Abstract:
A dual independent phaser, including: one only single locking cover; a first phaser section including a first stator, a first rotor, a first plurality of chambers formed by a first rotor and the first stator, and first locking pin non-rotatably engaged with the first rotor and axially displaceable to non-rotatably connect the first rotor and the one only single locking cover; and second phaser section including second stator, a second rotor, a second plurality of chambers formed by a second rotor and the second stator, and second locking pin non-rotatably engaged with the second rotor and axially displaceable to non-rotatably connect the second rotor and the one only single locking cover.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/864,928, filed Aug. 12, 2013, which application is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a dual independent phaser with a single dual-sided locking cover for use in locking respective rotors for the two phasing sections in the phaser 
     BACKGROUND 
     For a dual independent phaser, undesirable oscillation and vibration can occur while the chambers for the two phaser sections are filled with oil, for example, when an engine to which the phaser is connected, is started up. To prevent the oscillation and vibration while the chambers are filling, it is known to lock the respective rotors for each of the two phaser sections to respective separate locking covers using respective locking pins. Thus, it is known to use two locking covers in a dual independent phaser. However, the use of two locking covers increases the cost, complexity, and axial space requirements of the phaser. 
     SUMMARY 
     According to aspects illustrated herein, there is provided a dual independent phaser, including: one only single locking cover; a first phaser section including a first stator, a first rotor, a first plurality of chambers formed by a first rotor and the first stator, and first locking pin non-rotatably engaged with the first rotor and axially displaceable to non-rotatably connect the first rotor and the one only single locking cover; and second phaser section including second stator, a second rotor, a second plurality of chambers formed by a second rotor and the second stator, and second locking pin non-rotatably engaged with the second rotor and axially displaceable to non-rotatably connect the second rotor and the one only single locking cover. 
     According to aspects illustrated herein, there is provided a dual independent phaser, including: one only single locking cover; a first phaser section disposed on a first axial side of the one only single locking cover and including a drive sprocket arranged to receive torque from an engine, a first stator non-rotatably connected to the drive sprocket, a first rotor, a first plurality of chambers formed by a first rotor and the first stator, and a first locking pin non-rotatably engaged with the first rotor and axially displaceable to non-rotatably connect the first rotor and the one only single locking cover; a second phaser section disposed on a second axial side, axially opposite the first axial side of the one only single locking cover and including a second stator non-rotatably connected to the drive sprocket, a second rotor, a second plurality of chambers formed by a second rotor and the second stator, and a second locking pin non-rotatably engaged with the second rotor and axially displaceable to non-rotatably connect the second rotor and the one only single locking cover; and a drive sprocket non-rotatably connected to the first and second stators and arranged to receive torque from an engine. The first plurality of chambers is arranged to circumferentially position, in response to fluid pressure in the first plurality of chambers, the first rotor with respect to the drive sprocket. The second plurality of chambers is arranged to circumferentially position, in response to fluid pressure in the second plurality of chambers, the second rotor with respect to the drive sprocket. 
     According to aspects illustrated herein, there is provided a method of fabricating a dual independent phaser, including: non-rotatably connecting a drive sprocket and a first stator for a first phaser section to a first axial side of one only single locking cover; forming a first plurality of chambers with the first stator and a first rotor; non-rotatably engaging a first locking pin with the first rotor so that the first locking pin is axially displaceable to non-rotatably connect the first rotor to the one only single locking cover; non-rotatably connecting second stator for a second phaser section to a second axial side, axially opposite the first axial side, of the one only single locking cover; forming a second plurality of chambers with the second stator and a second rotor; non-rotatably engaging a second locking pin with the second rotor so that the second locking pin is axially displaceable to non-rotatably connect the second rotor to the one only single locking cover. The first plurality of chambers is arranged to circumferentially position, in response to fluid pressure in the first plurality of chambers, the first rotor with respect to the drive sprocket. The second plurality of chambers is arranged to circumferentially position, in response to fluid pressure in the second plurality of chambers, the second rotor with respect to the drive sprocket. 
    
    
     
       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. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used in the present application; 
         FIG. 1B  is a perspective view of an object in the cylindrical coordinate system of  FIG. 1A  demonstrating spatial terminology used in the present application; 
         FIG. 2  is a side view of a dual independent phaser with a single locking cover; 
         FIG. 3  is an exploded view showing one phaser section from the dual independent phaser of  FIG. 2 ; 
         FIG. 4  is an exploded view of another phaser section of the dual independent phaser of  FIG. 2  and shows the phaser section of  FIG. 3  assembled; 
         FIG. 5  is a cross-sectional view generally along line  5 - 5  in  FIG. 4 ; 
         FIG. 6A  is a perspective view of the single locking cover as seen from one side; and, 
         FIG. 6B  is a perspective view of the single locking cover as seen from another side. 
     
    
    
     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. 
