Butterfly valve

A fluid flow controlling butterfly valve assembly is disclosed which comprises a valve body defining a through passage for fluid, a butterfly valving member supported within the body, a shaft extending transversely through the passage and drivingly connected to the valving member, and a shaft supporting structure rotatably supporting the shaft in the body while sealing against leakage from the valve. In a preferred embodiment the shaft supporting structure includes a band extending about the body and defining recesses aligned with shaft portions emerging from the body. Resilient flexible elements are disposed within the recesses and compressively engage the shaft and body to provide both bearings and seals.

BACKGROUND OF THE INVENTION 
The present invention relates to valves and more particularly to so-called 
butterfly valves for controlling fluid flow through a conduit. 
Butterfly valves have long been used to control fluid flowing in conduits 
and problems relating to the general design and constructional features of 
such valves have been recognized. Generally butterfly valves are formed by 
a plate-like valving member disposed in a fluid flow passage and supported 
by a shaft or hinge structure for rotation about an axis transverse to the 
passage to alter the flow rate. The valving member itself is usually 
configured so that when moved to a closed position the flow passage is 
completely blocked by the valving member with a fluid tight seal being 
formed along the juncture of the valving member periphery and the passage. 
When moved to its opened position the valving member extends generally 
parallel to the direction of fluid flow and the fluid can flow around it 
through the passage. The supporting shaft or hinge usually extends through 
the passage wall to an actuator operable to control the valving member 
position. 
Butterfly valves employed in closed fluid systems tend to develop leaks 
along the valve supporting shaft. The shaft is normally subjected to 
bending forces and therefore must generally be provided with some sort of 
bearing structure in addition to a shaft seal. Various bearing and seal 
constructions have been proposed by the prior art to minimize the leakage 
problem. The proposed constructions have, for the most part, required the 
usage of multi-part bearing and seal components with increase the cost, 
complexity and degree of difficulty of assembly of the valves. 
The construction of the valving members has also presented problems in many 
butterfly valve applications. Where the valve is used in a liquid system, 
the periphery of the valving member must effectively seal against the 
surrounding flow passage yet be readily opened without tending to stick 
closed. The valving members are generally urged toward the closed 
positions by fluid pressure differential forces acting on them and as a 
result of valve actuator over-travel and these forces tend to jam the 
valving member into its closed position. Various valving member 
constructions have been proposed to alleviate this problem. Rubber-like 
flexible, resilient valving members have been frequently employed to 
assure positive closure of the valves but many of these constructions have 
tended to stick closed because of the excessive flexibility of the valving 
member material which tends to promote not only jamming but wear and 
abrasion of the valving member sealing face. Composite valving members 
formed of rubber or plastic parts supported by structurally strong 
components have been proposed. Some of these have employed molded-in steel 
plates while others have clamped rubber-like valving elements to 
structurally stronger parts. 
Butterfly valves have been proposed for use in automotive fluid systems for 
controlling the flow of engine coolant to heat exchangers which are used 
to heat air flowing into the passenger compartment of vehicles. Such 
valves must be extremely reliable in operation while at the same time 
being of simple enough design to enable low cost, high volume production 
with a minimum number of complicated assembly steps. Low cost high volume 
production tends to dictate the use of a one piece valve body defining a 
tubular flow passage for the liquid. 
Prior art butterfly valve constructions utilizing a one piece valve body 
have encountered assembly problems because the butterfly valving member 
and its driving shaft must be assembled with the valving member already 
positioned inside the valve body. To do this the valve body has been 
provided with shaft supporting openings on opposite sides and the valving 
member has been positioned within the tubular valve body. The shaft was 
inserted through the valve body so and a joining operation between the 
valving member and the shaft was performed with the components of the 
assembly held together but suitable fixturing. In some proposals the shaft 
was spot welded to the valving member. In others a one-piece plastic 
valving member was held in place within the valve body and a serrated 
shaft was driven through the valving member to create the driving 
interconnection. 
These approaches have in general been either difficult to perform quickly 
and efficiently or have not produced a sufficiently strong and durable 
valve, or both. 
Still another problem with the one piece cast valve bodies was encountered 
because the valve body wall itself was used to journal the shafts. This 
required the use of relatively heavy valve body wall sections and the 
selection of alloys which functioned wall as bearings. These factors added 
to valve body costs. 
