US20170138227A1

US20170138227A1 - Multi-position camshaft phaser with two one-way clutches

Info

Publication number: US20170138227A1
Application number: US15/295,404
Authority: US
Inventors: Eric Berndt
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2015-11-16
Filing date: 2016-10-17
Publication date: 2017-05-18

Abstract

A camshaft phaser, including an input component receiving torque from an engine, an advance hub, an advance wedge plate radially between the input component and advance hub, and an actuation assembly including an advance shoe arranged in a channel in a camshaft and an actuator pin. For an advance mode, the actuator pin can radially displace the advance shoe into non-rotatable connection with the advance hub, the advance hub is arranged to rotate, with respect to the input component, in a first circumferential direction, and the advance wedge plate is arranged to block rotation of the advance hub, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction. Components permitting operation in a phase retard mode where retard shoes are in non-rotatable connection with a retard hub and a drive mode where the advance and retard shoes are both in contact with their hubs.

Description

TECHNICAL FIELD

The present disclosure relates to camshaft phasers with two one-way wedge clutches. An axially displaceable component is used to engage and disengage the one-way clutches to enable the phaser to shift between advance and retard modes.

BACKGROUND

It is known to use hydraulic fluid in an internal combustion engine to phase a camshaft for the engine. However, for some engines, in particular smaller engines for outboard motors, motorcycles, or all-terrain vehicles, the supply of hydraulic fluid is limited, which limits the use of the fluid for phasing and may compromise the operation of the engine and the camshaft phasing.

SUMMARY

According to aspects illustrated herein, there is provided a camshaft phaser, including an input component arranged to receive torque from an engine, an advance hub, an advance wedge plate radially disposed between the input component and the advance hub, and an actuation assembly including an advance shoe assembly and an actuator pin. The advance shoe assembly has an advance shoe portion and may have an advance support leg portion where the advance support leg portion is arranged to be disposed in an advance channel in a camshaft. In an advance mode, the actuator pin is arranged to radially displace the advance shoe assembly, often by advancing a support leg of the advance shoe assembly, to place the advance shoe into non-rotatable connection with the advance hub, the advance hub is arranged to rotate, with respect to the input component, in a first circumferential direction, and the advance wedge plate is arranged to block rotation of the advance hub, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction.
According to an option illustrated herein, there is provided a camshaft assembly, including a camshaft including an advance channel and a retard channel, and a camshaft phaser. The camshaft phaser includes an advance hub, a retard hub, and an actuation assembly including an advance shoe assembly having an advance leg portion disposed in the advance channel, a retard shoe assembly having a retard shoe portion and a retard leg portion disposed in the retard channel, and an actuator pin. In an advance mode, the actuator pin is arranged to radially displace the advance leg of the advance shoe assembly to place the advance shoe into frictional contact with the advance hub, the camshaft is arranged to rotate, with respect to an input component from an engine, in a first circumferential direction, and the advance hub is arranged to block rotation of the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction. The input component may provide rotational energy using any suitable apparatus known to those skilled in the art, such as a gear, pinion or sprocket connected to an engine through a known transfer system, e.g., sprocket system, belt or chain. In a retard mode, the actuator pin is arranged to radially displace the retard leg portion of the retard shoe assembly to place the retard shoe portion into frictional contact with the retard hub, the camshaft is arranged to rotate, with respect to the input component, in the second circumferential direction, and the retard hub is arranged to block rotation of the camshaft, with respect to the input component in the first circumferential direction.
According to aspects illustrated herein, there is provided a method of phasing a camshaft, including the steps of receiving torque from an engine using an input component for a camshaft phaser. In an advance mode, the steps of the method include axially′ displacing an actuator pin, to radially displace an advance shoe portion of an advance shoe assembly into frictional contact with an advance hub for the camshaft phaser, an advance leg of the advance shoe assembly being located in an advance channel in the camshaft, rotating the camshaft, with respect to the input component, in a first circumferential direction, blocking, with the advance hub, rotation of the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, and, for a retard mode, axially displacing an actuator pin to radially displace a retard shoe portion of a retard shoe assembly into frictional contact with a retard hub for the camshaft phaser, a retard leg of the retard shoe assembly being located in a retard channel in the camshaft, rotating the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, and blocking, with the retard hub, rotation of the camshaft, with respect to the input component, in the first circumferential direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which:

FIG. 1 is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application;

FIG. 2 is a top view of a camshaft assembly with a camshaft phaser, having two one-way wedge clutches with rotatable hubs;

FIG. 3 is a cross-sectional view taken generally along line 3-3 in FIG. 2 with the camshaft phaser in an advance mode;

