MXPA01001443A - Spool valve for fluid control - Google Patents

Abstract

A spool valve is provided with a stem portion (60f) that defines a fluid passageway (56f) formed by either (a) a single central support having a non-cylindrical curved surface shaped hydrodynamically, or (b) only a pair of sidewalls with, preferably, interior surfaces that are also shaped hydrodynamically. These stem passageways, which are designed to facilitate the flow of high-speed/high-pressure fluids controlled by the valve, are maintained in a predetermined orientation relative to the ports of the valve cylinders by a mechanism preferably including (a) a cam-following roller (66a) supported in a tang (62a) fixed to each spool and (b) a two-element cam that captures the roller (66a) within two of the parallel sides of a cam-track groove formed in the respective interior surfaces of each cam element.

Description

REEL VALVE FOR FLUID CONTROL TECHNICAL FIELD This invention relates to the valve used to control the flow of fluids, for example, radial valves incorporated as an integral part of pump / hydraulic motors; and, more particularly, it relates to the apparatus for controlling the operation of reels used in such valves and the shape of the reels themselves.

BACKGROUND The valve that uses reciprocating reels to control the flow of fluids is well known in the hydraulic field. For example, spool valves, positioned radially, are used as part of a pump / hydraulic motor apparatus (for example, see U.S. Patent No. 5,513,553 entitled "Hydraulic ^ Machine with Gear-Mounted Swash- Plate "). In most such known valves, each spool alternates axially within a cylinder formed in the valve body. More commonly, each cylinder is provided with a pair of ports defining first and second fluid passages, and the reel has a pair of port locking portions separated by a rod so that, when the reel moves axially towards In a first position, the first passage of fluid is blocked while the fluids are allowed to move past the rod and through the second fluid passage. Similarly, when the spool moves axially to a second position, the second passage of fluid is blocked while allowing the fluids to move past the rod and through the first fluid passage. Commonly in such a valve, one end of the spool portion of the valve acts as a cam follower which travels on a rotating cam surface, and each reel is spring-biased toward the cam surface so that the rotation of the cam cam controls the successive and continuous axial movement of the respective reels in each valve assembly. However, it is known that the response time and the general operation of such spring-deflected reel systems are often affected by dirt and back pressure problems. Also, it is well known that individual reels of such known valve often rotate (albeit very slowly) around the central axis of the cylinder. Therefore, the rod section is reduced from each reel that has been preferably designed with a cylindrical shape (see Figures 3 and 4), so that when such reel rotation occurs, changes in the orientation of its section of The rod does not result in any change in the shape of the fluid passage formed around the cylindrical rod section when the valve is opened. The valve design is of particular importance when the valve is used to control the flow of hydraulic fluids kdan ~ t¿2? L. FaM3? 3i.l «? - He. iaí *. ** 4 ^ -? . - Under high-speed and high-pressure conditions, for example, in automotive pumps / engines that are capable of high horsepower and must be capable of high speeds of about 4000 rpm and withstand pressures as high as 281.2 kg / cm2. Consistent fluid flow under such conditions is critical. The invention described herein is directed primarily to such a critical fluid flow. The valving according to the invention overcomes the problems of response time of the Valve spring deflected and not only ensures the consistency of valve timing but also significantly increases the efficiency of fluid luxury that passes the rod portion of each reel.

