BACKGROUND

Technical Field:

[0001] This disclosure relates to clutches or clutch modules for transmissions of machines.

Description of the Related Art:

[0002] An internal combustion engine of an automobile generates power in the form of reciprocating motion of its pistons. The crankshaft converts this reciprocal motion into rotary motion. The rotary motion of the crankshaft, however, is not transmitted directly to the driving wheels or to the drivetrain because the crankshaft rotates at high rotational speeds, which are inappropriate for starting, stopping and normal travel. Specifically, automobile engines typically operate over a range of about 600 to about 7000 rpm, while the wheels rotate between 0 rpm and about 1800 rpm. It is the function of the transmission to convert the high rotational speed of the crankshaft to a slower wheel speed and to increase torque in the process. Both manual and automatic transmissions provide the same basic functions of speed reduction and torque increase.

[0003] Instead of connecting directly to the transmission, the crankshaft connects to a flywheel, which connects to a transmission input shaft, sometimes referred to as a mainshaft. In one example, the transmission selectively couples the input shaft through two gear sets, each providing a gear ratio, and eventually to an output shaft, sometimes referred to as the driveshaft. In many designs, the input shaft fixedly connects to an input pinion that meshes with an input gear fixedly connected to a parallel counter shaft. Thus, the counter shaft rotates with the input shaft, but at a somewhat lower speed to the gear ratio provided by the input pinion and the input gear of the counter shaft. The counter shaft also fixedly connects to a plurality of gears, typically numbered from one to four, five or six. Each of these numbered gears, which rotate with the counter shaft, also mesh with and form gear sets with like-numbered gears through which an output shaft passes. The numbered gears of the output shaft do not connect to the output shaft, but instead ride on bearings. Each pair of enmeshed numbered gears, one on the counter shaft and one on the output shaft, form a gear set and provide a gear ratio. Because the output shaft is not fixedly connected to the numbered gears through which it passes, the transmission also includes a plurality of clutches or clutch modules that selectively couple the output shaft to one of these numbered gears and therefore to one of the gear sets.

[0004] Manual transmissions are available in a variety of different designs and clutch modules may be required to connect gear sets to an input shaft, one or more counter shafts or an output shaft. Hence, use of the term "transmission shaft" below may refer to any shaft of a transmission that may be selectively coupled to a gear set by a clutch module.

[0005] Clutch modules can be complex in design, difficult to assemble and therefore costly to produce. Further, as noted above, multiple clutch modules may be required. Accordingly, a need exists for improved clutch modules that are easy to assemble, reliable and cost efficient to produce.

SUMMARY OF THE DISCLOSURE

[0006] In one aspect, this document discloses a clutch and gear module for a transmission that includes a transmission shaft rotatable about a transmission axis. The clutch and gear module includes a first gear assembly rotatably coupled to the transmission shaft and a second gear assembly rotatably coupled to the transmission shaft. The clutch and gear module also includes an actuator carrier fixedly coupled to the transmission shaft and mounted between the first gear assembly and the second gear assembly, the actuator carrier including an inner hub connected to an outer ring with a window disposed between the inner hub and the outer ring. Also included in the clutch and gear module are a first actuator that extends radially between the inner hub and the outer ring and across the window of the actuator carrier, the first actuator being rotatable about a first actuator axis that extends radially between the inner hub and the outer ring, the first actuator including a first pawl disposed in radial alignment with the window. The first actuator further includes an outwardly directed first offset pin that is parallel to but not coaxial with the first actuator axis, the first pawl having a clockwise orientation relative to the transmission axis. A second actuator that extends radially between the inner hub and the outer ring and across the window of the actuator carrier, the second actuator being rotatable about a second actuator axis that extends radially between the inner hub and the outer ring, the second actuator including a second pawl disposed in radial alignment with the window, the second actuator further includes an outwardly directed second offset pin that is parallel to but not coaxial with the second actuator axis, the second pawl having a counter-clockwise orientation relative to the transmission axis is included in the clutch and gear module. Lastly, the clutch and gear module includes a first shift sleeve coupled to the first actuator at the first offset pin and a second shift sleeve coupled to the second actuator.