FIG. 4 is a cross-sectional view of the camshaft assembly in FIG. 3 with the camshaft phaser in a retard mode;

FIG. 5A is a front view of advance hub 110 and advance wedge plate 112, also shown in FIG. 3;

FIG. 5B is a rear view of retard hub 122 and retard wedge plate 124, also shown in FIG. 3;

FIG. 6 is a cross-sectional view taken generally along line 6-6 in FIG. 3;

FIG. 7 is a cross-sectional view of the camshaft assembly shown in FIG. 3 in a drive mode;

FIG. 8 is a front perspective view of advance hub 110, also shown in FIG. 3;

FIG. 9 is a rear perspective view of retard hub 122, also shown in FIG. 3;

FIG. 10 is a cross-sectional view of a camshaft phaser of the disclosure taken generally along line 10-10 of FIG. 3; and,

FIG. 11 is a cross sectional view of a camshaft phaser of the disclosure taken generally along line 11-11 of FIG. 3.

DETAILED DESCRIPTION

At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the disclosure. It is to be understood that the disclosure as claimed is not limited to the disclosed aspects.
Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this present disclosure belongs. It should be appreciated that the term “substantially” is synonymous with terms such as “nearly”, “very nearly”, “about”, “approximately”, “around”, “bordering on”, “close to”, “essentially”, “in the neighborhood of”, “in the vicinity of”, etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term “proximate” is synonymous with terms such as “nearby”, “close”, “adjacent”, “neighboring”, “immediate”, “adjoining”, etc., and such terms may be used interchangeably as appearing in the specification and claims.
FIG. 1 is a perspective view of cylindrical coordinate system 10 demonstrating spatial terminology used in the present application. The present application is at least partially described within the context of a cylindrical coordinate system. System 10 includes longitudinal axis 11, used as the reference for the directional and spatial terms that follow. Axial direction AD is parallel to axis 11. Radial direction RD is orthogonal to axis 11. Circumferential direction CD is defined by an endpoint of radius R (orthogonal to axis 11) rotated about axis 11.
To clarify the spatial terminology, objects 12, 13, and 14 are used. An axial surface, such as surface 15 of object 12, is formed by a plane co-planar with axis 11. Axis 11 passes through planar surface 15; however any planar surface co-planar with axis 11 is an axial surface. A radial surface, such as surface 16 of object 13, is formed by a plane orthogonal to axis 11 and co-planar with a radius, for example, radius 17. Radius 17 passes through planar surface 16; however any planar surface co-planar with radius 17 is a radial surface. Surface 18 of object 14 forms a circumferential, or cylindrical, surface. For example, circumference 19 is passes through surface 18. As a further example, axial movement is parallel to axis 11, radial movement is orthogonal to axis 11, and circumferential movement is parallel to circumference 19. Rotational movement is with respect to axis 11. The adverbs “axially,” “radially,” and “circumferentially” refer to orientations parallel to axis 11, radius 17, and circumference 19, respectively. For example, an axially disposed surface or edge extends in direction AD, a radially disposed surface or edge extends in direction R, and a circumferentially disposed surface or edge extends in direction CD.
FIG. 2 is a top view of an example of a camshaft assembly 100 with a camshaft phasing having two one-way wedge clutches with rotatable hubs in an advance mode. The embodiments shown in the drawings are for illustration and are not intended to limit other embodiments that can be envisioned by those skilled in the art in view of the present specification.
FIG. 3 is a cross-sectional view taken generally along line 3-3 in FIG. 2 with the camshaft phaser in an advance mode.
FIG. 4 is a cross-sectional view of camshaft assembly 100 in FIG. 3 with the camshaft phaser in a retard mode.
The following should be viewed in light of FIGS. 2 through 4. Assembly 100 includes camshaft 102 and camshaft phaser 104 arranged for rotation about axis of rotation AR. Camshaft 102 includes advance channel 106. Phaser 104 includes input component 108, e.g., a gear or sprocket, arranged to receive torque from an engine (not shown), advance hub 110, advance wedge plate 112 radially disposed between input component 108 and advance hub 110, and actuation assembly 114. Assembly 114 includes advance shoe assembly 116 having an advance shoe 1164 and advance shoe leg 116B disposed in advance channel 106, and actuator pin 118. Radially outermost portion 112A of wedge plate 112 is in frictional contact with input component 108, for example with chamfered groove 1084. In an example embodiment, component 108 is an input sprocket 108C.
In the discussion that follows, input component 108 rotates in direction CD1. In an advance mode, actuator pin 118 is arranged in actuator channel 119 to radially displace advance shoe leg 116B and thus advance shoe 116A into non-rotatable frictional contact with advance hub 110, camshaft 102 is arranged to rotate, with respect to input component 108, in circumferential direction CD1, and advance hub 110 is arranged to block rotation of the camshaft, with respect to the input component 108, in circumferential direction CD2, opposite circumferential direction CD1.
Camshaft 102 may also include retard channel 120. Maser 100 may also include retard hub 122, and retard wedge plate 124 radially disposed between input component 108 and retard hub 122. Actuation assembly 114 may also include retard shoe assembly 126 having a retard shoe 126A and a retard shoe leg 126B disposed in retard channel 120. Radially outermost portion 124A of wedge plate 124 is in frictional contact with input component 108, for example with chamfered groove 108B. In a retard mode, actuator pin 118 is arranged to radially displace retard shoe leg 126B and thus retard shoe 126A into non-rotatable frictional contact with retard hub 122, camshaft 102 is arranged to rotate, with respect to input component 108, in circumferential direction CD2, and retard hub 122 is arranged to block rotation of the camshaft, with respect to the input component, in circumferential direction CD1.
