Patent Application
20180080845
The present disclosure generally pertains to a modular testing fixture, and is directed toward a modular testing fixture for high cycle fatigue and modal testing of industrial machine components.
Components for industrial machines, such as high speed rotary machines, may operate in harsh conditions and are generally tested to determine the viability of the component's design and to determine how long the component may be used within the industrial machine before it is replaced. Testing fixtures are generally used to hold the component during the testing processes. Testing fixtures may be large, heavy, cumbersome, and may require a significant amount of storage space.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors or that is known in the art.
A testing fixture for testing a component of an industrial machine is disclosed herein. In one embodiment, the testing fixture includes a fixture block, a component interfacing fixture, a fastener, and a loading mechanism. The fixture block includes a block body with a block front surface and a block tapered bore. The block tapered bore extends into the block body from the block front surface forming a block tapered bore wall. The block tapered bore wall includes a block tapered surface with a first frustoconical shape within the block body where a larger diameter of the first frustoconical shape is adjacent the block front surface. The component interfacing fixture includes an interfacing portion and a stem. The interfacing portion includes a receiving slot that receives a root of the component. The stem extends from the component interfacing fixture opposite the receiving slot and includes a tapered portion and a threaded portion. The tapered portion includes a stem tapered surface with a second frustoconical shape where a larger diameter of the second frustoconical shape is adjacent the interfacing portion. The threaded portion is distal to the interfacing portion. The stem inserts into the fixture block such that the stem tapered surface mates with the block tapered surface. The fastener couples to the threaded portion adjacent the block body opposite the block front surface. The loading mechanism applies a load to the root of the component to secure the root within the receiving slot.
A method for testing a component for an industrial machine using the testing fixture that include a fixture block and a component interfacing fixture is also disclosed herein. In one embodiment, the method includes inserting a root of the component into a receiving slot formed in an interfacing portion of the component interfacing fixture. The method also includes applying a load to the root with a loading mechanism to secure the component to the component interfacing fixture. The method further includes inserting a stem of the component interfacing fixture into a block tapered bore of the fixture block, the block tapered bore extending into a block body of the fixture block from a block front surface of the block body and forming a block tapered bore wall with a block tapered surface that includes a first frustoconical shape with the larger diameter of the block tapered bore wall adjacent the block front surface. The stem extends from the interfacing portion and includes a tapered portion with a stem tapered surface that includes a second frustoconical shape with the larger diameter of the stem tapered surface adjacent the interfacing portion. The stem tapered surface mates with the block tapered surface. The method yet further includes securing the component interfacing fixture to the fixture block to prevent relative motion there between at step by securing a fastener to a fastening portion of the stem that is distal to the interfacing portion and tightening the fastener on the back side of the block tapered bore wall. The method still further includes conducting a material test of the component after the component interfacing fixture is secured to the fixture block to prevent relative motion there between.
The systems and methods disclosed herein include a testing fixture for holding a component of an industrial machine during testing of the component, such as high cycle fatigue testing and modal testing. In embodiments, the testing fixture includes a fixture block that can be affixed to a mounting plate and a component interfacing fixture. The fixture block includes a block tapered bore that forms a block tapered bore wall, and the component interfacing fixture includes a stem with a tapered portion that mates with the block tapered bore. The component interfacing fixture can be affixed to the fixture block by securing a fastener to the stem a by tightening down the fastener against the fixture block. The interface between the block tapered bore wall and the tapered portion allows the component interfacing fixture holding a component to rotate relative to the fixture block and orient the component into an optimal position for testing. Further, forming the testing fixture from two components may significantly reduce the amount of weight that an operator is required to lift.
The testing fixture 700 includes a fixture block 710, a component interfacing fixture 740, and a loading mechanism 780 (refer to
The modal testing mechanism 630 may affix directly to the component interfacing fixture 740 which may allow for a more direct transfer of forces and vibrations from the modal testing mechanism 630 to the component 800.
