Fluid Velocity-Type Governors

body. The width of the front pump gears is more

(1) A 31-tooth sun gear (38), 59-tooth (in-

than twice the width of the rear pump gears, giving

ternal) ring gear (29), and a planetary carrier

the front pump greater pumping capacity.

assembly (37) with six 14-tooth pinions make up

the reverse-range gear set. The sun gear is the

b. Operation of Oil Pumps (fig. 2-1).

driving member, the ring gear is the reaction

(1) The front oil pump (11) is driven by the

member, and the carrier assembly is the driven

torque converter pump hub. It supplies oil to the

member.

hydraulic system at any time the vehicle engine is

(2) The sun gear (38) is splined to reverse-

running. Oil is picked up (through the oil filter

range sun gear shaft (40) which, in turn, is splined

(55)) from the oil pan (42).

to the low-range ring gear (23) which meshes with

(2) The rear oil pump (32) is driven by the

the low-range carrier pinions. The carrier assembly

reverse-range planetary carrier (37) at any time the

(37) is splined to the transmission output shaft

vehicle is moving forward. Oil is picked up

(33). Its pinions mesh with both the ring gear (29)

(through the oil filter (55)) from the oil pan (42).

and sun gear (38). The ring gear (29) has external

Oil flow produced by the rear pump supplements

splines which engage the reverse-range, internal-

that of the front pump during vehicle forward

splined plates. A retainer at the outer circumference

operation. It is the only source of oil flow and

of the ring gear (29) prevents the gear moving

pressure during push or tow starting.

forward or rearward.

2-7. Fluid Velocity-Type Governors

c. Operation of Reverse-Range Clutch and

a. Components of Front and Rear Governors

Planetary Gears (fig. 2.1).

(fig. 2-1).

(1) When the reverse-range clutch (28) is

(1) There are two governors in the trans-

applied, the clutch piston (27) compresses the

mission for controlling the automatic functions.

clutch plates against the reaction plate (30). This

The front governor (14) is located at the front of

holds the ring gear (29 ) stationary. The sun gear

the high-range clutch housing (16). The rear

(38) drives the carrier assembly (37) at a reduced

governor (39 ) is located at the rear of the reverse-

speed but in the same direction as the sun gear

range planetary (37).

(38). To actually obtain reverse rotation which the

(2) Each governor includes a collector ring

sun gear and carrier must have, the reverse-range

which rotates with the component to which it is

gears are compounded with the low-range gears.

attached, and a pitot tube which is stationary. Each

(2) Reversing actually takes place in the low-

collector ring has a channel around the inside of its

range gear set and its output (ring gear (23))

rim. There are radial vanes at close intervals in the

transmits reverse rotation to the input (sun gear

channel. A port supplies oil to keep the channel

(38) ) of the reverse-range gear set. The overall

filled. When the collector ring is rotating, the

reverse-rotation speed reduction ratio is 4.35 to 1.

channel remains full due to centrifugal force acting

(3) When hydraulic pressure is exhausted from

to retain the oil.

the clutch piston housing, springs (43) push the

(3) The vanes in the channel keep the oil

piston (27) back into the housing (26). This

moving at virtually the same speed as the channel.

permits the reverse-range, internal-splined plates to

The pitot tube is a simple tube, stationarily

rotate independently of the stationary, external-

positioned in the oil which fills the channel. The

tanged clutch plates.

open end of the tube faces against the direction of

2-6. Oil Pumps

oil travel. The other end of the tube connects to

a. Components of Front and Rear Oil Pumps

passages leading to control valves.

(fig. 2-1).

b. operation of Fluid Velocity-Type Governors

(1) The front oil pump (11) includes a pump

(fig. 2-1).

body, cover. 19-tooth drive gear, and a 22-tooth

(1) The fluid velocity governors (14 and 39)

driven gear. The drive gear has external teeth and

derive their name from the fact that governor

the driven gear has internal teeth. Both gears have

pressure is dependent upon the velocity of fluid in

6-pitch teeth.

the channels of the collector rings. When the

(2) The rear oil pump (32) includes a pump

collector rings rotate, oil is thrown directly into the

body, cover, 26-tooth drive gear, and a 30-tooth

open ends of the pitot tubes.

driven gear. The drive gear has external teeth and

(2) The front governor collector ring is welded

the driven gear has internal teeth. Both gears have

to the high-range clutch housing and rotates with it.

8-pitch teeth.

Since the clutch housing is connected to the torque

(3) In both oil pumps, the driven gear is

converter turbine by the turbine shaft (59), front

mounted eccentrically in mesh with the drive gear.

governor pressure is proportional to turbine speed.

The gears are separated at their unmeshed side by a

Front governor pressure is called G1 pressure.

crescent-shaped partition which is part of the pump

(3) The rear governor collector ring is riveted

2-5