Expansion and gear couplings helicopter

These couplings are used to connect shafts with axes and misalignment deformable base. They compensate for small radial, axial, angular or combined misalignment. The reason for the inaccuracy of the displacements may be mounted, the deformation of the attachment units connected in the operation of the helicopter, and in some cases, pre-regulated bias during assembly by helicopter transmission shafts.

Job Expansion joints associated with the cost of power to overcome the forces of friction with the movements of the individual elements relative to each other or to the deformation of the elastic element coupling. The occurrence of the bending moment in the installation site Mizg coupling

Self-couplings: a - free travel; b - centrifugal; 1 - drive sprocket; 2 - rollers; 3 - slave holder; 4 - housing; 5 - friction lining.

reduces resource parts shaft causes vibration transmission between the units. Reduce Mizg can decrease stiffness of joints, the work force of friction clutches, operational skew angle, and rational methods of installation (ie the introduction of the pre-bias in the clutches in the opposite direction of imbalance arising under operational loads).

The longitudinal compression (tension) VT occurs during operation when changing the mounting distance between the connected units and the absence (or not working) node compensates for changes in the length of the shaft (such as "pinching"

movable spline shaft under the action of torque).

The axial force is dangerous at the time of compression - may lose stability and residual deformation of the shaft.

The design of the compensating coupling and its parameters determine the Mach torque, rotational speed and with the necessary

and skew angle. The parameters are determined by the spring type clutches and the selected assumed value misalignment couplings

In VT, the following types of angular and linear compensators:

• - toothed;
• - articulated (cardan) with splined connection;
• - elastic using non-metallic elements (bushings, blocks);
• - elastic using metal elements.

Couplings operate over a wide range of loads, in different

conditions. Note that the positive experience of the couplings a type in certain conditions could give negative results in their operation in other.

Gear couplings

Gear couplings are compact, high-tech, and have stable performance. Their disadvantages include: the need for lubrication and periodic monitoring in operation, an insignificant permissible skew angle. Couplings can transmit M from 800 Nm to 1 • 10 Nm (in fact, Mcr are regulated from 400 Nm to 7000 Nm at n = 3000 rpm).

Managed couplings: a - cam; b - with gear synchronizer; in - friction with electromagnetic control; g - with a mixture of ferromagnetic; d - synchronous electromotive; 1 - half of the coupling; 2 - external teeth; 3 - conical friction surfaces; 4 - mobile ring with internal teeth; 5 - wheel coupling halves; 6 - ferromagnetic mixture; 7 - excitation coil; 8, 9 - magnetic cores coupling halves with separated poles.

Teeth clutches must have a high contact resistance. If you change the skew angle from the 0 ° to 1 ° 30 'bearing stress (7SM increased more than 3 times. Teeth cartridges and holders have the usual involute profile. In order to ensure the strength of the radio tooth cartridges and holders engagement usually corrected. The number of teeth Each crown 30-80 depending on the size.

To be able to compensate for errors in linear and angular position of the shafts should:

• - make the gear connection with a side clearance:
• - grind the bushing blank for cutting teeth on a spherical surface;
• - to give the tooth a barrel-shaped shape.