A two piece vane seal for a variable cam timing phaser for an internal combustion engine that reduces leakage. The two piece vane seal having a first portion including a first end, a second end, and a flange extending axially from the first end. Also having a second portion including a first end, a second end, and a flange extending axially from the first end. The first portion is assembled relative to and connected to the second portion. Also having a spring having a first end and a second end and a length, extending over the curved ledge of the longitudinally extending wall of the first portion and the second portion.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention pertains to the field of vane seals. More particularly, the invention pertains to a two-piece vane seal for a phaser of a variable cam timing system.

Description of Related Art

Internal combustion engines have employed various mechanisms to vary the relative timing between the camshaft and the crankshaft for improved engine performance or reduced emissions. The majority of these variable camshaft timing (VCT) devices use one or more “vane phasers” on the engine camshaft (or camshafts, in a multiple-camshaft engine). Vane phasers have a rotor assembly with one or more vanes, mounted to the end of the camshaft, coaxially located within a housing assembly. The rotor assembly has at least one vane separating a chamber formed between the housing assembly and the rotor assembly into an advance chamber and a retard chamber. The vane is capable of rotation to shift the relative angular position of the housing assembly and the rotor assembly. A vane seal is received within the end of at least one of the vanes. The vane seal provides a seal between the advance and retard chambers on either side of the vane, such that when fluid pressure is applied to either of the advance or retard chambers and the vane rotates, the seal prevents leakage across the chambers. A conventional vane seal is typically one piece and made of molded plastic with a fixed geometry. Wear and thermal expansion can cause changes to the fixed geometry of the conventional vane seal.

SUMMARY OF THE INVENTION

A two piece vane seal reduces leakage across the vane seal. The vane seal having a first portion and a second portion, the second portion being a mirror image of the first portion. The first portion and the second portion each have a first end, a second end connected to the first end, and a flange extending axially from the first end. The first end and the second end are connected by a longitudinally extending wall, whereas the longitudinally extending wall includes an inner surface, a rectangular structure extending radially outward from and parallel to the inner surface of the longitudinally extending wall, a flat surface extending parallel to and radially outward from the inner surface of the longitudinally extending wall. A first longitudinal recess defined by the rectangular structure adjacent to at least the flat surface defining a second longitudinal recess between the flat surface and the rectangular structure and including a radially outward exposed surface and at least one spring end retainer extending radially outward from the inner surface of the longitudinally extending wall. An edge protruding radially outward from the inner surface of the longitudinally extending wall projecting from the second end a length and aligned with the second longitudinal recess including a first end with a protrusion and a second end. A curved ledge extending radially outward from and parallel to the inner surface of the longitudinally extending wall between the second end and the spring end retainer. A ramp extending radially outward from and parallel to the inner surface of the longitudinally extending wall connecting the curved ledge to the flat surface. The first portion assembled relative to and connected to the second portion with the inner surface of the longitudinally extending wall of the first portion opposite the inner surface of the longitudinally extending wall of the second portion, such that the second longitudinal recess of the second portion receives the edge extending from the longitudinally extending wall of the first portion. A spring comprising a first end, a second end, and a length, the first end received by the spring end retainer on the inner surface of the longitudinally extending wall of the second portion, the second end received by the spring end retainer on the inner surface of the longitudinally extending wall of the first portion

In another embodiment, a two piece vane seal has a first portion having a first end, a second end connected to the first end, and a flange extending axially from the first end. Whereas the first end and the second end are connected by a first longitudinally extending wall including an inner surface with a rectangular structure extending radially outward from and parallel to the inner surface of the first longitudinally extending wall defining a first longitudinal recess, the rectangular structure being adjacent to at least a flat surface defining a second longitudinal recess between the flat surface and the rectangular surface and having a radially outward exposed surface. At least one spring end retainer extending radially outward from the inner surface of the first longitudinally extending wall and an edge extending radially outward from the inner surface of the first longitudinally extending wall protruding from the second end a length and aligned with the second longitudinal recess. A second portion including a first end, a second end connected to the first end, and a flange extending axially from the first end. Whereas the first end and the second end are connected by a second longitudinally extending wall having an inner surface with a rectangular structure extending radially outward from and parallel to the inner surface of the second longitudinally extending wall defining a first longitudinal recess, the rectangular structure being adjacent to at least a flat surface defining a second longitudinal recess of the second longitudinally extending wall between the flat surface and the rectangular surface and having a radially outward exposed surface. At least one spring end retainer extending radially outward from the inner surface of the second longitudinally extending wall. An edge extending radially outward from the inner surface of the second longitudinally extending wall protruding from the second end a length and aligned with the second longitudinal recess of the second longitudinally extending wall. The first portion is assembled relative to and connected to the second portion with the inner surface of the first longitudinal wall opposite the inner surface of the second longitudinal wall, such that the second longitudinal recess of the second longitudinally extending wall receives the edge extending from the first longitudinally extending wall and the second longitudinal recess of the first longitudinally extending wall receives the edge extending from the second longitudinally extending wall. A spring having a first end, a second end, and a length, the first end received by the spring end retainer on the inner surface of the second longitudinally extending wall of the second portion, the second end received by the spring end retainer on the inner surface of the first longitudinally extending wall of the first portion.

