Information
-
Patent Grant
-
6819742
-
Patent Number
6,819,742
-
Date Filed
Friday, December 7, 200123 years ago
-
Date Issued
Tuesday, November 16, 200420 years ago
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Inventors
-
Original Assignees
-
Examiners
- Glick; Edward J.
- Thomas; Courtney
Agents
-
CPC
-
US Classifications
Field of Search
US
- 378 125
- 378 131
- 378 132
- 378 143
- 378 144
-
International Classifications
-
Abstract
An integrated component mounting system that includes a component mounted to a shaft and secured in place by a nut. The component and the nut each define respective annular shaped surfaces. The shaped surfaces are each inclined at a similar angle and are arranged for sliding contact with respect to each other. As the nut is tightened on the shaft, the shaped surface of the nut exerts both radial and axial forces on the shaped surface of the component, thereby automatically centering the component radially on the shaft as well as securing the component at a desired location along the shaft.
Description
BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates generally to mounting systems for positioning and securing a component on a shaft. More particularly, embodiments of the present invention relate to target anode mounting systems and devices that include various features which serve to reliably and effectively establish and maintain the both the axial and radial position of the target anode in a variety of operating conditions.
2. Related Technology
X-ray producing devices are valuable tools that are used in a wide variety of industrial, medical, and other applications. For example, such equipment is commonly used in areas such as diagnostic and therapeutic radiology, semiconductor manufacture and fabrication, and materials analysis and testing. While they are used in various different applications, the different x-ray devices share the same underlying operational principles. In general, x-rays, or x-ray radiation, are produced when electrons are produced, accelerated, and then impinged upon a material of a particular composition.
Typically, these processes are carried out within a vacuum enclosure. Disposed within the vacuum enclosure is an electron generator, or cathode, and a target anode, which is spaced apart from the cathode. In operation, electrical power is applied to a filament portion of the cathode, which causes a stream of electrons to be emitted by the process of thermionic emission. A high voltage potential applied across the anode and the cathode causes the electrons emitted from the cathode to rapidly accelerate towards a target surface, or focal track, positioned on the target anode.
The accelerating electrons in the stream strike the target surface, typically a refractory metal having a high atomic number, at a high velocity and a portion of the kinetic energy of the striking electron stream is converted to electromagnetic waves of very high frequency, or x-rays. The resulting x-rays emanate from the target surface, and are then collimated through a window formed in the x-ray tube for penetration into an object, such as the body of a patient. As is well known, the x-rays can be used for therapeutic treatment, or for x-ray medical diagnostic examination or material analysis procedures.
Due to the nature of the operation of an x-ray tube, components of the x-ray tube are subjected to a variety of demanding operating conditions. For example, in addition to stimulating the production of x-rays, the kinetic energy of the striking electron stream also causes a significant amount of heat to be produced in the target anode. As a result, the target anode typically experiences extremely high operating temperatures, as high as 2300° C. during normal operations. However, the anode is not the only element of the x-ray tube subjected to such operating temperatures. For example, components such as the shaft, and the nut which secures the target anode on the shaft, are also exposed to these high temperatures as a result of their proximity to, and substantial contact with, the target anode.
In addition to experiencing high operating temperatures, the components of the x-ray device are also exposed to thermal stress cycling situations where relatively wide variations in operating temperature may occur in a relatively short period of time. By way of example, the temperature in the region of the target anode may, in some cases, increase from about 20° C. to about 1250° C. in a matter of minutes. The relatively rapid rate at which such temperature changes take place imposes high levels of thermally-induced stress and strain in the x-ray tube components.
Further, many of the rotating components of a typical rotating anode type x-ray device are additionally subjected to high levels of non-thermally induced mechanical stress induced by high speed rotation of the anode and shaft. For example, in many rotating anode type x-ray devices, the anode, the shaft and the nut used to attach the anode to the shaft, are subjected to high stress “boost and brake” cycles. In a typical boost and brake cycle, the anode may be accelerated from zero to ten thousand (10,000) revolutions per minute (RPM) in less than ten seconds. This high rate of acceleration imposes significant mechanical stresses on the anode, the shaft and the nut. Thus, the components which are used to secure the anode in position are exposed not only to extreme thermal stresses, but are simultaneously exposed to significant stresses imposed by the mechanical operations of the x-ray device.
The operating conditions just described have a variety of effects that may be detrimental to the operation and service life of the x-ray tube. At least some of such effects concern the attachment of the target anode to the shaft.
For example, it may be desirable in some instances to define a gap between the outside diameter of the shaft and the opening in the anode through which the shaft passes. Such a gap would permit manipulation of anode orientation prior to operation of the x-ray device. In particular, the gap allows the assembler to attempt to minimize anode run-out with respect to the shaft by shifting the lateral, or radial, position of the anode slightly prior to tightening the nut. However, while such a gap may be useful in the sense that it permits initial positioning of the anode with respect to the shaft, the gap also allows the possibility of undesirable lateral movement, or radial runout, of the anode when the anode is subjected to mechanical and thermal stresses.
