A two-stage screw air compressor

Abstract

The application relates to the technical field of air compressors, in particular to a two-stage screw air compressor which comprises an air compressor main shell, an air compressor auxiliary shell is fixed outside the air compressor main shell, a main screw rod and an auxiliary screw rod are arranged inside the air compressor auxiliary shell, a main protection shell for protecting the top of the main screw rod and the auxiliary screw rod is arranged above the main screw rod and the auxiliary screw rod, two auxiliary protection shells for protecting the lower part of the main screw rod and the auxiliary screw rod are further arranged below the main screw rod and the auxiliary screw rod, and a limiting mechanism for limiting the main screw rod and the auxiliary screw rod is further arranged outside the main screw rod and the auxiliary screw rod; the limiting mechanism, the sleeve, the threaded rod and the key pin can be correspondingly embedded into the key groove of the shaft of the main screw rod and the auxiliary screw rod, reliable circumferential locking of the two screw rods is formed in the static state of equipment shutdown and disassembly, the defect that the screw rod is easy to rotate freely after the shell is disassembled is solved, the safety hidden danger that the rotor accidentally deflects and scratches the operator is eliminated, and the screw rod precision profile is prevented from being bumped.

Description

Technical Field

[0001] This invention relates to the field of air compressor technology, and in particular to a two-stage screw air compressor. Background Technology

[0002] Dual-mode solar heat pump air conditioning units integrate solar thermal collection, photovoltaic power generation, and heat pump heating and cooling technologies. They can intelligently switch between solar-dominated mode and conventional heat pump mode to achieve efficient heating and cooling operation in winter and summer, with significant energy-saving effects. These units are typically equipped with pneumatic control structures such as multi-path reversing, automatic sewage discharge, and pneumatic pressure stabilization of the expansion tank. The operation process requires a continuous and stable supply of compressed air, so a two-stage screw air compressor is required to meet the pneumatic operating conditions of the system.

[0003] Most existing two-stage screw air compressors have bolt-removable casings to facilitate disassembly and maintenance of the internal screw rotor. However, after the casing is removed, the screw rotor loses its circumferential constraint and is prone to free rotation. This poses safety hazards during maintenance, can easily cause damage to the precision mating surfaces of the rotor, and requires recalibration of phase and clearance during reassembly, increasing the difficulty and cost of operation and maintenance. Therefore, there is an urgent need for a two-stage screw air compressor. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a two-stage screw air compressor.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A two-stage screw air compressor includes a main air compressor housing, an auxiliary air compressor housing fixed to the outside of the main air compressor housing, a main screw and an auxiliary screw arranged inside the auxiliary air compressor housing, a main protective shell above the main screw and auxiliary screw to protect the top of the main screw and auxiliary screw, and two auxiliary protective shells below the main screw and auxiliary screw to protect the bottom of the main screw and auxiliary screw, a limiting mechanism outside the main screw and auxiliary screw to limit their movement, and two supporting mechanisms between the main protective shell and the two auxiliary protective shells to limit their movement. The limiting mechanism can limit the main screw and the auxiliary screw in a static state, thereby preventing them from rotating. The limiting mechanism includes a sleeve disposed outside the main screw and the auxiliary screw. Inside the sleeve are two key pins that can move laterally. Inside the sleeve are also an adjustment mechanism that pushes the key pins to move laterally. The supporting mechanism can connect the main protective shell and the secondary protective shell, and can also support the secondary protective shell.

[0006] As a preferred embodiment of the present invention, the adjusting mechanism includes a threaded rod screwed to the top of the sleeve, and two hinged rods are provided between the threaded rod and the two key pins; The hinge rod is hinged to a movable rod at the end away from the threaded rod, and the movable rod is fixed to a key pin at the end away from the hinge rod.

