German SIT coupling SIT model SIT price

SIT coupling is a torsionally rigid coupling. It has no backlash even under load, and rigidly transmits torque even when misalignment generates loads. Lightweight, ultra-low inertia, and high sensitivity. Maintenance-free, with excellent oil resistance and corrosion resistance. Made of aluminum alloy and stainless steel. Available in set screw, clamping, and split types. Models with different bore sizes at both ends are also in stock.

SIT coupling structure

Consists of two hubs and a center slider. The center slider, acting as a torque transmission element, is typically made of engineering plastic; in special cases, other materials such as metal can be selected. The center slider is connected to the hubs on both sides via slots distributed at 90° relative positions, thereby achieving torque transmission. A slight pressure fit between the center slider and the hubs ensures zero-backlash operation during equipment running. Over time, the slider may lose its backlash-free function due to wear, but the center slider is inexpensive and easy to replace, restoring original performance after replacement. Slider couplings are commonly used with general-purpose motors and, in some cases, to connect servo motors, correcting relative displacement through the sliding of the center slider. Since the half-couplings and the intermediate disc form a sliding pair and cannot rotate relative to each other, the angular velocity of the driving shaft must equal that of the driven shaft. However, when operating with relative displacement between the two shafts, the intermediate disc generates significant centrifugal force, increasing dynamic loads and wear. Therefore, care must be taken during selection to ensure the operating speed does not exceed the specified value. This type of coupling is generally used for speeds n<250r/min, where shaft stiffness is high and there are no severe impacts.

SIT coupling features

The material for slider coupling parts can be 45 steel, with heat treatment required on the working surfaces to increase hardness; for lower requirements, Q275 steel can be used without heat treatment. To reduce friction and wear, lubricate by injecting oil through the oil hole in the intermediate disc during use. Since the half-couplings and the intermediate disc form a sliding pair and cannot rotate relative to each other, the angular velocity of the driving shaft must equal that of the driven shaft. However, when operating with relative displacement between the two shafts, the intermediate disc generates significant centrifugal force, increasing dynamic loads and wear. Therefore, care must be taken during selection to ensure the operating speed does not exceed the specified value. This type of coupling is generally used for speeds n<250r/min, where shaft stiffness is high and there are no severe impacts. A slight pressure fit between the center slider and the hubs ensures zero-backlash operation during equipment running. Over time, the slider may lose its backlash-free function due to wear, but the center slider is inexpensive and easy to replace, restoring original performance after replacement. Slider couplings are commonly used with general-purpose motors and, in some cases, to connect servo motors, correcting relative displacement through the sliding of the center slider. Since resistance to relative displacement comes from the friction between the slider and the hubs, the bearing load does not increase with greater relative displacement. Slider couplings can eliminate additional loads between shafts during automatic motor control. The fixed body uses internal splines for sliding, while the sliding body's inner and outer sleeves can slide relatively in the axial direction. This coupling integrates sliding and rotation. For the same outer diameter, its shortest dimension is far smaller than that of a cross-axis coupling. It improves the uniformity of load distribution on the working surface and can transmit higher torque, though elasticity is slightly reduced.

SIT coupling applications

Unlike other couplings, the slider coupling has no elastic elements that work like springs, so bearing loads do not increase with greater relative displacement between shafts. In any case, this series of couplings offers good value for money, and the ability to choose sliders of different materials is its greatest advantage. Juren Company can provide a variety of raw material options for center sliders to suit different applications based on specific customer requirements. Generally, one type of material is suitable for zero-backlash, high-torque rigidity, and high-torque conditions, while another type is suitable for low-precision positioning where zero-backlash is not required, but vibration absorption and noise reduction are needed. Non-metallic sliders also provide excellent electrical insulation and can act as mechanical fuses. When the engineering plastic slider is damaged, torque transmission is completely terminated, thereby protecting expensive mechanical parts. This design is suitable for large parallel relative displacements. The three-part split design of the slider coupling limits its ability to compensate for axial misalignment, so it cannot be used in push-pull applications. Additionally, since the center slider is floating, the motion of the two shafts must ensure that the slider does not disengage.

Weidou Intelligent Technology specializes in selling German SIT rigid couplings, SIT flexible couplings, SIT safety couplings, SIT universal joints, SIT disc couplings, SIT jaw couplings, SIT flange couplings, SIT cross-slide couplings, SIT slider couplings, SIT gear couplings, SIT tire couplings, SIT elastic couplings, SIT bellows couplings, SIT roller chain couplings, SIT spring couplings, SIT original German imports. Welcome inquiries and orders from customers.