A structure for repairing a broken shaft of a screw compressor
By using hot-fit interference fit and small-clearance fit design between hexagonal connecting blocks and slots, the problems of material embrittlement and high cost in traditional repair methods are solved, achieving efficient repair and stable operation of screw compressor shaft breakage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGHAI SALT LAKE YUANPIN CHEM CO LTD
- Filing Date
- 2025-07-18
- Publication Date
- 2026-06-26
AI Technical Summary
Traditional methods for repairing broken screw compressor shafts suffer from problems such as material embrittlement due to thermal stress concentration after welding, difficulty in controlling post-weld deformation, reduced strength after repair, and high costs. Furthermore, ordinary splicing repair cannot meet the requirements of high-speed operation.
The rotor, half-shaft, and bushing are connected by a heat-fitted interference fit, and the small clearance fit between the hexagonal connecting block and the slot, as well as the screw fixing, ensure accurate circumferential positioning, transmit torque and axial force, and prevent loosening.
It achieves a high-strength and stable connection, is suitable for high-speed operation, reduces repair costs and cycles, and facilitates maintenance.
Smart Images
Figure CN224413875U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of screw compressor repair, and in particular to a structure for repairing a broken shaft in a screw compressor. Background Technology
[0002] Screw compressors are commonly used power equipment in the industrial field. Their core component, the rotor shaft, is prone to shaft breakage due to excessive torque and stress concentration under long-term high-speed operation, load fluctuations, or assembly errors.
[0003] Traditional shaft breakage repair methods have the following drawbacks: Welding repair connects the broken shaft segments using arc welding, but the welding process easily generates thermal stress concentration, leading to embrittlement of the shaft material. Furthermore, post-weld deformation is difficult to control, resulting in reduced shaft strength and a high risk of re-fracture. Replacing the entire shaft requires replacing it with a brand new rotor shaft, which is costly and has a long procurement cycle, severely impacting production continuity. Ordinary sleeve repair uses a simple sleeve connection and bolt fixation, which can only transmit small torques. Moreover, the large clearance between the sleeve and the shaft easily generates vibration and abnormal noise, failing to meet the high-speed operation requirements of the compressor. Utility Model Content
[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a structure for repairing broken shafts in screw compressors.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A structure for repairing a broken shaft of a screw compressor includes a rotor, a half-shaft, a bushing, and screws. The rotor is connected to the half-shaft, and the half-shaft is connected to the bushing. The bushing is fitted onto the half-shaft. A connecting hole is provided at the center of one side of the rotor, and a hexagonal connecting groove is provided along the outer edge of the connecting hole. Screw holes are provided at the hexagonal corners of the hexagonal connecting groove. The front end of the half-shaft is a shaft insertion end, and a hexagonal connecting block is located behind the shaft insertion end. Connecting holes corresponding to the screw holes are provided at the hexagonal corners of the hexagonal connecting block. The connecting holes are corresponding to the screws. The shaft insertion end of the rotor is inserted into the connecting hole, and the hexagonal connecting block is inserted into the hexagonal connecting groove and fixed by screws.
[0007] Furthermore, the rotor and the half-shaft are connected by a heat-fitted interference fit, and the half-shaft and the bushing are connected by a heat-fitted interference fit.
[0008] Furthermore, the hexagonal connecting block and the hexagonal connecting groove are fitted with a small clearance. The distance between opposite sides of the hexagonal connecting block is 0.02-0.06mm smaller than that of the hexagonal connecting groove, ensuring accurate circumferential positioning and no relative rotation.
[0009] Furthermore, the screw is an internal hexagon head screw.
[0010] Furthermore, the bushing is made of 45 steel, and the heat fitting interference between its inner hole and the half shaft is 0.03-0.07mm.
[0011] Furthermore, the rotor is made of QT600-3 ductile iron, and the half-shaft is made of 40CrNiMo alloy.
[0012] The beneficial effects of this utility model are as follows:
[0013] 1. High and stable connection strength: The dual connection method of hot-fit interference fit and screw fixation not only uses the interference fit to transmit axial force and part of the torque, but also uses screws to ensure circumferential positioning and connection reliability, thus improving the ability to withstand high-speed alternating loads.
[0014] 2. The small gap fit design between the hexagonal connecting block and the hexagonal connecting groove enables precise circumferential positioning, avoids the slippage problem of traditional circular connections, ensures lossless torque transmission, and is suitable for high-load conditions.
[0015] 3. Low repair cost and short cycle: The split structure allows the rotor, half shaft, and bushing to be processed separately without replacing the entire shaft system, resulting in low repair cost and a shorter processing cycle.