Failure to compensate for, or otherwise eliminate, such radial runout by limiting or preventing the movement of the target anode may cause problems with the operation of the device. For example, high operational speeds and mechanical stresses may cause a target anode that is relatively unconstrained from radial movement to vibrate and produce noise during operation of the x-ray device. Vibration may also result when the target anode is not centered with respect to the rotor shaft. Such vibration and noise, in turn, have various negative consequences with respect to the performance and operational life of the x-ray device.
For example, vibration and/or movement of the target anode will cause corresponding movement of the focal spot on the target surface of the anode. Because high quality imaging depends upon reliable maintenance of focal spot positioning, any such focal spot movement will compromise the quality of the images that can be produced with the x-ray device. Furthermore, unchecked vibration may ultimately damage the target anode, shaft, the nut, or other components of the x-ray device. Moreover, noise and vibration may be unsettling to the x-ray device operator and the x-ray subject, particularly in mammographic applications where the subject is in relatively intimate contact with the x-ray device.
In view of the foregoing problems, and others, a need exists for a component mounting system that substantially prevents radial runout of the mounted component and thereby substantially reduces the noise, vibration, and other effects associated with unbalanced and inadequately unconstrained components.
BRIEF SUMMARY OF VARIOUS FEATURES OF THE INVENTION
The present invention has been developed in response to the current state of the art, and in particular, in response to these and other problems and needs that have not been fully or adequately resolved by currently available component mounting systems.
Briefly summarized, embodiments of the present invention provide an integrate component mounting system that facilitates radial positioning of the component, relative to a shaft to which the component is mounted, as well as the maintenance of a desired radial and axial position of the component.
Embodiments of the present invention are particularly well suited for use in rotating anode type x-ray tubes. However, embodiments of the present invention are suitable for use in any application or environment where it is useful to establish and maintain a desired lateral and axial position of a shaft mounted component and thereby reduce the noise, vibration, and the other undesirable effects associated with unbalanced and inadequately secured components.
In one embodiment of the invention, an integrated component mounting system is provided that includes a component configured to be mounted to a shaft. The shaft includes a threaded segment and a support member. The shaft is configured so that at least a portion of the threaded segment resides within a hole defined by the component when the component is seated on the support member. A nut serves to secure the component to the shaft. Finally, the nut and the component each comprise a respective surface having a geometry that is complementary with the geometry of the other.
As the nut is tightened and comes into contact with the component, the shaped surfaces cooperate in such a way that radial and axial forces are simultaneously applied to the component. The axial force serves to facilitate positioning of the component against the support member of the shaft, while the radial force facilitates the centering of the component with respect to the shaft.
In this way, the shaped surfaces cooperate with each other to insure that, regardless of the initial orientation of the component on the shaft, the component will be centered on the shaft, and securely positioned against the support member, upon completion of the tightening of the nut. Further, the axial force exerted as a result of the cooperation of the shaped surfaces acts to substantially foreclose radial runout of the component during operation and thereby helps prevent unbalanced rotary motion of the component.
These and other features and advantages of the present invention will become more fully apparent from the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the manner in which the above-recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1
illustrates an exemplary operating environment for embodiments of the present invention, and specifically illustrates a rotating anode type x-ray device;
FIG. 2
is an exploded view indicating various components of an embodiment of an integrated component mounting system;
FIG. 3
is a cross-section view of an embodiment of the integrated component mounting system illustrated in
FIG. 2A
;
FIG. 3A
is a diagram depicting exemplary forces exerted on the mounted component by the nut;
FIG. 4
is an exploded cross-section view illustrating an alternative embodiment of an integrated component mounting system, wherein the nut, component, and shaft all include shaped surfaces;
FIG. 5
is an exploded cross-section view illustrating another embodiment of an integrated component mounting system, wherein the nut, component, and shaft all include shaped surfaces characterized by various curved geometries;
FIG. 6
is an exploded cross-section view illustrating yet another alternative embodiment of an integrated component mounting system, wherein only the component and the shaft include shaped surfaces;
FIG. 7
is an exploded cross-section view illustrating a further alternative embodiment of an integrated component mounting system wherein the component and shaft include shaped surfaces and wherein a portion of the component is threaded; and
FIG. 8
is an exploded cross-section view illustrating yet another alternative embodiment of an integrated component mounting system wherein one of the shaped surfaces is defined by other than the nut, anode, or shaft.
DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION
Reference will now be made to figures wherein like structures will be provided with like reference designations. It is to be understood that the drawings are diagrammatic and schematic representations of various embodiments of the invention, and are not to be construed as limiting the present invention, nor are the drawings necessarily drawn to scale.
Reference is first made to
FIG. 1
, wherein an x-ray tube is indicated generally at
100
. Note that x-ray tube
100
is simply an exemplary operating environment for embodiments of the present invention and that such embodiments may profitably be employed in any other environment where it is desired to implement the functionality disclosed herein. By way of example, some embodiments of the invention may be used in conjunction with components such as pump impellers.
As indicated in the illustrated embodiment, x-ray tube
100
includes a vacuum enclosure
102
, inside which is disposed an electron source
104
, such as a cathode. An integrated component mounting system (“ICMS”)
200
, rotatably supported by bearing assembly
300
, is likewise disposed within vacuum enclosure
102
and includes an anode
202
arranged in a spaced-apart configuration with respect to electron source
104
.
