CRANKSHAFT DRIVEN VALVE ACTUATION
A hydraulic valve actuation system (30) and a method of assembly can include a plurality of hydraulically actuatable valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) operably associated with an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis. The actuation system (30) can include at least one cam lobe (52) mounted on or integrally formed with the crankshaft for rotation with the crankshaft (50). At least one fluid piston pump (36, 36a, 36b) connected to the at least one cam lobe (52) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe (52). At least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) in fluid communication with the reciprocal fluid flow generated by the at least one fluid piston pump (36, 36a, 36b) to drive the valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled toward an open position.
Latest Borgwarner Inc. Patents:
- Radial air bearing device and method for producing a radial air bearing device
- Variable cam timing phaser and system including the same
- Cooling automotive power electronics
- Multiple disk clutch and dual clutch device having such a multiple disk clutch
- Method of reducing turbine wheel high cycle fatigue in sector-divided dual volute turbochargers
The invention relates to a method and apparatus for hydraulic actuation of valves in an internal combustion engine, and more particularly, to hydraulic actuation of intake and exhaust valves of an internal combustion engine.
BACKGROUNDAn internal combustion engine generates power by burning fuel in a combustion chamber. Current intake and exhaust valves can be controlled and operated by camshafts and cams located in the engine. Intake valves can be opened in order to admit fuel and air into a cylinder for combustion, while exhaust valves can be opened to allow combustion gas to escape from the cylinder. The cams can be fixed profile cams which can provide difficulty in adjusting timings or amounts of engine valve lifts needed to optimize valve opening times and lift for varying engine operations. A lost motion device can be used between a valve and the cam for transmitting varying amounts of the cam motion to the valve. Current lost motion systems use a master piston which displaces fluid from a hydraulic chamber into a hydraulic chamber of a slave piston. The slave piston can act on the engine valve for opening the valve. The hydraulic system generally includes added components such as cam sensors, oil control valves, phasers, guides, timing chains, tensioners, sprockets, bearing caps, and miscellaneous bolts and fasteners. The need for the added components in order to operate a lost motion system can increase valve train inertia, which can be problematic at high engine speeds. The added components can also increase complexity and cost such that it can be desirable to minimize the additional components. Valve actuation systems have been disclosed in U.S. Pat. No. 8,365,691; U.S. Pat. No. 6,997,148; U.S. Pat. No. 6,425,357; U.S. Pat. No. 5,645,031; U.S. Pat. No. 4,716,863; U.S. Pat. No. 2,072,437; U.S. Patent Application No. 2011/0197833; and W.O. Patent Application No. 2007/142724.
SUMMARYIt can also be desirable to eliminate the camshaft as an additional component due to the added size and weight of the camshaft to the valve train. To overcome the limitation of current technology, the disclosed hydraulic valve actuation system uses at least one cam lobe connected to a crankshaft to be driven in rotation for reciprocating a master piston for pressurizing fluid to drive reciprocal fluid flow within the hydraulic valve actuation system. The use of a cam lobe connected directly to the crankshaft can eliminate added components currently used in valve actuation systems such as the cam sensors, oil control valves, phasers, guides, timing chains, tensioners, sprockets, bearing caps, and miscellaneous bolts and fasteners. The hydraulic valve actuation system can control the opening and closing of a plurality of hydraulically actuatable valves, either intake valves or exhaust valves, or both intake and exhaust valves. The valves can be associated with a plurality of cylinders of an internal combustion engine and can have a corresponding slave piston for each valve. Each of the plurality of slave pistons can be normally biased by a spring toward a first position corresponding to the valve being in a closed valve position. The slave piston can be driven toward a second position corresponding to the valve being in an open position by fluid pressure overcoming a biasing force of the spring. The hydraulic valve actuation system can include at least one accumulator operable for reciprocally receiving and releasing fluid in a lost motion manner when valve actuation is not desired, and for maintaining fluid pressure and volume in the hydraulic valve actuation system.
