Hydraulic speed changing box and parking braking device thereof

Abstract

The invention relates to the field of vehicle transmission, in particular to a hydraulic speed changing box and a parking braking device thereof. The parking braking device comprises a braking shaft positioned in a speed changing box shell through a bearing and a brake cover connected to the speed changing box shell. The speed changing box shell and the braking shaft are connected through an inner-outer friction plate pair. The inner end of the brake cover is connected with a hydraulic drive assembly. The output end of the hydraulic drive assembly can move in the axial direction of the brakingshaft and acts on the inner-outer friction plate pair. The scheme has the advantages that on one hand, the speed changing box shell and the braking shaft are directly connected through the inner-outer friction plate pair, a multi-shell connecting structure is replaced, and accordingly, the self-strength and connecting strength of shells and end covers do not need to be worried; and on the other hand, a braking clutch part of the parking braking device is completely located on the speed changing box shell, a lubricating system in the speed changing box shell can be shared, and the problem about sealing performance of connecting parts of the multiple shells and the end covers does not need to be worried.

Description

technical field [0001] The invention relates to the field of vehicle transmission, in particular to a hydraulic gearbox and a parking brake device thereof. Background technique [0002] Internal combustion forklifts are used in a wide variety of applications in the material handling industry. The gearboxes for internal combustion forklifts include common mechanical gearboxes and hydraulic gearboxes. Since the hydraulic transmission transmits energy through the hydraulic medium (transmission oil), compared with the mechanical transmission, it has the advantages of smooth transmission, low noise, and comfortable operation, so it has been widely used. The driving and parking brakes of the current hydraulic transmission are all integrated brakes, some of which use external accumulator independent control to achieve parking, and some use internal dual-piston split control to achieve parking, but they all belong to hub brakes form. When the hydraulic system or a single brake br...

AI Technical Summary

Problems solved by technology

The disadvantage of the above scheme is that in the normally closed wet parking brake, the left and right end covers are respectively connected to both ends of the static housing, and the left end cover is also connected to the gearbox housing through bolts. Braking is achieved, but the left and right end covers and the static shell are used, the structure is complex and the strength and connection strength of the left and right end covers and the static shell need to be ensured to meet the braking strength requirements

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