[0007] The key pin is adapted to the keyway on the outer wall of the main screw and auxiliary screw shaft. The sleeve has an internal cavity with movable grooves on both sides of the inner wall of the cavity to facilitate the movement of the key pin. The top of the sleeve also has a threaded hole adapted to the threaded rod. The lower half of the threaded rod passes through the threaded hole and extends into the cavity. The hinge rod is inclinedly hinged to the end of the movable rod away from the key pin and the lower half of the threaded rod. When the threaded rod is rotated, it moves downward and pushes the hinge rod from an inclined state to a horizontal state. The hinge rod drives the key pin to move through the movable rod, so that the key pin is inserted into the keyway of the main screw or auxiliary screw, thus limiting the movement of the main screw or auxiliary screw.

[0008] As a preferred embodiment of the present invention, a base plate is provided below the movable rod to support it, and a support rod is fixed to the bottom of the base plate to support it. The sleeve is also fixed inside a positioning rod, and the bottom of the threaded rod is provided with an insertion hole that matches the positioning rod. The top of the base plate has a groove that matches the moving rod. The bottom of the moving rod is installed in the groove. The upper half of the positioning rod is inserted into the insertion hole. The outer wall of the hinge rod is in contact with the top of the base plate. The base plate limits the hinge rod to ensure that the hinge rod can smoothly change from an inclined state to a horizontal state.

[0009] As a preferred embodiment of the present invention, a connecting rod is fixed to the bottom of the sleeve, and a wedge block is fixed to the end of the connecting rod away from the sleeve. A wedge groove adapted to the wedge block is opened on the opposite side of the two secondary protective shells. Two bolts are screwed to the bottom of the two secondary protective shells, and the tops of the two bolts pass through the two secondary protective shells and are screwed to the wedge block.

[0010] As a preferred technical solution of the present invention, the supporting mechanism includes a first insert rod fixed to the outer wall of the main protective shell and a second insert rod fixed to the outer wall of the secondary protective shell, and a supporting frame is provided at the end of the first insert rod and the second insert rod away from the main protective shell and the secondary protective shell. The inner wall of the support frame is also equipped with a lifting rod, and a load-bearing plate fixed to the inner wall of the main housing of the air compressor is also provided below the support frame; The load-bearing plate is Z-shaped, the bottom of the lifting rod is provided with a slope, the bottom of the support frame contacts the top of the load-bearing plate, and the bottom of the lifting rod passes through the support frame and contacts the top of the load-bearing plate.

[0011] As a preferred embodiment of the present invention, a card plate is also fixed inside the support frame, a swing rod is provided on the side of the card plate, and a spring is provided between the swing rod and the lifting rod. The card plate is fixed inside the support frame, and a pivot is provided on the side of the card plate. The swing rod is sleeved on the outside of the pivot. Pushing the lifting rod causes the spring to move via the secondary connecting column, causing the spring to rotate around the axis of the rotating shaft. This causes the secondary connecting column to swing inside the support frame, with the swing direction of the end of the secondary connecting column away from the rotating shaft being the same as the direction of movement of the lifting rod.

[0012] As a preferred embodiment of the present invention, a main connecting column is fixed to the side of the lifting rod, and a secondary connecting column is fixed to the side of the swing rod. Two connecting hooks are fixed at both ends of the spring, and the two connecting hooks are respectively hooked onto the outer walls of the main connecting column and the auxiliary connecting column.

[0013] As a preferred technical solution of the present invention, two buffer columns are also fixed inside the support frame, and rubber balls are provided on one side of the two buffer columns facing each other. The support frame is also fixed with an installation sleeve on the side near the secondary protective shell. The installation sleeve has a limiting groove inside that matches the first and second insert rods. The ends of the first and second insert rods furthest from the support frame are inserted into the limiting groove of the mounting sleeve.