A hydraulic valve actuation system can include at least one fluid pressure piston pump having at least one reciprocal master piston for movement within a housing defining at least one fluid pumping chamber. The fluid piston pump can include at least one biasing spring for biasing the corresponding reciprocal master piston toward a first position within the housing. The hydraulic valve actuation system can include a crankshaft rotatable about a longitudinal axis and having at least one cam lobe carried on the crankshaft for rotation therewith. The at least one cam lobe can be driven in rotation about the longitudinal rotational axis of the crankshaft and can be engageable with a cam follower connected to a corresponding reciprocal master piston. The cam follower can drive the at least one reciprocal master piston toward a second position into the at least one fluid pumping chamber when driven by the at least one cam lobe to pressurize the working fluid for reciprocal flow through the fluid passages of the hydraulic valve actuation system. The biasing spring can normally bias the corresponding reciprocal master piston and associated cam follower toward the first position and into continuous engagement with the at least one cam lobe of the crankshaft located outside of the pump chamber.
The at least one reciprocal master piston can be operable for pressurizing fluid located in the at least one fluid pumping chamber when driven by the at least one cam lobe mounted on the crankshaft to overcome the biasing force of the at least one biasing spring creating sufficient working fluid pressure and volume to operably actuate one or more of a plurality of valves in fluid communication with the hydraulic valve actuation system as fluid flow reciprocates within the hydraulic valve actuation system fluid passages in response to reciprocation of the master piston driven by the cam lobe mounted on and driven in rotation with the crankshaft. The pump chamber can be in fluid communication with the plurality of valves allowing pressurized fluid flow toward one or more of the plurality of valves during a driven stroke of the reciprocal master piston by the cam lobe and allowing fluid flow to be drawn back into the pump chamber from one or more of the plurality of valves during a return stroke of the reciprocal master piston driven by the biasing spring. The pump chamber can also be operable for fluid communication with the at least one accumulator for maintaining working fluid volume and pressure during the operating cycle and to make up for working fluid volume losses and pressure losses due to normal leakage during operation cycles. The working fluid, being an essentially incompressible working fluid, can allow reciprocal flowing movement of the working fluid through the hydraulic valve actuation system in response to reciprocal movement of the master piston as the master piston reciprocal movement follows the cam lobe rotation corresponding to rotation of the crankshaft. The master piston is in continuous fluid communication with the hydraulic valve actuation system fluid passages during operation of the internal combustion engine.
The hydraulic valve actuation system can further include at least one first control valve operable between a first position isolating fluid flow between the at least one accumulator and the hydraulic valve actuation system fluid passages and a second position for providing fluid communication between the hydraulic valve actuation system fluid passages and the at least one accumulator. The at least one first control valve can provide for fluid communication between the at least one fluid pressure piston pump and the at least one valve assembly.
A method of operating a normally closed valve of an internal combustion engine having a rotatable crankshaft can include driving reciprocal fluid flow within a fluid passage in response to rotation of the crankshaft of the internal combustion engine, and selectively communicating an expandable fluid chamber associated with a normally closed valve with the reciprocal fluid flow within the fluid passage for cyclically driving the normally closed valve between an open position and a closed position in response to fluid flow within the passage. The method can include rotating a cam lobe mounted on a crankshaft of an internal combustion engine, and driving at least one fluid pressure piston pump having at least one reciprocal master piston in movement within a housing defining at least one fluid pumping chamber in response to rotation of the cam lobe. The method can include biasing the corresponding reciprocal master piston toward a first position within the housing with a spring for maintaining continuous contact between a cam follower connected to the corresponding reciprocal master piston and the rotating cam lobe.
A method of assembling a hydraulic valve actuation system can include mounting a cam lobe on a crankshaft of an internal combustion engine for rotation with the crankshaft, and connecting a cam follower to at least one reciprocal master piston of at least one fluid pressure piston pump for driving reciprocal movement of the master piston in response to rotation of the cam lobe driven in rotation by the crankshaft to create a reciprocal fluid flow cycle within a closed fluid flow path, and biasing the master piston toward a first position for maintaining the cam follower in continuous contact with the cam lobe. The method can include connecting at least one valve for selectively allowing and preventing fluid communication between an expandable fluid chamber operably associated with a valve to be actuated and the closed fluid flow path carrying the reciprocal fluid flow driven by the reciprocal movement of the master piston. The method can include connecting an engine control unit for selectively controlling fluid communication with each of the expandable fluid chambers associated with a valve to be actuated to prevent and allow fluid communication during a reciprocal fluid flow cycle carried within the closed fluid flow path to open and close each valve to be actuated in a predetermined sequence according to signals received from an engine control unit. The method can include connecting at least one valve for selectively allowing and preventing fluid communication between the closed fluid flow path and at least one accumulator.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings.