SUMMARY OF THE INVENTION 
The present invention provides a new and improved butterfly valve assembly 
which is quickly and easily assembled and is of relatively simple design. 
One important feature of the new valve construction resides in an actuating 
shaft supporting structure which provides a combined shaft bearing and 
seal arrangement for reliably preventing the escape of fluid from the 
valve assembly. In a preferred valve assembly embodying this feature a 
valving member is supported in a valve body for rotation by an actuating 
shaft which extends through openings in the valve body. A shaft supporting 
structure supports the shaft for rotation while sealing against the loss 
of fluid from the assembly. The supporting structure includes a band 
structure extending about the valve body and defining recesses aligned 
with the valve body openings. 
Resilient flexible elements within each recess surround the shaft. The band 
structure is secured about the valve body so that the resilient elements 
are compressively engaged with the valve body, band structure and the 
shaft to provide a bearing support for the shaft while sealing against 
leakage. 
Another important feature of the invention resides in the construction of a 
butterfly valve assembly having a composite valving member enabling 
effective and reliable valving member operation while minimizing sticking 
or jamming in the closed position and which enables simplified assembly of 
the valve. The preferred valving member includes a supporting hub, a 
disk-like valving element supported by the hub and sandwiched between 
plates which are clamped against the valving member by the hub. The plates 
are resiliently deflectable and tend to deflect when the valving member is 
subjected to forces which would otherwise jam the valve closed. 
The hub is constructed from a structurally strong flowable metallic 
material and is deformed to clamp the plates against the valving element 
when the valving member is being assembled. The valving element is 
controllably and lightly compressed between the plates so that a 
fluid-tight seal between the hub and the valving element is established. 
Another important feature of the valving member construction resides in the 
interconnection between the shaft and the hub. The hub defines a 
shaft-receiving opening through which the shaft is pressed during assembly 
of the valve. The shaft and hub opening are provided with a spline-like 
driving interconnection which is formed by a series of spline-like teeth 
on the shaft which are driven into the hub material to yield and flow the 
hub material into conformity with the spline teeth. The valving element 
support plates resiliently deflect in response to relatively high force 
levels transmitted to the valving member, and tend to resiliently cushion 
shock loadings which might otherwise be applied to the interconnection 
between the hub and the shaft. 
Other features and advantages of the present invention will become apparent 
from the following detailed description of a preferred embodiment made in 
reference to the accompanying drawings which form a part of the 
specification.

DESCRIPTION OF A PREFERRED EMBODIMENT 
A flow controller 10 embodying the present invention is illustrated in part 
by FIGS. 1 and 2 of the drawings. The flow controller 10 includes a 
butterfly valve assembly 12 and a valve actuator 14. The illustrated flow 
controller 10 is of the type used to control the flow of liquid engine 
coolant in parts of an automotive vehicle engine coolant system for the 
purpose of governing heating of air circulating in the vehicle passenger 
compartment. The valve assembly 12 is operated between opened and closed 
positions by the actuator 14 to start and stop coolant flow to a "heater 
core." The heater core is formed by a suitable coolant-to-air heat 
exchanger, may be of any suitable construction and therefore is not 
illustrated or described. 
The actuator 14 may be of any conventional or suitable construction but is 
illustrated as a vacuum motor 14a and associated articulating linkage 14b 
by which motion is transmitted to the valve assembly 12. The motor 14a is 
formed by a rigid cup-like body assembly 16 supporting a flexible diagram 
assembly 18 across its open end to define an expansible chamber 20 within 
the motor (See FIG. 1). The cup-like body 16 further defines a port 22 for 
communicating the chamber 20 with a source of vacuum pressure such as may 
exist in the vehicle engine intake manifold or a vacuum pressure reservoir 
on-board the vehicle. 
The pressure within the chamber 20 is governed by a control valve, not 
shown, which may be constructed to alternately communicate the chamber to 
the vacuum source or to atmospheric pressure. When the chamber 20 is 
communicated to vacuum pressure the diaphragm assembly 18 is shifted to 
reduce the volume of the chamber 20 (toward the left as viewed in FIG. 1). 
Venting the chamber 20 to atmospheric pressure eliminates the pressure 
differential across the diaphragm assembly and the diaphragm assembly is 
moved toward the right, as viewed in FIG. 1, by the action of a 
compression spring 24 reacting between the diaphragm assembly and the 
body. 