BRIEF DESCRIPTION OF THE INVENTION The general format of the valving in accordance with this invention follows the conventional known spool valve arrangements described above. Namely, each reel alternates axially within a cavity, preferably a cylinder, formed in the valve body. The cylinder may include ports that form only a single fluid passage. However, in the modes designed for use with pump / hydraulic motors (for example, as described in Figures 1 and 2), each cylinder is provided with first and second ports defining first and second fluid passages. The reel ^ * * ^ ^ fff-fff flfffH has a pair of port locking portions separated by a rod so that, when the reel moves axially to a first position, the first passage of fluid is blocked while allowing it to the fluids move past the rod and through the second fluid passage; and, when the spool moves axially to a second position, the second passage of fluid is blocked while allowing the fluids to move past the rod and through the first fluid passage. However, in comparison with the prior art arrangements, in the valve of the invention, the reciprocating axial movement of each reel is not controlled by a spring-deflected cam follower. Instead, direct reel control is achieved with a cam follower trapped within the cam profile that is set to rotate with a drive shaft. The cam profile has at least two parallel cam surfaces between which the cam follower is trapped. In preferred embodiments, the cam follower is a roller. In the preferred valving arrangement illustrated in Figures 1 and 2, a plurality of individual valves are positioned radially about the driving shaft of a pump / hydraulic motor. The spool within each valve includes a spike extending from the bottom of the spool. The spigot is provided with a hole through which a cam follower roller supported and received in a predetermined orientation is received and supported allowing rolling engagement of the roller with the parallel surfaces of the cam profile. In the described embodiment, the parallel surfaces of the cam profile are divided into two mirror image portions that provide a balanced positive pulse to control the position of the cam followers. The combination of the cam groove, roller and spigot controls the synchronization of the alternation of each reel and, simultaneously, also serves as an orientation mechanism that prevents rotation of the reel within its respective cylinder. The rod portion of each reel defines a passage formed by either (a) an individual central support having a non-cylindrical curved surface formed hydrodynamically, or (b) only a pair of side walls. Preferably, the interior surfaces of the side walls are also formed hydrodynamically. The respective hydrodynamic shapes of the central supports and the side walls are designed to facilitate the flow at high velocity / high pressure of fluids through the fluid passages controlled by the valve. That is, these hydrodynamic surfaces are formed to to facilitate (i) the flow of fluids through the spool and (ii) the direction of fluid flow to and from the fluid passages defined by the respective cylinder ports when the rod portion is aligned therewith. Of course, those rod surfaces hydrodynamics must be maintained in an orientation predetermined in relation to the ports of the valve cylinders in order to ensure a maximum flow of fluid through those rod and cylinder passages. The orientation mechanism of the invention avoids any axial rotation of the reels. That is, the mechanism includes the cam followers that are mounted on each reel. As mentioned before, those cam followers (preferably, rollers) are trapped between the parallel surfaces of a rotating cam so that each reel, while being positively driven by the cam profile can not rotate about its axis, maintaining in this way the desired orientation of the spool shank passage.

DRAWINGS Figure 1 is a schematic cross-sectional view (with minor and cross-hatched portions omitted to improve clarity) of selected portions of a hydraulic motor / pump machine (e.g., of the type described in U.S. Pat. North America No. 5, 513, 553), which show the improved radial spool valve of the invention positioned within the left end of the housing. Figure 2 is a similar schematic cross-sectional view of the radial spool valve portion of Figure 1, taken along the plane 2-2 (with parts removed) representing (a) the nine pump cylinders of the machine and the respective valve openings, (b) one half of the cam profile positive of the invention and c) only the shank and the roller portions of the reels. Figures 3, 4 and 5 illustrate three respective schematic views of a conventional well-known valve reel of the prior art, in which: Figure 3 is a side view, Figure 4 is another side view taken along the plane 4-4 of Figure 3; and Figure 5 is a cross-sectional view taken along plane 5-5 of Figure 4, using dashed lines to indicate the directions of fluid flow passing the rod portion