Note: Descriptions are shown in the official language in which they were submitted.
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HYDRA~LIC AND SPRING ACTUATED
DOUBLE CLUTCH
This invention relates to a friction clutch and
more particularly to a hydraulic and spring actuated
double clutch for selectively and alternatively actuating
two clutches. The actuator selectively moves in one of
two directions to selectively actuate one or the other of
the clutches. The hydraulic actuator overcomes the spring
force to actuate a clutch in one direction and the spring
actuates another clutch in the other direction when fluid
pressure is released.
Power shift transmissions hydraulically and
selectively engage and disengage clutches and can be used
for shifting while the vehicle is in motion. The clutches
being friction clutches tolerate a certain amount of
slippage when engaging or disengaging the clutches, but
excessive overlap in engagement of one clutch and
disengagement of another can cause excessive wear.
Annular hydraulic clutches tend to produce a delayed
disengagement or residual engagement due to the
centrifugal forces of the hydraulic fluid in the supply
line and hydraulic actuator. Release of the residual
pressures in the hydraulic actuator may be accomplished
through check valves or relief valves which release the
fluid responsive to the centrifugal forces set up in the
hydraulic actuator. Modulating pressures of the hydraulic
actuators can be controlled to avoid overlap and similarly
to control engagement and disengagement to avoid a lapse
of time between disengagement and engagement of the
clutches. Simultaneous operation of the disengagement and
engagement of the clutches can also be controlled with a
single actuator which operates between two clutch packs
and the engagement and disengagement depending upon the
direction of movement of the hydraulic actuator. The
applicant has provided for a clutch actuator which is
spring operated in one direction and hydraulically
operated in the other. A single on-and-off valve will
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control communication of pressurized fluid to the
pressurizing chamber in the hydraulic actuator. The
hydraulic fluid pressure overcomes the spring force to
actuate the clutch in one direction and the release of the
hydraulic fluid allows the spring to actuate the other
clutch. The hydraulic actuator and spring also eliminates
any possibil~ty o$ residual drag due to forces caused by
the rotating fluid in the supply line or hydraulic
actuator. This simplifies the hydraulic passages required
to operate the hydraulic clutch and also reduces the
overall cost and avoids the need for check valves to
release the pressure in hydraulic actuator to avoid
residual pressures causing drag on the clutch discs.
The U.S. patent 3,566,707, Schultz, shows a
double-acting hydraulic actuator in which hydraulic fluid
is used to actuate in either of two directions. The
applicant, however, has provided for a spring operating in
one direction and hydraulic fluid in the other and
simplifies the hydraulic circuit and the construction of
the clutch.
~ ccordingl,y, it is an ob~ect of this invention
to provlde a double-actuating clutch actuator actuated
hydraulically in one direction and mechanically in the
other, wherein engagement of one clutch and disengagement
of the other is simultaneous.
It is another object of this invention to
provide a double-clutch actuator for a hydraulic and
mechanical actuator for selective operation in each of two
directions.
It is a further object of this invention to
provide a double-actuated clutch having hydraulic means to
operate the clutch in one direction and mechanical means
to operate a clutch in the other direction to operate the
clutches in a power shift transmission.
It is a further object of this invention to
provide a double-actuated clutch having a single
reciprocating piston selectively operating one or another
clutch hydraulically or mechanically as selected by the
operator.
SUMMARY OF THE INVENTION
This invention provldes a double-acting
clutch actuator for a transmission which includes a
first clutch`having one clutch pack and a second clutch
having another clutch pack carried sn an integral
clutch drum mounted on a layshat. A clutch actuator
is disposed between the clutch packs and includes a
hydraulic cyclinder formed by the clutch drum which
receives a piston orming a hydraulic pressurizing
chamber for actuating the first clutch. A pressure
plate in the second clutch is connected to the piston
and a clutch actuating spring means normally biases the
pressure plate toward an engaging position of the other
of the clutch packs. Each clutch includes an integral
clutch hub and drive gear. A hydraulic system is
provided which includes a source of pressurized fluid,
a control valve to supply pressurized fluid to the
pressurizing chamber and to release pressurizing fluid
from the chamber to thereby selectively actuate the
clutches in response to operat:ion of the control valve
admitting and releasing pressllrized fluid in the
pres~urizing chamber. The transmission is a
counter~haft transmission incLuding a drive shaft and a
countershaft, a yearset connected between the clutch
hub of each of the clutches and the drive shaft for
selective drive of the countershaft transmission, a
plurality of gearsets between the drive shaft and the
countershaft and a plurality of clutches on the
countershaft for selecting drive through the
countershaft transmission.
Referring to the drawings:
Fiy. 1 shows a main transmission and
double-actuated clutch; and
Fig. 2 illustrates a diagram of the
transmission and related components in the drive line.
Referring to the drawings, the input shaft 1
is connected to the clutch 2 and drives the PTO shat
B
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3. The clutch 2 is selectively engaged for drive from
the input shaft 1 to the driving shaft 5 and driving
the gear 18. The driving shaft 5 is rotatably mounted
in the bearing assembly 6, which is supported in the
transmission housing 7.
A main transmission 8 drives through a range
transmission 9 to the differential 10 and the planetary
final drive gearsets 11 and 12. The brakes 13 and 14
selectively brake the rear axles of the vehicle. The
PTO shaft 3 operates through the PTO clutch 15 and the
PTO brake 16 to drive out of the coupling 17.
B
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The drive gear 18 is integral with the quill
shaft 5 and drives through the power shift clutches 57 and
59 in power shift transmission 120. The main transmission
8 is a manual transmission for selectively providing the
desired gear ratio by shifting manually. The main
transmission 8 includes the gear 21 of the gearset 22
which includes gear 100 in power shift trans~ission 120.
