A driving shaft for power transmission of a heavy load device

Abstract

The utility model discloses a kind of driving shafts for power transmission of heavy load equipment, comprising: shaft body, the shaft body is used to connect power source;Rotor, the rotor is driven load component, and the center of the rotor is provided with shaft hole;Expansion connection assembly, the expansion connection assembly is set between the shaft body and the shaft hole of the rotor of the rotor, for the shaft body with the rotor keyless connection.The utility model in, through the great hug tightness and friction force generated by high-strength bolt pre-tightening, connection gapless stable reliable, can transmit extremely high torque, fully meet the harsh requirements of heavy load such as mine machinery.And because cancel keyway, fundamentally eliminate the stress concentration caused by keyway, significantly improve the fatigue strength of shaft and rotor, effectively prevent the occurrence of fracture accident.And the installation of expansion sleeve only needs to use standard wrench to tighten bolt according to predetermined torque, greatly simplifies assembly process.

Description

Technical Field

[0001] This utility model relates to the field of mechanical power transmission technology for heavy-duty equipment, and in particular to a drive shaft for power transmission in heavy-duty equipment. Background Technology

[0002] In heavy industries such as mining, metallurgy, and building materials, equipment such as mixing equipment, crushers, and ball mills are core production equipment. These machines are typically characterized by high starting torque, heavy operating loads, and harsh working environments (such as high dust levels, strong vibrations, and impact loads). Their power transmission systems, especially the connection method between the drive shaft and the working rotor (such as mixing blades and crushing rollers), directly affect the operational stability, safety, and maintenance efficiency of the entire equipment.

[0003] Traditional drive shaft connections primarily use keyed connections, such as flat keys or splines. Keyed connections are simple in structure and low in cost, but they reveal several insurmountable drawbacks in heavy-duty applications: 1. Stress Concentration and Fatigue Failure: The machining of keyways creates stress concentration points on shafts and hubs. Under heavy loads and impact loads, fatigue cracks are easily generated at the root of the keyway, leading to shaft or hub fracture and causing major equipment accidents.

[0004] 2. Difficult installation and disassembly: For large and heavy rotors, keyed connections require precise alignment, often using press-fit or heat-fitting methods. The installation process is complex and labor-intensive. Disassembly is equally difficult, and sometimes corrosion or deformation makes disassembly impossible, requiring destructive removal and resulting in the scrapping of core components and high maintenance costs.

[0005] 3. Fit clearance and impact: Keyed connections inevitably have fit clearance, which will generate impact and vibration when the equipment starts up or stops or when the load changes suddenly. This will aggravate the wear of transmission components such as gears and bearings, reduce the service life of the equipment, and generate more noise.

[0006] 4. Inability to achieve overload protection: The key connection is a rigid connection. When the equipment jams or other extreme overload conditions occur, the huge torque will be directly transmitted to the transmission chain, which may lead to a chain of damage such as motor burnout and gear tooth breakage. There is a lack of effective mechanical protection mechanism.

[0007] Therefore, this utility model proposes a drive shaft for power transmission in heavy-duty equipment. Utility Model Content

[0008] The purpose of this invention is to overcome the shortcomings of keyed connections in heavy-duty applications and to provide a drive shaft for power transmission in heavy-duty equipment. This drive shaft uses a shrink-fit sleeve structure, eliminating the need for keys to transmit force and instead transmitting torque through friction. It offers advantages such as reliable connection, convenient installation, no stress concentration, and overload protection.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a drive shaft for power transmission in heavy-duty equipment, comprising: A shaft for connecting a power source; The rotor is a load component to be driven, and a shaft hole is provided at the center of the rotor; An expansion joint assembly is disposed between the shaft body and the shaft hole of the rotor, for keyless connection of the shaft body and the rotor; The expansion connection assembly includes an inner ring, an outer ring, and multiple sets of corresponding high-strength bolts and expansion sleeves. The expansion sleeves generate radial clamping force between the inner ring and the shaft and between the outer ring and the rotor shaft hole through the tensile force of the high-strength bolts, thereby transmitting torque by relying on friction.

[0010] Furthermore, the outer ring abuts against the inner wall of the shaft hole, and a connector is fixedly connected to the inner side of the outer ring, and the inner side of the connector is fixedly connected to the outer surface of the inner ring.

[0011] Furthermore, mounting holes are provided at the top and bottom of the inner ring, and the inner sides of the two mounting holes abut against the limiting members, and the shaft body passes through and abuts against the inner walls of the inner ring and the two limiting members respectively.

[0012] Furthermore, there are two sets of high-strength bolts and expansion sleeves, which are arranged along the axial direction of the shaft on the side walls of the two limiting members. Each set of high-strength bolts and expansion sleeves consists of two groups and is symmetrically arranged at both ends of the radial length of the limiting member.

[0013] Furthermore, the side wall of the limiting member has an inner hole, the inner wall of the inner hole abuts against the corresponding expansion sleeve, and the inner side of the expansion sleeve is threaded with a high-strength bolt.