[0007] In another aspect of the disclosure, a clutch assembly for a transmission has a transmission shaft rotatable about a transmission axis, a first gear assembly, and a second gear assembly, each of the first and second gear assemblies rotatably disposed on the transmission shaft and including an actuator carrier fixedly coupled to the transmission shaft and mounted between the first gear assembly and the second gear assembly. The actuator carrier includes an inner hub connected to an outer ring with a window disposed between the inner hub and the outer ring. The clutch assembly also includes a first actuator that extends radially between the inner hub and the outer ring and across the window of the actuator carrier, the first actuator being rotatable about a first actuator axis that extends radially between the inner hub and the outer ring, the first actuator including a first pawl disposed in radial alignment with the window. The first actuator further includes an outwardly directed first offset pin that is parallel to but not coaxial with the actuator axis, the first pawl having a clockwise orientation relative to the transmission axis. The clutch assembly similarly includes a second actuator that extends radially between the inner hub and the outer ring and across the window of the actuator carrier, the second actuator being rotatable about a second actuator axis that extends radially between the inner hub and the outer ring, the second actuator including a second pawl disposed in radial alignment with the window. The second actuator further including an outwardly directed second offset pin that is parallel to but not coaxial with the second actuator axis, the second pawl having a counter-clockwise orientation relative to the transmission axis. The clutch module further includes a first shift sleeve coupled to the first actuator at the first offset pin and a second shift sleeve coupled to the second actuator at the second offset pin. The first shift sleeve is independently operable to cause the first pawl to engage one of the first gear assembly or the second gear assembly and the second shift sleeve is independently operable to cause the second pawl to engage one of the first gear assembly or the second gear assembly at the second offset pin.

[0008] In yet another aspect of the disclosure, a method of activating gears includes providing a gear and clutch assembly having a first actuator and a second actuator disposed at a window of an actuator carrier, the actuator carrier being mounted to a transmission shaft, a first gear assembly disposed on the transmission shaft on a first side of the actuator carrier and a second gear assembly disposed on the transmission shaft on a second side of the actuator carrier. The method continues by deflecting the first actuator to engage either the first gear assembly or the second gear assembly responsive to movement of a first shift sleeve and deflecting the second actuator to engage either the first gear assembly or the second gear assembly responsive to movement of a second shift sleeve.

[0009] Other advantages and features will be apparent from the following detailed description when read in conjunction with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a more complete understanding of the disclosed methods and apparatuses, reference should be made to the embodiment illustrated in greater detail in the accompanying drawings, wherein:

[0011] Fig. 1 is an end view of an actuator carrier in accordance with the current disclosure;

[0012] Fig. 2 is a side view of the actuator carrier and gear assemblies; [0013] Fig. 3 is a side view of a clutch and gear module;

[0014] Fig. 4 is a side view of an alternate embodiment of the clutch and gear module of Fig. 3;

[0015] Fig 5 is a side view of another alternate view of the clutch and gear module of Fig. 3; and

[0016] Fig. 6 is a flowchart of an exemplary method of engaging gears in a clutch and gear module.

[0017] The drawings are not necessarily to scale and may illustrate the disclosed embodiments diagrammatically and in partial views. In certain instances, the drawings omit details which are not necessary for an understanding of the disclosed methods and apparatuses or which render other details difficult to perceive. Further, this disclosure is not limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION

[0018] Referring now to the drawings, and with specific reference to Fig. 1, an actuator carrier 100 and related components are described. The actuator carrier 100 is used in a clutch module that is described in more detail below. The actuator carrier 100 includes an inner hub 102 connected to an outer ring 104 forming a window 105. A first actuator 106 is rotatably mounted between the inner hub 102 and the outer ring 104 at the window 105. The first actuator 106 has a first pawl 108 that extends radially into the window 105 and a first offset pin 110. A first actuator axis 112 defines an axis of rotation of the first actuator 106. The first offset pin 110 has a centerline 114 that is parallel to but not coaxial with the first actuator axis 112.

[0019] A second actuator 116 is also rotatably mounted at the window 105 between inner hub 102 and the outer ring 104. Like the first actuator 106, second actuator 116 has a second pawl 118 and a second offset pin 120. Actuator 116 rotates about a second actuator axis 122. The second offset pin 120 has a centerline 124 that is parallel to but not coaxial with the second actuator axis 122. A splined aperture 126 in the inner hub 102 may be used to attach the actuator carrier 100 to a transmission shaft (not depicted in Fig. 1) so that the actuator carrier 100 rotates in unison with the transmission shaft.

[0020] In the illustrated embodiment, the first and second actuators 106 and 116 face each other in a common window 105. In another embodiment, the first and second actuators 106, 116 may be mounted in separate windows. The first actuator 106 has a clockwise orientation and the second actuator 116 has a counterclockwise orientation with respect to the current view. As will be shown more clearly below, force applied to either offset pin 110, 120 will cause the corresponding pawl 108, 118 to rotate out of axial alignment with the actuator carrier 100 in the direction of the force.

