Direccion diferencial

Lesson 5: Differential Steering

Fig. 2.5.1 Differential Steering

Introduction This lesson discusses differential steering. Differential steering is used in Challenger Agricultural Tractors and is an option in some models of track-type tractors. This lesson identifies the components of a differential steering system and describes the operation of a differential steering system. Objectives 1.Know the components of a differential steering system. 2. Understand the operation of a differential steering system.

Lesson 5: Differential Steering

Unit 2 Lesson 5

2-5-2

Power Train II

DIFFERENTIAL STEERING
STEERING DRIVE PLANETARY PLANETARY SET SET TRANSMISSION INPUT EQUALIZING PLANETARY SET

LEFT DIFFERENTIAL OUTPUT

STEERING INPUT RING PLANET GEAR GEARS CARRIER SUN GEARRIGHT DIFFERENTIAL OUTPUT

Fig. 2.5.2 Differential Steering

Differential Steering The purpose of differential steering is to equalize power distribution to the drive wheels. Differential steering divides power equally between the two axles when the machine is going straight. When a turn is required, a steering motor causes one track to speed up and the other to slow down by an equalamount. The center speed of the machine does not change. The diagram in Figure 2.5.3 shows the relationship between the components in the differential steering system. The differential steering system contains the steering, drive and equalizing planetary set. There are two power inputs, a speed and direction input from the transmission and a steering input from the steering motor. The steering motor ispart of a closed loop hydraulic system and does not turn unless the steering controls are being used. The sun gears are all connected to the center shaft. All three sun gears are driven at the same speed. The ring gear of the equalizing planetary set is always stationary and bolted to the right brake housing. The left axle shaft is splined to the carrier for the steering planetary set. The rightaxle shaft is splined to the carrier for the equalizing planetary set.

Unit 2 Lesson 5

2-5-3

Power Train II

DIFFERENTIAL STEERING
STRAIGHT FORWARD
STEERING DRIVE PLANETARY PLANETARY SET SET TRANSMISSION INPUT EQUALIZING PLANETARY SET

LEFT DIFFERENTIAL OUTPUT

STEERING INPUT RING PLANET GEAR GEARS CARRIER SUN GEAR

RIGHT DIFFERENTIAL OUTPUT

Fig. 2.5.3 Straight ForwardStraight Forward The transmission input comes in through a pinion and bevel gear set. The bevel gear shaft is splined to the drive carrier. The drive carrier splits the power between the drive ring gear and the drive sun gear. This power is transmitted through the planetary gears. The power that flows through the drive ring gear is low speed and high torque. The drive ring gear is directly connectedto the steering carrier, which is connected to the left outer axle. The power from the sun gear is high speed and low torque, and is transmitted through the center shaft to the equalizing sun gear. The equalizing planet gears walk around the stationary ring gear and drive the carrier at a lower speed and higher torque than the sun gear. The equalizing carrier is connected to the right outer axle.The gear ratios are designed so that the left axle and the right axle rotate at the same speed and torque if no other inputs are present, and the machine travels in a straight line. When no steering inputs are present, the ring gear on the steering planetary set is stationary.

Unit 2 Lesson 5

2-5-4

Power Train II

DIFFERENTIAL STEERING
LEFT TURN FORWARD
STEERING DRIVE PLANETARYPLANETARY SET SET TRANSMISSION INPUT EQUALIZING PLANETARY SET

LEFT DIFFERENTIAL OUTPUT

STEERING INPUT RING PLANET GEAR GEARS CARRIER SUN GEAR

RIGHT DIFFERENTIAL OUTPUT

Fig. 2.5.4 Left Turn Forward

Left Turn Forward The differential steering system uses power from a hydraulic motor to increase the speed of one track and equally decrease the speed of the other track. The resulting track...