[0014] Furthermore, the surfaces in contact between the inner ring and the shaft, between the limiting member and the shaft, between the limiting member and the inner ring, and between the outer ring and the shaft hole of the rotor are provided with an anti-slip coating or are hardened.

[0015] Furthermore, the drive shaft is used in mixing equipment, crushers, or large conveyors of mining machinery.

[0016] This utility model has the following beneficial effects: In use, this utility model utilizes a drive shaft for power transmission in heavy-duty equipment. The high-strength bolts, pre-tightened to generate immense clamping and frictional forces, ensure a seamless, stable, and reliable connection, resulting in smooth operation without impact or vibration. It can transmit extremely high torque, possesses strong load-bearing capacity, and fully meets the stringent requirements of heavy-duty equipment such as mining machinery. Furthermore, by eliminating the keyway, the shaft and rotor form a complete cylindrical structure, fundamentally eliminating stress concentration caused by the keyway. This significantly improves the fatigue strength of the shaft and rotor, effectively preventing fracture accidents and extending the service life of core components. The installation of the expansion sleeve only requires tightening the bolts to the predetermined torque using a standard wrench, eliminating the need for heating or a press, greatly simplifying the assembly process. During disassembly, simply loosening the bolts allows the inner and outer rings to automatically return to their original positions, easily separating the shaft from the rotor. For heavy-duty equipment requiring frequent maintenance or component replacement, this significantly reduces downtime, maintenance costs, and labor intensity.

[0017] Meanwhile, when the equipment encounters extreme overload conditions such as unexpected jamming, if the transmitted torque exceeds the maximum frictional torque that the expansion sleeve can generate, relative slippage will occur between the shaft and the rotor (i.e., "slippage"). This slippage can cut off power transmission, thereby protecting upstream critical equipment such as motors and reducers from damage, and acting as a mechanical safety clutch. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present utility model; Figure 2 This is a front sectional view of the present invention; Figure 3 For the present utility model Figure 2 Enlarged view of point A in the middle.

[0019] Legend: 1. Shaft; 2. Rotor; 3. Outer ring; 4. Connecting part; 5. Inner ring; 6. Limiting part; 7. High-strength bolt; 8. Expansion sleeve; 9. Inner hole; 10. Mounting hole; 11. Shaft hole. Detailed Implementation

[0020] Figures 1 to 3 As shown, a drive shaft for power transmission in heavy-duty equipment is disclosed. The drive shaft is used in mixing equipment, crushers, or large conveyors in mining machinery, and includes: Shaft 1 is used to connect a power source (such as a motor or reducer). One end of shaft 1 is connected to a reducer (not shown) via a coupling. Rotor 2 is a load component to be driven (such as a stirring impeller hub). The other end of the shaft 1 is a smooth shaft for mounting rotor 2, and a shaft hole 11 is provided in the center of rotor 2. An expansion joint assembly is disposed between the shaft hole 11 of the shaft body 1 and the rotor 2, and is used to connect the shaft body 1 and the rotor 2 without keys. The expansion connection assembly includes an inner ring 5, an outer ring 3, and multiple sets of corresponding high-strength bolts 7 and expansion sleeves 8. The expansion sleeves 8 generate radial clamping force between the inner ring 5 and the shaft 1, and between the outer ring 3 and the shaft hole 11 of the rotor 2, through the tensile force of the high-strength bolts 7, thereby transmitting torque by means of friction.

[0021] Specifically, the outer ring 3 abuts against the inner wall of the shaft hole 11, and a connector 4 is fixedly connected to the inner side of the outer ring 3, with the inner side of the connector 4 fixedly connected to the outer surface of the inner ring 5. The inner ring 5 has mounting holes 10 at both its top and bottom, with the inner sides of both mounting holes 10 abutting against limiting members 6. The shaft 1 passes through and abuts against the inner walls of the inner ring 5 and the two limiting members 6.

[0022] To transmit greater torque and ensure connection stability, two sets of high-strength bolts 7 and expansion sleeves 8 are arranged along the axial direction of the shaft 1 on the side walls of the two limiting members 6. Each set of high-strength bolts 7 and expansion sleeves 8 consists of two groups and is symmetrically arranged at both ends of the radial length of the limiting member 6, forming a double-point support, which makes the force more balanced and ensures that the applied axial force is balanced, thus avoiding off-center loading.

[0023] The side wall of the limiting member 6 has an inner hole 9, the inner wall of which abuts against the corresponding expansion sleeve 8. A high-strength bolt 7 is threaded through the inner side of the expansion sleeve 8. When the high-strength bolt 7 is screwed into the expansion sleeve 8, the expansion sleeve 8 expands outward. The outer side of the limiting member 6, the inner ring 5, and the outer ring 3 are radially expanded outward in sequence, while the inner side of the limiting member 6 is radially contracted inward. This generates a huge radial clamping force between the inner ring 5 and the shaft 1, and between the outer ring 3 and the shaft hole 11 of the rotor 2, thus forming a strong static friction force on the contact surface. This friction force is used to transmit the large torque required by the drive shaft, achieving a keyless connection.

