Sliding bearing type electric main shaft

Abstract

A slide bearing type electric mainshaft is composed of mainshaft, rotor and stator of motor, front and back slide bearings, and casing. It is used for high-speed precise machine tool.

Description

technical field [0001] The invention belongs to the field of mechanical manufacturing, and in particular relates to a structural improvement of a high-speed precision electric spindle. Background technique [0002] High-speed machining, which is characterized by high cutting speed, high feed speed, and high machining accuracy, is one of the four contemporary advanced manufacturing technologies, and it is a high-tech that makes the second revolutionary leap in manufacturing technology after numerical control technology. It not only has extremely high productivity, but also can significantly improve the machining accuracy and surface quality of parts. As the core functional component of high-speed CNC machine tools, the high-speed precision electric spindle directly affects the overall development level of high-speed machine tools. [0003] The high-speed precision electric spindle is a high-tech product with a high degree of mechatronics that directly depends on bearing tech...

AI Technical Summary

Problems solved by technology

Rolling bearings are the main supporting structure of machine tool spindles at present. They have the advantages of high speed, simple structure, mass production, and can be replaced as a whole during maintenance. , there are inevitably friction wear and fatigue wear, and the service life is short. After working for a period of time, the main shaft must be disassembled for maintenance; More time and cost, reducing the production efficiency of the machine tool

Second, because the rolling bearing relies on the rigid contact of a limited number of rolling elements to provide bearing capacity, the stress in the place where the inner and outer raceways of the bearing are in contact with the balls is very high, while the stress in the place where there is no contact is small, and there must be deformation in the circumferential direction Inhomogeneity

However, liquid sliding bearings have disadvantages such as high friction loss of liquid medium and high bearing temperature, which lead to low operating speed of machine tool spindles supported by liquid sliding bearings.

At the same time, due to the interference connection between the front and rear bearings of the main shaft using liquid sliding bearings and the main shaft housing, two unfavorable situations often occur: 1. If the bearing is installed first and then the stator of the motor is installed, due to the radial direction of the outer circle of the motor stator The size is larger than the size of the inner hole of the bearing. The motor stator cannot be directly installed between the two bearings. It can only be placed at the rear of the main shaft outside the two bearings. Rigidity becomes worse; 2. If the motor stator is to be installed between the two bearings, the motor stator must be installed in the housing first, and then the rear bearing should be installed in the rear of the housing. When the motor stator needs to be repaired and replaced, it must be The motor stator can only be taken out by taking out the rear bearing which is interference-connected with the casing first. Since the interference connection between the motor stator and the casing is usually a "locked" structure that will not be disassembled, it is very difficult to disassemble

[0006] Due to the above defects, the electric spindle supported by liquid sliding bearing has not been fully applied in machine tools at present, and the mass production of sliding bearing electric spindle as a unit functional part has not been realized.

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