Shaft support block is a key component used to fix and support shaft parts in mechanical transmission system, and its core purpose is to ensure the stability and positioning accuracy of the shaft in rotary or linear motion, and to withstand the loads transmitted by the shaft (such as radial force, axial force, or composite force), and the specific functions can be described in detail from the following scenarios:
I. Fixing the position of the shaft and restricting unnecessary displacement
The shaft needs to move along a predetermined trajectory (rotating or moving in a straight line) in a mechanical system (e.g., motor shaft, screw shaft, conveyor belt roller shaft, etc.), and the shaft support block strictly restricts the displacement of the shaft in the non-operating direction through the cooperation with the shaft:
Radial positioning: Prevents the shaft from wobbling in the direction perpendicular to the axis (radial). For example, the ball screw shaft of a CNC machine tool is fixed by the support blocks at both ends to ensure that the nut will not be offset due to radial runout when the screw is rotating, thus ensuring the positioning accuracy of the table (error ≤ 0.01mm);
Axial limitation: Some of the support blocks are designed with axial blocking shoulders or locking structures, which can limit the runout of the shaft along the axial direction. For example, the support blocks at both ends of the active roller shaft of the conveying equipment are fixed by bearing end caps to prevent the roller shaft from running away from the conveyor belt due to axial displacement during high-speed rotation.
Second, bear the load, protect the shaft and related components
Shaft will be subjected to a variety of forces when working (such as radial force generated by gear meshing, axial thrust of the screw drive, bending moment generated by the self-weight of the equipment, etc.), the shaft support block through its own structure and the internal bearings (if integrated bearings) will be transferred to the equipment frame, to avoid bending, deformation or fracture of the shaft due to excessive force:
Radial force bearing: For example, the transmission shaft in a gearbox is fixed by the support block, the radial force generated when the gears mesh (up to thousands of Nm) is borne by the rolling bearings inside the support block, and then transmitted to the box through the body of the support block to protect the middle section of the shaft from excessive bending moments;
Axial force bearing: for the scene with axial force (such as screw-driven table), the support block can be matched with thrust bearing to transfer the reaction force (axial force) of the table to the frame, preventing the screw from tampering or being damaged due to excessive axial force.
Third, reduce friction to ensure smooth movement of the shaft
Most shaft support blocks will be integrated with bearings (such as deep groove ball bearings, needle roller bearings, plain bearings, etc.), through the rolling or sliding fit between the bearings and the shaft, the frictional resistance of the shaft movement is greatly reduced:
Scenario for rotating shafts: The rolling bearing in the support block converts the sliding friction of the shaft into rolling friction (the coefficient of friction is reduced from 0.1 to 0.001-0.005), which reduces the wear of the shaft and the consumption of drive power. For example, the support block of the motor output shaft is supported by bearings, which enables the motor to maintain low noise and heat generation even when rotating at high speeds (3000r/min);
Linear Shaft Scenario: Some of the support blocks are used to support shafts in linear motion (e.g., optical shafts), and the internal structure of linear bearings or slides allows the shafts to slide smoothly along the direction of the shaft line (e.g., the support block of the piston rod of the pneumatic actuator ensures that there is no snag when the actuator is telescoped).
Simplify the assembly process and reduce maintenance costs
The shaft support block adopts a standardized modular design, which can greatly simplify the assembly and maintenance process of the mechanical system:
High-efficiency assembly: the support block can be quickly docked with the frame through the preset bolt holes, and the shaft parts can be directly embedded into the bearing holes of the block, and can be fixed without the need for complicated adjustment, so that it can be fixed without the need for complicated adjustment, and can be fixed without the need for complicated adjustment. It can be fixed without complicated alignment adjustment or secondary processing. For example, when assembling a guide shaft for an automated production line, only the shaft body needs to be inserted into the bearing holes of the support block and locked, which improves the assembly efficiency by more than 50% compared with the traditional welded fixing or one-piece casting structure, and avoids the deformation of the shaft system caused by welding stress.
Convenient Maintenance: When the shaft or bearing is worn out or has abnormal noise, there is no need to dismantle the whole equipment, just loosen the fixing bolts of the support block, and then the parts can be taken out for replacement or overhauling. Take the roller shaft of the conveying equipment as an example, if abnormal noise occurs in the area of the support block, the corresponding support block can be directly removed to replace the internal bearing, which reduces the maintenance time of a single part to 1/3 of the traditional way, significantly reduces the downtime of the equipment, and reduces the loss caused by the interruption of production.
Five, adapting to the special needs of different scenes
According to the differences in the application environment, the shaft support block can meet the special requirements through the material and structural design:
Adaptation to harsh environments: In dust-intensive, humid or corrosive media scenes (such as the cleaning equipment in the food processing plant, the stirring shaft of the chemical reaction kettle), the shaft support block needs to be made of corrosion-resistant materials (e.g., 304 stainless steel) and achieve full-seal design by sealing ring, The shaft support block should be made of corrosion-resistant material (e.g. 304 stainless steel), and the sealing ring, dust cover and other structures can realize the full sealing design, which can block the contact of water vapor and dust with the internal bearings from the source, avoiding the stagnation or failure caused by corrosion and significantly prolonging the maintenance cycle.
Adaptation to lightweight requirements: For weight-sensitive equipment such as drones and small robots, the support blocks are mostly made of high-strength aluminum alloy (such as 6061-T6). By optimizing the structural wall thickness (thickening in stress-concentrated areas and thinning in non-stressed areas), the weight of the blocks is reduced by more than 40% compared with the traditional steel blocks under the premise of meeting the support strength, which indirectly improves the endurance or movement flexibility of the equipment.
Summary
The core function of the shaft support block can be summarized as **"three-dimensional positioning, load buffer, friction optimization "**: it ensures the stability of the motion trajectory by accurately restraining the spatial position of the shaft; through the structured force transfer path, the composite load on the bearing is dispersed to the frame to avoid local stress overload; at the same time, with the help of the bearing, the composite load on the bearing is dispersed to the frame to avoid local stress overload. stress overload; at the same time with the help of bearing integration design to reduce friction loss. As the key node of "static and dynamic connection" in the mechanical system, its performance directly determines the operating accuracy, structural reliability and service life of the equipment, and is an indispensable functional component from basic machinery to precision equipment.
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