Actuator pin 118 may be biased, for example, by resilient member 170, toward actuator pin moving source 154, e.g., a solenoid. Resilient member 170 thus stores potential energy by movement of actuator pin 118 toward resilient member 170. The stored potential energy is released to return actuator pin 118 toward moving source 154 when counter-force applied by moving source 154 is sufficiently reduced.
FIG. 5A is a front view of advance hub 110 and advance wedge plate 112 shown in FIG. 3. Advance hub 110 preferably includes ramps 128A extending radially outward in direction RD1 along circumferential direction CD1. Advance wedge plate 112 preferably includes ramps 130A extending radially inward in radial direction RD2 along circumferential direction CD2 and engaged with ramps 128A. In the advance mode, when the camshaft is rotating relative to the input component, in circumferential direction CD1 (further described below), ramps 128A and 130A are arranged to circumferentially displace with respect to each other so that advance wedge plate 112 contracts in radial direction RD2 and advance hub 110 rotates with respect to input component 108, e.g., sprocket 108C in direction CD1. For example, the frictional engagement of wedge plate 112 and sprocket 108C rotates wedge plate 112 and ramps 130A in direction CD2 and ramps 128A, rotating in direction CD1, slide “down” ramps 130A in direction CD1. Since the radially inward retraction of plate 112 lessens the frictional engagement of sprocket 108C and plate 112, hub 110 is able to rotate with respect to sprocket 108C in direction CD1.
In the advance mode, when the camshaft is rotating relative to the input component, in circumferential direction CD2 (further described below), ramps 128A and 130A are arranged to circumferentially displace with respect to each other to displace wedge plate 112 radially outward to non-rotatably connect the input component, advance wedge plate 112, and advance hub 110, preventing rotation of hub 110, with respect to input component 108, in direction CD2. For example, the frictional engagement of wedge plate 112 and input component 108 rotates wedge plate 112 and ramps 130A in direction CD1. As ramps 128A rotate in direction CD2 with respect to ramps 130A, the more radially outward portions of ramps 128A engage and push the more radially inward portions of ramps 130A in direction RD1, pushing portion 112A radially outward.
FIG. 5B is a rear view of retard hub 122 and retard wedge plate 124 shown in FIG. 3. Retard hub 122 includes ramps 128B extending radially outward in direction RD1 along circumferential direction CD2. Retard wedge plate 124 includes ramps 130B extending radially inward in radial direction RD2 along circumferential direction CD1 and engaged with ramps 128B. For the retard mode and rotation of the camshaft, with respect to the input component, in circumferential direction CD2 (further described below), ramps 128B and 130B are arranged to circumferentially displace with respect to each other so that retard wedge plate 124 contracts in radial direction RD2 and hub 122 rotates with respect to plate 124 and input component 108. For example, the frictional engagement of wedge plate 124 and input component 108 rotates wedge plate 124 and ramps 130B in direction CD1 and ramps 128B, rotating in direction CD2, slide “down” ramps 130B in direction CD2. Since the radially inward retraction of retard wedge plate 124 lessens the frictional engagement of input component 108, e.g., sprocket 108C and retard wedge plate 124, hub 122 is able to rotate with respect to sprocket 108C in direction CD2.
In the retard mode when the camshaft is rotating relative to the input component, in circumferential direction CD1 (further described below), ramps 128B and 130B are arranged to circumferentially displace with respect to each other to displace retard wedge plate 124 radially outward to non-rotatably connect the input component, retard wedge plate 124, and retard hub 122, preventing rotation of hub 122, with respect to input component 108, in direction CD1. For example, the frictional engagement of retard wedge plate 124 and input component 108 rotates wedge plate 124 and ramps 130B in direction CD2. As ramps 128B rotate in direction CD1 with respect to ramps 130B, the more radially outward portions of ramps 128B and engage and push the more radially inward portions of ramps 130B in direction RD1, pushing portion 124A radially outward.
In the advance mode, retard hub 122 is rotatable with respect to retard shoe 126A or input component 108. For example, retard shoe 126A is radially inward of hub 122 so that retard shoe 1264 is not frictionally engaged with hub 122. For the retard mode, advance hub 110 is rotatable with respect to advance shoe 116A or input component 108. For example, advance shoe 116A is radially inward of hub 110 so that advance shoe 1164 is not frictionally engaged with hub 110.
In an example embodiment, actuator pin 118 includes portions 118A and 118B, having outer radii 132 and 134, respectively, and portion 118C having outer radius 136 greater than radii 132 and 134, respectively. In the advance mode, actuator pin 118 is displaceable so that portions 118C and 118B directly engage advance shoe assembly 116 and retard shoe assembly 126, respectively. In the retard mode, actuator pin 118 is displaceable so that portions 118A and 118C directly engage advance shoe assembly 116 and retard shoe assembly 126, respectively.
FIG. 6 is a cross-sectional view taken generally along line 6-6 in FIG. 3. In an example embodiment, camshaft 102 includes at least one slot 138 and phaser 104 includes at least one pin 140 non-rotatably connected to camshaft phaser assembly 104 and disposed in slot(s) 138. Slot 138 includes ends E1 and E2. Each pin 140 and each respective slot 138 act as stops for the rotation of camshaft 102, with respect to sprocket 108C, in directions CD1 and CD2. For example, in the retard mode, once camshaft 102 rotates far enough, with respect to sprocket 108C, end E1 contacts pin 140 to prevent further rotation of camshaft 102, with respect to sprocket 108C, in direction CD2. For example, in the advance mode, once camshaft 102 rotates far enough, with respect to sprocket 108C, end E2 contacts pin 140 to prevent further rotation of camshaft 102, with respect to sprocket 108C, in direction CD1.