Anode
202
includes a target surface
202
A, preferably comprising a refractory metal such as tungsten or the like, positioned to receive electrons emitted by electron source
104
. Finally, x-ray tube
100
includes a window
106
, preferably comprising beryllium or a similar material, through which the x-rays produced by x-ray tube
100
pass.
With continuing attention to
FIG. 1
, details are provided regarding various operational features of the illustrated embodiment of x-ray tube
100
. In operation, a stator (not shown) disposed about bearing assembly
300
causes anode
202
to rotate at high speed. Power applied to electron source
104
causes electrons, denoted at “e” in
FIG. 1
, to be emitted by thermionic emission and a high voltage potential applied across electron source
104
and anode
202
causes the emitted electrons “c” to rapidly accelerate from electron source
104
toward target surface
202
A of anode
202
. Upon reaching anode
202
, electrons “e” strike target surface
202
A causing x-rays, denoted at “x” in
FIG. 1
to be produced. The x-rays, denoted at “x,” are then collimated and directed through window
106
and into an appropiate subject, such as the body of a patient.
Directing attention now to
FIG. 2
, various details are provided regarding an embodiment of ICMS
200
. Generally, the ICMS is referred to as “integrated” because, in some embodiments of the invention, a portion of the component that is to be mounted is itself an element of the mounting system.
In the illustrated embodiment, ICMS
200
includes, in addition to anode
202
discussed above, a shaft
204
having a threaded segment
204
A, configured to be at least partially received within a hole
202
B defined by anode
202
, as well as a support member
204
B that may or may not be integral with shaft
204
. Any other structure that provides the functionality of support member
204
B may alternatively be employed. Note that, as discussed in the context of various alternative embodiments of ICMS
200
, shaft
204
need not include a support member
204
B in all cases.
In general, shaft
204
is composed of metals or metal alloys having properties that are appropiate for use in high energy and high heat environments such as are commonly associated with rotating anode type x-ray devices. However, various other materials may alternatively be employed as required to suit a particular application or operating environment.
Finally, ICMS
200
includes a nut
206
configured to engage threaded segment
204
A of shaft
204
and thereby establish and maintain anode
202
in a desired location and orientation. Nut
206
includes wrench flats
206
A, or equivalent structure, which permit advancement and tightening of nut
206
on threaded segment
204
A of shaft
204
. As in the case of shaft
204
, nut
206
may comprise metals or metal alloys having properties that are appropriate for use in rotating anode type x-ray devices. Other materials for nut
206
may be substituted as required to suit a particular application.
With continuing reference to
FIG. 2
, anode
202
and nut
206
each define respective shaped surfaces
202
C and
206
B which are generally annular in configuration and substantially continuous. However, one or both of shaped surfaces
202
C and
206
B may alternatively comprise a plurality of discrete surfaces disposed about axis “y” in a desired arrangement.
In the illustrated embodiment, shaped surfaces
202
C and
206
B describe, respectively, inclination angles α (alpha) and β (beta) having values such that shaped surfaces
202
C and
206
B are able to implement the functionality disclosed herein. For a given inclination angle α, a range of values of inclination angle β may be effectively employed, and vice versa. Further, inclination angles α and/or β may be varied as required to suit particular applications, or the use of particular materials.
While, in the illustrated embodiment, shaped surfaces
202
C and
206
B are preferably defined by anode
202
and nut
206
, respectively, such shaped surfaces may also be defined by one or more separate discrete structures attached to, or used in conjunction with, anode
202
and nut
206
. By way of example, shaped surface
206
B may alternatively be defined by a separate threaded element, disposed on threaded segment
204
A, and retained in position by way of a jam nut (not shown). Furthermore, shaped surfaces may alternatively be defined by components other than, or in addition to, anode
202
and nut
206
. For example, in one alternative embodiment discussed herein, shaft
204
defines one of the shaped surfaces.
As discussed above, the particular structural elements used to implement the functionality disclosed herein may be varied as required to suit a particular application, and the scope of the present invention should, accordingly, not be construed to be limited to any particular structural configuration. The same is likewise true with respect to the geometry of shaped surfaces, such as
202
C and
206
B. Thus, variables including, but not limited to, the number, size, and geometry of the shaped surfaces, as well as the nature of the structural elements that define such shaped surfaces, may be varied as required to suit a particular application. In general, any structure or structural combination that implements the functionality disclosed herein may be employed. Shaped surfaces
202
C and
206
B, as well as the other embodiments disclosed herein, simply represent exemplary geometries.
As suggested by the foregoing and as discussed in detail below, various means may be employed to perform the functions, disclosed herein, of nut
206
and shaped surfaces
202
C and
206
B illustrated in FIG.
2
. Thus, the structural configuration comprising nut
206
and shaped surfaces
202
C and
206
A is but one example of a means for exerting and transmitting a radial force. Accordingly, it should be understood that the structural configurations disclosed herein are presented solely by way of example and should not be construed as limiting the scope of the present invention in any way. Other exemplary structural configurations are discussed herein with reference to
FIGS. 4 through 7
.