       FIG. 1A  is a perspective view of cylindrical coordinate system  80  demonstrating spatial terminology used in the present application. The present disclosure is at least partially described within the context of a cylindrical coordinate system. System  80  has a longitudinal axis  81 , used as the reference for the directional and spatial terms that follow. The adjectives “axial,” “radial,” and “circumferential” are with respect to an orientation parallel to axis  81 , radius  82  (which is orthogonal to axis  81 ), and circumference  83 , respectively. The adjectives “axial,” “radial” and “circumferential” also are regarding orientation parallel to respective planes. To clarify the disposition of the various planes, objects  84 ,  85 , and  86  are used. Surface  87  of object  84  forms an axial plane. That is, axis  81  forms a line along the surface. Surface  88  of object  85  forms a radial plane. That is, radius  82  forms a line along the surface. Surface  89  of object  86  forms a circumferential plane. That is, circumference  83  forms a line along the surface. As a further example, axial movement or disposition is parallel to axis  81 , radial movement or disposition is parallel to radius  82 , and circumferential movement or disposition is parallel to circumference  83 . Rotation is with respect to axis  81 . 
     The adverbs “axially,” “radially,” and “circumferentially” are with respect to an orientation parallel to axis  81 , radius  82 , or circumference  83 , respectively. The adverbs “axially,” “radially,” and “circumferentially” also are regarding orientation parallel to respective planes. 
       FIG. 1B  is a perspective view of object  90  in cylindrical coordinate system  80  of  FIG. 1A  demonstrating spatial terminology used in the present application. Cylindrical object  90  is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present invention in any manner. Object  90  includes axial surface  91 , radial surface  92 , and circumferential surface  93 . Surface  91  is part of an axial plane, surface  92  is part of a radial plane, and surface  93  is a circumferential surface. 
       FIG. 2  is a side view of dual independent phaser  100  with a single locking cover. 
       FIG. 3  is an exploded view showing one phaser section from dual independent phaser  100  of  FIG. 2 . 
       FIG. 4  is an exploded view of another phaser section of dual independent phaser  100  of  FIG. 2  and shows the phaser section of  FIG. 3  assembled. 
       FIG. 5  is a cross-sectional view generally along line  5 - 5  in  FIG. 4 . The following should be viewed in light of  FIGS. 2 through 5 . Dual independent phaser  100  includes single locking cover  102 , phaser section  104 , and phaser section  106 . Section  104  includes stator  108 , rotor  110 , chambers  112  formed by rotor  110  and stator  108 , and locking pin  114  non-rotatably engaged with rotor  110  and axially displaceable to non-rotatably connect rotor  110  and locking cover  102 . 
     Section  106  includes stator  116 , rotor  118 , chambers  120  formed by rotor  118  and stator  116 , locking pin  122  non-rotatably engaged with rotor  118  and axially displaceable to non-rotatably connect rotor  118  and locking cover  102 . In an example embodiment, phaser  100  includes drive sprocket  124  non-rotatably connected to stators  108  and  116  and arranged to receive torque from an engine. 
     Chambers  112  are arranged to circumferentially position, in response to fluid pressure in chambers  112 , rotor  110  with respect to the drive sprocket. Chambers  120  are arranged to circumferentially position, in response to fluid pressure in chambers  120 , rotor  118  with respect to the drive sprocket. Section  104  is disposed on axial side  126  of locking cover  102 , and section  106  is disposed on axial side  128 , axially opposite axial side  126 , of locking cover  102 . 
       FIG. 6A  is a perspective view of locking cover  104  as seen from one side, for example, for the side of section  104 . 
       FIG. 6B  is a perspective view of locking cover  104  as seen from another side, for example, for the side of section  106 . The following should be viewed in light of  FIGS. 2 through 6B . Locking cover  102  includes slots  130  and  132  in sides  126  and  128 , respectively. Slot  130  is arranged to receive locking pin  114  to non-rotatably connect rotor  110  and locking cover  102 . Slot  132  in side  128  is arranged to receive locking pin  122  to non-rotatably connect rotor  118  and locking cover  102 . 
     Slot  130  is arranged to receive fluid to urge pin  114  in axial direction AD 1  out of cover  102  such that rotor  110  is rotatable with respect to stator  108  and locking cover  102 . Slot  132  is arranged to receive fluid to urge pin  122  in axial direction AD 2  out of cover  102  such that rotor  118  is rotatable with respect to stator  116  and locking cover  102 . Operation of pins  114  and  122  is further described below. 
     In an example embodiment, section  104  includes spring  134  and peg  136 . Peg  136  is inserted into opening  138  of rotor  110 . Spring  134  and pin  114  are placed over peg  136  with end  114 A of pin  114  in contact with spring  134 . Spring  134  reacts against head  136 A of peg  136  to urge pin  114  in axial direction AD 2  toward locking cover  102 . In an example embodiment, section  106  includes spring  138  and peg  140 . Peg  140  is inserted into rotor  118 . Spring  138  and pin  122  are placed over peg  140  with end  122 A of pin  122  in contact with spring  138 . Spring  138  reacts against head  140 A of peg  140  to urge pin  122  in axial direction AD 1  toward locking cover  102 . 