In yet another embodiment, a variable cam timing phaser for an internal combustion engine having a housing assembly, a rotor assembly coaxially located within the housing assembly having vanes extending therefrom, the end of the vane defining a groove. A vane seal received within the groove, the vane seal having a first portion having a first end, a second end, and a flange extending axially from the first end. Whereas the first end and the second end are connected by a first longitudinally extending wall including an inner surface with a rectangular structure extending radially outward therefrom and parallel to the inner surface of the first longitudinally extending wall defining a first longitudinal recess. The rectangular structure being adjacent to at least a flat surface defining a second longitudinal recess between the flat surface and the rectangular surface and having a radially outward exposed surface. At least one spring end retainer extending radially outward from the inner surface of the first longitudinally extending wall. An edge extending radially outward from the inner surface of the first longitudinally extending wall extending from the second end a length and aligned with the second longitudinal recess. A second portion including a first end, a second end attached to the first end, and a flange extending axially from the first end. Whereas the first end and the second end are connected by a second longitudinally extending wall having an inner surface with a rectangular structure extending radially outward from and parallel to the inner surface of the second longitudinally extending wall defining a first longitudinal recess. The rectangular structure being adjacent to at least a flat surface defining a second longitudinal recess of the second longitudinally extending wall between the flat surface and the rectangular surface and having a radially outward exposed surface. At least one spring end retainer extending radially outward from the inner surface of the second longitudinally extending wall. An edge extending radially outward from the inner surface of the second longitudinally extending wall extending from the second end a length and aligned with the second longitudinal recess of the second longitudinally extending wall. The first portion is assembled relative to and connected to the second portion with the inner surface of the first longitudinal wall opposite the inner surface of the second longitudinal wall, such that the second longitudinal recess of the second longitudinally extending wall receives the edge extending from the first longitudinally extending wall. The second longitudinal recess of the first longitudinally extending wall receives the edge extending from the second longitudinally extending wall. A spring having a first end, a second end, and a length, the first end received by the spring end retainer on the inner surface of the second longitudinally extending wall of the second portion, the second end received by the spring end retainer on the inner surface of the first longitudinally extending wall of the first portion.

DETAILED DESCRIPTION OF THE INVENTION

A two piece vane seal100includes a first portion10aand a second portion10b. The second portion10bmay be smaller, larger, or a mirror image of the first portion10a. Therefore, the first portion10aand the second portion10bmay have identical, or differing, surfaces and recesses described in further detail below. When the first portion10ais assembled relative to the second portion10b, with like surfaces interfacing relative to each other, the two piece vane seal100forms a complete vane seal enclosing and sealing a spring50, such as leaf spring, such that the two piece vane seal100can be placed within an end of the vane104of a rotor assembly105as shown inFIGS. 9-11.

Referring toFIGS. 1-8 and 11-15, each portion or piece10a,10bof the two piece vane seal100has a first end90and a second end91.

The first end90and the second end91are connected through a longitudinally extending side wall60a,60b. The longitudinally extending side wall60a,60bhas an outer surface61which will be adjacent the vane104of the rotor assembly105when installed and an inner surface62. The first end90of each portion10a,10bof the two piece vane seal100has a flange12a,12bperpendicular to the side wall60a,60b. The flange12a,12bcontains a bore25a,25bwhich receives a protrusion22a,22bdiscussed in further detail below. Ends of the flange12a,12bhave an interlock protrusion13a,13bwhich is received within an opening25a,25bpresent within the opposing portion of the flange12a,12bof the vane seal as shown inFIG. 12d.

The second end91has an end wall16a,16b, perpendicular to the flanges12a,12bextending transversely opposite the flange12a, and12b. Between the end wall16a,16band the flange12a,12bwith the interlocking protrusion13a,13bis a flat surface17a,17badjacent the inner surface62of the longitudinally extending side wall60a,60b. The flat surface17a,17bextends from the flange12a,12bto a ramp18a,18b, with the ramp18a,18bterminating in a curved ledge20a, and20b.

Adjacent the flat surface17a,17band below the curved ledge20a,20bis another flat surface88a,88bwith a side edge24band an exposed edge29b.

Below the flat surfaces17a,17b,88a,88bis a rectangular structure85a,85bwith a longitudinal recess21a,21bwhich is spaced a distance to form another longitudinal recess19a,19bbetween the flat surfaces17a,17band the rectangular structure85a,85b. The rectangular structure has a side surface86a,86band an exposed surface30a,30band forms the bottom70a,70bof the two piece vane seal100. The bottom70a,70bis preferably contoured.

Along the inner surface62of the side walls60a,60baligned with the longitudinal recess19a,19bis an angular surface89a,89bwith an edge23a,23bwhich terminates just prior to the end of the side wall60a,60bin a protrusion22a,22bperpendicular to the end walls16a,16b.