[0021] As shown, any number of actuators may be incorporated in the actuator carrier 100. It is anticipated that all clockwise- facing actuators 106 will operate in concert and that all counterclockwise-facing actuators 116 will work in concert, although other operating strategies may be accommodated at the time of design. [0022] Turning to Fig. 2, a side view of a portion of a clutch and gear module is shown. The actuator carrier 100 is shown mounted on a transmission shaft 130 that rotates about a transmission axis 131. A first gear assembly 132 includes a gear 133 and a first plate 134 that are rigidly affixed to each other and rotatably coupled to the transmission shaft 130 on one side of the actuator carrier 100. A second gear assembly 136 includes a gear 137 rigidly affixed to a second plate 138. The second gear assembly 136 is rotatably attached to the transmission shaft 130 next to the actuator carrier 100 opposite the first gear assembly 132.

[0023] Movement of the offset pin 110 causes the clockwise-facing first pawl 108 of the actuator 106 to engage either the first plate 134 or the second plate 138, depending on the direction of movement of the offset pin 110. When the first pawl 108 engages either plate 134 or 138, movement of the actuator carrier 100 in the clockwise direction will cause respective gear assembly 132, 136 to move synchronously in the clockwise direction. Due to the shape of the first pawl 108, when engaged with either gear assembly 132, 136, movement of the actuator carrier 100 in the counterclockwise direction will allow the respective first gear assembly 132 or second gear assembly 136 to ratchet like a one-way clutch.

[0024] Similarly, movement of the offset pin 120 causes the second pawl 118 of the second actuator 116 to engage either the first plate 134 or the second plate 138. The counterclockwise-facing second pawl 118 will engage either plate 134 or 138 and cause synchronous movement of the engaged gear assembly 132 or 136 with the actuator carrier 100 in the counterclockwise direction and ratcheting in the clockwise direction.

[0025] Fig. 3 illustrates a clutch and gear module 140. The clutch and gear module 140 is similar to the assembly illustrated in Fig. 2 with the addition of a first shift sleeve 142 and a second shift sleeve 144. The actuator carrier 100, with its actuators 106, 116 and the shift sleeves 142, 144 form a clutch assembly 141. The addition of the gear assemblies 132, 136 and the transmission shaft 130 form a clutch and gear module 140. [0026] The first shift sleeve 142 has a groove 143 for accepting a shift yoke (not depicted) that moves the first shift sleeve 142 axially, parallel to the transmission shaft axis 131.

Similarly, the second shift sleeve 144 has a groove 145 that accepts another yoke (not depicted) for axially moving the second shift sleeve 144. In an embodiment, the first shift sleeve 142 and the second shift sleeve 144 can be moved independently by their respective yokes. The shift sleeves 142, 144 have tabs 146, 148 that capture the offset pins 110, 120 of the first and second actuators 106 and 116 respectively. Movement of the shift sleeves 142, 144 causes corresponding movement of the offset pins 110, 120 and therefore, deflects the pawls 108, 118 into contact with one of the gear assemblies 132, 136. The setting of a gap 150 with the first and second actuators 106, 116 at the neutral position defines different variations of operation of the clutch and gear module 140. Specific embodiments of different gap 150 settings are described below with respect to Figs. 4-5.

[0027] Referring to Fig. 4, an embodiment 160 of the clutch and gear module 140 of Fig. 3 is illustrated. When the gap 150 is sufficiently large, either shift sleeve 142, 144 and its corresponding actuator (or actuators) can operate in both a right direction (toward gear assembly 136), remain in a neutral position, or operate in a left direction (toward gear assembly 132). Table 1 illustrates the combinations of gear motion based on the position of the shift sleeves 142 and 144 and their corresponding actuators 106 and 116. Table 1 assumes the directional conventions established above, which are, obviously, arbitrary based on a selection of viewpoint.

[0028]

Neutral Left CCW Free

Neutral Neutral Free Free

Neutral Right Free CCW

Right Left CCW CW

Right Neutral Free CW

Right Right Free Locked

Table 1

[0029] Locked = Dog clutch type action, gear rotates with actuator carrier 100

[0030] Free = Free to rotate with respect to actuator carrier 100

[0031] CW = Clockwise rotation with actuator carrier 100, free to rotate ccw

[0032] CCW = Counterclockwise rotation with actuator carrier 100, free to rotate cw

[0033] Using the conventions established, the actuator 106 is designated the clockwise actuator. Engaging the first pawl 108 with either gear assembly 132 or 134 will cause that gear assembly 132 or 134 to turn clockwise when the transmission shaft 130 is operating in the clockwise direction. As shown in Table 1, when the actuator 106, in conjunction with the first shift sleeve 142, is moved to the left to engage the first pawl 108 with gear assembly 132, the gear assembly 132 will rotate in the clockwise direction when the transmission shaft 130 is rotating in a clockwise direction. Similarly, the actuator 116 causes counterclockwise rotation when engaged with either gear assembly 132, 136, given a counterclockwise direction of rotation of the transmission shaft 130. Note that when both the first and second actuators 106, 116 are engaged with the first gear assembly 132, the first gear assembly 132 is locked to the transmission shaft 130 because the first actuator 106 will engage for clockwise rotation and the second actuator 116 will simultaneously engage for counterclockwise rotation. When both the first and second actuators 106, 116 are engaged with the second gear assembly 136, the second gear assembly 136 is locked to rotation of the transmission shaft 130. In the embodiment illustrated, both gear assemblies 132 and 136 may not be locked at the same time. In another configuration of shift sleeves 142, 144, locking of both gear assemblies 132, 136 may be achieved.