[0014] Rotating the threaded rod engages with the threaded hole of the sleeve, causing the threaded rod to move horizontally downwards. The threaded rod pushes the hinge rod to contact the base plate, changing the hinge rod from an inclined state to a horizontal state. The hinge rod then pushes the moving rod to move away from the threaded rod, which in turn pushes the key pin to move, causing the key pin to enter the keyways of the main screw and the auxiliary screw respectively, thus limiting the movement of the main screw and the auxiliary screw.

[0015] Compared with the prior art, the beneficial effects that this invention can achieve are: 1. The present invention uses a limiting mechanism, sleeve, threaded rod, and key pin to be embedded in the keyway of the main screw and the auxiliary screw shaft respectively, so as to reliably lock the two screws in the static state of the equipment being stopped and disassembled, thus solving the defect that the screws can easily rotate freely after the housing is removed. This not only eliminates the safety hazard of the rotor accidentally deflecting and scraping the operator, but also avoids the damage to the working surface caused by the collision between the precision surface of the screw and the surrounding parts. 2. This invention uses the threaded transmission of the threaded rod and the sleeve to smoothly drive the key pin to extend and retract to complete the limiting and unlocking. In the limiting state, the main screw and the auxiliary screw always maintain the original assembly phase and meshing position. During reassembly, there is no need to recalibrate the meshing clearance and coaxiality of the two-stage rotors, which greatly shortens the maintenance operation time and lowers the skill threshold for maintenance personnel. 3. The present invention forms a plug-in positioning by means of a support mechanism, a support frame, a mounting sleeve, a first plug and a second plug, which can simultaneously realize the lateral connection and bottom support of the main protective shell and the secondary protective shell, stably bear the self-weight load of the secondary protective shell, avoid the protective shell from falling and misaligning during assembly, and improve the installation accuracy and stability of the overall structure. 4. When the support frame is pushed into the main housing of the air compressor along with the protective shell, the bottom slope of the lifting rod abuts against the load-bearing plate and retracts upward. Through the transmission linkage, the swing rod swings around the rotating shaft and finally locks against the buffer column to form a reverse self-locking. The axial fixation of the protective shell in the main housing can be completed without the need for additional fasteners. The disassembly and assembly are simple and the connection is strong. 5. The present invention adopts a modular integrated design for both the limiting mechanism and the supporting mechanism, which can be disassembled and assembled synchronously with the protective shell assembly, making the maintenance process simple and smooth. This not only reduces the damage to precision components such as screw rotors caused by misoperation during disassembly and maintenance, and extends the service life of core components, but also significantly reduces the working hours and labor costs of a single maintenance, and improves the operating economy of the equipment throughout its entire life cycle. 6. The present invention covers the upper and lower areas of the screw assembly with a main protective shell and two sets of secondary protective shells respectively, and connects the three into an overall protective structure with the support mechanism. During disassembly, transportation and static storage, the meshing working surfaces of the main screw and secondary screw are fully shielded, effectively preventing the intrusion of dust and foreign objects, and isolating external collisions and impacts. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the main housing structure of the air compressor of the present invention; Figure 3 This is a schematic diagram of the limiting mechanism of the present invention; Figure 4 This is a schematic diagram of the sleeve structure of the present invention; Figure 5 This is a schematic diagram of the threaded rod of the present invention; Figure 6 This is a schematic diagram of the key pin structure of the present invention; Figure 7 This is a schematic diagram of the hinge rod of the present invention; Figure 8 This is a schematic diagram of the structure of the first insertion rod of the present invention; Figure 9 This is a schematic diagram of the lifting rod of the present invention; Figure 10 This is a schematic diagram of the structure of the second insert of the present invention.