When the first portion10aand the second portion10bare mated together by sliding the first portion10aand second portions10brelative to each other, with surface87bof the angular surface89bis placed adjacent surface87aof the angular surface89a, such that ramps20aand20bare adjacent, with ramp20abeing on top of surface88band ramp20bbeing on top of surface88a, such that exposed surfaces29aand29bof the flat surface88a,88bare adjacent. Additionally, protrusion22bis received within recess19aand protrusion22ais received within recess19bto lock the first portion10arelative to the second portion10b. Exposed surface30ais also adjacent exposed surface30b.

Extending perpendicular from the inner surface62of the longitudinally extending side wall60a,60band above the flat surface17a,17bis a spring end retainer14a,14b. When the first portion10aand the second portion10bare mated to form the two piece vane seal100, the spring end retainer14a,14bextends from the inner surface62of the longitudinally extending side wall60aof a first portion10ato the inner surface62of the longitudinally extending side wall60bof the second portion10bforming three partitions or recesses. A first end recess200is formed by the flange12aof the first portion10a, the flat surface17aof the first portion10a, the spring end retainer14aof the first portion10a, the inner surface62of the longitudinally extending wall60aof the first portion10aand the inner surface62of the longitudinally extending wall60bof the second portion10b. A second end recess201an end opposite the first recess200is formed by the flange12bof the second portion10b, the flat surface17bof the second portion10b, the spring end retaining14bof the second portion10b, the inner surface62of the longitudinally extending wall60aof the first portion10aand the inner surface62of the longitudinally extending wall60bof the second portion10b. A medial recess203between the first end recess200and the second end recess201is formed by spring end retainer14a, spring end retainer14b, flat surface17a,17b, and ramp18a,18band curved protrusions20a,20b. A spring50, preferably a leaf spring is received within the recesses of the two piece vane seal100. In another embodiment, spring50is capable of being an accordion spring, a blade spring, or a compression spring. The spring50is an elongated rectangle with curled ends. In a free unanchored state, the spring50curls. When the spring50is installed into the vane seal100, the spring50is in an uncurled state. The spring50has a first curled end50a, a second curled end50bwith a length50cbetween the first curled end50aand the second curled end50b. A first curled end50aof the spring50is received within the first recess200and abuts the spring end retainer14a. A second curled end50bof the spring50is received with the second recess201and abuts the spring end retainer14b. The length50cof the spring50is received within the medial recess203between the spring end retainers14a,14b. The first end50aof the spring50, and second end50bof the spring50are preferably rounded to allow for easy rotation within the recesses although other geometries may also be used. Spring50provides radial and axial force on each portion10a,10bof the two piece vane seal100to preload the vane seal100against the sliding sealing surfaces of the rotor assembly as shown inFIGS. 9-11.

InFIGS. 9-11, the two piece vane seal100is received within a channel108within the end104aof the vane104that contacts the housing assembly101when the rotor assembly105is assembled within a phaser. The front104aand back104bof the vane104each have side channels109which terminate in recesses106. The flanges12a,12bare received within the side channels109on the front104aand the back104bof the vane104, with the interlocking protrusions13a,13breceived within the recesses106of the vanes.

After the two piece vane seal100is installed within the end of the vane104, a first seal land220ais preferably formed between the contoured surfaces of bottom surfaces70a,70band the housing assembly101, and around the perimeter of the two piece vane seal100, a second seal land220bis formed between an edge of the flange12a,12band the vane104, and a third seal land220cis formed between an edge of the flange12a,12bwhich connects to the bottom70a,70band the end plates of the housing assembly101. The seal coefficient of friction will be altered based upon qualitative differences in the materials, surface finishes, and fluids used for the vane seal100and in the rotor assembly105.

As shown inFIG. 9, an additional flange205may be secured to flanges12a,12bto add in centering the vane seal100within the vane104of the rotor assembly105.

In one embodiment, the rotor assembly105and two piece vane seal100slide to one side allowing a clearance of 0.030 mm from the rotor assembly105to the inner plate of the housing assembly101, enabling oil or hydraulic fluid to flow in the path of least resistance and to move around the seal100between the rotor assembly and inner plate of the housing assembly101.

The two piece vane seal100can extend or retract to conform to geometric irregularities. Each half or portion,10a,10bis free to individually move axially to decrease close axial clearances and provide lower leakage past the seal and conform to geometric irregularities resulting from manufacturing tolerance.

While vane seal spring50is only shown being attached to retaining shoulders31aand31b, vane seal spring50is capable of being molded into one half, first vane seal component10aand second vane seal component10b, of the two piece vane seal100to simplify assembly.

The two piece vane seal100is preferably formed of a single material such as metal. Two piece vane seal100can expand and contract to compensate for the differing thermal expansion. Two piece vane seal100is capable of compensating for component wear and extending the compensation to vane seal performance.