The linkage 14b is preferably formed by a stamped sheet metal operating rod 
26 connected to the diaphragm assembly 18, a stamped sheet metal crank 28 
connected to the valve assembly 12 and a bearing pin 30 which pivotally 
interconnects the rod 26 and crank 28. The rod 26 is secured to the 
diaphragm assembly 18 by a connection which allows limited universal, or 
swiveling, motion of the rod relative to the diaphragm assembly to 
accommodate the slightly nonlinear travel path of the pin 30 (See FIG. 1). 
The bufferfly valve assembly 12 is formed by a valve body 32 which defines 
a through passage for the coolant flow, a butterfly valving member 34 
disposed within the valve body, a shaft structure 36 which is drivingly 
connected to the valve member 34 for shifting the valve member between 
open and closed positions and a shaft supporting structure 38 which 
rotatably supports the shaft structure 36 with respect to the valve body 
32 while preventing the escape of fluid from the valve assembly. 
The valve body 32 is preferably a tubular member which defines a through 
flow passage 40 in which the valving member is supported. As is best seen 
in FIG. 1, the valve body is preferably formed from a one piece metal tube 
and defines a valve seat portion 32 having a mounting flange formation 44 
at one end and a reduced diameter hose nipple 46 at its opposite end. The 
flange 44 and nipple 46 are continuous with the valve seat portion 42. 
The valve seat portion is preferably a one-piece thin walled cylindrical 
structure defining holes 52, 54 through which the shaft structure 36 
extends (See FIG. 2.) The interior of the valve seating portion 42 is 
formed by a smooth cylindrical valve member seating surface 58. 
In the illustrated valve the mounting flange formation 44 extends radially 
outwardly from the valve seating portion 42 and has projecting fingers, 
only one of which is illustrated at 44a, which are deformed to grip a 
separate hose nipple member 60 and a structural support element 62 (which 
is shown only in part). The mounting flange section defines a 
circumferentially extending seal seat 64 supporting a continuous seal ring 
66 compressively engaged between the hose nipple member 60 and the valve 
body flange. The cross sectional flow area of the hose nipple section 46 
and the hose nipple member 60 are about equal and are substantially the 
same as the effective flow area through the valve seating portion 42 when 
the valving member 34 is in its fully opened position. This tends to 
minimize flow restrictions and consequent pressure drops across the valve. 
The preferred valving member 34 is a composite assembly of components which 
coact to provide improved valving member performance. Referring to FIG. 3 
the valving member 34 is formed by a hub 70, a valving element 72 which is 
supported on the hub and first and second plates 74, 76 carried by the hub 
and disposed on opposite sides of the valving element. 
The hub 70 is drivingly connected to the shaft 36 and preferably formed of 
a suitable metal which is flowable when worked yet structurally strong and 
corrosion resistant. The hub has a central cylindrical barrel portion 80, 
a keeper flange 82 at one end of the barrel and a thin walled reduced 
diameter skirt 84 (broken lines, FIG. 3) which projects in the direction 
of the extent of the barrel 80 from a radial shoulder 86 at the end of the 
barrel. A shaft-receiving opening 88 extends through the hub 70 and is 
illustrated as a straight cylindrical hole aligned with the transverse 
axis 56 for reception of the valve-supporting shaft 36. 
The valving element 72 is preferably a molded disc of flexible resilient 
rubber-like material which has generally elliptical major surfaces. The 
valving element defines a continuous, cylindrical peripheral sealing face 
90 configured to engage the valve body seating surface 58 over a 
relatively broad area completely about the periphery of the valving 
element when the valve is closed. The valving element defines an opening 
92 through which the barrel 80 extends. The opening 92 provides for 
sealing engagement with the barrel 80 so that leakage through the valving 
member is avoided. 
In the preferred embodiment the valving element is lightly compressed 
between the plates 74, 76 to enhance the seal between the inner periphery 
92 and the barrel 80. The plates 74, 76 are preferably formed from thin 
structurally strong sheets of spring metal, are elliptical in shape and 
define central openings for receiving the hub 70. The plate 74 surrounds 
the barrel 80 and is engaged with the end flange 82 while the plate 76 
surrounds the skirt 84 which, when the valving member is assembled, is 
upset to clamp the plate 76 firmly against the shoulder 86. In this regard 
the hub 70 is similar to a rivet in permitting quick and easy assembly. 
The combined thicknesses of the plate 74 and the valving element 72 are 
slightly greater than the length of the barrel 80. When the skirt 84 is 
upset in the manner described compression of the valving element occurs in 
a controlled manner to assure that the valving element seals about the 
barrel. 
Each plate 74, 76 is shaped substantially like the respective major face of 
the valving element against which it is placed but is of smaller 
diametrical extent than the valving member to permit a flexible valving 
element "lip" to extend about the valving member periphery. In the 
illustrated embodiment (FIGS. 3 and 4) the plate 76 is provided with an 
opening through which a molded-in alignment lug of the valving element 
extends to assure that the plate 76 and valving element are appropriately 
aligned for assembly. The valving element and plate 74 are each formed 
with shaft accommodating recessed portions (FIG. 4) which are aligned with 
the hub opening 88 to assure that these elements are properly positioned 
for assembly. 
The plates 74, 76 function as leaf springs and can deflect if the valving 
member is urged to or from its closed position by an excessively great 
force and when shock loadings occur. Flexure of the plates when the 
valving member is urged closed tends to prevent the valving element 
material from being cut by the plates and/or unduly compressed against the 
valve body. Flexure of the plates as a result of valve opening forces 
better enables the valve member to be opened without jamming and abrasion 
or cutting. If sudden opening or closing forces are applied to the valving 
member deflection of the plates cushions shock loadings which might 
otherwise be applied to the driving connection between the hub 70 and the 
shaft 36. 
The shaft structure 36 is supported on opposite sides of the valve body 32 
and is drivingly connected to the valving member 34 to rotate the valving 
member between its open and closed positions. The valve body, valving 
member and shaft structure are assembled by inserting the valving member 
in the valve body and then inserting an end 36a of the shaft structure 
through the valve body opening 52, the hub opening 88 and the valve body 
opening 54. The shaft structure defines spaced bearing sections 100, 102 
at which it is supported with respect to the valve body, a connector 
section 104 between the bearing sections by which the shaft is connected 
to the valving member and an actuator connector section 106 at the shaft 
end nearest the actuator 14. 
The bearing section 102 is defined by a smooth cylindrical surface of the 
shaft which projects loosely through the valve body opening 54. The 
diameter of the bearing section 102 is less than that of the valve body 
holes 52, 54 and of the hole 88 through the hub 70 so that the bearing 
section 102 is not abraded during assembly. 
The connector section 104 has a non-circular cross sectional shape and is 
constructed and arranged so that when the shaft is moved through the hub 
opening 88 the hub material is deformed and flows to at least partially 
conform to the shaft connector section shape to produce a driving 
connection. In the preferred embodiment the connector section 104 is 
defined by a series of circumferentially spaced apart spline-like teeth 
and has a maximum diametrical extent which is greater than that of the 
shaft bearing section 102 and of the hub opening 88. The teeth, which may 
be formed on the shaft by a knurling tool, move into the hub opening 88 
during assembly and effectively form a conforming splined hub opening 
interior by deforming and flowing the hub material into conformity with 
the connector section. The axial extent of the connector section is 
limited to minimize the force required for pressing the shaft through the 
hub while assuring that the hub-to-shaft connection transmits adequate 
torque to operate the valve under all reasonably expected conditions of 
operation. 
The bearing section 100 is formed by an enlarged smooth cylindrical portion 
of the shaft loosely received by the valve body opening 52. The bearing 
section 100 does not extend into the hub opening 88 and preferably has a 
diametrical extent which is at least as great as the maximum extent of the 
connector section 104. 
The actuator connector section 106 is illustrated as a splined, or knurled, 
shaft section which has the same diametrical extent as the connector 
section 104 and which is pressed into engagement with the crank 28. The 
crank 28 is provided with a return bent end portion 28a having aligned 
shaft-receiving holes to prevent the crank from twisting relative to the 
shaft as well as to increase the torque transmitting capability of the 
crank-to-shaft connection. The aligned crank holes and the shaft section 
106 have an interference fit so that the driving connection between the 
crank and the shaft is formed, like the connection between the valving 
member and the shaft, by pressing the connector section 106 through the 
crank openings. 
The shaft supporting structure 38 supports the shaft structure 36 and the 
valving member 34 for rotation relative to the valve body without imposing 
bearing stresses on the valve body material and seals against the leakage 
of liquid from the valve body along the shaft. The shaft supporting 
structure 38 includes band structure 110 extending about the exterior of 
the valve body, bearing and sealing elements 112, 114 carried by the band 
structure, and a connecting structure, generally indicated by the 
reference character 116, for maintaining the band structure and elements 
assembled to the valve body and shaft structure. 