[0017] The components include: 1. Air compressor main housing; 2. Air compressor auxiliary housing; 3. Main screw; 4. Auxiliary screw; 5. Main protective housing; 6. Auxiliary protective housing; 7. Limiting mechanism; 701. Sleeve; 702. Threaded rod; 703. Key pin; 704. Connecting rod; 705. Wedge block; 706. Bolt; 707. Hinge rod; 708. Moving rod; 709. Base plate; 710. Support rod; 711. Positioning rod; 8. Supporting mechanism; 801. Support frame; 802. First insert rod; 803. Second insert rod; 804. Lifting rod; 805. Main connecting column; 806. Clamping plate; 807. Swing rod; 808. Spring; 809. Auxiliary connecting column; 810. Buffer column; 811. Load-bearing plate; 812. Mounting sleeve. Detailed Implementation

[0018] To make the technical means, creative features, and achieved objectives and effects of this invention easier to understand, the invention is further described below with reference to specific embodiments. However, the following embodiments are merely preferred embodiments of this invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the protection scope of this invention. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0019] Example: The present invention provides, as follows Figure 1 and Figure 2 The illustrated two-stage screw air compressor includes a main air compressor housing 1, an auxiliary air compressor housing 2 fixed to the outside of the main air compressor housing 1, a main screw 3 and an auxiliary screw 4 disposed inside the auxiliary air compressor housing 2, a main protective shell 5 disposed above the main screw 3 and the auxiliary screw 4 to protect their tops, and two auxiliary protective shells 6 disposed below the main screw 3 and the auxiliary screw 4 to protect their bottoms. The drive shaft of the main screw 3 is connected to the output shaft of an energy-saving motor, and the model of the energy-saving motor can be referenced as YE3-250M-4 manufactured by Shaanxi Asynchronous Xima Motor Co., Ltd.

[0020] As can be seen from the above, when in use, after separating the main housing 1 and the auxiliary housing 2 of the air compressor, the main protective housing 5 and the auxiliary protective housing 6 are taken out from the inside of the main housing 1 of the air compressor.

[0021] refer to Figure 3 , Figure 4 and Figure 5 As shown, the main screw 3 and the auxiliary screw 4 are also provided with limiting mechanisms 7 to limit the main screw 3 and the auxiliary screw 4, and two supporting mechanisms 8 to limit them are provided between the main protective shell 5 and the two auxiliary protective shells 6. The limiting mechanism 7 can limit the main screw 3 and the auxiliary screw 4 in a static state, thereby preventing the main screw 3 and the auxiliary screw 4 from rotating. The limiting mechanism 7 includes a sleeve 701 disposed outside the main screw 3 and the auxiliary screw 4. The sleeve 701 is provided with two key pins 703 that can move laterally. The sleeve 701 is also provided with an adjustment mechanism that pushes the key pins 703 to move laterally. refer to Figure 5 , Figure 6 and Figure 7 As shown, the adjusting mechanism includes a threaded rod 702 screwed to the top of the sleeve 701, and two hinged rods 707 are provided between the threaded rod 702 and the two key pins 703; A movable rod 708 is hinged to the end of the hinge rod 707 away from the threaded rod 702, and the end of the movable rod 708 away from the hinge rod 707 is fixed to the key pin 703.

[0022] The key pin 703 is adapted to the keyway on the outer wall of the main screw 3 and the auxiliary screw 4. The sleeve 701 has a cavity inside, and the inner wall of the cavity has moving grooves on both sides to facilitate the movement of the key pin 703. The top of the sleeve 701 also has a threaded hole adapted to the threaded rod 702. The lower half of the threaded rod 702 extends into the cavity after passing through the threaded hole. The hinge rod 707 is inclinedly hinged to the end of the moving rod 708 away from the key pin 703 and the lower half of the threaded rod 702. When the threaded rod 702 is rotated, the threaded rod 702 moves downward and pushes the hinge rod 707 from the inclined state to the horizontal state. The hinge rod 707 drives the key pin 703 to move through the moving rod 708, so that the key pin 703 is inserted into the keyway of the main screw 3 or the auxiliary screw 4, and limits the main screw 3 or the auxiliary screw 4.