of the spool. Figures 6, 7 and 8 illustrate three respective views of an improved spool in accordance with a first embodiment of the invention in which: Figure 6 is a schematic side view; Figure 7 is a side view taken along plane 7-7 of Figure 6; and Figure 8 is a cross-sectional view taken along plane 8-8 of Figure 7, using dashed lines to indicate the direction of fluid flow passing the rod portion of the spool. Figures 9, 10 and 11 illustrate three respective views of an improved spool according to a second embodiment of the invention in which: Figure 9 is a schematic side view; Figure 10 is another side view taken along the plane 10-10 in Figure 9; and Figure 11 is a cross-sectional view taken along the plane 11-11 of Figure 10, using dashed lines to indicate the direction of fluid flow passing the rod portion of the spool. Figures 12, 13 and 14 illustrate three respective views of an improved spool in accordance with a third embodiment of the invention in which: Figure 12 is a schematic side view; Figure 13 is another side view taken along the plane 13-13 in Figure 12; and Figure 14 is a cross-sectional view taken along the plane 14-14 of Figure 13, using dashed lines to indicate the directions of fluid flow passing the rod portion of the spool. Figures 15, 16 and 17 illustrate three respective views of an improved spool in accordance with a fourth embodiment of the invention in which: Figure 15 is a schematic side view; Figure 16 is another side view taken along the plane 16-16 in Figure 15; and Figure 17 is a cross-sectional view taken along the plane 17-17 of Figure 16, using dashed lines to indicate the directions of fluid flow passing the rod portion of the spool. Figures 18, 19 and 20 illustrate three respective views of an improved spool according to a fifth embodiment of the invention in which: Figure 18 is a schematic side view; Figure 19 is another side view taken along the plane 19-19 in Figure 18; and Figure 20 is a cross-sectional view taken along plane 20-20 of Figure 19, using lines S pj RÍ? 5A - r ^ jjl? M? = ára - * «£, of stripes to indicate the directions of the flow of fluid that passes the portion of rod of the reel. Figures 21, 22 and 23 illustrate three respective views of an improved spool in accordance with a sixth embodiment of the invention in which: Figure 21 is a schematic side view; Figure 22 is another side view taken along the plane 22-22 in Figure 21; and Figure 23 is a cross-sectional view taken along plane 23-23 of Figure 22, using dashed lines to indicate the directions of fluid flow passing the rod portion of the spool.

DETAILED DESCRIPTION Figure 1 shows portions of a hydraulic pump 10 that includes a drive shaft 12 that is rotatable by an external power source, for example, an automotive motor coupled to its right end (neither the right end of the shaft 12 nor the source of energy are shown). The pump 10 has a cylinder block portion 14 in which a plurality of pump cylinders 16 are positioned radially about the axis 42 of the drive shaft 12 and the axis of each cylinder 16 is aligned parallel to the shaft 42. A pump piston 18 is fitted within each pump cylinder 16 and is connected by means of a "dog bone" piston rod 20 to a tiltable but non-rotating plate 22 of an oscillating plate 24 which also includes an incunable and rotating rotor 26. In a manner well known in the art, Tt. : ** £ £ Lí & l < f¡ á & = J-is the rotor 26 of the oscillating plate 24 pivotally connected to the drive shaft 12 for rotation therewith and the angle of the oscillating plate 24 relative to the drive shaft 12 is controlled by means including a link 28. The swing plate 22 is supported within an inner gear 32 of a pair of spherical gears, the outer gear 34 of the pair that is mounted to the inner wall of an oscillating plate housing portion 30 that is connected to the right end of the cylinder block portion 14 of the pump 10. The alternation of the pump pistons 18 in response to the rotation of the drive shaft 12 moves the fluid in and out of the pump cylinders 16 through a hole 17. As each respective piston 18 moves to the right, the low pressure fluid inlet port 17 allows the piston to fill its respective cylinder 16; and, subsequently, as each respective piston 18 is driven to the left, the high pressure fluid is forced out of the respective cylinder 16 through the orifice 17. This high velocity fluid flow of low and high pressure is controlled by the valve of spool transported within a valve block 36 connected to the left end of the cylinder block 14 by the bolts 38. The valve block 36 is drilled with a plurality of valve cylinders 40 positioned around the axis 42 of the drive shaft 12, and the axis of each valve cylinder 40 extends radially from the shaft 42. Within each valve cylinder 40, a respective spool 44a moves axially to sequentially open and close a pair of ports 46, 48 defining high fluid passages. and respective low pressure connecting respective