Note that, in connection with the foregoing, “radial force” refers to any force, whether positive or negative, that acts primarily along an axis generally perpendicular to longitudinal axis “y” defined by shaft
204
. Moreover, in at least some embodiments of the invention, the means for exerting and transmitting a radial force also exerts an “axial force.” Generally, “axial force” refers to any force, whether positive or negative, that acts primarily along an axis generally parallel to longitudinal axis “y”. The axial force serves to, among other things, control axial motion of anode
202
, wherein such control includes permitting, or imposing, a desired amount of axial motion of/on anode
202
, as well as substantially preventing axial motion of anode
202
. Similarly, the radial force serves to, among other things, control radial motion of anode
202
, wherein such control includes permitting, or imposing, a desired amount of radial motion of/on anode
202
, as well as substantially preventing radial motion of anode
202
. As discussed in greater detail elsewhere herein, the radial force and axial force are, in some instances, exerted simultaneously.
Directing attention now to
FIGS. 3A and 3B
, and with continuing attention to
FIG. 2
, various details are provided regarding the operation of the illustrated embodiment of ICMS
200
. In general, anode
202
is mounted to shaft
204
so that at least a portion of threaded segment
204
A is received within hole
202
B defined by anode
202
, and anode
202
is oriented such that shaped surface
202
C faces shaped surface
206
B of nut
206
. Anode
202
is then positioned, and securely retained in place, by advancing nut
206
along threaded segment
204
A until anode
202
is positioned and secured as desired.
With specific reference now to
FIGS. 3A and 3B
, details are provided regarding various aspects of the interaction of shaped surface
202
C and shaped surface
206
B. Note that some of the features and benefits of embodiments of the invention are manifested as ICMS
200
is being assembled, while other features and benefits of embodiments of the invention become more apparent after assembly of ICMS
200
is complete.
With regard to assembly of ICMS
200
, as nut
206
is advanced along threaded segment
204
A of shaft
204
, shaped surface
206
B of nut
206
comes into sliding contact with shaped surface
202
C of anode
202
. As nut
206
is tightened further, shaped surface
206
B of nut
206
exerts a force, denoted as “F” in
FIG. 3A
, on shaped surface
202
C of anode
202
. The respective geometries of shaped surface
202
C and shaped surface
206
B permit this force “F” to be exerted in a manner that has various useful implications.
Specifically, such force “F” may be represented as acting along a line generally perpendicular to shaped surface
202
C and comprising two components. One component is an axial force, denoted at “A,” which can be approximated as (F x cosine α) and which acts on shaped surface
202
C of anode
202
in a direction generally parallel to axis “y.” The other component of force “F” is a radial force, denoted at “R,” which can be approximated as (F x sine α) and which acts on shaped surface
202
C of anode
202
in a direction generally perpendicular to axis “y.”
If anode
202
is not centered relative to shaft
204
prior to the tightening of nut
206
, the radial force R will be exerted on only a portion of shaped surface
202
C and will thus cause anode
202
to shift in a radial direction. However, as anode
202
shifts, that portion of shaped surface
202
C not initially subjected to the radial force moves into contact with nut
206
and is also subjected to the radial force. As a result of this subsequent application of the radial force to such portion of shaped surface
202
C, the lateral movement of anode
202
may cease and/or change direction.
Such lateral movements of anode
202
continue until the tightening of nut
206
progresses to the point that a state of static equilibrium is reached wherein the radial force “R” is being exerted on all portions of shaped surface
202
C. That is, at static equilibrium, the radial force “R” is exerted uniformly about axis “y.” At such time as static equilibrium is established, significant lateral movement of anode
202
will cease. Because a lateral shift of anode
202
generally only occurs when anode
202
is off-center with respect to axis “y,” the cessation of lateral motion of anode
202
indicates that anode
202
has achieved a centered position with respect to axis “y.” Thus, the means for exerting and transmitting a radial force is effective in, among other things, aiding in the radial positioning of anode
202
and, ultimately, ensuring that anode
202
is centered with respect to shaft
204
. The magnitude of the radial force thus exerted may be readily adjusted by tightening, or loosening, as applicable, nut
206
.
Note that some embodiments of the invention are configured so that the anode
202
, or other component, ultimately achieves a desired off-center position, rather than the centered position described above. Such embodiments may be employed in applications where, for example, it is desired to induce a vibration by way of a rotating off-center component.
As suggested earlier, the means for exerting and transmitting a radial force, exemplary embodied as nut
206
in combination with shaped surface
206
B of nut
206
and shaped surface
202
C of anode
202
in
FIGS. 3A and 3B
, also acts to exert an axial force in at least some instances. In particular, and as suggested in
FIGS. 3A and 3B
, the axial force “A” acts on anode
202
along an axis generally parallel to longitudinal axis “y.” As a result, the axial force “A” is effective in, among other things, positioning anode
202
at a desired location with respect to longitudinal axis “y,” as well as retaining anode
202
at such desired location. As with the magnitude of the radial force “R,” the magnitude of the axial force “A” may be readily adjusted by tightening, or loosening, as applicable, nut
206
.
Finally, at least some embodiments of the present invention include a variety of additional features that contribute to the radial and axial positioning of components such as anode
202
. For example, in at least some embodiments of the invention, shaped surface
206
B of nut
206
and shaped surface
202
C of anode
202
are characterized by a relatively low coefficient of friction so as to enable the position of anode
202
to be readily adjusted as nut
206
advances along shaft
204
. Such low friction coefficients may be achieved in various ways, such as by polishing shaped surface
206
B and/or shaped surface
202
C, or through the application of appropriate coatings or layers to shaped surface
206
B and/or shaped surface
202
C. Support member
204
B and/or anode
202
include similar low friction characteristics in at least some embodiments of the invention.