[0023] refer to Figure 5 , Figure 6 and Figure 7 As shown, a base plate 709 is provided below the movable rod 708 to support it, and a support rod 710 is fixed to the bottom of the base plate 709 to support it. The sleeve 701 also has a positioning rod 711 fixed inside, and the bottom of the threaded rod 702 has an insertion hole that matches the positioning rod 711. The top of the base plate 709 has a groove that matches the moving rod 708. The bottom of the moving rod 708 is installed in the groove. The upper half of the positioning rod 711 is inserted into the insertion hole. The outer wall of the hinge rod 707 is in contact with the top of the base plate 709. The base plate 709 limits the hinge rod 707 to ensure that the hinge rod 707 can smoothly change from an inclined state to a horizontal state.

[0024] refer to Figure 5 , Figure 6 and Figure 7 As shown, a connecting rod 704 is also fixed to the bottom of the sleeve 701. A wedge block 705 is also fixed to the end of the connecting rod 704 away from the sleeve 701. A wedge groove adapted to the wedge block 705 is opened on the opposite side of the two secondary protective shells 6. Two bolts 706 are screwed to the bottom of the two secondary protective shells 6. The tops of the two bolts 706 pass through the two secondary protective shells 6 and are screwed to the wedge block 705.

[0025] Rotating the threaded rod 702, the threaded rod 702 engages with the threaded hole of the sleeve 701, causing the threaded rod 702 to move horizontally downwards. The threaded rod 702 pushes the hinge rod 707 to contact the base plate 709, causing the hinge rod 707 to change from an inclined state to a horizontal state. The hinge rod 707 pushes the moving rod 708 to move away from the threaded rod 702. The moving rod 708 pushes the key pin 703 to move, causing the key pin 703 to enter the keyways of the main screw 3 and the auxiliary screw 4 respectively, thus limiting the movement of the main screw 3 and the auxiliary screw 4.

[0026] refer to Figure 8 , Figure 9 and Figure 10 As shown, the support mechanism 8 can connect the main protective shell 5 and the secondary protective shell 6, and the support mechanism 8 can also support the secondary protective shell 6. The support mechanism 8 includes a first insert rod 802 fixed to the outer wall of the main protective shell 5 and a second insert rod 803 fixed to the outer wall of the secondary protective shell 6. A support frame 801 is provided at the end of the first insert rod 802 and the second insert rod 803 away from the main protective shell 5 and the secondary protective shell 6. A lifting rod 804 is also inserted into the inner wall of the support frame 801, and a load-bearing plate 811 fixed to the inner wall of the air compressor main housing 1 is also provided below the support frame 801; The load-bearing plate 811 is Z-shaped, the bottom of the lifting rod 804 is provided with a slope, the bottom of the support frame 801 contacts the top of the load-bearing plate 811, and the bottom of the lifting rod 804 passes through the support frame 801 and contacts the top of the load-bearing plate 811.

[0027] refer to Figure 8 , Figure 9 and Figure 10 As shown, a card plate 806 is also fixed inside the support frame 801. A swing rod 807 is provided on the side of the card plate 806. A spring 808 is provided between the swing rod 807 and the lifting rod 804. The card plate 806 is fixed inside the support frame 801. A pivot is provided on the side of the card plate 806, and the swing rod 807 is sleeved on the outside of the pivot. Pushing the lifting rod 804 causes the spring 808 to move via the secondary connecting column 809, causing the spring 808 to rotate around the axis of the rotating shaft, causing the secondary connecting column 809 to swing inside the support frame 801, and the swing direction of the end of the secondary connecting column 809 away from the rotating shaft is the same as the direction of movement of the lifting rod 804.

[0028] refer to Figure 8 , Figure 9 and Figure 10 As shown, a main connecting column 805 is fixed to the side of the lifting rod 804, and a secondary connecting column 809 is fixed to the side of the swing rod 807. Two connecting hooks are fixed at both ends of the spring 808, and the two connecting hooks are respectively hooked to the outer walls of the main connecting post 805 and the auxiliary connecting post 809.