FIG. 7 is a cross-sectional view of camshaft assembly 100 in FIG. 3 in a drive mode. In an example embodiment, phaser 104 operates in only the advance mode or the retard mode. However, phaser 104 can also be locked in an intermediate drive mode. For the drive mode, actuator pin 118 is displaceable so that portion 118C directly engages both advance shoe assembly 116 and retard shoe assembly 126. Thus, in the drive mode both advance shoe 116A and retard shoe 126A cause both hub 110 and hub 122 to be non-rotatably connected to camshaft 102. As a result, the rotational position of camshaft 102 with respect to input component 108 is substantially fixed. For example: a relative rotation of hub 110, with respect to wedge plate 112 in direction CD2, of less than one degree is needed to non-rotatably connect hub 110, wedge plate 112 and sprocket 108C; and: a relative rotation of hub 122, with respect to wedge plate 124 in direction CD1, of less than one degree is needed to non-rotatably connect hub 122, wedge plate 124 and input component 108.
FIG. 8 is a front perspective view of advance hub 110, also shown in FIG. 3.
FIG. 9 is a rear perspective view of retard hub 122, also shown in FIG. 3. As an example, to initiate the advance mode starting at the retard mode, advance shoe 116A is non-rotatably frictionally engaged with advance hub 110, wedge plate 112, and camshaft 102, and retard shoe 126A is radially withdrawn from frictional engagement with retard hub 122. As noted above, in the advance mode, hub 122 is rotatable with respect to camshaft 102, and the frictional engagement of wedge plate 124 and sprocket 108C rotates plate 124 and hub 122 in direction CD1. As an example, for the drive mode, the position of the retard shoe 126A may be selected for desired advance phase shift. Actuator pin 118 may be moved so that radially greater actuator pin portion 118C engages and radially advances both advance shoe leg 116B and retard shoe leg 126B so that both advance shoe 116A and retard shoe 126A frictionally engage advance hub 110 and retard hub 122 in an intermediate phase drive position.
As an example, to initiate the retard mode starting at the advance mode, retard shoe 126A is non-rotatably frictionally engaged with hub 122 and camshaft 102, and advance shoe 116A is radially withdrawn from advance hub 110. As noted above, in the retard mode, hub 110 is rotatable with respect to camshaft 102, and the frictional engagement of wedge plate 112 and input component 108 rotates plate 112 and hub 110 in direction CD2.
Shoes 116A and 126A can thus be positioned so they simultaneously frictionally engage hubs 110 and 122, respectively, to initiate a phase stable drive mode.
FIG. 10 is a cross-sectional view of the camshaft phaser taken generally along line 1040 of FIG. 3 illustrating the advance mode and showing shoe 116A in contact with advance hub 110. The position of resilient element 146 is in compressed energy storing mode, i.e., when shoe 116A is forced into contact with advance hub 110 by actuator 118. Resilient element 146 expands to pull advance shoe 116A away from advance hub 110, when actuator 118 is positioned to permit advance shoe 116A to be withdrawn from advance hub 110, e.g., in retard mode.
FIG. 11 is a cross-sectional view of the camshaft phaser taken on line 11-11 of FIG. 3 illustrating retard mode and showing retard shoe 126A withdrawn from retard hub 122 and held in withdrawn position by expanded resilient element 148. When retard shoe 126A is forced into contact with retard hub 122 by actuator 118, e.g., in retard mode, resilient element 148 is compressed to store energy such that resilient element 148 can be withdrawn from retard hub 122 by resilient element 148 when the position of actuator 118 permits it, e.g., in advance mode. As seen in FIGS. 10 and 11, shoes 116A and 126A can be in a different configuration when withdrawn from their respective hubs, and may form to the shape of their respective hubs when forced into contact with their respective hubs. Shoes 116A and 126A may, for example be in the form of a flat leaf spring that forms to the shape of a hub when forced into contact with the hub. Bending of shoes 116A and 126A stores potential energy in the leaf spring type shoes that causes the shoes to retract from the advance and retard hubs when permitted to do so when the actuator is no longer in a position to force the shoes to contact and bend to the shape of the advance or retard hub curvature. A friction coating may be applied to the surface of the shoes to aid in improved friction holding power and abrasion resistance. When leaf springs are used as the shoes, additional resilient members to cause the shoes to retract from the advance or retard hobs may not be necessary.
FIGS. 10 and 11 show positions of the advance and retard shoes in the advance mode. It should be understood that in the retard mode, positions of the advance and retard shoes are the opposite of the positions shown in FIGS. 10 and 11.
As is known in the art, torsional forces T1 and T2 are generated by camshaft 102, in directions CD1 and CD2, respectively. The torsional force forces are due to interaction of cam lobes (not shown) on camshaft 102 with various components of a valve train (not shown) of which camshaft 102 is a part. Torsional forces T1 and T2 are transmitted in a repeating cycle. Wedge plates 112 and 124 rotate in direction CD1 (due to torque from sprocket 108C). For the advance mode, torsional force T1 urges huh 110 in direction CD1 with respect to wedge plate 112 and torsional force T2 urges hub 110 in direction CD2 with respect to wedge plate 112. During operation, input component 108 and wedge plates 112 and 124 are always rotating in direction CD1. However, unchecked, torque T1 and T2 cause: in the advance mode, camshaft 102 and hub 110 to speed up relative to input component 108; and in the retard mode, camshaft 102 and hub 122 to slow down relative to input component 108.
