BACKGROUND AND SUMMARY

The present invention relates to three-way valves.

Conventional val ve arrangements of the type that are used for oil temperature control in, e.g., diesel engines are driven by a solenoid and are often limited by the manner of operation of the solenoid and the valve packaging. Conventional designs only allow for valve windows to be as tall as a distance that a spool of the valve can travel. This has limited the design to very small windows through which 100% of the oil must travel. Another limitation of conventional oil temperature control valves is a complex force balance due to the effect of oil flow into the valve which makes control very difficult.

It is desirable to provide a valve that facilitates maximization of the flow area through the valve and reduces pressure loss in the valve. Reducing the pressure drop helps to make the oil system more efficient and ultimately contributes to fuel economy. It is also desirable to provide a valve that will not create any or will minimize areas where pressure or flow ean act on the valve to create an unbalanced system so that the valve will not have to act against any flow and will only have to overcome factional forces in the valve itself in order to turn.

It is further desirable to provide an oil temperature control valve that facilitates providing greater control of oil temperature. Such a valve can assist in enhancing system efficiency and fuel economy.

According to an aspect of the present invention, a three-way valve comprises a tubular valve cage having an open first cage end and a closed second cage end, a cage side surface extending between the first cage end and the second cage end, a first cage opening in the cage side surface at a cage first axial and circumferential position, and a second cage opening in the cage side surface at a cage second axial and circumferential position, the cage first axial position and the cage second axial position being non-overlapping, and a tubular spool disposed in the valve cage, the spool having an open first spool end and a second spool end, a spool side surface between the first spool end and the second spool end. a first spool opening in the spool side surface at a spool first axial and circumferential position, and a second spool opening in the spool side surface at a spool second axial and circumferential position, the first spool end being disposed closer to the first cage end than to the second cage end, and the second spool end being disposed closer to the second cage end than to the first cage end. The spool is rotatable about a longitudinal axis thereof relative to the cage between a first position in which the first cage opening and the first spool opening are aligned and together define a first valve opening and a second position in which the second cage opening and the second spool opening are aligned and together define a second valve opening. BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present, invention are well understood by reading the following detailed description in conjunction with the drawings in which like numerals indicate similar elements and in which:

FIG. I is a perspective view of a three-way valve according to an aspect of the present invention;

FIG. 2A is a side, cross-sectional view of a three-way valve in a first position, according to an aspect of the present invention, and FIGS. 213 and 2C are cross- sectional views of the valve of FIG, 2A taken at sections 2.B-2B and 2C-2C, respectively;

FIG.3 A is a side, cross-sectional view of a three-way vaive in an intermediate position according to an aspect of the present invention, and FIGS, 3B and 3C are cross-sectional views of the valve of FIG. 3A taken at sections 3B-3B and 3C-3C, respectively;

FIG. 4 A is a side, cross-sectional view of a three-way valve in a second position according to an aspect of the present invention, and FIGS. 4B and 4C are cross-sectional views of the vaive of FIG, 4A taken at sections 4B-4B and 4G-4C, respectively;

FIGS. 5A-5C are side, cross-sectional views of a three-way valve with a motor drive according to an aspect of the present invention and showing the valve in three different positions;

FIGS. 6A-6C are side, cross-sectional views of a three-way valve with a motor drive according to another aspect of the present invention and showing the vaive in three different positions; and FIGS. 7A-7C are side, cross-sectional views of a three-way valve with a motor drive according to yet another aspect of the present in vention and showing the valve in three different positions. DETAILED DESCRIPTION

A three-way valve 21 according to an aspect of the present invention is seen in FIGS. 1- 4C. The valve 21 comprises a tubular valve cage 23 having an open first cage end 25 and a closed second cage end 27. The second cage end 27 can. include a flange as shown in FIG. 1 for securing the vai ve 21 relative to another structure, A cage side surface 29 extends between the first cage end 25 and the second cage end 27. A first cage opening 31 is provided in the cage side surface 29 at a cage first axial and circumferential position, and a second cage opening 33 is provided in the cage side surface at a cage second axial and circumferential position. The cage first axial position and the cage second axial position are non-overlapping such that the first cage opening 31 and the second cage opening 33 are discrete openings at different axial positions on the case side surface 29. The cage first circumferential position and the cage second

circumferential position are ordinarily also non-overlapping, typically in the sense that no part of the first and second cage openings 31 and 33 are vertically above or below each other (vertical being in a direction of a longitudinal axis of the cage 23), An interior surface 35 (FIG. 2) of the cage 23 is circularly cylindrical.