[0029] refer to Figure 8 , Figure 9 and Figure 10 As shown, two buffer pillars 810 are also fixed inside the support frame 801, and rubber balls are provided on the opposite side of the two buffer pillars 810. A mounting sleeve 812 is also fixed on the side of the support frame 801 near the secondary protective shell 6. The mounting sleeve 812 has a limiting groove inside that is adapted to the first insertion rod 802 and the second insertion rod 803. The ends of the first insertion rod 802 and the second insertion rod 803, away from the support frame 801, are inserted into the limiting groove of the mounting sleeve 812.

[0030] Rotating the threaded rod 702, the threaded rod 702 engages with the threaded hole of the sleeve 701, causing the threaded rod 702 to move horizontally downwards. The threaded rod 702 pushes the hinge rod 707 to contact the base plate 709, causing the hinge rod 707 to change from an inclined state to a horizontal state. The hinge rod 707 pushes the moving rod 708 to move away from the threaded rod 702. The moving rod 708 pushes the key pin 703 to move, causing the key pin 703 to enter the keyways of the main screw 3 and the auxiliary screw 4 respectively, thus limiting the movement of the main screw 3 and the auxiliary screw 4.

[0031] After assembling the main protective shell 5 and the two auxiliary protective shells 6, push the support frame 801 to move. The support frame 801 drives the mounting sleeve 812 to move. Through the cooperation of the mounting sleeve 812 with the support frame 801 and the first insertion rod 802, insert the support frame 801 and the first insertion rod 802 into the slot of the mounting sleeve 812. Install the support frame 801 on the side of the main protective shell 5 and the auxiliary protective shells 6. Press the lifting rod 804 so that the lower half of the lifting rod 804 extends to the outside of the support frame 801, pushing the auxiliary protective shells 6 into the air compressor. Inside the main housing 1, the inclined surface of the lifting rod 804 contacts the load-bearing plate 811, causing the lifting rod 804 to move upward. The lifting rod 804 drives the main connecting column 805 to move upward. The main connecting column 805 drives the clamping plate 806 to move upward via the spring 808. The auxiliary connecting column 809 drives the swing rod 807 to rotate upward around the axis of the rotating shaft, so that the end of the swing rod 807 away from the rotating shaft contacts the buffer column 810. The buffer column 810 limits the swing rod 807, and then the swing rod 807 limits the lifting rod 804.

[0032] Working principle: Rotating the threaded rod 702, and utilizing the engagement between the threaded rod 702 and the threaded hole on the sleeve 701, causes the threaded rod 702 to move downward in the horizontal direction. The threaded rod 702 pushes the hinge rod 707, causing the hinge rod 707 to contact the base plate 709 and forcing the hinge rod 707 to change from an inclined state to a horizontal state. The hinge rod 707 then pushes the moving rod 708 to move away from the threaded rod 702. The moving rod 708 then pushes the key pin 703 to move, causing the key pin 703 to enter the keyways of the main screw 3 and the auxiliary screw 4 respectively, thereby limiting the movement of the main screw 3 and the auxiliary screw 4. After the main protective shell 5 and the two auxiliary protective shells 6 are assembled into one unit, the support frame 801 is pushed to move, and the support frame 801 moves the mounting sleeve 812 together. With the cooperation of the mounting sleeve 812, the support frame 801 and the first insertion rod 802 are inserted into the slot of the mounting sleeve 812, thereby installing the support frame 801 on the side of the main protective shell 5 and the auxiliary protective shells 6. The lifting rod 804 is pressed, so that the lower half of the lifting rod 804 extends outside the support frame 801. Then, the assembly of the main protective shell 5 and the auxiliary protective shells 6 is pushed into the interior of the air compressor main housing 1. During the entry process, the inclined surface of the lifting rod 804 contacts the load-bearing plate 811, forcing the lifting rod 804 to move upward. The lifting rod 804 drives the main connecting column 805 to move upward, and the main connecting column 805 drives the auxiliary connecting column 809 to move upward through the spring 808. The auxiliary connecting column 809 then drives the swing rod 807 to swing upward around its axis of rotation, so that the end of the swing rod 807 away from the axis of rotation contacts the buffer column 810. The buffer column 810 limits the swing rod 807, and in turn, the swing rod 807 limits the lifting rod 804.

