PGH Series Planetary Gearbox

A planetary gear transmission is a transmission that uses a planetary gear mechanism to achieve speed change. It is usually installed behind the torque converter to form a hydraulic automatic transmission.

Description

A Planetary Gearbox Is Also Called a Planetary Gear Transmission.

A planetary gear transmission is a transmission that uses a planetary gear mechanism to achieve speed change. It is usually installed behind the torque converter to form a hydraulic automatic transmission. Planetary gears get their name from their resemblance to the solar system. At its center is the sun wheel. Around the sun gear, there are several planet wheels that revolve around it. There is a shared planet carrier between the planet wheels. There is a large ring gear on the outer side of the planetary gear.

A planetary gearbox is a type of gearbox. It consists of planetary gears, sun gears, planetary gears (also known as satellite gears), and gear shafts. According to the motion relationship of the ring gear, the sun gear, and the planetary gear, the input shaft and the output shaft can be separated from the rigid transmission relationship, and the input shaft and the output shaft can be driven in the same direction or in the same direction. In the opposite direction, the transmission ratio of the input and output shafts changes. Widely used in land, sea, aviation, and other transportation vehicles.

In this way, the planetary gearbox has three moving parts that can rotate relative to each other: the sun gear, the planet carrier and the ring gear. It can achieve four different gear combinations:

① The low gear sun gear is active, the planetary carrier is passive, and the ring gear does not move.
② The sun gear of the intermediate gear does not move, the planet carrier is passive, and the ring gear is active.
③High gear (overdrive gear), the sun gear does not move, the planetary carrier is active, and the ring gear is passive.
④ The reverse sun gear is active, the planetary carrier is stationary, and the ring gear is passive.

The transmission is neutral when all moving parts are free.

The planetary gear transmission usually consists of two to three sets of planetary gear mechanisms, and the combination of the above-mentioned moving parts is controlled by a multi-plate clutch to achieve different gear positions.

Classification

1. According to the change mode of the transmission ratio, the transmission can be divided into three types: stepped type, step-less type, and integrated type.

(a) Stepped transmission: There are a variety of optional fixed transmission ratios and gear transmissions. It can be divided into two types: ordinary gear transmission with fixed gear shaft and planetary gear transmission with partial gear (planetary gear) shaft rotation.
(b) Continuously variable transmission: The transmission ratio can be continuously changed within a certain range, and the common ones are hydraulic, mechanical, and electric.
(c) Integral transmission: It is composed of stepped transmission and stepless transmission, and its transmission ratio can be continuously changed within several ranges between the maximum value and the minimum value.

2. According to the operation mode, the transmission device can be divided into three types: forced operation, automatic operation, and semi-automatic operation.

(a) Forced-operated transmission: The driver directly manipulates the gear lever to change gears.
(b) Automatically operated transmission: Selection of gear ratios and shifting are performed automatically. The driver only needs to operate the accelerator pedal, and the transmission can control the actuator according to the load signal of the engine and the vehicle speed signal to realize the gear shift.
(c) Semi-automatic gearbox: It can be divided into two types, one is automatic shifting of some gears, and manual (forced) shifting of some gears; the other is to select gears in advance with buttons and use clutches. When the pedal or accelerator pedal is released, the actuator shifts gears by itself

Transmission Shaft

During the operation of the transmission, each bearing is subjected to changing torque and bending moment, and the tooth part is also subjected to loads such as extrusion, impact, and sliding friction. Common damage to each axis are:

(1) Journal wear Excessive journal wear will not only cause the gear axis to shift but also change the gear meshing clearance, causing noise during transmission. At the same time, the matching relationship between the journal and the bearing is destroyed, and it may not be able to run. cause ablation. Therefore, it is required that the journal wear amount of the interference fit of the roller bearing should not be greater than 0.02mm. The journal wear of needle roller bearing accessories should not exceed 0.07mm, otherwise, it needs to be replaced or repaired by chrome plating.

(2) The stressed side of healthy teeth is more severely worn. Check with a splined socket. When the wear of the key teeth exceeds 0.25mm or the original keyway exceeds 0.40mm, the meshing ring gear of the gear is combined with the sleeve. When the circumference of the healthy tooth is greater than 0.30mm, the half-round key and journal keyway when the training exceeds 0.08mm, the circumference of the healthy tooth or the shaft with the keyway should be repaired or replaced.

(3) Driveshaft bending maintenance Use the thimble pin to withstand the thimble holes at both ends of the drive shaft and check the radial runout of the shaft with a dial gauge. The deviation should be less than 0.10mm. Pressure correction and repair should be carried out when it is exceeded.

 

Synchronizer

a. Overhaul of lock ring inertia synchronizer: lock ring cone angle a is about 6°-7°. During use, if the cone angle becomes larger due to deformation and cannot be synchronized quickly, it should be replaced in time.

b. Pin inertia synchronizer: The main damage of the lock pin synchronizer is the wear of the cone ring and the cone disc. When the 0.40 mm deep thread groove on the bevel of the cone ring is worn down to 0.10 mm deep, it should be replaced. If the end surface of the cone ring is scratched, the end surface needs to be turned, but the cumulative turning amount should not exceed 1mm, otherwise, it should be replaced