The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
Referring now to
By way of example and not limitation, a four stroke—four cylinder cycle can refer to travel of each engine piston between an intake stroke, a compression stroke, an ignition/combustion/power stroke, and an exhaust stroke, such that the at least one cam lobe 52 can drive the master piston within the master piston chamber to force fluid into the closed fluid flow path in order to open one of the valves 34a with the at least one switching valve 70 in the position shown and the cam lobe in the 0° position as illustrated in
It should be recognized by those skilled in the art that the single switching valve can be replaced with two separate individually actuated valves, where each valve has a closed position and an open position for selectively directing fluid flow to a corresponding valve to be controlled without departing from the disclosure of the present invention. It should be recognized by those skilled in the art that the cam lobe can be mounted directly to the crankshaft or can be formed integrally with the crankshaft, in either case, the cam lobe is rotated at crankshaft speed. It should further be recognized by those skilled in the art, that additional master fluid piston pump chambers and closed fluid flow paths can be provided similar to the disclosure above to provide hydraulic valve actuation of the exhaust valves. It should be recognized by those skilled in the art that the two cam lobes illustrated in
Each cam lobe 52 can include a cam follower for driving a master piston pump for actuating at least one or more valves. A single cam lobe 52 can drive either two intake valves and two exhaust valves associated with a first and fourth cylinder if cam followers are located angularly offset by approximately 220° from one another, or two intake valves associated with the first and fourth cylinder and two intake valves associated with a second and third cylinder if cam followers are located angularly offset by approximately 180° from one another. In order for the single cam lobe 52 to drive two intake valves and two exhaust valves associated with the first and fourth cylinder, or second and third cylinder, shorter hydraulic channel lengths can be used and the corresponding cam followers can be located approximately 220° with respect to one another. In order for the single cam lobe 52 to drive two intake valves associated with the first and fourth cylinder and two intake valves associated with the second and third cylinder, the cam followers can be located approximately 180° with respect to one another. Finally, it should be recognized by those skilled in the art that the four stroke—four cylinder engine cycle is by way of example and not limitation, since the crankshaft driven hydraulic valve actuation system can be modified to accommodate different engine configurations, such as by way of example and not limitation, two or more cylinder engine configurations, such as three cylinder, six cylinder, eight cylinder, or more than eight cylinder engine configurations without departing from the disclosure of the present invention.
The improvement of the hydraulic valve actuation system 30 can include at least one fluid piston pump 36, a crankshaft 50, and at least one first control valve 56. The at least one fluid piston pump 36 can include at least one reciprocal master piston 38, at least one fluid pumping chamber 40, and at least one biasing spring 42. The biasing spring 42 can normally bias the master piston 38 toward a first position with respect to the pump chamber 40. The master piston 38 can be operable for reciprocally driving fluid in and out of the pump chamber 40 when driven by rotation of the crankshaft. The pump chamber 40 can be in continuous fluid communication with the plurality of valves 34a, 34b, and can selectively be placed in fluid communication for fluid flow with respect to the at least one accumulator 46. The crankshaft 50 can be rotatable about a longitudinal axis and can have at least one cam lobe 52 mounted to or integrally formed as part of the crankshaft for rotation with the crankshaft. The at least one cam lobe 52 can be driven in rotation about the longitudinal axis and can be continuously engageable with a cam follower 54. The cam follower 54 can be connected to the at least one reciprocal master piston 38 for reciprocal driven motion with respect to the at least one fluid pumping chamber 40 in response to rotation of at least one cam lobe 52. The at least one first control valve 56 can provide for fluid communication between the at least one fluid pressure piston pump 36 and the at least one accumulator 46.