corresponding passages 50, 52 in multiple respective coils 53 (only one of which is shown in FIG. hidden lines) formed in an end cover 54, which forms the left end of the housing of the pump 10. The operation of the spool valves mounted on the valve block 36 will generally be described first using reels according to a first embodiment of the invention. [NOTE: all the valve reels of the invention share the same basic arrangement of similar elements which are identified in a general way by the same reference numbers, the elements of each different modality that are differentiated by the use of letter suffixes ( aaf) specific to each modality]. Referring now to Figures 2, 6 and 7, each reel 44a includes a pair of port locking portions 56a, 58a separated by a rod 60a; and, in the preferred embodiments, a tang 62a extends from the port blocking portion 58a. The pin 62a has a guide hole 64a that receives and supports a cam follower roll 66a. As shown in Figures 1 and 2, a pair of mirror-image cam elements 70, 72 are mounted inside the valve block 36, which is equipped on the left end of the drive shaft 12. Machined as grooves in the faces internally of the cam elements 70, 72 is a pair of respective cam profiles 74, 76 each having at least two parallel surfaces forming the side walls of each respective profile 74, 76. The cam elements 70, 72 they are fixed to rotate with the drive shaft 12 and are held in position by a key 78 so that the cam profile 76 forms the mirror image of the cam profile 74. To assemble, then each reel 44 has been fitted within its respective valve cylinder 40, the cam member 72 is closed on the shaft 12. And then each respective roller 66a is adjusted through the respective guide hole 64 formed in the tang 62 of its respective spool 44. Each cam follower roller 66a is then placed with one end inside of the cam profile 76 of the cam member 72. Subsequently, the cam member 70 is also closed to the shaft 12 so that the other end of each roller 66a is received within the cam profile 74 of the cam member 70 and the Cam element 70 is properly locked in position. Since, as indicated before, the pin 62a is fixed relative to the spool 44a and since the cam follower roller 66a is trapped within the cam profiles 74, 76 of the cam elements 70, 72, the reel 44a can not rotate about the axis of its respective valve cylinder 40 at all times during the operation. Also, since the position of the shank 60a is also fixed in relation to the other elements of the reel 44a, the orientation of the rod portion 60a is similarly prevented from rotating about the axis of its respective valve cylinder 40 at all times during operation. A principal feature of the invention resides in the shape and orientation of the rod portion of each reel and in facilitating the flow and direction of the fluid through the passage formed by each portion of the rod when the latter is aligned with the rod (s). ports of its respective valve cylinder 40. In this regard, it should be remembered that the axial movements of each reel 44a control the sequential and bidirectional fluxes of the fluids, ie they also flow out of each pump cylinder 16. The importance of the facilitation of the fluid flow is best appreciated when compared to the prior art reels of the type illustrated in Figures 3 and 4. In each well-known and widely used prior art reel 44, the port blocking portions 56 and 58 are separated by a rod 60 that is cylindrical in shape. The bottom of the port blocking portion 58 is provided with a spherical surface 59 that is designed to travel on the surface of a conventional control cam (e.g., similar to the surface of the internal wall of the cam follower 74 in the Figure 2). The spherical surface 59 of each prior art reel 44 serves as a cam follower, being held in conventional manner in * ^^ -. «'LvjL?« W ^ r «Sfí» íís £ a4 «¡i ^ ^': contact with the surface of the control cam by spring deflection (not shown). As indicated in the background section, each rod 60 of the prior art reel 44 is centered on the spool axis and has a cylindrical shape. Therefore, the spool 44 must rotate axially within its respective valve cylinder during the valve operation, the relative size and shape of the fluid passage formed by the rod portion of the spool 44 which remain constant. As is well known in the art hydraulic, when a fluid flows past a cylinder at high speed (for example, the movement of air passing through a flagpole or the mast of a sailboat), turbulences form in the fluid in motion resulting in an undulating turbulence. The turbulence resulting from the movement of the fluid through the The shank passage of the reel 44 is illustrated schematically in Figure 5 by the fluid flow arrow 80 which, as noted above, indicates the bidirectional flow of the fluid through each valve. Each turbulent flow decreases the efficiency of the valve, particularly at high speeds and pressures. The invention is directed in the