As the foregoing discussion indicates, embodiments of the present invention include a variety of useful features and advantages. For example, one advantage of embodiments of the present invention is that an assembler can mount a component, anode
202
for example, to shaft
204
and can quickly and easily center such component simply by tightening nut
206
. No time-consuming adjustments by the assembler are required because shaped surface
206
B of nut
206
and shaped surface
202
C of anode
202
cooperate with each other to automatically exert a radial force on anode
202
, and thereby adjust the radial position of anode
202
, as nut
206
is tightened. At the same time as the component is being automatically centered on shaft
204
by exertion of the radial force, exertion of the axial force serves to establish and maintain the position of the component along the longitudinal axis “y” defined by shaft
204
. Thus, the tightening and centering functionalities are both implemented, and simultaneously in at least some cases, by way of nut
206
and shaped surface
206
B of nut
206
and shaped surface
202
C of anode
202
or, more generally, by the means for exerting and transmitting a radial force.
As another example, embodiments of the present invention are also helpful in preventing “wobble,” and other undesirable phenomena often associated with uncentered rotating components, by facilitating the ready and reliable centering of a component on a rotatable shaft. Further, by reducing or eliminating phenomena such as wobbling of the component, embodiments of the invention are thereby effective in reducing vibration and mechanical stresses and strains that typically accompany rotation of uncentered components. These features of embodiments of the present invention are particularly useful in environments such as rotating anode x-ray tubes where the component may be exposed to boost and brake cycles, high rotational speeds and/or high operating temperatures.
Finally, by substantially eliminating or foreclosing radial runout, or lateral motion of components such as anode
202
, during operation, embodiments of the present invention provide a stable and reliable mechanical joint which ensures that optimum positioning and balancing of the component are maintained over a wide range of operating conditions. This feature is especially useful in applications such as rotating anode type x-ray tubes where proper orientation of the rotating anode is an important factor in focal spot stabilization, and thus the quality of the image that can be obtained with the x-ray device.
Directing attention now to
FIGS. 4 through 7
, details are provided concerning various features of alternative embodiments of the invention. Because at least some of the structural and/or operational features of the embodiment illustrated in
FIGS. 1 through 3B
are also characteristic of the embodiments illustrated in
FIGS. 4 through 7
, the following discussion of
FIGS. 4 through 7
will not address those common features and will instead focus primarily on selected differences between such embodiments.
Reference is first made to
FIG. 4
, where various features of an alternative embodiment of ICMS
300
are illustrated. As indicated there, the ICMS
300
includes a component, anode
302
for example, that defines first and second shaped surfaces
302
A and
302
B, respectively. In the illustrated embodiment, first and second shaped surfaces
302
A and
302
B comprise substantially continuous annular surfaces defining inclination angles of α and δ, respectively. Such inclination angles α and β may be varied individually or collectively as required to suit particular applications and may be substantially identical to each other or, alternatively, may be of differing values. In general however, any value(s) of inclination angles α and δ effective in implementing the functionality disclosed herein may be employed.
The ICMS
300
additionally includes a shaft
304
, upon which anode
302
is mounted, with a support member
304
A that defines a shaped surface
304
B arranged for operative contact with second shaped surface
302
B of anode
402
. The shaft
304
further includes a threaded segment
304
C. In the illustrated embodiment, shaped surface
304
A comprises a substantially continuous annular surface and is characterized by an inclination angle ε. The value of inclination angle ε may be generally the same as the value of inclination angle δ, but may alternatively be varied, either alone or in conjunction with inclination angle δ, as necessary to suit the requirements of a particular application. As with inclination angles α and δ, any value of inclination angle ε that is consistent with implementation of the functionality disclosed herein may be employed.
Finally, ICMS
300
includes a nut
306
that defines a shaped surface
306
A, as well as wrench flats
306
B, and engages threaded segment
304
C so as to, among other things, retain anode
302
on shaft
304
. The shaped surface
306
A comprises a substantially continuous annular surface characterized by an inclination angle β. As with inclination angles α, δ, and ε, any value of inclination angle β that is consistent with implementation of the functionality disclosed herein may be employed.
Generally, the operational principles of the embodiment of ICMS
300
illustrated in
FIG. 4
are similar to those of the embodiment of ICMS
200
illustrated in FIG.
3
A. However, in the embodiment illustrated in
FIG. 4
, the presence of four different shaped surfaces permit two forces, denoted at F
1
and F
2
in
FIG. 4
, to be exerted on anode
302
. That is, the respective geometries and orientation of first and second shaped surfaces
302
A and
302
B, shaped surface
304
A, and shaped surface
306
A permit force F, to be exerted by nut
306
, and force F
2
to be exerted by shaft
304
in response to the force exerted by nut
306
. As a direct consequence of its geometry then, shaft
304
affirmatively aids in the centering of anode
302
, rather than simply providing axial support to anode
202
, as in the case of the embodiment illustrated in
FIGS. 3A and 3B
. This is in contrast with the embodiment illustrated in
FIG. 3A
wherein the configuration and arrangement of ICMS
200
is such that only a single force is exerted and wherein shaft
204
plays no affirmative role in the centering of anode
202
.