Referring now to
As illustrated in
In operation, rotation of the crankshaft 50 rotates the cam lobe 52 for driving the master piston from a first position (shown in
A fluid reservoir or sump 90 can provide fluid to a fluid pump 92 for delivery through a check valve 96a to the accumulator 46 when the first control valve 56 is in either the first position 62, or the second position 60, and can additionally supply fluid to the pump chamber 40 when the first control valve 56 is in the second position 60. The accumulator 46 can operate as a lost fluid motion reservoir when valve actuation is not desired during reciprocation of the fluid pump 36, while also acting as a pressurized fluid reservoir for holding a volume of the fluid under pressure and for maintaining the fluid pressure and volume in the hydraulic valve actuation assembly 30. In other words, the accumulator 46 can be used to modify the shape of the timing curve and allow for lost motion in the hydraulic system by reducing motion of the valve while directing fluid flow to the accumulator 46. The inclusion of the accumulator 46 in the system can allow a valve in fluid communication with the accumulator to open late, close early, open partially, or prevent opening of the valve all together. The accumulator 46 can include an accumulator spring 47 for maintaining pressure of the fluid in the absence of the pump 92 running. The accumulator 46 can provide fluid flow to the hydraulic valve actuation assembly 30 when the first control valve 56 is in the second valve position 60 to replenish any fluid losses from the closed fluid flow path, dampen pressure fluctuations, and supply supplemental fluid pressure when required for changes in valve timing operation or to assist valve operation during engine startup.
The fluid can flow between the first control valve 56 and the second control valve 64. The second control valve 64 can be a high-speed switching valve for switching or skipping fluid flow between each of the plurality of intake valves 34a, 34b. The switching or skipping function can be used to make use of the lost fluid motion that would otherwise occur when controlling a single engine valve function with the hydraulic valve actuation assembly 30. It is contemplated that more than one switching valve could be used with an internal combustion engine 86 having additional cylinders and intake/exhaust valves. By way of example and not limitation, as illustrated in
As illustrated in
As illustrated in
Referring now to
As illustrated in
The hydraulic valve actuation system 30 can further include a control system, or electronic engine control unit 98, for operation. The control system can include at least one controller and sensor in electrical connection with the at least one first control valve 56 and the at least one second control valve 64. The controller can include an electronic control module having at least one microprocessor and at least one memory module. The controller can be adapted to control the actuation of the at least one first control valve 56 and the at least one second control valve 64 in response to a control program stored in memory based on signals received from one or more sensors. The sensors can detect a cam angle of the at least one cam lobe 52 with respect to the crankshaft 50. The controller can control the operation of the internal combustion engine 86, such as the operation of the sump pump 92, control valves 70, 70a, and control valves 56, 156, 64
Advantages of implementing the disclosed hydraulic actuation system 30 in an engine 86 include weight savings by eliminating additional components such as cam sensors, oil control valves, phasers, guides, timing chains, tensioners, sprockets, bearing caps, and miscellaneous bolts and fasteners. The disclosed hydraulic actuation system 30 can also reduce parasitic losses in the engine 86 resulting from the use and wear of the additional components. The package size of the engine 86 can also be reduced significantly by particularly removing camshafts. The disclosed hydraulic valve actuation system 30 can provide significant economic advantages by reducing production costs associated with the engine 86 due to removing the cost of the additional components. The use of multiple control valves and cam lobes can also provide flexibility of intake and exhaust valve motion control including control of advance and retard timing events for valves.
A method of assembling a hydraulic valve actuation system 30 for controlling the opening and closing of a plurality of hydraulically actuatable valves 34a, 34b corresponding to a plurality of cylinders of an internal combustion engine 86 having a crankshaft can include mounting a cam lobe on the crankshaft for rotation with the crankshaft, driving reciprocation of at least one fluid pressure piston pump 36 in response to rotation of the cam lobe by the crankshaft, connecting the at least one fluid pressure piston pump 36 to a closed fluid flow path for directing reciprocal fluid flow from the at least on fluid pressure piston pump 36 in fluid communication with at least one valve to be controlled, and inserting at least one control valve 56 within the reciprocal closed fluid path for selectively directing reciprocal fluid flow between at least one valve to be controlled. The method can also include positioning a cam follower 54 between the cam lobe and the fluid pressure piston pump 36. The method can include hydraulically actuating at least one engine valve 34a, 34b with at least one slave piston 44a, 44b, biasing each of the slave pistons 44a, 44b normally toward a closed valve position, selectively applying fluid pressure to selected slave pistons to drive the valve to be controlled toward the open position. The method can also include providing lost fluid motion and maintaining fluid volume and pressure in the hydraulic valve actuation system 30 with at least one accumulator 46 operable for receiving and releasing pressurized fluid into the reciprocal closed fluid flow path. The method can also include reciprocating at least one master piston 38 within at least one fluid pumping chamber 40 of at least one fluid pressure piston pump 36 for generating reciprocal fluid flow in response to rotation of the cam lobe, and biasing the at least one master piston 38 toward a first position with at least one biasing spring 42. The method can also include positioning a cam follower 54 interposed between the at least one cam lobe 52 and the at least one fluid pressure piston pump 36.