In the advance mode, camshaft 102, hub 110, and wedge plate 112 are rotatable in direction CD1 with respect to sprocket 108C. Therefore, each iteration of force T1 causes relative rotation of camshaft 102 and hub 110 by amount 150 (from assumed starting point P) with respect to sprocket 108C, in direction CD1. Each iteration of force T2 non-rotatably connects input component 108, e.g. sprocket 108 C wedge plate 112, hub 110, and camshaft 102, preventing rotation of camshaft 102, with respect to input component 108, in direction CD2. Thus, for every cycle of forces T1 and T2, camshaft 102 rotates by amount 150 in direction CD1.
In the retard mode, camshaft 102, hub 122, and wedge plate 124 are rotatable in direction CD2 with respect to sprocket 1080. Therefore, each iteration of force T2 causes relative rotation of camshaft 102 and hub 122 by amount 152 (from assumed starting point P) with respect to input component 108, in direction CD2. Each iteration of force T1 non-rotatably connects input component 108, wedge plate 124, hub 122, and camshaft 102, preventing rotation of camshaft 102, with respect to input component 108, in direction CD1. Thus, for every cycle of forces T1 and T2, camshaft 102 rotates by amount 152 in direction CD2.
Since both hubs 110 and 122 are non-rotatably connected to camshaft 102 in the drive mode, the effect of forces T1 and T2 is substantially neutralized in the drive mode. For example, for each iteration of force T1, a very nominal rotation of hub 122 in direction CD1 non-rotatably connects input component 108, wedge plate 124, hub 122, and camshaft 102, preventing rotation of camshaft 102, with respect to input component 108, in direction CD1. For example, for each iteration of force T2, a very nominal rotation of hub 110 in direction CD2 non-rotatably connects input component 108, wedge plate 112, hub 110, and camshaft 102, preventing rotation of camshaft 102, with respect to input component 108, in direction CD2. The nominal rotation noted above is significantly smaller than distance 150 or distance 152. For example, distances 150 and 152 are greater than one degree of rotation for hub 110 and 122, respectively, and the nominal rotation is less than one degree of rotation for hub 110 and 112, respectively.
In an example embodiment, phaser 104 includes actuator 154 (schematically represented in FIGS. 3, 4, and 7) arranged to displace pin 118 in axial directions AD1 and AD2 to control respective positions of pin portions 118A, 118B, and 118C as described above. Actuator 154 can be any actuator known in the art, including but not limited to, a hydraulic actuator, a mechanical actuator, an electric actuator, or a pneumatic actuator.
In an example embodiment, phaser 104 includes resilient elements 156 and 158 arranged to urge wedge plates 112 and 124 in axial directions AD1 and AD2, respectively, for example, into contact with portions 110A and 122A of hubs 110 and 122, respectively. Elements 156 and 158 maintain respective axial positions of wedge plates 112 and 124, respectively.
In an example embodiment, phaser 104 includes cover 142, radial bearings 160, thrust bearings 162, and cover 164. Covers 142 and 164 are fixed to input component 108 by any means known in the art, for example, bolts 166. In an example embodiment, nut 168 secures phaser 104 to camshaft 102.
The following should be viewed in light of FIGS. 2 through 11. The following describes a method for phasing a camshaft. A first step receives, using an input component for a camshaft phaser, torque from an engine. A second step, for an advance mode, radially displaces, with an actuator pin for an actuator assembly, an advance shoe into non-rotatable connection with an advance hub for the camshaft phaser, the actuator pin located in an advance channel in the camshaft, rotates the camshaft, with respect to the input component, in a first circumferential direction; and blocks, with the advance hub, rotation of the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction. A third step, for a retard mode, axially displaces the actuator pin, radially displaces, with the actuator pin, a retard shoe into non-rotatable connection with a retard hub for the camshaft phaser, the retard shoe located in a retard channel in the camshaft; rotates the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, and blocks, with the retard hub, rotation of the camshaft, with respect to the input component, in the first circumferential direction.
A fourth step, for the advance mode, engages a first plurality of ramps, for the advance hub, extending radially outward along the first circumferential direction with a second plurality of ramps, for an advance wedge plate radially located between the input component and the advance hub, extending radially inward in the second circumferential direction, for rotation of the camshaft, with respect to the input component, in the second circumferential direction, circumferentially displaces the first and second pluralities of ramps with respect to each other, and displaces the advance wedge plate radially outward to non-rotatably connect the input component, the advance wedge plate, and the advance hub.
A fifth step, for the retard mode, engages a first plurality of ramps, for the retard hub, extending radially outward along the second circumferential direction with a second plurality of ramps, for a retard wedge plate radially located between the input component and the retard hub, extending radially inward in the first circumferential direction, for rotation of the camshaft, with respect to the input component, in the first circumferential direction, circumferentially displaces the first and second pluralities of ramps with respect to each other, and displaces the retard wedge plate radially outward to non-rotatably connect the input component, the retard wedge plate, and the retard hub.
Advantageously, camshaft assembly 100 and a method of phasing a camshaft presented above address the problems noted above regarding phase control of a camshaft in an engine having limited availability of hydraulic fluid. For example, phaser 104 does not use hydraulic fluid to phase camshaft 102.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