[0034] Referring to Fig. 5, another embodiment 170 of the clutch and gear module 140 where the gap 150 is narrow is illustrated. In this embodiment, movement of either shift sleeve 142 or 144 toward the opposite side will cause movement of the opposing shift sleeve in that direction also. The result is that some combinations of position are not available, as shown in Table 2 below.

Table 2

[0035] As can be readily seen from the drawings, while both shift sleeves 142 and 144 may be independently moved away from each other, movement of one shift sleeve toward the opposite gear assembly will cause the other shift sleeve to move in that direction as well. Therefore, referring to the first row in Table 2, in order to get both actuators 106, 116 to the left, both shift sleeves 142, 144 may be actively moved to the left, or alternatively, only the second shift sleeve 144 may be actively moved to the left causing the first shift sleeve 142 to move to the left as a result. Also as can be seen, the condition where a crossover occurs (actuator 106 to the right or actuator 116 to the left) is not compatible with the other actuator remaining in the neutral position or the opposite position. In practice, designs using a narrow gap 150 need to incorporate a mechanism to prevent the shift sleeves 142, 144 from conflicts while shifting occurs in the transmission.

INDUSTRIAL APPLICABILITY

[0036] The disclosed clutch and gear module 140 includes one or more actuators 106, 116 that extend radially outward from the transmission shaft 130 or radially between the inner hub 102 and the outer ring 104 of the actuator carrier 100. While the first and second actuators 106, 116 are disposed radially with respect to the transmission shaft 130, they rotate about respective actuator axes 112, 122 that are perpendicular to the transmission shaft axis 131. Employment of offset pins 110, 120 that are securely coupled to their respective shift sleeves 142, 144 enables the lateral or axial movement of the shift sleeves 142, 144 parallel to the transmission shaft axis 131 to cause the first and second actuators 106, 116 to rotate about their actuator axes 112, 122. This results in pawls 108, 118 engaging the first gear assembly 132 when either shift sleeve 142, 144 is shifted to the left, as shown in Figs. 3-5, or the second gear assembly 136 when either shift sleeve 142, 144 is shifted to the right. The disclosed clutch and gear module 140 is easy to assembly and install between the two gear assemblies 132, 136.

[0037] A method 200 of activating gears is illustrated in the flowchart of Fig. 6. At block 202 a clutch and gear module 140 is provided, the clutch and gear module 140 having a first actuator 106 and a second actuator 116 at a window 105 of an actuator carrier 100, the actuator carrier 100 being mounted to a transmission shaft 130. The clutch and gear module 140 may also include a first gear assembly 132 disposed on the transmission shaft 130 on a first side of the actuator carrier 100 and a second gear assembly 136 disposed on the transmission shaft 130 on a second side of the actuator carrier 100.

[0038] At block 204, the first actuator 106 may be deflected, for example, by movement of the first shift sleeve 142. The first actuator 106 may be deflected to engage the first gear assembly 132 by movement of the first shift sleeve 142 axially parallel to a transmission shaft 130 in a first direction or to engage the second gear assembly 136 by axial movement of the first shift sleeve 142 in a second, opposite, direction. In so doing, the first actuator 106 can engage either gear assembly 132, 136 to cause rotation with the transmission shaft 130 in one direction, for example, in a clockwise direction as described above.

[0039] At block 206, the second actuator 116 may be deflected, for example, by movement of the second shift sleeve 144. The second actuator 116 may be deflected to engage the either the first gear assembly 132 or the second gear assembly 136 depending on the direction of deflection. As above with respect to the first actuator 106, the movement of a corresponding second shift sleeve 144 may be used to cause the actuator 116 to deflect and engage either gear assembly 132, 136. As shown above in Fig. 4 and Fig. 5, a gap 150 may be set at the time of design to determine the combinations of gear drive and ratcheting that are available in a particular instance of the clutch and gear module 140.

[0040] A clutch and gear module 140 in accordance with the current disclosure benefits both transmission suppliers and users. The actuator carrier 100 is easy to assemble and install and the simple axial movement of the shift sleeves 142 and 144 reduces complexity associated with prior art radially-actuated clutch and gear mechanisms. For a user, the simple construction reduces complexity providing, in some cases, for a longer life of the

transmission as well as easier and less costly repairs.

[0041] While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims.