561M Pipelayer Caterpillar

Introduction

The transmission has five hydraulically activated clutches. This gives the transmission three speeds FORWARD and three speeds REVERSE. Speed and direction are manually selected by the operator.

Illustration 1	g00289007
Clutch operation (typical example) (1) Piston (2) Spring (3) Plates (4) Ring gear (5) Discs (6) Clutch housing

The five transmission clutches are the disc type. These clutches are in separate housings. Each clutch has discs (5) and plates (3). The inside teeth of discs (5) are engaged with the outside teeth of ring gear (4). Notches on the outside diameter of plates (3) are engaged with pins in the clutch housing. The pins keep the plates from rotating.

In the example in Illustration 1, springs (2) are between clutch housing (6) and piston (1). The springs keep the clutches disengaged. The clutches are engaged when oil is sent into the area behind piston (1).

When the pressure of the oil in the area behind the piston increases, the piston moves to the right. The piston moves against the force of spring (2), pushing the discs and plates together. The clutch is now engaged. The discs keep ring gear (4) from rotation. When the clutch is released, the pressure in the area behind piston (1) decreases and the force of spring (2) moves the piston to the left. The discs and plates now move apart and the clutch is not engaged.

Both a speed clutch and a direction clutch must be engaged in order to send power through the transmission. Table 1 lists the combination of the clutches that is engaged for the different FORWARD and REVERSE speeds.

Illustration 2	g00483311
Transmission components (1) Ring gear for No. 1 clutch (2) No. 1 clutch REVERSE (3) No. 2 and No. 3 carrier (4) No. 2 clutch FORWARD (5) Ring gear for No. 2 clutch (6) No. 3 clutch THIRD SPEED (7) Ring gear for No. 3 clutch (8) No. 4 clutch SECOND SPEED (9) Ring gear for No. 4 clutch (10) No. 5 clutch FIRST SPEED (11) hub (12) No. 4 carrier (13) No. 4 sun gear (14) Input shaft (15) Output shaft (16) Housing assembly (17) No. 4 planetary gears (18) No. 3 Sun gear (19) No. 3 Planetary gears (20) No. 2 planetary gears (21) No. 2 sun gear (22) Coupling gear (23) No. 1 planetary gears (24) No. 1 sun gear (25) No. 1 carrier

The transmission is fastened to the case at the rear of the machine. Power from the torque converter is sent to input shaft (14) by a drive shaft. Power flows from the transmission through output shaft (15). The power then goes from the output shaft to the transfer gears.

The transmission has five hydraulically activated clutches. These clutches have three speeds FORWARD and three speeds in REVERSE. Both speed and direction are manually selected by the operator.

The No. 1 and the No. 2 clutches are the direction clutches. These clutches are located at the rear of the transmission. The No. 1 clutch is the REVERSE direction clutch. The No. 2 clutch is the FORWARD direction clutch.

The No. 3, No. 4, and No. 5 clutches are the speed clutches. The No. 3 clutch gives THIRD speed. The No. 4 clutch gives SECOND speed. The No. 5 clutch gives FIRST speed.

The No. 5 clutch is the only clutch that turns.

First Speed FORWARD

Illustration 3	g00483300
Power flow in first speed FORWARD. The No. 2 clutch and the No. 5 clutch engaged. (3 ) No. 2 and No. 3 carrier (4) No. 2 clutch FORWARD (5) Ring gear for no. 2 clutch (7) Ring gear for no. 3 clutch (9) Ring gear for no. 4 clutch (10) No. 5 clutch FIRST SPEED (11) Hub (12) No. 4 carrier (13) No. 4 sun gear (14) Input shaft (15) Output shaft (16) Housing assembly (17) No. 4 planetary gears (18) No. 3 sun gear (19) No. 3 Planetary gears (20) No. 2 Planetary gears (21) No. 2 Sun gear

When the transmission is in first speed FORWARD, No. 5 and No. 2 clutches are engaged. The No. 2 clutch holds ring gear (5) for the No. 2 clutch stationary. The No. 5 clutch holds hub (11) stationary. Input shaft (14) turns No. 2 sun gear (21). No. 2 sun gear turns No. 2 planetary gears (20) .

The No. 2 clutch holds ring gear (5) stationary. This causes planetary gears (20) to rotate inside the ring gear. The movement of planetary gears (20) causes No. 2 and No. 3 carrier (3) to turn in the same direction as input shaft (14). As the No. 2 and No. 3 carrier turns, No. 3 planetary gears turn. The No. 3 planetary gears turn ring gear (7) for the No. 3 clutch and No. 3 sun gear (18). The No. 3 sun gear turns output shaft (15) .

