First, fault phenomenon:
A ZL30E loader often appears out of gear at high and low speeds in the working process, which finally leads to the failure of the whole machine to work and walk, seriously affecting the project progress.
The second, high and low speed shift structure principle:
ZL30 transmission adopts fixed shaft type power shift and mechanical fork structure combined structure, to achieve four forward and two back. Mechanical fork structure is mainly to achieve high and low speed conversion mechanism. Its structure is shown below:
It mainly consists of bracket 1, fork shaft 2, fork 4 and so on. When the loader needs to change the high and low speed, the position of the fork shaft is changed to change the high and low speed meshing sleeve of the fork to achieve the meshing of the gear, and then the on and off of the variable speed control valve is changed to achieve the shift.
Bracket 1 is bolted to the gearbox box. End 2- of the fork shaft is connected to the fork by a set screw 3. Set screws are connected with steel wire to the fork to prevent falling off. The shape of the fork pulling shaft is shown in Figure 2. The steel ball 7 is positioned in the positioning slot of a gear position through the spring 8 and the screw plug 6, and locked in the positioning slot of a certain gear position to achieve the transformation of high and low speed.
The third, fault analysis:
According to the analysis of the structural principle, the causes of high and low speed out of gear fault are as follows:
(1) The slot for the positioning ball at the gear position of the fork shaft is ground flat, so that the steel ball cannot be positioned.
(2) The steel ball is seriously worn.
(3) Spring damage.
(4) The depth of the positioning hole of the locking screw is insufficient, so that the screw cannot lock the fork.
(5) Locking screw slide wire.
Four, troubleshooting
When the whole high and low speed mechanism was removed from the gearbox, it was found that the forks and screws had fallen off and fell into the oil pan of the gearbox, and the screw positioning was seriously worn. Take out the slip wire of the fork and screw to determine the cause of high and low speed dislocating. The cause is that the depth of the positioning hole of the screw is not enough. Remove the fork shaft, drill the positioning hole deep, and replace the screw. Install high and low speed mechanism, debug and restore normal work. The machine has not been out of gear in 1000 hours.