# US 10,865,666 B2 · Check valve for exhausting flow of fluid from a variable cam timing phaser > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,666 B2 - Document ID: US10865666B2 - Status: Granted - Kind: B2 - Application number: 16/671,483 - Filed: 2019-11-01 - Published: 2020-05-07 - Granted: 2020-12-15 - Earliest claimed: 2018-11-05 - Assignees: BorgWarner Inc. - Applicants: BorgWarner Inc. - Inventors: Adam Bruce; Keith Feldt; Braman Wing - Web page: https://patentgrep.com/patent/US10865666B2 ## CPC - F01L 1/3442: {using hydraulic chambers with variable volume to transmit the rotating force} - F01L 1/34409: {by torque-responsive means} - F01L 2001/34426: {Oil control valves} - F01L 2001/3443: {Solenoid driven oil control valves} - F01L 2001/34433: {Location oil control valves} - F01L 2001/34436: {Features or method for avoiding malfunction due to foreign matters in oil} - F01L 2001/34453: {Locking means between driving and driven members} - F01L 2250/02: the camshaft being driven by chains - F01L 2250/04: the camshaft being driven by belts - F01L 2250/06: the camshaft being driven by gear wheels - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES ## Abstract A variable cam timing phaser mounted to a camshaft and including a housing assembly having an outer circumference for accepting a drive force; a rotor assembly received by the housing assembly defining a chamber separated into an advance chamber and retard chamber by a vane; a control valve in fluid communication with the advance chamber and the retard chamber, a source of fluid, and a sump through at least one exhaust line connected to at least one exhaust port; and at least one check valve in the at least one exhaust line between the control valve and the sump. The at least one check valve prevents air from the sump connected to the at least one exhaust port from being sucked into the variable cam timing phaser through the at least one exhaust port during a torque reversal of the camshaft. ## Claims ### Claim 1 A variable cam timing phaser mounted to a camshaft, of an internal combustion engine, the variable cam timing phaser comprising: a housing assembly having an outer circumference configured to accept a drive force; a rotor assembly received by the housing assembly so as to define a chamber separated into an advance chamber and a retard chamber by a vane; a control valve in fluid communication with the advance chamber and the retard chamber, a source of fluid, and a sump through at least one exhaust line of the control valve connected to at least one exhaust port of the control valve; and at least one check valve in the at least one exhaust line between the control valve and the sump; wherein during a torque reversal of the camshaft, the at least one check valve prevents air from the sump from being sucked into the variable cam timing phaser through the at least one exhaust port. ### Claim 2 (depends on 1) The variable cam timing phaser of claim 1, wherein the control valve comprises a sleeve comprising: an outer surface receiving the at least one check valve at the at least one exhaust port; and a bore configured to slidably receive a spool within the sleeve. ### Claim 3 (depends on 2) The variable cam timing phaser of claim 2, wherein the at least one check valve is a flap of a flapper spring secured to the outer surface of the sleeve. ### Claim 4 (depends on 3) The variable cam timing phaser of claim 3, wherein the flapper spring is secured to the outer surface of the sleeve via a fastener. ### Claim 5 (depends on 3) The variable cam timing phaser of claim 3, wherein the flapper spring is overmolded onto the outer surface of the sleeve. ### Claim 6 (depends on 3) The variable cam timing phaser of claim 3, wherein the flapper spring is preloaded against the at least one exhaust port. ### Claim 7 (depends on 1) The variable cam timing phaser of claim 1, wherein the at least one check valve is selected from a group consisting of: a ball check valve, a band check valve, and a disc check valve. ### Claim 8 (depends on 1) The variable cam timing phaser of claim 1, further comprising an intermediate chamber between the sump and the at least one exhaust port, the intermediate chamber configured to accumulate exhausted fluid. ### Claim 9 (depends on 1) The variable cam timing phaser of claim 1, wherein the control valve is received within a center bolt housing of a center bolt in the rotor assembly. ### Claim 10 A variable cam timing phaser mounted to a camshaft, of an internal combustion engine, the variable cam timing phaser comprising: a housing having an outer circumference configured to accept a drive force; a rotor received by the housing so as to define a chamber separated into an advance chamber and a retard chamber by a vane; a control valve comprising: a sleeve having a bore and an outer surface receiving a first check valve at a first exhaust port of the control valve and a second check valve at a second exhaust port of the control valve; and a spool having a plurality of lands slidably received within the bore; wherein during a torque reversal of the camshaft, the first check valve and the second check valve prevent air from a sump connected to the first exhaust port and the second exhaust port from being sucked into the advance chamber or the retard chamber through the first exhaust port and the second exhaust port, respectively. ### Claim 11 (depends on 10) The variable cam timing phaser of claim 10, wherein the first check valve is a first flap of a flapper spring secured to the outer surface of the sleeve and the second check valve is a second flap of the flapper spring. ### Claim 12 (depends on 11) The variable cam timing phaser of claim 11, wherein the flapper spring is secured to the outer surface of the sleeve via a fastener. ### Claim 13 (depends on 11) The variable cam timing phaser of claim 11, wherein the flapper spring is overmolded onto the outer surface of the sleeve. ### Claim 14 (depends on 11) The variable cam timing phaser of claim 11, wherein the flapper spring is preloaded against the first exhaust port and the second exhaust port. ### Claim 15 A variable cam timing phaser mounted to a camshaft, of an internal combustion engine, the variable cam timing phaser comprising: a housing assembly having an outer circumference configured to accept a drive force; a rotor assembly received by the housing assembly so as to define a chamber separated into an advance chamber and a retard chamber by a vane; a control valve received in a center bolt housing in the rotor assembly, the control valve in fluid communication with the advance chamber and the retard chamber, a source of fluid, and a sump through at least one exhaust line of the control valve through the center bolt housing, the control valve comprising: a sleeve having a bore and an outer surface receiving at least one check valve at an exhaust port of the control valve; and a spool having a plurality of lands slidably received within the bore of the sleeve; wherein during a torque reversal of the camshaft, the at least one check valve prevents air from the sump from being sucked into the variable cam timing phaser through the at least one exhaust port line of the control valve.