Arbre central inférieur droit de sous-boîte: Déconstruction 4 Pièces critiques pour un entraînement de prise de force impeccable

Bienvenue dans cette déconstruction en profondeur du Arbre central inférieur droit de sous-boîte, a foundational component for the CA10TA160M 10-speed transmission in the FAW Jiefang CA3250P66K2L1T1E 6×4 tombereau. Ce guide est destiné aux techniciens, analyser le 4 critical parts that form the complete Arbre central inférieur droit de sous-boîte assemblée, which is essential for the auxiliary box’s “range-split” fonction.

Le Arbre central inférieur droit de sous-boîte is a high-torque countershaft for the auxiliary (Salut/Lo) boîte de vitesse. Its logic is to receive power from the main box and transmit it to the final output gears. This specific component also includes the provision “avec prise de force,” making it a critical link for powering auxiliary equipment like hydraulic pumps.

Cœur 1: Le “Arbre & PTO Drive” Logique (The Core Assembly)

This component is the literal foundation of the Arbre central inférieur droit de sous-boîte assemblée. C'est un seul, integrated part that provides the “conduire” for the auxiliary gearbox and, crucialement, the Power Take-Off.

1. Composant: ‘Welded intermediate shaft assy – boîte auxiliaire’ (1701515AA1K)
Ce (Comp 4) est le composant central. The name ‘Welded intermediate shaft assy’ (焊接中间轴总成) confirms it is a non-serviceable assembly. C'est le Arbre central inférieur droit de sous-boîte lui-même, and its gears are permanently welded to the shaft for maximum strength.

Le Welded Logic is a design choice for extreme strength. Instead of using splines or keys that can shear under the immense, multiplied torque of the low-range gears, the manufacturer has welded the gear(s) directly to the shaft. This creates a single, solid piece of steel that can withstand the brutal forces of a fully-loaded dump truck. This is a hallmark of the Arbre central inférieur droit de sous-boîte.

Le Logique de l'arbre intermédiaire est sa fonction. Ce Arbre central inférieur droit de sous-boîte agit comme le “countershaft” ou “layshaft” for the auxiliary gearbox. It is part of a “à double arbre intermédiaire” système (avec le “Supérieur gauche” arbre), which splits the power from the main box. This load-sharing is what gives the transmission its high torque rating.

Le Logique de prise de force is the distinguishing feature of this specific Arbre central inférieur droit de sous-boîte. La remarque “(Avec prise de force)” means “with Power Take-Off.” This implies that one of the welded gears on this shaft (Comp 4) est le principal “pignon d'entraînement” for the truck’s PTO.

C'est critique: when the driver engages the PTO to run the hydraulic dump body, the PTO’s idler gear meshes with this specific gear on the Arbre central inférieur droit de sous-boîte. This allows the truck to be stationary (au neutre) while the clutch is engaged, spinning this shaft to power the hydraulic pump. The strength of this assembly is paramount.

Cœur 2: Le “Palier & Soutien” Logique (Le système de montage)

This group represents the complete bearing assembly that supports the Arbre central inférieur droit de sous-boîte. A high-load shaft like this, especially one driving a PTO, requires a bearing system that can handle massive, multi-directional forces.

1. Composant: ‘Tapered roller bearing outer ring’ (306/42-1-1) – Quantité 2
Ce (Comp 1) est le “tasse” ou “outer race” of the bearing. Deux d'entre eux sont utilisés, one for the front bearing and one for the rear. This cup is precision-machined and is pressed *into the bore* of the auxiliary gearbox housing, where it remains stationary. This is a high-wear part in the Arbre central inférieur droit de sous-boîte système.

2. Composant: ‘Tapered roller bearing inner ring’ (306/42-1-2) – Quantité 2
Ce (Comp 2) est le “cône” ou “inner ring” of the bearing, which includes the tapered rollers in their cage. This cone is pressed *onto the journals* (fin) de la Arbre central inférieur droit de sous-boîte (Comp 4) and spins with it.

Le Logique du rouleau conique is the most important concept for this Arbre central inférieur droit de sous-boîte. Unlike a simple ball bearing, a tapered roller bearing is specifically designed to handle *both* massive radial loads (le “pousser” force provenant de l'engrenage) and massive *axial* loads (le “poussée” force generated by helical-cut gears) *at the same time*.

Le Opposed Mounting Logic is how they work. The two tapered bearings (Comp 1 + Comp 2) are mounted in “opposition” at the front and rear of the Arbre central inférieur droit de sous-boîte. This creates an extremely rigid assembly that can support the shaft against thrust forces in *both* directions (avant et arrière), ensuring perfect gear mesh alignment under all load conditions, which is critical when the PTO is engaged.

Le Logique de service is why they are listed as separate inner and outer rings. Ils sont un “matched set” and must be replaced as one. A technician presses the outer rings into the housing and the inner rings onto the Arbre central inférieur droit de sous-boîte before final assembly.

Cœur 3: Le “Pre-load & Positionnement” Logique (The Shim)

This final component is one of the most critical parts of the entire Arbre central inférieur droit de sous-boîte assemblée. It is a single washer that ensures the longevity of the expensive bearings and shaft.

1. Composant: ‘Positioning washer’ (1701518-A7G)
Ce (Comp 3) is the ‘Positioning washer’. In a tapered roller bearing application, this is not a simple washer; c'est un “cale” ou “gasket-shim.” Its thickness is precisely controlled, and its function is to set the “bearing pre-load.”

Le Logique de préchargement is a high-precision assembly task. Tapered roller bearings cannot be “lâche” (with end play), nor can they be “too tight.” They require a specific, slight amount of “presser” ou “pré-chargement” to function correctly and maximize their lifespan.

During assembly of the Arbre central inférieur droit de sous-boîte, a technician installs the components and measures the “terminer la lecture” (the in-and-out movement) avec un indicateur à cadran. They then select a ‘Positioning washer’ (Comp 3) of the *exact* thickness required to eliminate that end play and add the correct, specified pre-load (Par exemple, 0.05mm).

This washer is often placed between a bearing’s outer ring (Comp 1) and the housing or bearing cover. Its thickness is the only thing that guarantees the correct pre-load for the bearings supporting the Arbre central inférieur droit de sous-boîte.

UN Arbre central inférieur droit de sous-boîte with incorrect pre-load (Par exemple, a shim that is too thick or too thin) will suffer catastrophic bearing failure in a very short time. Too tight, and the bearings will overheat and seize. Too loose, and the shaft will “marcher” axialement, causing the gear teeth to misalign and destroying both the shaft (Comp 4) and the gears it meshes with. Donc, this ‘Positioning washer’ (Comp 3) est une critique, non-negotiable component for a successful gearbox rebuild.

Arbre central inférieur droit de sous-boîte: Répartition complète en 4 parties

Le tableau suivant fournit l'intégralité, ventilation détaillée de tous 4 types de composants dans le Arbre central inférieur droit de sous-boîte assemblage pour le FAW Jiefang CA3250P66K2L1T1E 6×4 tombereau.

Spécifications de base

Les spécifications pour le Arbre central inférieur droit de sous-boîte are defined by its role as a high-load, high-precision countershaft for the auxiliary gearbox, specifically featuring a PTO drive.