present to the reduction of said turbulence and, therefore, to an increase in the efficiency of the high speed / pressure hydraulic motors / pumps. ^ gksgaatí ^^ Reduction of Turbulent Flow 'a Referring to the first embodiment of the reel design of the invention illustrated in Figures 6, 7 and 8, the port locking portions 56a and 58a of the reel 44 are separated by the portion of shank 60a in which the interiors 80a of the two side walls define a passage for fluid flow when the shank portion 60a is aligned with ports 46 and 48 respectively of the cylinder 40. Since there is no intermediate shank element (for example, the rod 60 of the prior art reel 44), the fluid is free to move unimpeded and bidirectionally by passing the rod portion 60a of the reel 44a as indicated schematically by the fluid flow arrow 82a in FIG. Figure 8. It is important to note that the predetermined position of the side wall interiors 80a in relation to ports 46 and 48 is critical to the efficiency of the fluid passage through them; and the constancy of orientation of the side wall interiors 80a is ensured by the above-described orientation mechanism, ie, the predetermined and fixed position of the shank 62a and the roller 66a relative to the shank portion 60a. A second embodiment of the reel design of the invention is illustrated in Figures 9, 10 and 11. The port locking portions 56b and 58b of the reel 44b are separated by a central support 60b forming the rod portion which defines a double passage for fluid flow when the central support 60b is aligned with the ports 46 and 48 respectively of the cylinder 40. This second embodiment includes a further feature of the invention, ie the surfaces 80b of the central support 60b are provided with a predetermined hydrodynamic shape to facilitate the bi-directional flow of the fluid passing the surfaces 80b and to reduce the formation of turbulence in the fluid in motion, Again, the predetermined position of the central support 60b with respect to ports 46 and 48 is critical for efficiency of the fluid passages formed by this rod section, and the constancy of the orientation of the central support 60b it is secured through the predetermined and fixed position of the shank 62a and the roller 66b relative to the shank portion 60b.

Improvement of Flow Direction As indicated above, reel valves are widely used in hydraulic machines such as pumps and motors. As is well known in the hydraulic art, pumps have pistons responsible for the rotation of a driving shaft, the latter being driven by an external power source. The pistons remove the low pressure fluid inside the pump cylinders and then force the fluid out of the cylinders at high pressure. In hydraulic motors, the opposite is true, ie the high-pressure fluid moves the pistons of the motor, causing the rotation of the motor drive shaft and the fluid comes out after the cylinders at a lower pressure to return to "A closed hydraulic cycle shared with a hydraulic pump coupling (or in some cases, a collector). The direction of rotation of the motor drive shaft is reversed when the high pressure fluid flow is reversed in the hydraulic lines supplying the motor, etc. In any case, the hydraulic fluid enters and leaves the cylinders of the pump / motors through separate ports and the direction of the flow through those ports can be reversed. Referring again to the provision of reel valve shown in the upper left portion of the hydraulic machine illustrated in Figure 1, each valve cylinder 40 includes a hole 17 that connects to the left end of each pump cylinder 16. Each valve cylinder 40 also includes other two separate ports 46 and 48 that, respectively, connect to the fluid passages 50 and 52 formed in an end cap 53 of the pump 10. In the particular arrangement illustrated, the port 46 is positioned above the level of the hole 17 while the port 48 is positioned below the level of the orifice 17. For purposes of this explanation, it is assumed that the The pump 10 is operated in a closed fluid circuit arrangement with a coupling hydraulic motor. Furthermore, it is assumed that the high pressure fluid is present in the passage 50 and in the duct connecting to the port 46 and that the return fluid at lower pressure is present in the passage 52 and in the duct that connects with the the port 48. Figure 1 shows the oscillating plate 24 in the position of maximum angle of inclination in which the pump 10 is moving the fluid at its maximum flow velocity. Assuming that the oscillating plate 24 has reached the position shown, the reel 44a has reached its illustrated position in both ports 5 46 and 48 which are blocked. According to the pump cycle, the oscillating plate 24 initiates the movement of the piston 18 to the right and the cam elements 70, 72 move the reel 44a downwards, connecting the fluid return passage 52 to the hole 17 and allowing the fluid moves from port 48 towards above into the orifice 17 of the pump cylinder 