In general, forces F
1
and F
2
each include radial and axial components (not illustrated) and act on anode
302
in a manner substantially similar to that described in connection with the discussion of
FIGS. 3A and 3B
. Similar to the force “F” represented in
FIGS. 3A and 3B
, forces F
1
and F
2
serve to, among other things, aid in the ready and reliable centering of anode
302
with respect to shaft
304
. Specifically, the implementation of two forces that is accomplished by the embodiment of ICMS
300
illustrated in
FIG. 4
lends an additional degree of stability to the positioning and orientation of anode
302
.
Directing attention now to
FIG. 5
, details are provided regarding various features of another alternative embodiment of the ICMS
400
. With the exception of the geometry of the shaped surfaces, discussed below, the embodiment illustrated in
FIG. 5
is structurally and operationally similar to the embodiment illustrated in FIG.
4
. Specifically, the illustrated embodiment of ICMS
400
includes a component
402
, a rotating anode for example, that defines first and second shaped surfaces
402
A and
402
B, respectively. The first and second shaped surfaces
402
A and
402
B are substantially annular and form a portion of a circular curve, specifically, an arc of about ninety degrees. Of course, arcs of different magnitudes may likewise be employed. As in the case of the other embodiments disclosed herein, first and second shaped surfaces
402
A and
402
B need not be annular in every case, but may alternatively comprise a plurality of individual segments spaced apart from each other at regular, or other, intervals.
As an alternative, shaped surfaces that form parabolic curves may be employed. Further, parabolic and circular curve surfaces may be combined in a single embodiment. By way of example, in one embodiment, first shaped surface
402
A describes a portion of a circular curve and second shaped surface
402
B describes a parabolic curve. In another alternative embodiment, one or both of first and second shaped surfaces
402
A and
402
B describe concave forms, rather than the convex forms illustrated in FIG.
5
. In such an alternative embodiment, the nut and/or shaft would correspondingly define surfaces characterized by convex forms.
With continuing reference to
FIG. 5
, the illustrated embodiment of ICMS
400
further includes a shaft
404
upon which component
402
is mounted, with a support member
404
A that defines a shaped surface
404
B arranged for operative contact with second shaped surface
402
B of component
402
. The shaft
404
further includes a threaded segment
404
C. As is generally the case with the other embodiments disclosed herein, shaped surface
404
B has a geometry that is generally complementary with the geometry of second shaped surface
402
B of component
402
.
Specifically, shaped surface
404
B comprises a substantially annular convex surface in a form, parabolic for example, that permits shaped surface
404
B to cooperate with shaped surface
402
B of component
402
to at least partially implement the functionality of ICMS
200
as disclosed herein. As described below, shaped surface
404
B, as well as second shaped surface
402
B, is eliminated in some alternative embodiments.
As in the case of other embodiments of ICMS
400
, shaft
404
cooperates with a nut
406
to retain component
402
in a desired location. In the illustrated embodiment, nut
406
defines a shaped surface
406
A, as well as wrench flats
406
B, and engages threaded segment
404
C so as to, among other things, apply a desired force to component
402
and retain component
402
on shaft
404
. Similar to shaped surface
404
B, shaped surface
406
A comprises a geometry that is generally complementary with the geometry of second shaped surface
402
A of component
402
. In one alternative embodiment, support member
404
A of shaft
404
lacks shaped surface
404
B and, instead, generally takes the form of support member
204
B, illustrated in FIG.
3
A. In this alternative embodiment, only shaped surfaces
402
A and
406
A are present.
Turning now to
FIGS. 6 and 7
, various features of two further alternative embodiments are illustrated. As the embodiments illustrated in
FIGS. 6 and 7
are quite similar in many regards, the following discussion will focus primarily on
FIG. 6
but will address certain distinctions between
FIGS. 6 and 7
where appropriate.
As indicated in
FIG. 6
, ICMS
500
generally includes a component
502
disposed on shaft
504
and retained in place on shaft
504
by a nut
506
that includes wrench flats
506
A. The component
502
includes a shaped surface
502
A that is configured and arranged to cooperate with a shaped surface
504
A defined by shaft
504
. As in the case of some alternative embodiments disclosed herein, shaped surfaces
502
A and
504
A describe, respectively, inclination angles α (alpha) and β (beta) having values such that shaped surfaces
502
A and
504
A are collectively able to facilitate implementation of the functionality disclosed herein. For a given inclination angle α, a range of values of inclination angle β may be effectively employed, and vice versa Further, inclination angles α and/or β may be varied as required to suit particular applications, or the use of particular materials. As suggested in
FIG. 7
, shaft
504
also includes a threaded segment
504
B configured to engage nut
506
.