[0016] 4. The hot fitting process is simple to operate. The interference fit is achieved by heating, and the screw connection is easy to disassemble and repair. If the bushing is worn, it can be replaced separately without disassembling the entire connection structure, which reduces the later maintenance cost. Attached Figure Description
[0017] Figure 1 This is a cross-sectional view of the structure of this utility model;
[0018] Figure 2 This is a schematic diagram of the rotor structure of this utility model;
[0019] Figure 3 This is a side view of the rotor of this utility model;
[0020] Figure 4 This is a structural diagram of the half-shaft of this utility model;
[0021] Figure 5 This is a diagram of the screw structure of this utility model;
[0022] In the diagram: 1. Rotor; 11. Connecting socket; 12. Screw hole; 13. Hexagonal connecting groove; 2. Half shaft; 21. Shaft insertion end; 22. Hexagonal connecting block; 23. Connecting hole; 3. Shaft sleeve; 4. Screw. Detailed Implementation
[0023] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0024] Example 1
[0025] like Figure 1-5 As shown, this utility model provides a structure for repairing a broken screw compressor shaft. The structure includes a rotor 1, a half-shaft 2, a bushing 3, and screws. The rotor 1 is connected to the half-shaft 2, and the half-shaft 2 is connected to the bushing 3. The bushing 3 is fitted onto the half-shaft 2. A connecting hole 11 is provided at the center of one side of the rotor 1. A hexagonal connecting groove 13 is provided at the outer edge of the connecting hole 11. Screw holes 12 are provided at the hexagonal corners of the hexagonal connecting groove 13. The front end of the half-shaft 2 is a shaft insertion end 21. A hexagonal connecting block 22 is provided at the rear side of the shaft insertion end 21. A connecting hole 23 corresponding to the screw hole 12 is provided at the hexagonal corners of the hexagonal connecting block 22. The connecting hole 23 is correspondingly provided with the screw. The shaft insertion end 21 of the rotor 1 is inserted into the connecting hole 11. The hexagonal connecting block 22 is inserted into the hexagonal connecting groove 13 and fixed by screws.
[0026] Rotor 1 and half shaft 2 are connected by a heat-fitted interference fit, and half shaft 2 and bushing 3 are connected by a heat-fitted interference fit.
[0027] The hexagonal connecting block 22 and the hexagonal connecting groove 13 are fitted with a small clearance. The distance between opposite sides of the hexagonal connecting block 22 is 0.02-0.06mm smaller than that of the hexagonal connecting groove 13, ensuring accurate circumferential positioning and no relative rotation.
[0028] The screws are internal hexagonal head screws made of 40CrNiMo alloy structural steel.
[0029] The bushing 3 is made of 45 steel, and the heat fitting interference between its inner hole and the half shaft 2 is 0.03-0.07mm.
[0030] The rotor 1 is made of QT600-3 ductile iron, and the half shaft 2 is made of 40CrNiMo alloy.
[0031] The specific assembly process is as follows:
[0032] Pre-processing: The connecting hole 11 of rotor 1 is machined to a diameter of φ50mm, the hexagonal connecting groove 13 has a side-to-side distance of 80mm, and the screw hole 12 is M12; the shaft insertion end 21 of half shaft 2 has a diameter of φ50mm, the hexagonal connecting block 22 has a side-to-side distance of 80mm, and the connecting hole 23 is M12; the inner hole of bushing 3 is φ50mm.
[0033] Rotor and half-shaft assembly: Heat rotor 1 to 180℃ (hold for 30 minutes) to expand the connecting socket 11 and insert it into the shaft socket 21 of half-shaft 2. After natural cooling, an interference fit is formed; hexagonal connecting block 22 is inserted into hexagonal connecting groove 13 with a fit clearance of 0.02mm. Use an Allen wrench to screw M12 screw 4 into screw hole 12 and connecting hole 23.
[0034] Shaft sleeve assembly: Heat the shaft sleeve 3 to 200℃ (hold for 20 minutes) to expand its inner hole, then fit it onto the rear end of the hexagonal connecting block 22 of the half shaft 2. After natural cooling, an interference fit is formed.
[0035] When the compressor is running, the rotor 1 transmits axial force through the interference fit between the connecting hole 11 and the shaft insertion end 21 of the half shaft 2, and transmits torque through the fit between the hexagonal connecting block 22 and the hexagonal connecting groove 13. The screw 4 prevents both from loosening under alternating loads. The bushing 3 is in direct contact with the compressor bearing, bears radial force and protects the half shaft 2 from wear, thereby achieving efficient repair of broken shafts and long-term stable operation.
Claims
1. A structure for repairing a broken shaft in a screw compressor, characterized in that: The device includes a rotor, a half-shaft, a bushing, and screws. The rotor is connected to the half-shaft, and the half-shaft is connected to the bushing. The bushing is fitted onto the half-shaft. A connecting hole is provided at the center of one side of the rotor. A hexagonal connecting groove is provided along the outer edge of the connecting hole. Screw holes are provided at the hexagonal corners of the hexagonal connecting groove. The front end of the half-shaft is a shaft insertion end. A hexagonal connecting block is located behind the shaft insertion end. Connecting holes corresponding to the screw holes are provided at the hexagonal corners of the hexagonal connecting block. The connecting holes are corresponding to the screws. The shaft insertion end of the rotor is inserted into the connecting hole. The hexagonal connecting block is inserted into the hexagonal connecting groove and fixed by screws.
2. The structure for repairing a broken shaft of a screw compressor according to claim 1, characterized in that: The rotor and the half-shaft are connected by a heat-fitted interference fit, and the half-shaft and the bushing are connected by a heat-fitted interference fit.
3. The structure for repairing a broken shaft of a screw compressor according to claim 1, characterized in that: The hexagonal connecting block and the hexagonal connecting groove are fitted with a small clearance, and the distance between opposite sides of the hexagonal connecting block is 0.02-0.06 mm smaller than that of the hexagonal connecting groove.
4. The structure for repairing a broken shaft of a screw compressor according to claim 1, characterized in that: The screw is an internal hexagon head screw.
5. The structure for repairing a broken shaft of a screw compressor according to claim 1, characterized in that: The bushing is made of 45 steel.
6. The structure for repairing a broken shaft of a screw compressor according to claim 1, characterized in that: The rotor is made of QT600-3 ductile iron, and the half shaft is made of 40CrNiMo alloy.