LIST OF ELEMENTS IN THE DRAWINGS

10 cylindrical coordinate system
11 longitudinal axis
12 object illustrating an axial surface
13 object illustrating a radial surface
14 object illustrating a cylindrical surface
15 axial surface of object 12
16 radial surface of object 13
17 radius
18 cylindrical/circumferential surface of object 14
19 circumference passing through surface 18
AD axial direction.
CD circumferential direction
R radius
RD radial direction
100 camshaft assembly
102 camshaft
104 camshaft phaser
106 advance channel
108 input component
108A chamfered groove
108B chamfered groove
108C sprocket as input component
110 advance hub
110A advance hub contact portion
112 advance wedge plate
112A radial outermost portion of advance wedge plate 112
114 actuator assembly
116 advance shoe assembly
116A advance shoe
116B advance shoe leg
118 actuator pin
118A actuator pin advance shoe leg radial retract portion
118B actuator pin retard shoe leg radial retract portion
118C actuator pin shoe leg radial advance portion
119 actuator channel
120 retard channel
122 retard hub
122A retard hub contact portion
124 retard wedge plate
124A radial outermost portion of retard hub
126 retard shoe assembly
126A retard shoe
126B retard shoe leg
128A advance hub ramps
128B retard hub ramps
130A advance wedge plate ramps
130B retard wedge plate ramps
132 actuator pin portion radius
134 actuator pin portion radius
136 actuator pin portion radius
138 stop slot
140 stop pin
142 cover
146 resilient element
148 resilient element
150 rotational amount
152 rotational amount
154 actuator
156 resilient element
158 resilient element
160 radial bearings
162 thrust hearings
164 cover
166 bolts
168 nut
170 resilient element
AR axis of rotation
CD1 circumferential direction one
CD2 circumferential direction two
AD1 axial direction one
AD2 axial direction two
RD1 radial direction one
RD2 radial direction two
T1 torsional force one
T2 torsional force two
P assumed relative camshaft-hub starting point
E1 slot end one
E2 slot end two