With specific reference now to nut
506
, the illustrated embodiment indicates that nut
506
comprises a nut that, unlike, at least some other alternative embodiments disclosed herein, defines no shaped surfaces. As a consequence of this configuration of nut
506
, the illustrated embodiment of ICMS
500
operates in a somewhat different manner to achieve the functionality disclosed herein. Specifically, because nut
506
lacks a shaped surface, nut
506
cannot exert, or contribute to the exertion of, a radial force but rather is capable of exerting only an axial force. However, the exertion of an axial force “A
0
” on upper surface
502
B, by nut
506
, causes component
502
to react by imposing force “F” on shaped surface
504
A. As discussed elsewhere herein, force “F” has both axial and radial components that serve to, among other things, facilitate ready and reliable centering of component
502
as well as establish and maintain component
502
at a desired location on shaft
504
. Thus, in the embodiment of ICMS
500
illustrated in
FIG. 6
, the means for exerting and transmitting a radial force comprises, in addition to shaped surface
502
A and shaped surface
504
A, nut
506
.
In addition to nut
506
, a braze ring
504
C may be employed to further aid in the securement of component
502
on shaft
504
. In one alternative arrangement, a groove is provided in shaft
504
that is subsequently filled with a suitable brazing material.
As noted earlier, at least some of the features discussed in conjunction with
FIG. 6
are common to the embodiment of ICMS
600
illustrated in FIG.
7
. In the embodiment illustrated in
FIG. 7
, component
602
defines a shaped surface
602
A, an upper surface
602
B, and further includes a threaded portion
602
C. Shaft
604
includes a shaped surface
604
A arranged for contact with shaped surface
602
A, and further includes a threaded segment
604
B that engages both threaded portion
602
C as well as nut
606
. In this embodiment, nut
606
includes wrench flats
606
A and acts as a jam nut and cooperates with the threaded segment
604
B to aid in the reliable positioning and retention of component
602
on shaft
604
.
Directing attention now to
FIG. 8
, various features of another alternative embodiment of ICMS
700
are illustrated. Generally, the embodiment illustrated in
FIG. 8
is operationally and structurally similar to that illustrated in
FIG. 3
, except with respect to the shaped surface that interacts with the shaped surface of the nut.
As indicated in
FIG. 8
, ICMS
700
includes a component
702
, such as an anode, within which is fitted an interface structure
800
. Interface structure
800
defines a hole
802
configured and arranged to receive shaft
704
so that interface structure
800
may reside on support member
704
B. When interface structure
800
is so disposed, threaded segment
704
A extends through interface structure
800
and is positioned to threadingly engage a nut
706
that includes wrench flats
706
A and defines a shaped surface
706
B. Interface structure
800
defines a shaped surface
804
which is arranged for contact with shaped surface
706
B
Interface structure
800
may alternatively be configured so that it defines a shaped surface arranged for contact with a shaped surface defined by shaft
704
, similar to the embodiment illustrated in FIG.
7
. As another alternative, interface structure
800
may be configured in a manner similar to component
302
and
402
of
FIGS. 4 and 5
, respectively, in the sense that interface structure
800
may define not one, but two shaped surfaces. In the foregoing exemplary embodiments, interface structure
800
and nut
706
collectively comprise exemplary implementing structure for a means for exerting and transmitting a radial force.
When employed in x-ray tube environments, interface structure
800
comprises materials suitable for use in such environments, and is bonded or otherwise attached to component
702
in a manner, and with materials, suited for such environments. Both the material of interface structure
800
, as well as the manner and/or materials used to bond interface structure
800
to component
702
, may be varied as necessary to suit the requirements of a particular application.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore described by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims
- 1. An integrated component mounting system for use in an x-ray tube, comprising:(a) a shaft defining a longitudinal axis; (b) a target anode disposed on said shaft; and (c) means for exerting and transmitting a radial force to said target anode, wherein said means for exerting and transmitting a radial force controls radial movement of said target anode with respect to said longitudinal axis defined by said shaft.
- 2. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force prevents undesired radial movement of said target anode when said target anode is in a desired radial position.
- 3. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force at least partially controls axial movement of said target anode along said longitudinal axis defined by said shaft.
- 4. The integrated component mounting system for use in an x-ray tube as recited in claim 3, wherein said shaft further comprises a support member and said means for exerting and transmitting a radial force cooperates with said support member to prevent undesired axial movement of said target anode when said component is in a desired axial position.
- 5. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force moves said target anode to a desired radial position during assembly of the integrated component mounting system.
- 6. The integrated component mounting system for use in an x-ray tube as recited in claim 5, wherein when said target anode is in said desired position, said target anode is centered with respect to said longitudinal axis.
- 7. The integrated component mounting system for use in an x-ray tube as recited in claim 5, wherein when said target anode is in said desired position, said target anode is off-center with respect to said longitudinal axis.
- 8. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force automatically centers said target anode with respect to said longitudinal axis during assembly of the integrated component mounting system.
- 9. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force secures said target anode to said shaft.
- 10. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force transmits an axial force and a radial force to said target anode, and said transmission of said axial force and said transmission of said radial force occurs simultaneously.
- 11. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force comprises:(a) a nut configured to engage said shaft; (b) a first shaped surface defined by said target anode; and (c) a second shaped surface defined either by said shaft or by said nut and arranged for contact with said first shaped surface.
- 12. The integrated component mounting system for use in an x-ray tube as recited in claim 1, wherein said means for exerting and transmitting a radial force comprises:(a) a nut configured to engage said shaft; (b) an interface structure that is attached to the target anode and defines a first shaped surface; and (c) a second shaped surface defined either by said shaft or by said nut and arranged for contact with said first shaped surface.
