Multi-path valve structure with means providing smooth flow patterns

• US 4,008,737 A
• Filed: 08/26/1974
• Issued: 02/22/1977
• Est. Priority Date: 08/26/1974
• Status: Expired due to Term

• Current Assignee: The Bendix Corporation (Honeywell International Inc.)
• Original Assignee: The Bendix Corporation (Honeywell International Inc.)
• Inventors: Orme, Myrl E., Kluczynski, Matthew L.
• Primary Examiner(s): Cohan, Alan
• Assistant Examiner(s): Michalsky, Gerald A.
• Application Number:
  US05/500,440
• Time in Patent Office: 911 Days
• Field of Search: 137/625.3, 137/625.69, 251/127
• US Class Current: 137/625.3
• CPC Class Codes: F16K 3/34 Arrangements for modifying the way in which the rate of flow varies during the actuation of the valve
• CPC Class Codes: F16K 47/08 for decreasing pressure or noise level and having a throttling member separate from the closure member , e.g. screens, slots, labyrinths
• CPC Class Codes: Y10T 137/8671 With annular passage [e.g., spool]
• CPC Class Codes: Y10T 137/86734 With metering feature

Abstract

Multiple path means for a fluid flow control device is shown in connection with a typical spool type servo valve and a relief valve. The multiple path means consists of a stack of washer-like elements or disks which cooperate to define a number of finely divided flow paths across a stack of disks. To provide a configuration which is very economical of space, the disks are arranged such that the flow path turns back and forth through different planes. Groups of flow paths are defined by a number of groups of perforated disks confined between the imperforate disks. Two perforated disks having patterns of openings are positioned on opposite sides of a similar disk having a pattern of small orifices. By proper juxtaposition of the three or more disks, a circuitous flow pattern is established from a first chamber defined by a first slot and its side walls, axially through a series of small orifices to a second such chamber, substantially radially through said second chamber and axially in the opposite direction through more orifices to another such chamber and continuing in this manner across the stack of disks. The dimensions of the slots and orifices are chosen such that the velocity of flow through any orifice is maintained within a desired limit. To provide a substantially smoother flow vs. valve displacement relationship, the working faces of the valve lands are canted such that in a given position, edges of more than one of the disks of the stack are uncovered; or, alternatively, the stack of disks is canted such that the lands of the spool expose edges of more than one disk. In this manner, irregularities in the flow pattern caused when the lands of the spool pass a disk having no flow entrances are minimized. Also, the magnitude of flow irregularities are reduced by the number of flow paths opened during the spool displacement equivalent to one disk thickness; i.e., the more openings (one at a time), the smoother the flow pattern.

Claims

1. In a flow control valve wherein a spool valve member including at least one land is movable within a sleeve to open and close fluid passageways in said valve, a rigid structure forming part of said sleeve for dividing the flow entering and leaving said passageways into a plurality of streams comprising a stack of laminar disks having abutting faces and internal edge surfaces adjacent said pool member,

said disks including a first group having a pattern of openings therethrough including a pattern of slots affording entry into said stack, a first subgroup of said group being radially oriented in a desired position and a second subgroup of said group being radially displaced from said subgroup such that the openings therein overlap but do not directly register with openings in said first subgroup,

a second group of disks having a pattern of orifices therethrough interposed between members of said first and second subgroups, said orifices individually being of substantially smaller area than said openings and providing communication between members of said first and second subgroups, and

a third group of imperforate disks positioned between selected pairs of disks of said first group for confining flow to generally radial flow patterns across said stack,

one of said land and said stack of disks being canted relative to the other such that as said land moves past said stack, slots arranged around the inside circumferential edge of any of said disks are progressively uncovered.

2. A flow control valve as set forth in claim 1 wherein said stack of disks is canted relative to said spool valve and said land.

3. A flow control valve as set forth in claim 2 wherein said disks in said stack are brazed together to form a rigid structure.

4. A flow control valve as set forth in claim 1 wherein the edges of said land are canted relative to said stack of disks and the axis of said spool valve.

5. A flow control valve as set forth in claim 1 wherein said second group of disks includes a pattern of slots affording entry into said stack, which slots are radially displaced from the slots of either of said first or second subgroups but communicating with openings in at least one of said subgroups.

6. A valve comprising

a flow path including an openingg to said flow path;

means for closing said opening in variable degree;

and means for dividing the flow through said opening into a plurality of streams comprising a stack of members across said opening having abutting faces including a first group of said members having passageways therethrough arranged in a series of patterns across the width of said members, said patterns including slots admitting flow into said stack only at certain intervals around the edges of said members, a second group of said members wherein a single member of said second group is interposed between two members of said first group, members of said second group having a series of orifices therethrough substantially smaller than said passageways and registering with said passageways, each of said two members having its passageways in registry with the orifices in said single member but offset with respect to each other, and

a third group os said members which abut against opposite faces of at least some of said first group of member to confine said, streams to a pluarlity of generally serpentine paths across said stack, said passageways defining chambers of cross-sectional area substantially exceeding the area of said orifices, said members in said stack being canted such that as said closing means moves across said opening, slots arranged around the diameter of said members are progressively uncovered.

7. A valve as set forth in claim 6 wherein said second group of said members includes a pattern of slots affording entry into said stack, which slots are radially displaced from the slots of either of the adjacent members of said first group, but communicating with passageways in at least one of said adjacent members.

8. A valve as set forth in claim 6 wherein said members in said stack are brazed together to form a rigid structure.