Single Diaphragm Coupling vs. Double Diaphragm Coupling

Advantages of Diaphragm Couplings

Dry coupling, no need for lubrication

The elastic diaphragm coupling relies on the metal diaphragm to transmit the torque and absorb the deformation caused by misalignment. There is no relative movement between the parts and no friction and wear, so there is no need for lubrication, which is in line with the development direction of process equipment without oil. The coupling is a rigid movable coupling. It compensates for the misalignment of the two shafts by the relative slip between the tooth surfaces. Therefore, the coupling needs to be lubricated, and the lubrication conditions determine whether the tooth coupling works well or not. key. It is especially prominent during operation, such as separation and leakage of oil under the action of centrifugal force, as well as the selection of lubricating oil, often because the lubricating design uses the bearing lubricating oil of the connected machine, rather than the bearing capacity of the appropriate bearing capacity. Gear oil. Therefore, the lubrication problem of running gear couplings is particularly prominent. On the other hand, the wear caused by the relative sliding of the tooth surface will cause a series of problems such as sludge and imbalance. Therefore, although gear couplings were once the choice for high-power applications, with the emergence and development of diaphragm couplings, gear couplings have gradually faded out.

The ability to compensate for misalignment is large, and the installation and alignment are convenient

The diaphragm coupling adopts austenitic stainless steel diaphragm, which can withstand large deformation while transmitting torsion, thereby compensating for the misalignment of the two shafts. The non-metallic elastic coupling is restricted by the low strength and easy aging of the non-metallic elastic element, which not only has a short life, but also has a small compensation capacity. The coupling is restricted by the relative slip speed of the tooth surface and the lubrication conditions. According to the data, the relative slip speed of the tooth surface should be no more than 0.12m/s and the angular compensation capability is very small. Therefore, the installation and alignment requirements of non-metallic elastic couplings and gear couplings are relatively good. Once the misalignment exceeds the allowable range, it will cause the failure of the coupling.

All-metal structure, large torque transmission capacity and long service life

Diaphragm coupling uses metal diaphragm as elastic element, which has good strength and large load transmission capacity, and there are no non-metallic parts in the whole product, no aging problem, good service life, and suitable for harsh use environments. This is for non-metal elastic element couplings.

If the axial offset of the two halves of the diaphragm coupling is too large or the deflection angle is too large, it will also cause vibration and abnormal noise when the equipment is running. And make the diaphragm coupling abnormal sound. The connection of the diaphragm coupling is divided into two types: keyed connection and keyless connection. The shaft hole of the diaphragm coupling is divided into two forms: cylindrical shaft hole and tapered shaft hole.

The assembly of the diaphragm coupling is divided into three forms: dynamic press-in method, temperature difference assembly method and static press-in method. The static press-in method of the diaphragm coupling is to use a jack, a clamp, or a manual motor to assemble it according to the required press-in force.

Diaphragm couplings are generally used for tapered shaft bores. Because the static pressure method of the diaphragm coupling is limited by the pressure in use, it is difficult to apply pressure to it when the mechanical quantity is large. It should be pointed out that the static press-in method of the diaphragm coupling may cut off the uneven tiny convex peaks between the diaphragm coupling and the shaft during the press-in process, causing it to be damaged. Therefore, the other two assembly methods for diaphragm couplings are recommended.

The diaphragm coupling compensates the relative displacement of the two shafts connected by the elastic deformation of the diaphragm. It is a high-performance metal flexible coupling with good components. It does not need to be lubricated. It has a compact structure, good durability and long service life. Yes, there is no rotation gap, it is not affected by temperature and oil pollution, and it is not afraid of acid and alkali to prevent corrosion. It is suitable for shafting transmission in high temperature and corrosive medium working conditions.

The allowable speed range of the coupling is determined by the coupling manufacturer through calculation according to the allowable linear speed and outer edge size of different materials of the coupling. Couplings of different materials, varieties and specifications have different allowable speed ranges. Changing the material of the coupling can increase the allowable speed range of the coupling. The allowable speed of steel is greater than the allowable speed of cast iron. The bearing capacity of the elastic coupling with metal elastic elements is higher than that of the elastic coupling with non-metal elastic elements;

The difference between single-diaphragm coupling and double-diaphragm coupling

• Diaphragm couplings are often used in servo systems. The diaphragms of diaphragm couplings have good torque rigidity, but diaphragm couplings are slightly inferior to bellows couplings.
• The difference between the single-diaphragm coupling and the double-diaphragm coupling is the ability to handle various deviations. In view of the fact that the diaphragm coupling requires complex bending of the diaphragm, the single-diaphragm coupling Not very comfortable with eccentricity. The double-diaphragm coupling can be bent in different directions at the same time to compensate for eccentricity. Valve inlet pump.
• The characteristics of the diaphragm coupling are a bit like the bellows coupling. In fact, the way the diaphragm coupling transmits torque is similar. The diaphragm of the diaphragm coupling itself is very thin, so it is easy to bend when relative displacement loads occur, so the diaphragm coupling can withstand up to 1.5 degrees of deviation, while producing low bearing loads in the servo system.
• The diaphragm coupling consists of at least one diaphragm and two shaft sleeves. The diaphragm of the diaphragm coupling is pinned to the shaft sleeve generally without loosening or causing backlash between the diaphragm and the shaft sleeve. Some manufacturers offer two-diaphragm couplings, while others offer three-diaphragm couplings with one or two rigid elements in the middle, which are then attached to the bushing on both sides.
• On the other hand, the diaphragm coupling is very delicate and can be easily damaged if it is misused in use or not installed correctly. Therefore, it is very necessary to ensure that the deviation is within the bearing range of the normal operation of the diaphragm coupling.

The diaphragm coupling consists of at least one diaphragm and two shaft sleeves. The difference between the single-diaphragm coupling and the double-diaphragm coupling is the ability to handle various deviations, which requires the diaphragm to bend, so the single-diaphragm coupling is not suitable for eccentricity. The double-diaphragm coupling can be bent in different directions at the same time to compensate for eccentricity. ATO offers single diaphragm coupling or double diaphragm coupling, and the bore size can be 12mm to 25mm, 6mm to 14mm, or 12mm to 22mm.