- 13. An integrated component mounting system for use in an x-ray tube, comprising:(a) a shaft including a support member and defining a longitudinal axis; (b) a nut configured to engage said shaft; (c) an x-ray tube target anode component that defines a first shaped surface and is disposed on said shaft between said nut and said support member; and (d) a second shaped surfaced defined either by said shaft or by said nut and arranged for contact with said first shaped surface such that a radial force is applied to said target anode component with respect to the longitudinal axis defined by said shaft.
- 14. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said first shaped surface defines a first inclination angle and said second shaped surface defines a second inclination angle.
- 15. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said second shaped surface is defined by said shaft.
- 16. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said second shaped surface is defined by said nut.
- 17. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said first and second shaped surfaces each describe a portion of a circular curve.
- 18. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said first and second shaped surfaces each describe a parabolic curve.
- 19. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said first shaped surface is convex and said second shaped surface is concave.
- 20. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said first shaped surface is concave and said second shaped surface is convex.
- 21. The integrated component mounting system for use in an x-ray tube as recited in claim 13, wherein said second shaped surface is defined by said nut, and a third shaped surface is defined by said x-ray tube target anode component and said third shaped surface is arranged for contact with a fourth shaped surface defined by said shaft.
- 22. The integrated component mounting system for use in an x-ray tube as recited in claim 21, wherein at least two of said first, second, third, and fourth shaped surfaces describe a portion of a circular curve.
- 23. The integrated component mounting system for use in an x-ray tube as recited in claim 21, wherein at least two of said first, second, third, and fourth shaped surfaces describe a parabolic curve.
- 24. The integrated component mounting system for use in an x-ray tube as recited in claim 21, wherein said first, second, third, and fourth shaped surfaces each define an inclination angle.
- 25. An x-ray tube, comprising:(a) a vacuum enclosure; (b) a cathode disposed within said vacuum enclosure; and (c) an integrated component mounting system comprising: (i) a shaft defining a longitudinal axis; (ii) a target anode disposed on said shaft and positioned within said vacuum enclosure so as to receive electrons emitted by said cathode; and (iii) means for exerting and transmitting a radial force to said target anode, wherein said means for exerting and transmitting a radial force controls radial movement of said target anode with respect to said longitudinal axis defined by said shaft.
- 26. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force prevents undesired radial movement of said target anode when said target anode is in a desired radial position.
- 27. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force at least partially controls axial movement of said target anode along said longitudinal axis defined by said shaft.
- 28. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force moves said target anode to a desired radial position during assembly of said integrated component mounting system.
- 29. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force automatically centers said target anode with respect to said longitudinal axis during assembly of said integrated component mounting system.
- 30. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force transmits an axial force and a radial force to said target anode, and said transmission of said axial force and said transmission of said radial force occurs simultaneously.
- 31. The x-ray tube as recited in claim 25, wherein said means for exerting and transmitting a radial force comprises:(a) a nut configured to engage said shaft; (b) a first shaped surface defined by said target anode; and (c) a second shaped surface defined either by said shaft or by said nut and arranged for contact with said first shaped surface.
- 32. The x-ray tube as recited in claim 31, wherein said first shaped surface defines a first inclination angle and said second shaped surface defines a second inclination angle.
- 33. The x-ray tube as recited in claim 31, wherein said second shaped surface is defined by said shaft.
- 34. The x-ray tube as recited in claim 31, wherein said second shaped surface is defined by said nut.
- 35. The x-ray tube as recited in claim 31, wherein said second shaped surface is defined by said nut, and a third shaped surface is defined by said target anode and said third shaped surface is arranged for contact with a fourth shaped surface defined by said shaft.
- 36. The x-ray tube as recited in claim 31, wherein said first and second shaped surfaces each describe a portion of a circular curve.
- 37. The x-ray tube as recited in claim 31, wherein said first and second shaped surfaces each describe a parabolic curve.
- 38. An integrated component mounting system for use in an x-ray tube, comprising:(a) a shaft including a support member and defining a longitudinal axis; (b) a nut configured to engage said shaft; (c) an interface structure defining an opening and a first shaped surface; (d) a target anode that defines an opening wherein said interface structure is received, and said target anode is disposed on said shaft between said nut and said support member so that said shaft is received within said opening defined by said interface structure; and (e) a second shaped surfaced defined either by said shaft or by said nut and arranged for contact with said first shaped surface such that a radial force is applied to said target anode with respect to the longitudinal axis defined by said shaft.
- 39. The integrated component mounting system for use in an x-ray tube as recited in claim 38, wherein said second shaped surface is defined by said shaft.
- 40. The integrated component mounting system for use in an x-ray tube as recited in claim 38, wherein said second shaped surface is defined by said nut.
- 41. The integrated component mounting system for use in an x-ray tube as recited in claim 38, wherein said first shaped surface defines a first inclination angle and said second shaped surface defines a second inclination angle.
- 42. The integrated component mounting system for use in an x-ray tube as recited in claim 38, wherein said first and second shaped surfaces each describe a portion of a circular curve.
- 43. The integrated component mounting system for use in an x-ray tube as recited in claim 38, wherein said first and second shaped surfaces each describe a parabolic curve.
US Referenced Citations (19)