16. The return fluid under the lower pressure continues to move through the hole 17 and into the cylinder 16 until the rotation of the oscillating plate 24 has allowed the complete movement of the piston 18 to the right. At that time, reel 44a either moved up and ports 46 and 48 are again blocked. As the oscillating plate 24 begins to drive the piston 18 to the left, the continued upward movement of the reel 44a connects the orifice 17 to the port 46, allowing the piston 18 to force the high pressure fluid out of the cylinder 16 from the orifice 17 toward above inside port 46 and passage 50. The following embodiments relate to facilitating the direction of fluid flow through the rod passages of the reels of the invention. A third embodiment of the invention, the reel 44c is illustrated in Figures 12, 13 and 14; and the 44c reel combines alli - ^ .t ^ - »^ A ^ key characteristics of the first and second modes. Namely, in a design similar to the first embodiment, the shank portion 60c comprises a completely open fluid passage defined only by two side walls. However, in this embodiment, the inner surfaces 80c of the side walls are provided with a predetermined hydrodynamic shape selected to facilitate the flow of fluid to and from an individual port, (e.g., hole 17 of Figure 2 as described before) to a pair of ports (for example, ports 46 and 48 in Figure 1) opening, respectively to the left and right of the individual port. A fourth embodiment, the reel 44d is illustrated in Figures 15, 16 and 17. While the shank portion 60d also uses a pair of side walls to define the boundaries of the shank passage, a horizontal divider 79 with hydrodynamic surfaces 80d they separate the passage to direct the fluid flow as indicated by the arrows of the fluid flow 82d. In this embodiment, it is assumed that an individual port (eg, port 17 of Figure 2) is located on the right in Figure 17. This mode is designed to improve fluid flow to and from the ports of entry and exit located, respectively, up and down the individual port. Figures 18, 19 and 20 illustrate a fifth embodiment, reel 44e, which is a modification of the second embodiment. That is, the individual central support 60e is provided with Hydrodynamic surfaces 80e that are designed to direct the flow of fluid to and from separate ports (eg, ports 46 and 48 in Figure 1). 2) that are placed to the left and to the right, respectively, of an individual port (for example, 5 hole 17 in Figure 2). This directional fluid flow is indicated by arrows 82e in Figure 20. Finally, Figures 21, 22 and 23 illustrate a sixth embodiment, reel 44f, which is a preferred modification applicable to the first and third modes (see Figures 7 and 13) wherein the rod portion of the spool comprises a completely open fluid passage defined only by two side walls. In order to facilitate fluid flow, it may be desirable to reduce the thickness of those side walls. However, as the side walls become thinner, the passage of the high pressure fluid through the rod opening can result in a slight "bowing" of the side walls and undesirable reduction of the clearance between the outer surface of the spool and the inner surface of its respective cylinder. In this sixth modality, a pressure balance channel 84 is formed around the entire outer circumference of the rod portion 60f. (NOTE: the depth of channel 84 is shown very exaggerated in the illustrations). Although the width of the channel 84 (in Figures 21, 22 and 23) is shown extending along the entire vertical height of the portion of shank 60f, a narrower channel may be sufficient, since the The size of the channel 84 need not be greater than necessary to introduce an equilibrium pressure (between the outside of each side wall and the inner surface of the cylinder in which the reel 44f is mounted) sufficient to avoid distortion of the side walls. As explained above with respect to the first and third embodiments, the reel 44f does not have an intermediate rod element (for example, the rod 60 of the prior art reel 44), and this fluid is free to move uninterruptedly and bidirectionally passing the rod portion 60f of the spool 44f, as schematically indicated by the fluid flow arrow 82f in Figure 23. However, it should also be noted that the flow through the channels 84 formed in the external circumference of the shank portion 60f, since the depth of the channels 84 (which is greatly exaggerated) as long as it is appropriate to introduce the desired equilibrium pressure, is not large enough to allow any appreciable flow of fluid to through it. In the four foregoing embodiments, the orientation of the fluid passages through the rod portions of the reels is once again critical. As explained in relation to the first and second embodiments, this critical orientation is maintained through a mechanism that prevents rotation of the individual reels 44a-f around the axis of their respective valve cylinders 40. Such a targeting mechanism