As seen, for example, in FIGS. 2A-4C, a tubular spool 37 is disposed in the valve cage

23. The spool 37 has an open first spool, end 39 and a second spool end 41 that can be open or closed. A spool side surface 43 is disposed between the first spool end 39 and the second spool end 41 , is circularly cylindrical with minimal clearance between the spool side surface and. the interior surface 35 of the cage 23 to prevent unwanted fluid passage between the spool side surface and the interior surface of the cage. Ring gaskets (not shown) are typically disposed between in grooves in one or both of the spool side surface 43 and the interior surface 35 of the cage 23 to facilitate avoiding unwanted fluid passage between the spool side surface and the interior surface of the cage.

A first spool opening 45 is provided in the spool side surface 43 at a spool first axial and circiimferential position, and a second spool opening 47 is provided in the spool side surface at a spool second axial and circumferential position. The first spool end 39 is disposed closer to the first cage end 25 than to the second cage end 27, and the second spool end 41 is disposed closer to the second cage end than to the first cage end. The spool first axial position and the spool second axial position can he overlapping such that the first spool opening 45 and the second spool opening 47 form a single opening, or, as seen in FIGS. 2A-4C, they may be non- overlapping and form discrete openings. The spool first circumferential position and the spool second circumferential position overlap, typically such that the first spool opening 45 and the second spool opening 47 are directly vertically above and below each (vertical being in a direction of a longitudinal axis of the spool 37).

The spool 37 is rotatable about the longitudinal axis thereof relative to the cage 23 between a first position as seen in FIGS. 2A-2C in which the first cage opening 31 and tie first spool opening 45 are aligned or at least partially overlap and together define a first valve opening and the second cage opening 33 and the second spool opening 47 are not aligned, do not overlap, and do not form any opening, and a second position seen, in FIGS. 4A-4C in which the second cage opening and the second spool opening are aligned or at least partially overlap and together define a second valve opening while the first cage opening and the first spool opening are not aligned, do not overlap, and do not form any opening. If desired, the second cage opening 33 and the second spool opening 47 can partially overlap to form the second valve opening when the spool 37 is in the first position, and the first cage opening 31 and the first spool opening 45 can partially overlap and form the first valve opening when the spool is in. the second position. in the embodiment shown FIGS. 1-4C, ihe first cage opening 31 and the second cage opening 33 each ordinarily extend around between 90° - 180° of a circumference of the cage 23. More particularly, the first cage opening 3 i and the second cage opening 33 can each comprise two discrete cage opening portions 31 a, 3 lb and 33a, 33b disposed on opposite sides of the cage side surface from each other. In the embodiments illustrated in FIGS. 2A-4C, the cage opening portions 31 a, 31b and 33a, 33b each extend over an arc of 90° so that the cage openings 31 and 33 each comprise arcs totaling 180° of the circumference of the cage 23.

Similar to the cage 23, the first spool opening 45 and the second spool opening 47 each ordinarily extend around between 90° - 180° of a circumference of the spool 37. The first spool opening 45 and the second spool opening 47 can each comprise two discrete spool opening portions 45a, 45b and 47a, 47b disposed on opposite sides of the spool side surface 43 from each other, in the embodiments illustrated in FIGS. 2A-4C, the spool opening portions 45a, 45b and 47a, 47b each extend over an arc of 90" so that the spool openings 45 arid 47 each compose arcs totaling 180° of the circumference of the spool 37.

Typically, when the spool 37 is in the first position as seen in FIGS, 2A-2C, a size of the first valve opening is a maximum size as seen in FIG. 2B and, as the spool is moved away from the first position toward the second position, the size of the first valve opening decreases as seen, in FIGS 313 and 4B. Typically,, when the spool 37 is moved away from the first position toward the second position, the size of the first valve opening decreases to zero at least when the spool is moved to the second position as seen in FIG, 4B,

Typically, when the spool 37 is in the second position as seen in FIGS, 4A-4C, a size of the second valve opening is a maximum size and, as the spool, is moved away from the first position (FIGS. 2A-2C) toward the second position (FIGS. 4A-4C), the size of the second valve opening increases. Typically, when the spool 37 is moved away from the first position (FIGS. 2A-2C) toward the second position (FIGS. 4A-4C), the size of the first valve opening decreases to zero (FIG. 48} at least when the spool is moved to the second position, and the size of the second valve opening increases from zero (FIG. 2C) at least when the spool is in. the first position and increases to the maximum size (FIG. 4C) when the spool is moved to the second position.

In the embodiment shown in FIGS. 2A-4C, the spool 37 is moved from the first position (FIGS. 2A-2C) to the second position (FIGS. 4A-4C) by rotating the spool through 90" relative to the cage 23. It will be seen in FIGS. 3A-3C that, at at least an intermediate point between the first position and the second position, the spool 37 and the cage 23 can be positioned relative to each other so that both the first cage opening 31 and the second cage opening 33 overlap parts of the first spool opening 45 and the second spool opening 47. FIGS. 3A-3C show the spool 37 rotated halfway between the first and second positions shown in FIGS. 2A-2C and 4A-4C, respectively, more particularly, rotated 45° between first and second positions that are 90° apart, i.e., the spool is moved from the first position to the second position by rotating the spool through 90° relative to the cage 23. The spool 37 can be rotated by any suitable means, such as by manually rotating the spool via a handle 49 (FIG. 1 ) that extends through the second cage end 29 of the valve 21. As seen in FIGS. 5A.-5C, a shaft 51 can be attached to the spool 37 and can extend through the second cage end 27, and a motor 53 can be connected to the shaft and arranged to rotate the shaft and the spool about longitudinal axes thereo f to move the spool between the first position (FIG, 5 A) and the second position (FIG, 5€), including to positions between the first and second position ( FIG. SB). The motor 53 may be any suitable motor, such as an electric motor working against a spring. Increasing motor torque would change the position. The circumferential position of the spool 37 could also be changed using a stepper motor that has positional feedback control, or via a servo motor with feedback control.

An alternative technique for turning the spool 37 relative to the cage 23 is shown in FIGS. 6A-6C. A shaft 55 is axial iy movabl y disposed in the spool 37 between a first axial position (FIG. 6A) relative to the spool and a second axial position relative to the spool (FIG. 6C). A pin 57 is attached to the shaft 55 and extends circumferentially relative to an axial direction of movement of the shaft. The pin 57 engages with a hel ical groove 59 on an interior surface 61 of the spool 37 such that linear motion of the shaft is converted into rotational motion of the spool to move the spool between the first and the second positions. Suitable means such as an electric motor 63 and gear arrangement 65 is arranged to move the shaft 55 axially between the first axial position (FIG. 6A) and the second axial position (FIG. 6C) and/or to axial positions (FIG. 6B) between the first and second axial positions. By moving the shaft 55 in one direction (e.g., to the right in FIG. 6A-6C), the spool 37 is moved from the first position (FIG. 6A) to the second position (FIG. 6C) and, by moving the shaft in the opposite direction (e.g., to the left in FIGS. 6A.-6C), the spool is moved from the second position to the first position. The shaft 55 can. be dri ven in one direction by means such, as the motor 63 and gear arrangement 65 and also moved in the opposite direction by the motor and gear arrangement, or by some other means. such as a spring. In the embodiment shown in FIGS. 6A-6C, the shaft 55 extends through the second cage end 27 and the moving means is disposed outside of the cage 23, although it is possible to have a moving means disposed inside the cage.

FIGS. 7A-7C show another technique for turning the spool 37 relative to the cage 23 wherein the means for moving a shaft or piston is disposed inside the cage. A wax motor 67 can be (but is not necessarily) disposed inside of the cage 23. The wax motor 67 comprises a cylinder 69, a piston 71 (i.e., shaft) movably disposed in the cylinder, a temperature sensitive wax materia! (not shown) in the cylinder, the wax material being adapted to expand from a first volume at a first temperature to a second volume at a second temperature, the second volume being greater than the first volume and the second temperature being greater than the first temperature, to cause the piston to move from a first axial position (FIG. 7 A) relative to the spool 37 to a second axial position (FIG. 7C) relative to the spool. As with the embodiment of FKiiS. 6A-6C, a pin 73 is attached to the piston 71 and extends radially relative to an axial direc tion of mo vement of the piston. The pin 73 engages with a helical groo ve 75 on an interior surface 77 of the spool 37 such that linear motion of the piston 71 is converted into rotational motion of the spool to move the spool between the first position (FIG. 7A) and the second position (FIG. 7C) and to positions (e.g., FIG. 7B) between the first and second positions. Use of a device such as a wax motor 67 that does not require electrical power and that has few moving parts inside of the cage 23 can be useful to reduce the risk of damage to the moving means. Use of a wax motor 67 can be useful when the valve 21 is used as an oil temperature control valve when it is desired to change the degree of opening of the valve in response to temperature changes in the fluid passing through the valve. The valve 21 can facilitate maximization of the flow area through the valve as up to 180° of a circumference of the valve can be open. This can also help in reducing pressure drop across the valve. Reducing the pressure drop helps to make the oil system more efficient and ultimately contributes to fuel economy.

The valve 21 will also not create any or will minimize areas where pressure or flow can act on the valve to create an unbalanced system as there need not be surfaces against which the pressurized fluid can act so that the valve will not have to act against any flow and will only have to overcome frictional forces in the valve itself in order to turn.

The valve 21 is particularly useful as an oil temperature control valve and can facilitate providing greater control of oil temperature and, in turn, can assist in enhancing system efficiency and fuel economy. The valve 21 may. of course, be used in other applications.

In the present application, the use of terms such as "including" is open-ended and is intended to have the same meaning as terms such as "comprising" and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as "can" or "may" is intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.

While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.