The band structure 110 is preferably formed by a pair of sheet metal straps 
120, 122 each of which is bent in a generally semi-circular shape to 
approximate the outside diameter of the valve body. Each strap extends 
closely about the exterior of the valve body. The strap 122 is formed with 
a stamped cup-like recess 124 aligned with the valve body opening 54. The 
recess includes a circularly shaped recess wall 126 which is spaced 
radially away from the valve body and surrounds the projecting shaft end 
36a. A closed recess end portion is disposed about the end of the shaft so 
that the recess 124 defines a chamber 130 into which the shaft end 36a 
projects. 
The strap 120 is substantially like the strap 122 and defines a recess 134 
which is aligned with the valve body opening 52. The recess 134 is formed 
with a circular recess wall 136 which is spaced radially away from the 
outside of the valve body and an opening 138 through which the shaft 
structure extends. 
The bearing-sealing elements 112, 114 are preferably annular flexible, 
resilient rubber-like elements. Each element extends continuously about 
the respective shaft bearing section 100, 102 and is disposed within its 
respective recess 134, 124. In their unstressed, or relaxed, conditions 
the elements have inner diameters which are sized so that they are not 
appreciably stretched when the shaft extends through them. 
The axial thickness of each of the elements 112, 114, when relaxed, is 
greater than the distance between the valve body and the respective 
associated recess wall so that when the clamp structure 116 secures the 
straps 120, 122 in place, each bearing-sealing element is axially 
compressed between the valve body and its associated recess wall portion. 
This compression causes the inner diameter of each bearing-sealing element 
to firmly yet resiliently engage its associated shaft bearing section 
resulting in any shaft bearing loads being borne by the bearing-sealing 
elements without requiring the valve body wall to support the bearing 
loads. At the same time, the bearing-sealing elements are urged into 
compressive sealing engagement with the shaft and the valve body 
immediately surrounding the shaft with secondary seals being formed by the 
compressive engagement between the sealing-bearing elements and their 
associated recess walls. 
The shaft supporting structure thus permits the valve body walls to be 
relatively thin since the walls need not function as bearings for the 
shaft. Likewise the valve body alloy need not have properties which might 
otherwise be required if the valve body were to function as a bearing. The 
holes 52, 54 are sized to closely surround their associated shaft bearing 
sections to minimize the possibility of extrusion of the bearing-sealing 
elements through the valve body openings. The shaft supporting structure 
38 is sufficiently rigid that the shaft remains spaced from the valve body 
openings under loads normally encountered. 
The bearing-sealing element 112 is preferably formed by an O-ring, i.e., a 
ring having a circular cross sectional shape, and the inner diameter of 
the O-ring is preferably the same, at the very smallest, as the shaft 
connector section 104. When the shaft structure 36 passes through the 
O-ring 112 during assembly the inner diameter of the O-ring is thus not 
scored or otherwise abraded by the spline teeth on the section 104. 
The connecting structure 116 is formed by adjacent ends of the straps 120, 
122 which are deformed to clamp the straps together with the recess walls 
being drawn radially towards the valve body to accomplish the compression 
of the bearing-sealing elements referred to. In the preferred and 
illustrated embodiment both ends of the strap 122 are formed with a pair 
of axially spaced radially projecting fingers 140, 142. Both ends of the 
strap 120 are likewise formed with axially spaced pairs of radially 
projecting fingers 144, 146 which are of greater length than the fingers 
140, 142. When the valve assembly has been substantially completed the 
fingers 144, 146 are moved adjacent the corresponding fingers on the strap 
122 and bent over so that the strap fingers are clinched together as 
illustrated by FIG. 2. This operation clamps the straps together about the 
valve body and, because the clamping operation takes place at roughly 
90.degree. from each of the bearing-sealing elements the compressive force 
exerted by each recess wall on the associated bearing-sealing element 
tends to be uniformly distributed. 
While a single embodiment of the invention has been illustrated and 
described in considerable detail, the present invention is not to be 
considered to the precise construction shown. Various adaptations, 
modifications and uses of the invention may occur to those skilled in the 
art to which the invention relates and the intention is to cover all such 
adaptations, modifications and uses which come within the scope or spirit 
of the appended claims.