area of the meshing area rib 233, i.e. the surface of the female rotor housing 22, effectively transferring the heat from the high-temperature area to the low-temperature area through more contact. The surface of the female rotor housing 22 forms a concentrated heat dissipation area with more branch ribs, which effectively enhances the heat dissipation in this area and achieves faster cooling. It then forms a temperature difference with the high heat generation area again for heat conduction, continuously circulating. Compared with the traditional heat dissipation rib structure, fewer ribs are required, which can achieve better heat conduction and concentrated heat dissipation, effectively reducing costs while ensuring heat dissipation requirements.
[0023] The angle between the male rotor rib 231 and the female rotor rib 232 and the airflow direction is 15°-25°, and they are inclined towards the airflow direction to avoid airflow obstruction and vortex generation, which would prevent heat from being effectively dissipated. The male rotor rib 231 and the female rotor rib 232 have a trapezoidal cross-section, with a structure that is narrow at the top and wide at the bottom, which can reduce airflow separation, reduce wind noise, and enhance the structural rigidity of the ribs. At the same time, the top and rearward inclined edges are rounded to avoid scratching users during processing, installation, and cleaning. The surfaces of the male rotor rib 231 and the female rotor rib 232 are processed with parallel microgrooves to disrupt the airflow boundary layer and further improve the heat transfer coefficient.
[0024] The screw housing 2 is provided with a connecting end face 24 at one end of the male rotor connecting shaft 25. The connecting end face 24 is located on the side of the screw housing 2 away from the cooling fan 101, and the connecting end face 24 is provided with an inclined surface on the side facing the cooling fan 101, with the inclination angle being the same as that of the male rotor rib 231 and the female rotor rib 232.
[0025] The screw compressor housing 2 and the cooling fan 101 are set at the same horizontal height. The air tank and motor connected to the screw compressor housing 2 are fixed to the housing 1 by a bracket. This allows the screw compressor housing 2 to be better cooled by the cooling fan 101 while suspending itself and the motor and other structures in the air, effectively ensuring airflow and reducing vibration and noise, which is more suitable for the needs of household air compressor users.
[0026] The screw housing 2 is integrally cast and the meshing area ribs 233 are machined by milling, completely avoiding complex electrical control or assembly.
[0027] Working principle: The surface of the male rotor housing 21 is provided with a meshing zone rib 233. The meshing zone rib 233 is positioned corresponding to the meshing position of the male and female rotors, and the curvature of the meshing zone rib 233 is the curvature of the male rotor tooth tip plus the wall thickness of the male rotor housing 21. The meshing zone rib 233 does not directly contact the male rotor, but achieves indirect contact through curvature matching of the housing wall surface. The heat conduction path is short and efficient. The curvature of the inner wall surface of the housing that mates with the rotor is consistent with the curvature of the male rotor tooth tip. When the male and female rotors mesh, the contact area between the male rotor tooth tip and the inner wall surface of the housing is the largest. This is a natural and highly efficient heat conduction surface. The arc shape of the meshing zone rib 233... The curvature = male rotor tooth tip curvature + shell wall thickness, which makes the protruding shape of the guide rib on the outside of the shell correspond perfectly to the movement trajectory of the inner rotor tooth tip. This design allows the heat conduction path from rotor tooth tip → inner shell wall → shell body → arc-shaped guide rib to be straight, reducing thermal resistance by 25%-30% compared to traditional flat ribs. When the male and female rotors mesh, the frictional heat generated by the tooth tip is directly transferred to the inner shell wall. Because the curvature of the wall and the rotor tooth tip are matched, the heat is concentrated in a point shape and diffused in a planar shape within the shell wall, and is quickly transferred to the outer meshing area rib 233. The protruding structure of the meshing area rib 233 increases the contact area with the airflow.