Ring gear (7) turns No. 4 carrier (12). As the No. 4 carrier turns, No. 4 planetary gears (17) turn. The No. 4 planetary gears turn ring gear (9) for the No. 4 clutch, which is connected to housing assembly (16) by splines. No. 4 planetary gears also turn No. 4 sun gear (13). No. 4 sun gear turns output shaft (15) .

As rotating hub (11) is held stationary by No. 5 clutch (10), power is sent through the No. 5 clutch to rotating hub (11). Rotating hub (11) turns output shaft (15). As a result, torque to output shaft (15) is divided through No. 3 sun gear, No. 4 sun gear, and rotating hub (11). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

Second Speed FORWARD

When the transmission is in second speed FORWARD, No. 4 and the No. 2 clutches are engaged. The No. 2 clutch holds ring gear (5) for the No. 2 clutch stationary. The No. 4 clutch holds ring gear (9) for the No. 4 clutch stationary. Input shaft (14) turns No. 2 sun gear (21). No. 2 sun gear turns planetary gears (20) .

Ring gear (5) is held stationary by the No. 2 clutch. This causes planetary gears (20) to rotate inside the ring gear. The movement of planetary gears (20) causes No. 2 and No. 3 carrier (3) to turn in the same direction as input shaft (14). As the No. 2 and No. 3 carrier turns, No. 3 planetary gears (19) turn. The No. 3 planetary gears turn ring gear (7) for the No. 3 clutch and No. 3 sun gear. No. 3 sun gear (18) turns output shaft (15). Ring gear (7) turns No. 4 carrier (12) .

As a result, torque to output shaft (15) is divided through No. 3 sun gear (18) and No. 4 sun gear (13). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

Third Speed FORWARD

When the transmission is in third speed FORWARD, No. 2 and No. 3 clutches are engaged. The No. 2 clutch holds ring gear (5) for the No. 2 clutch stationary. The No. 3 clutch holds ring gear (7) for the No. 3 clutch stationary. Input shaft (14) turns No. 2 sun gear. No. 2 sun gear turns No. 2 planetary gears (20) .

Ring gear (5) is held stationary by the No. 2 clutch. This causes planetary gears (20) to rotate inside the ring gear. The movement of planetary gears (20) causes No. 2 and No. 3 carrier (3) to turn in the same direction as input shaft (14) .

Ring gear (7) is held stationary by the No. 3 clutch. Then, the movement of No. 2 and No. 3 carrier (3) causes No. 3 planetary gears (19) to rotate inside the ring gear. The No. 3 planetary gears turn No. 3 sun gear (18). No. 3 sun gear (18) turns output shaft (15). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

First Speed REVERSE

Illustration 4	g00483301
Power flow in first speed REVERSE. The No. 1 and the No. 5 clutches are engaged. (1) Ring gear for no. 1 clutch (2) No. 1 clutch REVERSE (3) No. 2 and No. 3 carrier (7) Ring gear for no. 3 clutch (9) Ring gear for no. 4 clutch (10) No. 5 clutch FIRST SPEED (11) hub (12) No. 4 carrier (13) No. 4 sun gear (14) Input shaft (15) Output shaft (17) No. 4 planetary gears (18) No. 3 sun gear (19) No. 3 planetary gears (22) Coupling gear (23) No. 1 planetary gears (24) No. 1 sun gear (25) No. 1 carrier

When the transmission is in first speed REVERSE, No. 1 and No. 5 clutches are engaged. The No. 1 clutch holds ring gear (1) for the No. 1 clutch stationary. The No. 5 clutch holds rotating hub (11) stationary.

Input shaft (14) turns No. 1 sun gear (24). No. 1 sun gear turns No. 1 planetary gear (23). No. 1 carrier (25) has a direct mechanical connection with ring gear (1) .

Ring gear (1) and No. 1 carrier (12) are held stationary by the No. 1 clutch. The movement of No. 1 planetary gears (23) causes coupling gear (22) to turn in the opposite direction as input shaft (14). Coupling gear (22) has a direct mechanical connection with No. 2 and No. 3 carrier (3).

As the No. 2 and No. 3 carrier turns, No. 3 planetary gears (19) turn. The No. 3 planetary gears turn ring gear (7) for the No. 3 clutch and No. 3 sun gear (18). No. 3 sun gear turns output shaft (15). Ring gear (7) turns No. 4 carrier (12). As the No. 4 carrier turns, No. 4 planetary gears (17) turn. The No. 4 planetary gears turn ring gear (9) for the No. 4 clutch, which is connected to housing assembly (16) by splines. The No. 4 planetary gears also turn No. 4 sun gear (13). No. 4 sun gear turns output shaft (15) .

