Calculation of automotive components -PU, drawings

2.2 Classification of hydromechanical gears

By location of hydraulic transmissions in hydromechanical transmissions are divided into:

- sequential;

- parallel.

When hydraulic transmission is arranged in sequence, engine power is transmitted by single flow through hydraulic and mechanical transmissions to driven shaft of transmission. In this case, power losses in the transmission are sequentially increased.

In parallel arrangement, the hydraulic transmissions may have a separation of the engine power flow or two independent power flows (active power and circulating power).

Hydromechanical transmissions with power flow division can be conditionally divided into two groups:

- with external separation of engine power flow;

- with internal separation of engine power flow.

In transmissions of the first group, the engine power flow is divided outside the hydraulic transmission; part of power is transmitted through hydraulic transmission, and part - through mechanical transmission, then power flows are added and power is transmitted to driven shaft in a single flow.

In transmissions of the second group, the engine power flow is divided inside the torque converter in two ways:

1) part of the power is transferred by the turbine, and the rest is transferred by the reactor, then both power flows are added on the driven shaft in one stream;

2) power is transmitted to separate turbines, then this power is added on the driven shaft using planetary gears in one stream.

Hydromechanical transmissions with external flow separation have become most widespread.