[0028] The screw housing 2 has main ribs 23 on both sides. The main ribs 23 have fishbone-shaped branch ribs on their upper and lower sides, which are staggered with the meshing area ribs 233. The branch ribs on one side of the male rotor housing 21 are male rotor ribs 231, and the branch ribs on one side of the female rotor housing 22 are female rotor ribs 232. The height of the male rotor rib 231 is greater than that of the female rotor rib 232, and the male rotor rib 231 extends towards the female rotor housing 22. The end of the male rotor rib 231 is located on the surface of the female rotor housing 22 and is staggered with the female rotor rib 232, forming a nested fin assembly. The ends of the ribs extending from the male side to the female side exactly cover the outer area of the meshing area rib 233. The concentrated heat conducted by the meshing area rib 233 is directly carried away by the airflow passing through the branch ribs, forming a relay heat dissipation process: localized high heat → heat accumulation in the meshing area rib 233 → heat diffusion in the branch ribs. This solves the problem of difficult dissipation of single-point high temperature in the meshing area. The diameter of the male rotor housing 21 is larger than that of the female rotor housing 22 not only because the internal rotor diameter is larger, but also because of the heat generation deviation. The male rotor is the active rotor, directly connected to the motor, and bears all the drive torque and power input. During compression, it needs to overcome air pressure to drive itself and the female rotor. Therefore, the male rotor shaft and tooth root bear greater torsional shear stress and bending stress. This part of the mechanical work is directly converted into heat, making the heat generated by the male rotor housing 21 greater than that of the female rotor housing 22. The larger housing and branch rib height not only effectively increase the heat exchange area, but also utilize the fact that the end of the male rotor rib 231 just covers the outer area of the meshing area rib 233, i.e. the surface of the female rotor housing 22, to effectively carry the heat from the high-temperature area to the low-temperature area through more contact. Furthermore, the more branch ribs on the surface of the female rotor housing 22 enhance heat dissipation. With fewer branch ribs, better heat conduction and concentrated heat dissipation can be achieved.
[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A single-phase household screw air compressor, comprising a housing (1), wherein a screw housing (2) and a cooling fan (101) are disposed within the housing (1), and a male rotor within the screw housing (2) is connected to a motor via a male rotor connecting shaft (25) extending from the screw housing (2), characterized in that: The screw housing (2) has a male rotor housing (21) and a female rotor housing (22) in the middle part. The male rotor housing (21) and the female rotor housing (22) are cavities for setting the male rotor and female rotor of the screw and compressed gas. The diameter of the male rotor housing (21) is larger than that of the female rotor housing (22). The surface of the male rotor housing (21) is provided with a meshing area rib (233). The meshing area rib (233) is positioned corresponding to the meshing position of the male rotor and the female rotor. The curvature of the meshing area rib (233) is the curvature of the male rotor tooth tip plus the wall thickness of the male rotor housing (21). The screw housing (2) has main ribs (23) on both sides. The main ribs (23) have fishbone-shaped branch ribs on the upper and lower sides. The branch ribs are staggered with the meshing area ribs (233).
2. A single-phase household screw air compressor according to claim 1, characterized in that: The branch ribs provided on one side of the male rotor housing (21) are male rotor ribs (231), and the branch ribs provided on one side of the female rotor housing (22) are female rotor ribs (232). The height of the male rotor ribs (231) is greater than that of the female rotor ribs (232), and the male rotor ribs (231) extend toward the female rotor housing (22). The ends of the male rotor ribs (231) are provided on the surface of the female rotor housing (22) and are staggered with the female rotor ribs (232) to form a nested fin group.
3. A single-phase household screw air compressor according to claim 2, characterized in that: The angle between the male rotor rib (231) and the female rotor rib (232) and the airflow direction is 15°-25°, and they are inclined towards the airflow direction.
4. A single-phase household screw air compressor according to claim 3, characterized in that: The male rotor rib (231) and female rotor rib (232) have trapezoidal cross-sections.
5. A single-phase household screw air compressor according to claim 3, characterized in that: The top and rearward tilted edges of the male rotor rib (231) and female rotor rib (232) are rounded.
6. A single-phase household screw air compressor according to claim 3, characterized in that: The surfaces of the male rotor rib (231) and female rotor rib (232) are machined with parallel microgrooves.
7. A single-phase household screw air compressor according to any one of claims 4-6, characterized in that: The screw housing (2) is provided with a connecting end face (24) at one end of the male rotor connecting shaft (25). The connecting end face (24) is located on the side of the screw housing (2) away from the cooling fan (101), and the connecting end face (24) facing the cooling fan (101) has an inclined surface with the same inclination angle as the male rotor rib (231) and the female rotor rib (232).
8. A single-phase household screw air compressor according to claim 7, characterized in that: The screw housing (2) and the cooling fan (101) are set at the same horizontal height, and the gas tank and motor connected to the screw housing (2) are fixedly set to the box (1) by a bracket.
9. A single-phase household screw air compressor according to claim 1, characterized in that: The screw housing (2) is integrally cast and the meshing area ribs (233) are machined by milling.