As rotating hub (11) is held stationary by No. 5 clutch (10), power is sent through the No. 5 clutch to rotating hub (11). Rotating hub (11) turns output shaft (15) .

As a result, torque to output shaft (15) is divided through No. 3 sun gear (18), No. 4 sun gear (13 ), and rotating hub (11). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

Second Speed REVERSE

When the transmission is in second speed REVERSE, No. 1 and No. 4 clutches are engaged. The No. 1 clutch holds ring gear (1) for the No. 1 clutch stationary. The No. 4 clutch holds ring gear (9) for the No. 4 clutch stationary. Input shaft (14) turns No. 1 sun gear (24). No. 1 sun gear turns No. 1 planetary gears (23). No. 1 carrier (25) has a direct mechanical connection with ring gear (1) .

Ring gear (1) and No. 1 carrier (25) are held stationary by the No. 1 clutch. The movement of the No. 1 planetary gears (23) causes coupling gear (22) to turn in the opposite direction of input shaft (14). Coupling gear (22) has a direct mechanical connection with No. 2 and No. 3 carrier (3). As the No. 2 and No. 3 carrier turns, No. 3 planetary gears (19) turn. The No. 3 planetary gears turn ring gear (7) for the No. 3 clutch and No. 3 sun gear (18). No. 3 sun gear turns output shaft (15). Ring gear (7) turns No. 4 carrier (12) .

Ring gear (9) is held stationary by the No. 4 clutch. This causes planetary gears (17) to rotate inside the ring gear. The movement of planetary gears (17) and No. 4 carrier (12) causes No. 4 sun gear (13) to turn. The No. 4 sun gear turns output shaft (15) .

As a result, torque to output shaft (15) is divided through No. 3 sun gear (18) and No. 4 sun gear (13). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

Third Speed REVERSE

When the transmission is in third speed REVERSE, No. 1 and No. 3 clutches are engaged. The No. 1 clutch holds ring gear (1) for the No. 1 clutch stationary. The No. 3 clutch holds ring gear (7) for the No. 3 clutch stationary. Input shaft (14) turns No. 1 sun gear (24). No. 1 sun gear turns No. 1 planetary gears (23). No. 1 carrier (25) has a direct mechanical connection with ring gear (1) .

Ring gear (1) and No. 1 carrier (25) are held stationary by the No. 1 clutch. The movement of No. 1 planetary gears (23) causes coupling gear (22) to turn in the opposite direction as input shaft (14). Coupling gear (22) has a direct mechanical connection with No. 2 and No. 3 carrier (3) .

As ring gear (7) is held stationary by the No. 3 clutch, the movement of No. 2 and No. 3 carrier (3) causes No. 3 planetary gears (19) to rotate inside the ring gear. The No. 3 planetary gears turn No. 3 sun gear (18). No. 3 sun gear (18) turns output shaft (15). From the output shaft, power goes through the transfer and bevel gears to the steering clutches and brakes.

NEUTRAL

Illustration 5	g00483303
Power flow in NEUTRAL. The No. 3 clutch is engaged. (6) No 3 clutch (third speed) (7) Ring gear for No. 3 clutch (14) Input shaft (15) Output shaft (20) No. 2 planetary gears (23) No. 1 Planetary gears

When the transmission is in NEUTRAL, the No. 3 clutch is engaged. The No. 3 clutch holds ring gear (7) stationary. Input shaft (14) turns No. 1 and No. 2 planetary gears. Neither No. 1 clutch nor No. 2 clutch are engaged, so there is no power flow to output shaft (15) .

Planetary Lubrication

Illustration 6	g00483304
Planetary lubrication (27) Orifice (28) Passage (29) Passage (30) Passage (31) Passage (32) Passage

Some of the oil from the torque converter and lubrication section (B) of the oil pump combines with excess oil flow over the main relief valve in order to provide lubrication for the transmission. All planetary gears and bearings are lubricated by pressure lubrication.

The oil flows through an external line to the bevel gear case. Then, the oil flows through an internal tube to passage (31) in the transmission cover. Part of the oil flows back through passage (30) in the transmission case assembly. Then, the oil flows through tubes for lubrication of the bevel and pinion gear, and the transfer gears.

Part of the oil flows through passage (32) for lubrication of the No. 1 and No. 2 planetary gears, bearings, and clutches. The remainder of the oil flows through passage (27) to passage (29) in the output shaft. The oil then flows through passage (28) for lubrication of the No. 3, No. 4, and No. 5 planetary gears, the bearings, and the clutches.

All oil leakage from the clutches and return oil drains to the bottom of the transmission case. The oil then drains to the sump in the bevel gear case.