Definition
Coupling refers to a device that connects two shafts or shafts and a rotating member, which rotates together during the transmission of motion and power, and does not disengage under normal conditions. Sometimes used as a safety device to prevent the connected parts from being subjected to excessive loads and to protect against overload.
Classifications
Couplings can be divided into two types: rigid couplings and flexible couplings.
The rigid coupling does not have the cushioning ability and the ability to compensate the relative displacement of the two axes. It requires two axes to be strictly centered, but the coupling has a simple structure, low manufacturing cost, and assembly and disassembly. It is easy to maintain and can ensure high alignment of the two shafts, large transmission torque and wide application. Commonly used are flange couplings, sleeve couplings and clamp couplings.
The flexible coupling can be further divided into an inelastic flexible coupling and a flexible coupling with elastic components. The former type only has the ability to compensate the relative displacement of the two axes, but can not buffer the vibration, and the common one is slippery. Block couplings, gear couplings, universal couplings and chain couplings; the latter category contains elastic elements, in addition to the ability to compensate the relative displacement of the two axes, it also has a buffering and damping effect, But the transmitted torque is affected by
The strength of the elastic element is generally limited to that of the non-elastic element flexible coupling, the common elastic sleeve pin coupling, the elastic pin coupling, the plum-shaped coupling, the tire coupling, the serpentine spring Couplings and reed couplings, etc.
Performance requirements
According to different working conditions, the coupling needs to have the following performance:
(1) Mobility. The transferability of the coupling refers to the ability to compensate for the relative displacement of the two rotating members. Factors such as manufacturing and installation errors between connected components, temperature changes during operation, and load deformation are all required for mobility. The movable performance compensates or mitigates additional loads between the shaft, bearings, couplings, and other components due to relative displacement between the rotating members.
(2) Buffering. For frequent load starting or working load changes, the coupling needs to have a damping and damping elastic element to protect the prime mover and the working machine from being damaged or damaged.
(3) Safe, reliable, with sufficient strength and service life.
(4) The structure is simple, easy to assemble, disassemble and maintain.
Selection
When selecting a coupling type for a coupling type, the following items should be considered.
1 The magnitude and nature of the required transmitted torque, the requirements for buffering and damping functions, and whether resonance may occur.
2 The degree of relative displacement of the two axis axes caused by manufacturing and assembly errors, shaft loading and thermal expansion deformation, and relative motion between components.
3 Applicable dimensions and installation methods, in order to facilitate the assembly, adjustment and maintenance of the necessary operating space. For large couplings, it should be possible to disassemble the shaft without axial movement.
In addition, consideration should be given to the working environment, service life, and lubrication, sealing, and economic conditions. Refer to the various coupling characteristics and choose a suitable coupling type.