Claims

What is claimed is:

1. A camshaft phaser, comprising:

an input component arranged to receive torque from an engine;

an advance hub;

an advance wedge plate radially disposed between the input component and the advance hub; and,

an actuation assembly including:

an advance shoe arranged to be disposed in an advance channel for a camshaft; and,

an actuator pin, arranged to radially displace the advance shoe into non-rotatable frictional contact with the advance hub, the advance hub arranged to rotate with respect to the input component, in a first circumferential direction, the advance wedge plate arranged to block rotation of the advance hub, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction in an advance mode.

2. The camshaft phaser recited in claim 1, wherein:

the advance hub includes a first plurality of ramps extending radially outward along the first circumferential direction;

the advance wedge plate includes a second plurality of ramps extending radially inward along the second circumferential direction and engaged with the first plurality of ramps; and,

the first and second pluralities of ramps are arranged to displace the advance wedge plate radially outward to non-rotatably connect the input component, the advance wedge plate, and the advance hub, in the second circumferential direction, in the advance mode.

3. The shaft phaser recited in claim 1, further comprising:

a retard hub; and,

a retard wedge plate radially disposed between the input component and the retard hub, wherein the actuation assembly includes a retard shoe arranged to be disposed in a retard channel for the camshaft, the actuator pin is arranged to radially displace the retard shoe into non-rotatable frictional contact with the retard hub, the retard hub is arranged to rotate, with respect to the input component, in the second circumferential direction, and, the retard wedge plate is arranged to block rotation of the retard hub, with respect to the input component, in the first circumferential direction, in a retard mode.

4. The camshaft phaser recited in claim 3, wherein the retard hub includes a first plurality of ramps extending radially outward along the second circumferential direction, the retard wedge plate includes a second plurality of ramps extending radially inward along the first circumferential direction and engaged with the first plurality of ramps, and, the first and second pluralities of ramps are arranged to displace the retard wedge plate radially outward to non-rotatably connect the input component, the retard wedge plate, and the advance hub, for rotation of the camshaft, with respect to the input component, in the first circumferential direction in the retard mode.

5. The camshaft phaser recited in claim 3, wherein the retard hub is rotatable with respect to the retard shoe or the input component in the advance mode, and the advance hub is rotatable with respect to the advance shoe or the input component in the retard mode.

6. The camshaft phaser recited in claim 3, wherein the actuator pin includes first and second portions having first and second outer radii, respectively, and a third portion having a third outer radius greater than the first and second radii, respectively, wherein the actuator pin is displaceable so that the third and second portions directly engage the advance and retard shoes, respectively, in the advance mode, and the actuator pin is displaceable so that the first and third portions directly engage the advance and retard shoes, respectively, in the retard mode.

7. The camshaft phaser recited in claim 6 wherein the camshaft includes at least one slot having first and second ends and the phaser includes at least one stop pin non-rotatably connected to the phaser and disposed in said at least one slot such that each stop pin in each respective slot act as stops for rotation of the camshaft with respect to the input component.

8. The camshaft phaser recited in claim 7, wherein for a drive mode:

the actuator pin is displaceable so that the third portion directly engages the advance and retard shoes;

the advance and retard shoes are in non-rotatable frictional contact with the advance and retard hubs, respectively, and,

the advance and retard hubs each transmit torque from the input component.

9. The camshaft phaser recited in claim 8, wherein:

the input component is arranged to rotate in the first circumferential direction;

the camshaft is arranged to rotate with respect to the input component in the first and second circumferential directions during first and second alternating time periods;

the retard hub is arranged to transmit torque from the input component to the camshaft during the first time period in the drive mode; and,

the advance hub is arranged to transmit torque from the input component to the camshaft during the second time period in the drive mode.