Referring now to
In either case, the cam lobe 52a, 52b can be rotatable in response to rotation of the crankshaft 50 about the longitudinal axis and can be continuously engaged by a cam follower 54a, 54b 54c, 54d. The cam follower 54a, 54b, 54c, 54d can drive the corresponding master piston 38a, 38b, 38c, 38d reciprocally with respect to the corresponding pump chamber 40a, 40b, 40c, 40d when driven in response to rotation of the cam lobe 52a, 52b. The hydraulic valve actuation system 30 can include a first control valve 56a, 56b, 56c, 56d and second control valve 64a, 64b, 64c, 64d, by way of example and not limitation a control valve having an actuator such as a solenoid operated actuator, a piezoelectric operated actuator, or any other mechanically or electrically operated actuator for a control valve. As illustrated in
Fluid can also be returned from the expandable chambers of the slave pistons 44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d associated with the valve 34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d to reciprocate back to the pump chamber 40a, 40b, 40c, 40d after passing through optional check valve 80b, 80c; 180b, 180c; 80d, 80e, 180d, 180e and/or by reversing fluid flow direction through the second control valve 64a, 64b, 64c, 64d. The second control valve 64a, 64b, 64c, 64d can be in the first position 68a, 68b, 68c, 68d preventing fluid flow to one of the two valves associated with the second control valve 64a, 64b, 64c, 64d.
As illustrated in
In operation, as illustrated in
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.
Claims
1. In a hydraulic valve actuation system (30) for controlling opening and closing a plurality of hydraulically actuated valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) associated with an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis, the improvement comprising:
- at least one cam lobe (52, 52a, 52b) mounted on the crankshaft (50) to be driven in rotation with the crankshaft (50);
- at least one fluid piston pump (36, 36a, 36b, 36c, 36d) operably connected to the at least one cam lobe (52, 52a, 52b) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe (52, 52a, 52b); and
- at least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) in fluid communication with the reciprocating fluid flow to drive the at least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) between a normally closed position and an open position.
2. The improvement of claim 1 further comprising:
- at least one accumulator (46a, 46b, 46c, 46d) for providing lost fluid flow motion to prevent valve actuation in response to the reciprocating fluid flow; and
- at least one first control valve (56, 56a, 56b, 56c, 56d) for selectively placing the reciprocating fluid flow in fluid communication with the at least one accumulator (46a, 46b, 46c, 46d).
3. The improvement of claim 1 further comprising:
- the at least one hydraulically actuated valves including a first hydraulically actuated valve (34a, 34c, 134a, 134c) and a second hydraulically actuated valve (34b, 34d, 134b, 134d); and
- at least one second control valve (64, 64a, 64b, 64c, 64d) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve (34a, 34c, 134a, 134c) and the second hydraulically actuated valve (34b, 34d, 134b, 134d).
4. The improvement of claim 1 further comprising:
- a slave piston (44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d) connected to each of the at least one hydraulically actuated valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled, each slave piston (44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d) normally biased toward a closed valve position, each slave piston (44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d) driven by reciprocating fluid flow toward an open valve position.
5. The improvement of claim 1, wherein the at least one fluid piston pump (36, 36a, 36b, 36c, 36d) further comprises:
- at least one reciprocal master piston (38, 38a, 38b, 38c, 38d), at least one fluid pumping chamber (40, 40a, 40b, 40c, 40d), and at least one biasing spring (42, 42a, 42b, 42c, 42d), the biasing spring (42, 42a, 42b, 42c, 42d) normally biasing the master piston (38, 38a, 38b, 38c, 38d) into engagement with the at least one cam lobe (52, 52a, 52b), the master piston (38, 38a, 38b, 38c, 38d) for reciprocally driving fluid in and out with respect to the at least one fluid pumping chamber (40, 40a, 40b, 40c, 40d).
6. The improvement of claim 1 further comprising:
- a cam follower (54, 54a, 54b, 54c, 54d) located between the at least one cam lobe (52, 52a, 52b) and the at least one fluid piston pump (36, 36a, 36b, 36c, 36d), the cam follower (54, 54a, 54b, 54c, 54d) reciprocally driving the at least one fluid piston pump (36, 36a, 36b, 36c, 36d) in response to rotation of the at least one cam lobe (52a, 52b).
