Patent Application
20210372300
The present disclosure relates to a camshaft phaser with a target wheel washer to eliminate rotation of a target wheel for the camshaft phaser during assembly of the camshaft phaser or connection of the camshaft phaser to a camshaft.
It is known to fix an oil control valve to a camshaft phaser or to connect a camshaft phaser to a camshaft with a bolt. The oil control valve and the bolt are rotated to connect to the camshaft phaser and the camshaft, respectively. During the rotation, the oil control valve and the bolt frictionally contact a target wheel for the respective camshaft. The frictional contact with the target wheel, which is typically fabricated from a low-carbon steel, can cause galling of the target wheel and rotation of the target wheel from a calibrated position of the target wheel, degrading the performance of the target wheel and the respective camshaft phaser. It is known to apply grease between the target wheel to prevent galling of the target wheel and rotation of the target wheel. However, applying the grease adds complexity and cost to fabrication of the respective camshaft phasers.
According to aspects illustrated herein, there is provided a camshaft phaser, including: a stator arranged to receive rotational torque, including a plurality of radially inwardly extending protrusions, and supported for rotation around an axis of rotation; a rotor including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions, and arranged to non-rotatably connect to a camshaft; a plurality of phaser chambers, each phaser chamber circumferentially bounded by a radially inwardly extending protrusion included in the plurality of radially inwardly extending protrusions and a radially outwardly extending protrusion included in the plurality of radially outwardly extending protrusions; an annular washer; and a target wheel including a first portion axially located between the annular washer and the rotor and in contact with the annular washer, arranged to detect a rotational position of the rotor for use in rotating the rotor with respect to the stator.
According to aspects illustrated herein, there is provided a camshaft phaser, including: a stator arranged to receive rotational torque, including a plurality of radially inwardly extending protrusions, and supported for rotation around an axis of rotation; a rotor arranged to non-rotatably connect to a camshaft, and including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions; a plurality of phaser chambers, each phaser chamber circumferentially bounded by a radially inwardly extending protrusion included in the plurality of radially inwardly extending protrusions and a radially outwardly extending protrusion included in the plurality of radially outwardly extending protrusions; an annular washer having a first hardness; and a target wheel including a first portion axially disposed between the annular washer and the target wheel, the first portion in contact with the annular washer, having a second hardness, the second hardness less than the first hardness, and arranged to detect a rotational position of the rotor for use in rotating the rotor with respect to the stator.
According to aspects illustrated herein, there is provided a camshaft phaser, including: a stator arranged to receive rotational torque. including a plurality of radially inwardly extending protrusions, and supported for rotation around an axis of rotation; a rotor arranged to non-rotatably connect to a camshaft, and including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions; a plurality of phaser chambers, each phaser chamber circumferentially bounded by a radially inwardly extending protrusion included in the plurality of radially inwardly extending protrusions and a radially outwardly extending protrusion included in the plurality of radially outwardly extending protrusions; an annular washer having a first hardness and including a first surface facing in a first axial direction parallel to the axis of rotation, and a second surface facing in a second axial direction, opposite the first axial direction; and a target wheel including a first portion axially disposed between the annular washer and the target wheel and in contact with the first surface of the annular washer, having a second hardness, the second hardness less than the first hardness, and arranged to detect a rotational position of the rotor for use in rotating the rotor with respect to the stator. The camshaft phaser includes an oil control valve non-rotatably connected to the rotor and including a flange, the oil control valve is arranged to distribute a fluid to the plurality of phaser chambers, the flange is in contact with the second surface of the annular washer, and the flange clamps the annular washer to the target wheel; or the second surface of the annular washer is arranged to contact a bolt arranged to non-rotatably connect the rotor to the camshaft, and the bolt is arranged to clamp the annular washer to the target wheel.
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:
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.
Target wheel 106 is arranged to detect a rotational position of rotor 104 for use in rotating rotor 104 with respect to stator 102 to control a rotational position of the camshaft. Target wheel 106 includes portion 112 axially disposed between washer 108 and rotor 104. Washer 108 is in contact with portion 112 of target wheel 106. Portion 112 is directly engaged with rotor 104. By one component “directly engaged with” another component, we mean that the components are in direct contact, or that the components are each in direct contact with one or more ancillary intermediate parts. In the example of
Stator 102 includes radially inwardly extending protrusions 114 and is supported for rotation around axis of rotation AR. Rotor 104 includes radially outwardly extending protrusions 116 circumferentially interleaved with radially inwardly extending protrusions 114 to form phaser chambers 118. Each phaser chamber 118 is circumferentially bounded by a radially inwardly extending protrusion 114 and a radially outwardly extending protrusion 116.
The hardness of washer 108 is greater than the hardness of target wheel 106. In the example of
In an example embodiment, rotor 104, target wheel 106, and annular washer 108 are each made of steel and the steel of rotor 104 and washer 108 has a higher carbon content than the steel of target wheel 106. For example, target wheel 106 is made of mild steel having a carbon content less than 0.29 percent. For example, target wheel 106 is made of mild steel having a carbon content less than 0.50 percent.
In an example embodiment, portion 132 of target wheel 106 is radially outward of washer 108 and extends past washer 108 in axial direction AD1. In an example embodiment, an entirety of washer 108 is radially inward of stator 102. In an example embodiment, hypothetical line L2, orthogonal to axis of rotation AR, passes through in sequence, washer 108, target wheel 106, rotor 104, and stator 102.
In the example of
It is necessary for a target wheel of a camshaft phaser to remain fixed in a predetermined rotational position with respect to a rotor of the camshaft phaser to enable the target wheel to accurately track the rotational position of the rotor, which in turn is necessary to properly control a camshaft connected to the camshaft phaser. As noted above, in known camshaft phasers, frictional and rotational forces associated with the assembly and/or installation of the camshaft phaser can displace the target wheel from the predetermined rotational position. However, washer 108 isolates target wheel 106 from rotational and frictional forces associated with assembly or installation of camshaft phaser 100, enabling target 106 to remain in the predetermined rotational position, with respect to rotor 104, necessary for the proper operation of camshaft CS1.
As noted above, target wheel 106 has a lower hardness and a lower carbon content than rotor 104 and target wheel 106. In the example of
In the example of
Washer 108 eliminates galling of target wheel 106 due to direct contact between target wheel 106 and valve 134 or bolt B. The galling can enable rotation of target wheel 106 from the predetermined rotational position. Further, washer 108 eliminates the use of grease during assembly of oil control valve 134, simplifying the assembly and installation of camshaft phaser 100 and reducing the costs associated with assembly and installation of camshaft phaser 100.
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.
