CENTAFLEX – Miki Pulley

List of Products

Applications

FAQ

	CF-A Models Power is transmitted by highly elastic rubber.Rubber is excellent at absorbing vibration and shock and also reduces machinery noise. The rubber components of the elastic body are constructed of polygonal rubber with aluminum inserts inserted into their tips. Each is formed by rigid vulcanizing adhesion. These rubber bodies are coupled by bolts in the radial and axial directions of the cylindrical hub and flange hub so that power is transmitted via the rubber body. The bolt coupling in the radial direction is particular has a pre-compressed construction and enables power transmission that is excellent in flexibility and absorption of vibration and shock. Basic Specifications Max. nominal torque : 5000 N･m Pilot-bore additional processing range : 9 mm to 130 mm Operating temperature : -30^o to 95_o
	CF-H Models Motive power is transmitted by polyester resin that has the elastic force of rubber.These models boast excellent vibration and shock absorption while achieving resistance to heat, cold and oil not shown by natural rubber. They can also easily engage or isolate input/output simply by moving in the axial direction, facilitating maintenance. Basic Specifications Max. nominal torque : 2500 N･m Pilot-bore additional processing range : 13 mm to 120 mm Operating temperature : -40^o to 120_o
	CF-X Models These models use high-quality nylon resin for the buffer material. This construction and element material mean they are rigid in the torsion direction, have excellent flexibility in the bending and axial direction, and have no backlash. They absorb vibration and shock while delivering accurate power transmission. These models have a simple construction comprised of element (buffer material), cylinder hub, flange hub, and a bolt for locking the element in place. Basic Specifications Max. nominal torque : 370 N･m Pilot-bore additional processing range : 9 mm to 65 mm Operating temperature : -30^o to 90_o
	CF-B Models Since a highly elastic resin (polyurethane/polyester) is used as the buffer material of the element, vibration and shock absorption during power transmission is excellent and noise is also reduced.The construction is a compact and simple design that sandwiches the element between two hubs, so mounting and removal is easy, facilitating maintenance of the device as a whole. Basic Specifications Max. nominal torque : 1400 N･m Pilot-bore additional processing range : 10 mm to 80 mm Operating temperature : -40_o to 80_o/CF-B, -40_o to 120_o/CF-B H
	CM Models These are couplings for engines that transmit power using highly elastic rubber and are excellent at absorbing vibration and shock. They are very soft in the bending direction, and are able to escape the resonance point caused by torsional vibration at or below engine low idle.Being short in the axial direction, they do not require space and can easily engage or isolate input/output simply by moving in the axial direction, facilitating maintenance. Basic Specifications Max. nominal torque : 18000 N･m Pilot-bore additional processing range : 11 mm to 180 mm Operating temperature : -30_o to 90_o

Q : There is resonance occurring in devices run using diesel engines. Is there anyway to prevent this from happening?

A : Resonance occurs in systems driven using diesel engines when the frequency of vibration matches the natural frequency of vibration of the torque transmission system overall along the direction of rotation due to the speed of rotation of the engine. The engine coupling works not only to transmit rotation and absorb vibration but also to bleed off the resonant rotation speed. For this reason, when there is resonant rotation present, changing the torsional stiffness of the coupling (by changing the type of coupling used, hardness of the rubber, etc.) enables the resonant rotation speed to be shifted from the rotation speed used. In models with low torsional stiffness that use natural rubber elements such as the CF-A and CM models, resonant rotation is more likely to occur at speeds lower than low idling speeds, while in models with high torsional stiffness such as CF-H models, it is more likely to occur at speeds higher than the high-idling speed.

Q : What does "Pre-compressed construction" refer to for the CF-A models?

A : Rubber has been shown to exhibit longer life if used while compressed rather than stretched. In particular, it has been found that even with compressed rubber in general, rubber that is first compressed to a certain degree before a force is applied has a longer life than other types of compressed rubber. This type of compression in which the rubber is compressed to a certain degree is referred to as pre-compression. CF-A models are assembled with rubber parts pre-compressed. The compressed parts have a long parts life and even sections with stretching rubber parts fail to stretch until a specified torque or higher is applied.

Q : Effects of heat on rubber couplings and coupling maintenance

A : When heat is applied to natural rubber, the oils on the surface of the rubber break down, which causes the rubber to lose elasticity and become hard. Although the rate and degree at which the rubber hardens varies according to the temperature, if heat is applied to a CF-A model part used within the engine housing, the surface rubber hardens. If torque is then applied to the affected section, cracks will begin to form in the hardened layer, causing the surface to break down. As part of maintenance guidelines, it is recommended that you change the rubber if the hardness increases by around 15 increments on the HS hardness scale compared to the hardness from before use.

Q : What is CENTA-LOCK?

A : When the hub is attached to the shaft, it can be attached using a CENTA-LOCK mechanism. Using a clamping screw to secure the parts in place causes the spline on the clamping hub to become warped, causing the spline on the shaft to be pushed up against it to ensure that the hub and spline shaft are securely fixed in place. Although it varies depending on the size used, if the clamping screw is screwed in at the specified torque, a retaining force equal to around 1 ton per clamping screw is produced along the shaft direction. This retaining force ensures that under normal conditions the parts are securely fastened in place at an adequate level.

Highly flexible elastic couplings

CF-A Models

CF-H Models

CF-X Models

CF-B Models

CM Models