QC/T 283-2025Automobile engine - Piston with ring carrier (English PDF)

3.3.2.3 of this Edition; 3.2 of the 1999 Edition)

--- Modify the English equivalent of main transmission or basic transmission (see 3.6.1.1 of

this Edition; 6.1.1 of the 1999 Edition);

--- Modify the English equivalent of splitter group or additional transmission (see 3.6.1.2 of

this Edition; 6.1.2 of the 1999 Edition);

--- Add a note on " ratio spread" (see 3.6.1.2 of this Edition);

--- Add the definition by arrangement (see 3.7 of this Edition);

--- Delete the terms for manual shift transmission and automatic shift mechanical

transmission (see 5.1 and 5.4 of the 1999 Edition);

--- Delete the terms for planetary gear pair transmission (see 6.3 of the 1999 Edition);

--- Delete the terms for transmission with main reducer (see 7.1 of the 1999 Edition).

Please note some contents of this Document may involve patents. The issuing agency of this

Document shall not assume the responsibility to identify these patents.

This Document was proposed by and under the jurisdiction of National Technical Committee

of Auto Standardization (SAC/TC 114).

Drafting organizations of this Document. Shanghai Automobile Gear Works; Shaanxi Fast Auto

Drive Group Co., Ltd.; Chongqing Tsingshan Industrial Co., Ltd.; Qijiang Gear Transmission

Co., Ltd.; and Harbin Dongan Automotive Engine Manufacturing Co., Ltd.

Chief drafting staffs of this Document. Chen Zhen, Gong Rongying, Hu Hao, Zhang Xiaohua,

Gao Tao, Jiang Kun, Guan Wanlong, Zhong Wenli, and Yuan Xiaoxing.

The historical editions replaced by this Document are as follows.

--- QC/T 465-1999;

--- It is first-time revised hereby.

Automotive Mechanical Transmission Terminology and

Definition

3.1 Basic definitions

3.1.1 Mechanical transmission

A transmission device that uses manual control to obtain multiple transmission ratios through

gears and other mechanical elements, giving the vehicle forward and reverse functions.

3.2 Definition by shaft motion

3.2.1 Fixed shaft transmission

A transmission in which the rotation center of all shafts remains unchanged. It is divided into

single countershaft transmission, dule countershafts transmission, multiple countershafts

transmission and two-shaft transmission.

3.2.1.1 Single countershaft transmission

A fixed shaft transmission with only one countershaft.

3.2.1.2 Dual countershafts transmission

A fixed shaft transmission with two countershafts.

3.2.1.3 Multiple countershafts transmission

A fixed shaft transmission with three or more countershafts.

3.2.1.4 Twin-shaft transmission

A fixed shaft transmission that consists of an input shaft and an output shaft, with a single-stage

gear transmission for the forward gear, and an output shaft (single or two) that is constantly

meshed with the main reduction driven gear.

3.2.2 Planetary transmission

A transmission that is driven by the planetary gears.

3.3 Definition by gear shifting

3.3.1 Sliding gear transmission

A transmission that most gears obtain different transmission ratios by axially sliding the gear

to mesh with another gear.

3.3.2 Constant mesh transmission

A transmission that the gears of most gears are often meshed, and obtains different transmission

ratios by axially moving the gear sleeve or synchronizer to engage with the meshing teeth of

the corresponding gears.

3.4 Definition by highest gear structure type

3.4.1 Direct drive transmission

A transmission whose highest gear is direct gear (its output speed is equal to the input speed).

3.4.2 Overdrive transmission

A transmission whose highest gear is an overdrive (its output speed is higher than its input

speed).

3.5 Definition by control form

3.5.1 Direct control transmission

A manual shift transmission in which gear changes are accomplished directly by a lever on the

outside of the transmission.

3.5.2 Remote control transmission

A manual shift transmission that completes the gear shifting function through a conversion

mechanism.

3.5.3 Power assisted shift transmission

A manual shift transmission that uses hydraulic, pneumatic, or electric power to assist in

shifting.

3.5.4 Semiautomatic mechanical transmission

A mechanical transmission in which part of the gear shifting is automated.

3.6 Definition by the combination of additional transmission and main transmission

3.6.1 Combinatory transmission

A multi-gear transmission that is composed of a main transmission and an additional

transmission.

3.6.1.1 Main transmission or basic transmission

The basic transmission that plays a major role in the combinatory transmission.

3.6.1.2 Splitter group or additional transmission

A transmission device with multiple gears, attached to the front or rear end of the main

transmission, used to increase the gears of the transmission and expand the transmission ratio

range.

NOTE. The transmission ratio range (ratio spread) is the ratio of the maximum transmission ratio to the

minimum transmission ratio.

3.6.2 Combinatory integral transmission

A multi-gear transmission that consists of a main transmission and an additional transmission

in a complete housing.

3.6.2.1 Integral front mounted splitter group

A transmission device that is equivalent to the main transmission assembled in a complete

housing and is equivalent to the front mounted splitter group.

3.6.2.2 Integral rear mounted range-change group

A transmission device that is equivalent to the main transmission assembled in a complete

housing and is equivalent to the rea-change group.

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