must include some form of closure arrangement using a key and a slot / slip combination shared by each valve and spool cylinder. However, once again, the preferred orientation mechanism comprises a driven cam follower directly trapped in a cam profile and placed in a fixed orientation relative to each reel as described above. The invention as described increases pump efficiency by (a) the direct drive of each spool, by (b) the facilitation of the direction of the fluid flow passing the rod portion of each reel and by (c) the use of the reel rod design to reduce fluid turbulence. The reduction of fluid turbulence in the pump / hydraulic motor valve system not only increases the efficiency of machine, but also significantly reduces the machine noise that accompanies the movement of fluid at high speed. ^ gg ^^ gg ^^ g ^ l

Claims (18)

1. CLAIMS 1. In the reel valve apparatus having a plurality of respective valves sequentially operated by rotating a drive shaft, each spool valve 5 comprising (a) a cylinder having at least a first port defining a first fluid passage, and (b) a spool having a rod portion and at least one port blocking portion, the spool which is axially movable within the cylinder between the first and second positions so that, when the The spool is in the first position, the fluids can move past the rod portion and through the first fluid passage and, when the spool is in the second position, the first fluid passage is blocked, the improvement comprises: cam rotated by the drive shaft and having at least two parallel surfaces, and - a plurality of cam followers, each cam follower which is associated with and aligned in a pre-position determined in relation to, a respective one of the reels and each cam follower that is trapped between the surfaces 20 parallel of the cam profile for relative movement in engagement therewith to control the axial movement of the respective spool and the sequential operation of the respective spool valves in response to the rotation of the drive shaft; and where: ^^^ »^^? ^^ g £ fagj ¡iÉÉ r r ° ^? ---- ^ ÍMrftj -? ^ JBrf - * ?, vA" '"-? "f" - the stem portion of each respective spool defines a passage formed by one of (a) without side walls with a central support comprising a non-cylindrical curved surface formed hydrodynamically, and (b) a pair of side walls with 5 the passage formed between them, the central support and the side walls which are placed in a predetermined orientation relative to the respective first fluid port of the cylinder to facilitate the flow of the fluids passing the rod portion and through the first port of fluid when the rod portion is aligned therewith. The reel valve improvement according to claim 1, characterized in that: the cylinder comprises a second port separated from the first port and defining a second passage of fluid; and 15 - when the spool is in the first position and the fluids can be moved past the rod portion and through the first port, the second fluid port is blocked; - when the spool is in the second position, the first fluid passage is blocked and fluids are allowed 20 move past the rod and through the second fluid port; and the predetermined orientation of the central support and the passage between the side walls of the rod portion is positioned to facilitate the flow of fluid (a) passing in the portion 25 of shank and through the first fluid passage when the portion - ^ - * ^^ of rod is aligned with the first fluid port and (b) passing the rod portion and through the second fluid passage when the rod portion is aligned with the second fluid port. 3. The reel valve upgrade according to claim 2, characterized in that the pair of side walls of the rod portion has inner surfaces forming the passage therebetween, and each inner surface is hydrodynamically formed to facilitate the flow of fluids. through the portion of the rod and to direct the flow of fluids to and from the respective first and second fluid ports when the rod portion is aligned therewith. The reel valve improvement according to claim 2, characterized in that the rod portion having a pair of side walls further comprises a pair of passages formed between the side walls, each passage which is oriented to direct the fluid towards and from a respective one of the cylinder ports when the rod portion is aligned therewith. The reel valve upgrade according to claim 2, characterized in that the non-cylindrical central support forms a pair of passages, each passage which is oriented to direct the fluid to and from a respective one of the cylinder ports when the portion of rod is aligned with them. 6. The reel valve improvement according to claim 1, characterized in that the predetermined portion of each cam follower relative to its respective spool prevents rotation of each reel around the axis of its respective cylinder when the roller is in rolling coupling with the cam profile and, therefore, maintains the predetermined orientation of the central support and the side walls of the rod portion to facilitate fluid flow. The reel valve improvement according to claim 6, characterized in that each cam follower comprises a roller coupled by the rolling coupling with the cam profile. 