Locking mechanism of rack-and-pinion lifting system

The invention discloses a locking mechanism of a rack-and-pinion lifting system, and belongs to the drilling platforms fitting field; the locking mechanism comprises a mount, two first locking devices, and two second locking devices; the two first locking devices are symmetrically arranged on two sides of a pile leg tooth bar; the two second locking device are symmetrically arranged on two sides of the pile leg tooth bar; each first locking device comprises a first locking oblique piece, a first locking tooth piece, a first horizontal jack and a first vertical oil cylinder; each second locking device comprises a second locking oblique piece, a second locking tooth piece, a second horizontal jack and a second vertical oil cylinder; the second and first locking oblique pieces are same in structure. Two first locking tooth pieces in the locking mechanism bear force through oblique surfaces, and the oblique surfaces can transfer partial load to the horizontal jacks, thus reducing vertical load, so the large power high cost vertical jack in the prior art can be replaced by the small power low cost vertical oil cylinder.