[0033] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A two-stage screw air compressor, comprising a main air compressor housing (1), an auxiliary air compressor housing (2) fixed to the outside of the main air compressor housing (1), a main screw (3) and an auxiliary screw (4) disposed inside the auxiliary air compressor housing (2), a main protective shell (5) for protecting the top of the main screw (3) and the auxiliary screw (4) disposed above the main screw (3) and the auxiliary screw (4), and two auxiliary protective shells (6) for protecting the bottom of the main screw (3) and the auxiliary screw (4) disposed below the main screw (3) and the auxiliary screw (4), characterized in that, The main screw (3) and the auxiliary screw (4) are also provided with limiting mechanisms (7) to limit the main screw (3) and the auxiliary screw (4), and two supporting mechanisms (8) to limit them are provided between the main protective shell (5) and the two auxiliary protective shells (6). The limiting mechanism (7) can limit the main screw (3) and the auxiliary screw (4) in a static state, thereby preventing the main screw (3) and the auxiliary screw (4) from rotating. The limiting mechanism (7) includes a sleeve (701) disposed outside the main screw (3) and the auxiliary screw (4). The sleeve (701) is provided with two key pins (703) that can move laterally. The sleeve (701) is also provided with an adjustment mechanism that pushes the key pins (703) to move laterally. The supporting mechanism (8) can connect the main protective shell (5) and the secondary protective shell (6), and the supporting mechanism (8) can also support the secondary protective shell (6).

2. A two-stage screw air compressor according to claim 1, characterized in that, The adjustment mechanism includes a threaded rod (702) screwed to the top of the sleeve (701), and two hinge rods (707) are provided between the threaded rod (702) and two key pins (703). The hinge rod (707) is hinged to a movable rod (708) at one end away from the threaded rod (702), and the movable rod (708) at one end away from the hinge rod (707) is fixed to a key pin (703); The key pin (703) is adapted to the keyway on the outer wall of the main screw (3) and the auxiliary screw (4). The sleeve (701) has a cavity inside. The inner wall of the cavity has moving grooves on both sides to facilitate the movement of the key pin (703). The top of the sleeve (701) also has a threaded hole adapted to the threaded rod (702). The lower half of the threaded rod (702) extends into the cavity after passing through the threaded hole. The hinge rod (707) is inclinedly hinged to the end of the moving rod (708) away from the key pin (703) and the lower half of the threaded rod (702). Rotating the threaded rod (702) The threaded rod (702) moves downward, and the threaded rod (702) pushes the hinge rod (707) to move away from the inclined state to the horizontal state. The hinge rod (707) drives the key pin (703) to move through the moving rod (708), so that the key pin (703) is inserted into the keyway of the main screw (3) or the auxiliary screw (4) to limit the main screw (3) or the auxiliary screw (4).

3. A two-stage screw air compressor according to claim 2, characterized in that, Below the movable rod (708) is a base plate (709) for supporting it, and a support rod (710) for supporting it is fixed at the bottom of the base plate (709). The sleeve (701) is also fixed inside a positioning rod (711), and the bottom of the threaded rod (702) is provided with an insertion hole that matches the positioning rod (711); The top of the base plate (709) is provided with a groove that matches the moving rod (708). The bottom of the moving rod (708) is installed in the groove. The upper half of the positioning rod (711) is inserted into the insertion hole. The outer wall of the hinge rod (707) is in contact with the top of the base plate (709). The base plate (709) limits the hinge rod (707) to ensure that the hinge rod (707) can smoothly change from an inclined state to a horizontal state.