The gearset 23 also includes a gear 24 of the main
transmission 8 which is driven by gear 131 fro~ the power
shift transmission 120.
The main trans;nission is a countershaft
transmission which includes a countershaft 25 rotatably
mounted on the bearing assemblies 26 an~ 27. The clutch
collar 28 is selectively operated to engage clutch teeth
]5 29 or 30 on gears 31 and 32. The clutch sleeve 33 is
mounted on a s~line 34 of the countershaft 25 and also is
Eormed with external splines mating the spline 35 with the
clutch collar 28. The gear 32 is a reverse gear and
engages an idler gear 110 (shown in ~ig. 2) which in turn
engages gear 38 on the output shaft. Gear 31 is also
driven by the gear 38 formed on the drive shaft 37.
Similarly the gear 40 drives gear 24 on the
~3riv~ shaEt 37. The gearset 41 includes gaar 42 on the
driv~ shaft 37 and gear 43 on the countershaft 25. 5ears
31, 32, 40 and 43 are rotatably mounted on the coulker-
shaft and are selectively engaged by their res~ective
clutches. Gears 40 and 43 are enga~e~ b~ the clutch
coll~r 44 through the gear teeth 45 and 46. The clutch
collar 44 i9 mounted on the cl~tcn sleeve 47 which is
~0 slidably fastened to the countershaft by the mating spline
48 while the ~ating spline 49 slidably engages the collar
44 with the sleeve 47. The clutch collar 44 operates with
synchronizers 39 and 50 in combination with the gears 40
and 43 to aid in synchronizing o~ the clutch and gear
speeds when shifting.
The power shift transmission 120 is driven
through the countershaft gearset 52 driven by the quill
shaft 5 and inclu~es the gear 18 and gear 53. Jear 53 is
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connected through sPline 54 to the layshaft 55. Layshaft
55 is also connected through a mating spline 56 to the
clutch drum 58. Gears 100 and 101 are rotatably mounted
on the layshaft 55. The clutches 57 and 59 selectively
connect the layshaft 55 to drive the gears 100 an~ 101.
Clutch 57 includes the clutch hub 60 which is integral
with gear 100 and carries clutch discs 61. The clutch
drum 58 carries the clutch discs 62 an~ the reaction plate
63. The hydraulic piston 64 reci~rocates in the cylinder
65 formed by the clutch drum 53 and forms a pressuriæin~
chamber 66 connected throu~h radial passa~e 57 and the
axial passage 68 and housing passage 122 to the hydraulic
system.
The clutch 59 includes the clutch drum 53 whicn
is connected to the clutch discs 63 and also carries the
reaction plate 69. The actuator including the plun~er 70
is connected through the bolt 71 to the piston 64. A
plurality of bolts are used. The clutch hub 72 is
integral with gear 101 and carries the clutch discs 73.
Springs such as belleville springs 74 bias clutch 59 to an
engagement position and retracts the piston 64 in clutch
57. The clutches 57 and 59 selectively engage drive
through layshaft 55 from the gear 53 to gears 100 or 101.
Operation of the clutch i9 controlled throu~n
the hydraulic system which includes the conduit 75 in
communication with the pump 76 which receives fluid from
the sump 77. A relief valve 78 returns flui~ to sump 77
in the event of excessive pressure in the conduit 75O
Control valve 79 selectively controls the transmission of
pressurized fluid to the pressurizin~ chamber 56 and to
sump 77.
The operation of the device will be described in
the following paragraphs.
The engine 80 drives the input shaft 1 which is
connected to the power takeoff shaft 3 which drives
through the power takeof clutch and is braked by the
power takeoff brake 16. The en~ine clutch 2 selectively
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connec~s the inpu~ shaft 1 to the driving shaf~ 5. The
driving shaft 5 drives througn the gearset 52 to drive the
power shift transmission 120. The main transmission 8 is a
countershaft transmission and is driven from the power shift
transmission 120 through gears 100 and 101u The main
transmission is selectively shifted through the clutch collars
28 and 44 to select the drive gear ratio for operating the
transmission.
The power shift transmission 120 is selectively
operated through ~he control valve 79~ The control valve 79
10 selectively transmits pressurized fluid from the pump 76 to
the pressurizing chamber 66 or releases pressurized fluid from
tne pressurizing chamber 66 to sump 77. When pressurized
fluid is admitted to the pressurizing chamber 66, the piston
64 compresses the clutch pack 161 to engage the clutch drum 58
15 with hub 60 to drive gear 100. Clutch drum 58 is connected
through the laysnaft 55 to gear 53. The gear 100 drives
through the gear 21 on the drive shaft 37.
When pressuriæed fluid is released through the
control valve 79, the springs 74 overcome the force of fluid
2U in the pressurizing chamber 66 to release the clutch 57 and
enyage the clut~h pack 16R in clutch 59. The springs 74 are
~u~iclently strong to engage the clutch 59 and release any
residual pressure which may be in the pressurized chamber 66.
Either one or the other of the clutches is normally engaged.
25 Engagement is controlled by the control valve 79.
The drive train is provided with additi~nal speed
ranges from the main transmission through the range trans-
mlssion. The range transmission has a clutch collar 81 which
can be reciprocated to selectively engage gear 82 or gear 83
30 to selectively drive directly from t~e shaft 160 to shaft 85
or through the gearset including gears 86 and 87 to provide a
second speed range. The drive is then transmitted to the
differential 10 and planetary final drives 11 and 12
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