Novel spiral transmission mechanism

Abstract

The invention relates to a novel spiral transmission mechanism which comprises a nut, a fixing sleeve fixedly assembled in the nut, and a screw rod which penetrates through the fixing sleeve and is inrunning fit with the fixing sleeve. A track formed by a plurality of rows of through holes which are distributed at equal intervals along the axial direction and are provided with balls on the fixingsleeve is consistent with a spiral raceway of the screw rod; and when the nut receives external torque, the balls rotating along the spiral raceway along with the fixing sleeve under the constraint of the inner circumferential cylindrical surface of the nut and the spiral raceway of the screw rod provides power for the axial movement of the screw rod. According to the novel spiral transmission mechanism provided by the invention, the movement of the balls along the spiral raceway is not pure sliding friction or pure rolling friction, and the friction property of the balls depends on the roughness of a screw rod raceway, a mounting hole in the fixing sleeve and a cylindrical surface A in the nut. As the surfaces of the balls are smooth, the friction coefficient smaller than the friction coefficient of thread pair transmission can be obtained. Therefore, the transmission efficiency of spiral transmission of the structure is between the transmission efficiency of sliding spiral transmission and the transmission efficiency of rolling spiral transmission.

Description

technical field [0001] The invention belongs to the technical field of mechanical transmission, and in particular relates to a novel screw transmission mechanism. Background technique [0002] The screw drives used in engineering can be divided into sliding screw drive, rolling screw drive and hydrostatic screw drive according to the friction properties. Because the static pressure screw drive needs a set of oil supply system with stable pressure, constant temperature and high filtration requirements, it takes up a lot of space. Due to its large volume, hydrostatic screw drives are generally used in specific occasions that have extremely high requirements for transmission efficiency, and the application range is limited, so it is not considered. [0003] Sliding screw transmission is to use the thread pair (the nut is processed as an internal thread, and the screw is processed as an external thread) as a transmission and load-bearing screw mechanism. It has the advantages of...

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Problems solved by technology

[0003] Sliding screw transmission is to use the thread pair (the nut is processed as an internal thread, and the screw is processed as an external thread) as a transmission and load-bearing screw mechanism. It has the advantages of simple structure and convenient processing, but it needs regular lubrication, and the frictional resistance is large and the transmission efficiency is low. , fast wear

[0004] The rolling screw transmission is also called the ball screw pair. Balls are placed between the screw and the nut. When the screw or the nut rotates, the balls roll along the spiral raceway, so that there is rolling friction between the screw and the nut, which reduces the frictional resistance. The transmission efficiency is improved, but because the ball needs to return the device, the structure of the rolling screw transmission is complicated, the processing is difficult, and the size is large

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