7. A hydraulic valve actuation system (30) for an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis comprising:
- a cam lobe (52, 52a, 52b) mounted on the crankshaft to be driven in rotation with the crankshaft (50);
- a fluid piston pump (36, 36a, 35b, 36c, 36d) connected to the cam lobe (52, 52a, 52b) for generating a reciprocating fluid flow in response to rotation of the cam lobe (52, 52a, 52b); and
- a hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) in fluid communication with the reciprocating fluid flow to drive the hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) between a normally closed position and an open position.
8. The hydraulic valve actuation system (30) of claim 7 further comprising:
- an accumulator (46a, 46b, 46c, 46d) for providing lost fluid flow motion to prevent valve actuation in response to the reciprocating fluid flow; and
- a first control valve (56, 56a, 56b, 56c, 56d) for selectively placing the reciprocating fluid flow in fluid communication with the accumulator (46a, 46b, 46c, 46d).
9. The hydraulic valve actuation system (30) of claim 7 further comprising:
- the hydraulically actuated valve including a first hydraulically actuated valve (34a, 34c, 134a, 134c) and a second hydraulically actuated valve (34b, 34d, 134b, 134d); and
- a second control valve (64, 64a, 64b, 64c, 64d) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve (34a, 34c, 134a, 134c) and the second hydraulically actuated valve (34b, 34d, 134b, 134d).
10. The hydraulic valve actuation system (30) of claim 7 further comprising:
- a slave piston (44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d) connected to the valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled, the slave piston (44a, 44b, 44c, 44d, 144a, 144b, 144c, 144d) normally biased toward a closed valve position and driven by reciprocating fluid flow toward an open valve position.
11. The hydraulic valve actuation system (30) of claim 7, wherein the fluid piston pump (36) further comprises:
- a reciprocal master piston (38), a fluid pumping chamber (40), and a biasing spring (42), the biasing spring (42) normally biasing the master piston (38) into engagement with the cam lobe (52), the master piston (38) operable for reciprocally driving fluid in and out with respect to the fluid pumping chamber (40).
12. The hydraulic valve actuation system (30) of claim 7 further comprising:
- a cam follower (54) located between the cam lobe (52) and the fluid piston pump (36), the cam follower (54) reciprocally driving the at least one fluid piston pump (36) in response to rotation of the cam lobe (52).
13. A method of assembling a hydraulic valve actuation system (30) for controlling opening and closing a plurality of hydraulically actuated valves (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) corresponding to a plurality of cylinders of an internal combustion engine (86) having a crankshaft (50) rotatable about a longitudinal axis, the method comprising:
- forming a cam lobe (52, 52a, 52b) connected to the crankshaft for rotation with the crankshaft (50);
- assembling a fluid pressure piston pump (36, 36a, 36b, 3) for generating a reciprocating fluid flow in response to rotation of the cam lobe (52) by the crankshaft (50); and
- connecting at least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled in fluid communication with the reciprocating fluid flow from the fluid pressure piston pump (36, 36a, 36b, 36c, 36d).
14. The method of claim 13 further comprising:
- connecting a first control valve (56, 56a, 56b, 56c, 56d) for selectively directing reciprocal fluid flow between the fluid pressure piston pump (36, 36a, 36b, 36c, 36d) and an accumulator (46, 46a, 46b, 46c, 46d) to prevent actuation of the at least one hydraulically actuated valve (34a, 34b, 34c, 34d, 134a, 134b, 134c, 134d) to be controlled.
15. The method of claim 13 further comprising:
- assembling the at least one hydraulically actuated valve to include a first hydraulically actuated valve (34a, 34c, 134a, 134c) and a second hydraulically actuated valve (34b, 34d, 134b, 134d); and
- connecting a second control valve (64, 64a, 64b, 64c, 64d) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve (34a, 34c, 134a, 134c) and the second hydraulically actuated valve (34b, 34d, 134b, 134d).
Type: Application
Filed: Apr 29, 2015
Publication Date: Jun 29, 2017
Applicant: Borgwarner Inc. (Auburn Hills, MI)
Inventors: Mark M. WIGSTEN (Lansing, NY), Daniel F. JAKIELA (Genoa, NY), Randy W. ADLER (Seneca Falls, NY), Michael Loren SMART (Locke, NY), James SISSON (Locke, NY)
Application Number: 15/309,463