     In an example embodiment, locking cover  102  includes threaded bores  142  and  144  and threaded fasteners  146  and  148 . Fasteners  146  pass through openings  150  and  152  in the drive sprocket and stator  108 , respectively, and are threaded into bores  142  to non-rotatably connect the drive sprocket and stator  108  to locking cover  102 . Fasteners  148  pass through openings  154  in stator  116  and are threaded into bores  144  to non-rotatably connect stator  116  to locking cover  102 . 
     In an example embodiment, rotor  110  includes channels  156  connecting inner circumferential surface  158  of rotor  110  with chambers  112 , and rotor  118  includes channels  160  connecting inner circumferential surface  161  of rotor  118  with chambers  120 . Channels  156  are arranged to flow fluid in and out of chambers  112  to circumferentially locate rotor  110  with respect to stator  108 . Channels  160  are arranged to flow fluid in and out of chambers  120  to circumferentially locate rotor  118  with respect to stator  116 . 
     In an example embodiment, rotor  110  includes separate vanes  162  inserted into respective slots  164  in rotor  110 , and rotor  118  includes separate vanes  166  inserted into slots  168  in rotor  118 . Chambers  112  are partially formed by vanes  162 , and chambers  120  are partially formed by vanes  166 . It should be understood that rotors  110  and  118  also can be formed as respective one-piece components having respective integral vanes. 
     In an example embodiment, section  104  includes spring  170  and cover  172 . Spring  170 , in particular, tab  170 A is engaged with rotor  110  to urge rotor  110  into a desired circumferential position when fluid pressure in chambers  112  falls below a predetermined level. In an example embodiment, section  106  includes side plate  174 , spring  176 , and cover  178 . Fasteners  148  pass through openings  180  in the side plate to secure the side plate against stator  116  and rotor  118  to seal one axial side of chambers  120 . Spring  176 , in particular, tab  176 A is engaged with rotor  118  to urge rotor  118  into a desired circumferential position when fluid pressure in chambers  120  falls below a predetermined level. 
     In an example embodiment, phaser  100  includes fluid feed  182 . Channels  184  in fluid feed  182  are in fluid communication with channels  156  in rotor  110  and are used to provide fluid to chambers  112 . Channels  186  in feed  182  are in fluid communication with channels  160  in rotor  118  and are used to provide fluid to chambers  120 . Feed  182  also includes oil rings  188 . 
     Displacement of pins  114  and  122  axially in and out of slots  130  and  132 , respectively, creates increased wear on the portions of plate  102  in contact with pins  114  and  122 . In an example embodiment, the portions of plate  102  in contact with pins  114  and  122  are hardened to compensate for the wear. In an example embodiment, phaser  100  includes hardened locking inserts  190 A and  190 B disposed in portions  130 A and  132 A of slots  130  and  132 , respectively. Pins  114  and  122  contact inserts  190 A and  190 B, respectively, shielding the remaining portions of plate  102  from the increased wear noted above. Advantageously, the use of inserts  190 A and  190 B eliminates the need to hardening plate  102 , simplifying operations and reducing costs associated with fabricating plate  102 . 
     The following provides further detail regarding phaser  100 . In an example embodiment, phase  104  is an exhaust phase, phase  106  is an intake phase, and phase  104  is assembled prior to assembling phase  106 . As part of the assembly of phase  104 , a locking clearance is set with locking pin  114  and return spring  170  is wound. In like manner, phase  106  is assembled onto plate  102 . Thus, plate  102  functions as a dual-sided locking plate. 
     When fluid pressure in chambers  112  and  120  falls below a certain value, for example, when fluid is not supplied to the chambers, springs  170  and  176  rotate rotors  110  and  118 , respectively, such that pins  114  and  122  are axially aligned with slots  130  and  132 , respectively. Springs  134  and  138  urge pins  114  and  122  into slots  130  and  132 , respectively, to rotationally lock rotors  110  and  118 . When fluid is initially supplied to chambers  112  and  120 , increasing the fluid pressure in the chambers, the rotational locking of rotors  110  and  118  prevents the undesirable oscillation and vibration noted above. When fluid pressure in chambers  112  increases to an operational level, the fluid pressure is great enough to overcome the force exerted by spring  134  in direction AD 2  and displace pin  114  in direction AD 1  such that pin  114  is displaced out of slot  130  and rotor  110  is rotatable with respect to plate  102  and stator  108 . In like manner, when fluid pressure in chambers  120  increases to an operational level, the fluid pressure is great enough to overcome the force exerted by spring  138  in direction AD 1  and displace pin  122  in direction AD 2  such that pin  122  is displaced out of slot  132  and rotor  118  is rotatable with respect to plate  102  and stator  116 . 
     Advantageously, phaser  100  enables the desired locking of rotors  110  and  118  during start up operations (raising fluid pressure in chambers  112  and  120 , respectively) while minimizing axial length  192  of the phaser. For example, since one locking cover, rather than two locking covers, is used in phaser  100 , length  192  is reduced at least by axial length  194  of locking cover  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.