[0024] To improve the coefficient of friction and wear resistance, the surfaces in contact with the inner ring 5 and the shaft 1, the limiting member 6 and the shaft 1, the limiting member 6 and the inner ring 5, and the outer ring 3 and the shaft hole 11 of the rotor 2 are provided with anti-slip coatings or hardened.

[0025] Installation process: 1. Insert the inner ring 5 onto the shaft 1, and under synchronous action, insert the outer ring 3 into the shaft hole 11 of the rotor 2.

[0026] 2. Insert the assembled expansion sleeve 8 into the inner hole 9 of the limiting member 6, so that the multiple sets of corresponding high-strength bolts 7 and expansion sleeves 8 are respectively in the predetermined positions.

[0027] 3. Using a torque wrench, tighten the high-strength bolts 7 gradually in a diagonal and sequential manner. As the high-strength bolts 7 are tightened, the outer ring 3 expands radially, tightly gripping the inner wall of the shaft hole of the rotor 2; at the same time, the limiting member 6 contracts radially, tightly gripping the outer surface of the shaft 1.

[0028] 4. When all the high-strength bolts 7 reach the designed pre-tightening torque, a huge radial clamping force is generated between the inner ring 5 and the shaft 1, between the limiting member 6 and the shaft 1, between the limiting member 6 and the inner ring 5, and between the outer ring 3 and the shaft hole 11 of the rotor 2. The resulting frictional force is sufficient to drive the mixing equipment to operate stably under full load or even impact load.

[0029] When using drive shafts for power transmission in heavy-duty equipment: During operation, the torque output by the motor is transmitted to the rotor 2 via the shaft 1 and the friction of the expansion joint assembly, driving the stirring blades to rotate. When material clumps or foreign objects fall into the mixing tank, causing a sharp increase in stirring resistance, if the load torque exceeds the rated friction torque of the expansion joint assembly, slippage will occur between the expansion sleeve 8 and the shaft / rotor. At this time, power transmission is interrupted, protecting the motor and reducer from burnout or damage due to overload. If the operator discovers that the equipment has stopped or is making abnormal noises, they can stop the machine for cleaning and then retighten the high-strength bolts 7 to resume use. The entire process will not cause structural damage to the equipment.

[0030] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A drive shaft for power transmission in heavy-duty equipment, characterized in that, include: Shaft (1), the shaft (1) is used to connect a power source; Rotor (2), the rotor (2) is a load component to be driven, and the center of the rotor (2) is provided with a shaft hole (11). An expansion joint assembly is disposed between the shaft (1) and the shaft hole (11) of the rotor (2) for keyless connection of the shaft (1) and the rotor (2); The expansion connection assembly includes an inner ring (5), an outer ring (3), and multiple sets of corresponding high-strength bolts (7) and expansion sleeves (8). The expansion sleeves (8) generate radial clamping force between the inner ring (5) and the shaft (1) and between the outer ring (3) and the shaft hole (11) of the rotor (2) through the tensile force of the high-strength bolts (7), thereby transmitting torque by friction.

2. The drive shaft for power transmission in heavy-duty equipment according to claim 1, characterized in that: The outer ring (3) abuts against the inner wall of the shaft hole (11), and a connector (4) is fixedly connected to the inner side of the outer ring (3), and the inner side of the connector (4) is fixedly connected to the outer surface of the inner ring (5).

3. The drive shaft for power transmission in heavy-duty equipment according to claim 1, characterized in that: The inner ring (5) has mounting holes (10) at its top and bottom. The inner sides of the two mounting holes (10) abut against the limiting members (6), and the shaft (1) passes through and abuts against the inner walls of the inner ring (5) and the two limiting members (6).

4. A drive shaft for power transmission in heavy-duty equipment according to claim 3, characterized in that: The corresponding high-strength bolts (7) and expansion sleeves (8) are two sets, which are arranged along the axial direction of the shaft (1) on the side walls of the two limiting members (6). Each set of corresponding high-strength bolts (7) and expansion sleeves (8) are two groups and symmetrically arranged at both ends of the radial length of the limiting member (6).

5. A drive shaft for power transmission in heavy-duty equipment according to claim 4, characterized in that: The side wall of the limiting member (6) has an inner hole (9), the inner wall of the inner hole (9) abuts against the corresponding expansion sleeve (8), and the inner side of the expansion sleeve (8) is threaded with a high-strength bolt (7).

6. A drive shaft for power transmission in heavy-duty equipment according to claim 5, characterized in that: The surfaces in contact between the inner ring (5) and the shaft (1), between the limiting member (6) and the shaft (1), between the limiting member (6) and the inner ring (5), and between the outer ring (3) and the shaft hole (11) of the rotor (2) are provided with anti-slip coatings or are hardened.

Images