10. A camshaft phaser, comprising:

a camshaft including an advance channel and a retard channel; and,

a camshaft phaser including:

an advance hub;

a retard hub; and,

an actuation assembly including:

an advance shoe disposed in the advance channel;

a retard shoe disposed in the retard channel; and,

an actuator pin, wherein:

the actuator pin is arranged to radially displace the advance shoe into non-rotatable frictional contact with the advance hub, the camshaft is arranged to rotate, with respect to the input component, in a first circumferential direction, and the advance hub is arranged to block rotation of the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, in an advance mode; and,

the actuator pin is arranged to radially displace the retard shoe into non-rotatable frictional contact with the retard hub, the camshaft is arranged to rotate, with respect to the input component, in the second circumferential direction, and the retard hub is arranged to block rotation of the camshaft, with respect to the input component in the first circumferential direction, in a retard mode.

11. The camshaft phaser recited claim 10, wherein:

the camshaft phaser includes an advance wedge plate radially disposed between the input component and the advance hub;

the first and second pluralities of ramps are arranged to circumferentially displace with respect to each other to displace the advance wedge plate radially outward to non-rotatably connect the input component, the advance wedge plate, and the advance hub for rotation of the camshaft, with respect to the input component, in the second circumferential direction, in the advance mode.

12. The camshaft phaser recited claim 10, wherein:

the camshaft phaser includes a retard wedge plate radially disposed between the input component and the retard hub;

the retard hub includes a first plurality of ramps extending radially outward along the second circumferential direction;

the retard wedge plate includes a second plurality of ramps extending radially inward in the first circumferential direction and engaged with the first plurality of ramps; and,

the first and second pluralities of ramps are arranged to circumferentially displace with respect to each other to displace the retard wedge plate radially outward to non-rotatably connect the input component, the retard wedge plate, and the retard hub for rotation of the camshaft, with respect to the input component, in the first circumferential direction, in the retard mode.

13. The camshaft phaser recited in claim 10, wherein:

the retard hub is rotatable with respect to the retard shoe or the input component, in the advance mod, and the advance hub is rotatable with respect to the advance shoe or the input component in the retard mode.

14. The camshaft phaser recited in claim 10, wherein:

the actuator pin includes:

first and second portions having first and second outer radii, respectively; and,

a third portion having a third outer radius greater than the first and second radii, respectively; and,

the actuator pin is displaceable so that the third and second portions directly engage the advance and retard shoes, respectively, in the advance mode, and the actuator pin is displaceable so that the first and third portions directly engage the advance and retard shoes, respectively, in the retard mode.

15. The camshaft phaser recited in claim 14, wherein for a drive mode:

the advance and retard hubs each transmit torque from the input component to the camshaft.

16. The camshaft phaser recited in claim 15, wherein:

17. The camshaft phaser recited in claim 10, wherein the camshaft phaser includes:

a first resilient element, for the advance shoe, arranged to displace the advance shoe radially away from friction contact with the advance hub in the retard mode, and

a second resilient element, for the retard shoe, arranged to displace the retard shoe radially away from the retard hub in the advance mode.

18. A method of phasing a camshaft, comprising:

receiving, using an input component for a camshaft phaser, torque from an input component from an engine;

radially displacing, with an actuator pin for an actuator assembly, an advance shoe into non-rotatable frictional contact with an advance hub for the camshaft phaser, the actuator pin being located in an advance channel in the camshaft, rotating the camshaft, with respect to the input component, in a first circumferential direction, and blocking, rotation of the camshaft, with the advance hub, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, in an advance mode; and,

axially displacing the actuator pin; radially displacing, with the actuator pin, a retard shoe into non-rotatable frictional contact with a retard hub for the camshaft phaser, the retard shoe being located in a retard channel in the camshaft, rotating the camshaft, with respect to the input component, in a second circumferential direction, opposite the first circumferential direction, and, blocking, with the retard hub, rotation of the camshaft, with respect to the input component, in the first circumferential direction, in a retard mode.

19. The method recited in claim 18, further comprising:

engaging a first plurality of ramps, for the advance hub, extending radially outward along the first circumferential direction, with a second plurality of ramps for an advance wedge plate radially located between the input component and the advance hub, extending radially inward in the second circumferential direction;

circumferentially displacing the first and second pluralities of ramps with respect to each other for rotation of the camshaft, with respect to the input component, in the second circumferential direction; and,

displacing the advance wedge plate radially outward to non-rotatably connect the input component, the advance wedge plate, and the advance hub in the advance mode.

20. The method recited in claim 18, further comprising:

engaging a first plurality of ramps, for the retard hub, extending radially outward along the second circumferential direction with a second plurality of ramps, for a retard wedge plate radially located between the input component and the retard hub, extending radially inward in the first circumferential direction;

displacing the retard wedge plate radially outward to non-rotatably connect the input component, the retard wedge plate, and the retard hub in the retard mode.