4. A two-stage screw air compressor according to claim 3, characterized in that, The bottom of the sleeve (701) is also fixed with a connecting rod (704), and a wedge block (705) is also fixed at the end of the connecting rod (704) away from the sleeve (701). The two sub-protective shells (6) have wedge grooves that are adapted to the wedge block (705) on their opposite sides. The bottom of the two sub-protective shells (6) is also screwed with two bolts (706). The tops of the two bolts (706) pass through the two sub-protective shells (6) and are screwed to the wedge block (705).

5. A two-stage screw air compressor according to claim 4, characterized in that, The supporting mechanism (8) includes a first insert rod (802) fixed to the outer wall of the main protective shell (5) and a second insert rod (803) fixed to the outer wall of the secondary protective shell (6). The first insert rod (802) and the second insert rod (803) are provided with a supporting frame (801) at the end away from the main protective shell (5) and the secondary protective shell (6). The inner wall of the support frame (801) is also provided with a lifting rod (804), and a load-bearing plate (811) fixed to the inner wall of the main housing (1) of the air compressor is also provided below the support frame (801); The load-bearing plate (811) is Z-shaped, the bottom of the lifting rod (804) is provided with a slope, the bottom of the support frame (801) contacts the top of the load-bearing plate (811), and the bottom of the lifting rod (804) passes through the support frame (801) and contacts the top of the load-bearing plate (811).

6. A two-stage screw air compressor according to claim 5, characterized in that, The support frame (801) is also fixed with a card plate (806), and a swing rod (807) is provided on the side of the card plate (806). A spring (808) is provided between the swing rod (807) and the lifting rod (804). The card plate (806) is fixed inside the support frame (801), and a pivot is provided on the side of the card plate (806). The swing rod (807) is sleeved on the outside of the pivot. Push the lifting rod (804), and the lifting rod (804) drives the spring (808) to move through the secondary connecting column (809), causing the spring (808) to rotate around the axis of the rotating shaft, causing the secondary connecting column (809) to swing inside the support frame (801), and the swing direction of the end of the secondary connecting column (809) away from the rotating shaft is the same as the direction of movement of the lifting rod (804).

7. A two-stage screw air compressor according to claim 6, characterized in that, The lifting rod (804) is fixed with a main connecting column (805) on its side, and the swing rod (807) is fixed with a secondary connecting column (809) on its side. Two connecting hooks are fixed at both ends of the spring (808), and the two connecting hooks are respectively hooked onto the outer walls of the main connecting post (805) and the auxiliary connecting post (809).

8. A two-stage screw air compressor according to claim 7, characterized in that, The support frame (801) also has two buffer columns (810) fixed inside, and rubber balls are provided on the opposite side of the two buffer columns (810); The support frame (801) is also fixed with an installation sleeve (812) on the side near the secondary protective shell (6). The installation sleeve (812) has a limiting groove inside that is adapted to the first insertion rod (802) and the second insertion rod (803). The ends of the first insert (802) and the second insert (803) away from the support frame (801) are inserted into the limiting groove of the mounting sleeve (812); Rotate the threaded rod (702), and the threaded rod (702) engages with the threaded hole of the sleeve (701), causing the threaded rod (702) to move horizontally downward. The threaded rod (702) pushes the hinge rod (707) to contact the base plate (709), causing the hinge rod (707) to change from an inclined state to a horizontal state. The hinge rod (707) pushes the moving rod (708) to move away from the threaded rod (702). The moving rod (708) pushes the key pin (703) to move, causing the key pin (703) to enter the keyway of the main screw (3) and the auxiliary screw (4) respectively, thus limiting the main screw (3) and the auxiliary screw (4).

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