8. The reel valve improvement according to claim 7, characterized in that each reel has a pin through which the respective roller is received and held in the predetermined position to allow the rolling coupling with the parallel surfaces of the reel profile. cam. The reel valve improvement according to claim 7, characterized in that the parallel surfaces of the cam profile are divided into two aligned mirror image portions, and wherein each roller is in rolling coupling with the mirror image portions. aligned at all times. 10. The reel valve improvement according to claim 2, characterized in that the plurality of cylinders ..- / JtóSá: it is placed equidistant from one another along axes that extend radially from a central axis. The reel valve improvement according to claim 1, characterized in that each side wall of the rod portion has an outer surface and further comprises a pressure balancing channel formed therein. 12. A spool for a valve for controlling the flow of fluids, the valve having a body including a cavity for receiving the spool, the cavity having an axis and at least one A port defining a first passage of fluid, and the reel comprising: - a first port blocking portion and a rod; - the spool which is axially movable within the cavity between the first and second positions so that, when the The spool is in the first position, the first fluid passage is blocked by the first port blocking portion and when the spool is in the second position, the fluids are allowed to move past the rod and through the first fluid passage.; and - the rod defining a shank passage formed by one of (a) without side walls with a central support comprising a non-cylindrically curved surface formed hydrodynamically, and (b) a pair of side walls with the shank passage formed between them, the central support and the side walls which are positioned relative to the respective first fluid port 25 of the cylinder to allow the flow of fluids through the "^? s ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ child passages and through the first fluid port when the rod portion is aligned with it The reel according to claim 12, further comprising an orientation mechanism for positioning the shank passage formed by the side walls and the central support in a predetermined orientation relative to the first fluid passage so that the flow Fluid through the first port is provided at all times when the rod is aligned with it. The reel according to claim 13, characterized in that the spool valve for controlling the flow of fluids is incorporated in a machine having a control cam surface rotated with a drive shaft, the control cam having at least two parallel surfaces, and wherein: - the orientation mechanism comprises a cam follower aligned at a predetermined position relative to the reel, the cam follower being trapped between the parallel surfaces of the control cam for relative movement coupling therewith to control the axial movement of the reel. 15. The reel according to claim 14, characterized in that the cam follower is a roller. The reel according to claim 12, characterized in that each side wall of the rod portion has an outer surface and further comprises a pressure balancing channel formed therein. 17. The reel according to claim 12, characterized in that the cavity in the valve body includes an additional port defining a second passage of fluid and the reel further comprises: a second port blocking portion separated from the first blocking portion of port through the rod and, when the spool is in the first position, the first port blocking portion of the spool blocks the first passage of fluid while allowing fluids to move through the rod passage and through the second passage of fluid, and when the spool is in the second position, the second blocking portion of the spool port blocks the second passage of fluid while allowing the fluids to move through the rod passage and through the first fluid passage; and - an orientation mechanism for positioning the shank passage in a predetermined orientation relative to the first fluid passage and the second fluid passage so that fluid flow through the shank passage is provided at all times when the shank is aligned respectively, with the first and second fluid passages. The reel according to claim 17, characterized in that the pair of side walls has inner surfaces forming the rod passage between them, and each inner surface is hydrodynamically formed to facilitate the flow of fluids through the rod passage and to direct the flow ^ - ^ ^ - of fluids to and from the respective first and second fluid ports when the rod portion is aligned therewith. g- «« H2 * s "g ^? a -t - ^ gg > §S gg? - * ^? é «SBÜ üi-