The fixture block 710 may also include a block tapered surface 725 that may be the inner surface of the block tapered bore wall 724. The block tapered surface 725 may be a frustoconical surface with the larger diameter of the block tapered surface 725 closer to the block front surface 717 than the block back surface 718 and the smaller diameter of the block tapered surface 725 closer to the block back surface 718 than the block front surface 717.
The fixture block 710 may also include a block tapered bore 722, a block counterbore 720, and a block through bore 726. The block tapered bore 722 and the block counterbore 720 may be formed in the block body 712 to form the block tapered bore wall 724 there between. The block counterbore 720 may extend from the block back surface 718 towards the block front surface 717 and toward the block tapered bore 722. The block counterbore 720 may be adjacent the narrow end of the frustoconical shape of the block tapered bore 722. The block tapered bore 722 may extend between two block bolt holes 714 that are adjacent the block front surface 717 and the block counterbore 720 may extend between two block bolt holes 714 that are adjacent the block back surface 718.
In the embodiment illustrated, the block tapered bore wall 724 and the block tapered bore 722 extend from the block front surface 717 towards the block counterbore 720. The edge 729 between the block tapered surface 725 and the block front surface 717 may be rounded. In some embodiments, the block tapered bore wall 724 and the block tapered bore 722 extend to the block counterbore 720. In the embodiment illustrated, the fixture block 710 includes a block through bore 726 that connects the block tapered bore 722 to the block counterbore 720.
Referring again to
The fastening portion 764 may extend from the narrow end of the tapered portion 762 in the direction opposite the interfacing portion 750. The fastening portion 764 may be threaded or may include other types of fastening features.
The stem 760 may also include a stem tapered surface 765 that may be the outer surface of the tapered portion 762. The stem tapered surface 765 may be a frustoconical surface and may mate with the block tapered surface 725 when the stem 760 is inserted into the block tapered bore 722. The larger diameter of the stem tapered surface 765 may be adjacent the interfacing portion 750 and the smaller diameter of the stem tapered surface may be adjacent the fastening portion 764.
Referring to
The loading bore 770 may include a loading counterbore 772, a threaded portion 774, and a spanner slot 776. The loading counterbore 772 may extend into the stem 760 at the fastening portion 764. The threaded portion 774 may be adjacent the loading counterbore 772, extending from the loading counterbore 772 to the spanner slot 776. The spanner slot 776 may be located between the threaded portion 774 and the receiving slot 752, may be adjacent the threaded portion 774, and may be adjacent the receiving slot 752.
The loading mechanism 780 may apply a load to the component 800 to secure the component 800 into the receiving slot 752. In the embodiment illustrated in
The testing fixture 700 may also include a fastener 704 and a washer 702. The fastener 704 may be fastened to the fastening portion 764 to secure the component interfacing fixture 740 to the fixture block 710. In the embodiment illustrated, the fastener 704 is a threaded nut that threads on to the end of the fastening portion 764. The fastener 704 may apply a load that pulls the tapered portion 762 and stem tapered surface 765 into an interference condition with the block tapered bore wall 724 and the block tapered surface 725. This load may prevent the component interfacing fixture 740 from rotating relative to the fixture block 710.
As illustrated in
In this embodiment, the loading mechanism 780 may include dividing slots 788. The dividing slots 788 may extend radially through the interfacing portion 750, subdividing the interfacing portion 750 into multiple sections 758. The radial direction may be relative to the axis of the receiving slot 752 and of the interfacing portion 750 illustrated by reference axis 799. Each section 758 may be a sector of the hollow cylinder shape of the interfacing portion 750. The dividing slots 788 may also extend radially through a portion of the stem 760, such as radially through a portion of the tapered portion 762, relative to the reference axis 799. In the embodiment illustrated, the dividing slots 788 extend through the tapered portion 762 to the fastening portion 764 in the axial direction relative to the reference axis 799, and each section 758 includes a portion of the interfacing portion 750 and a portion of the transition portion 763.
The dividing slots 788 may be wide enough so that the diameter of the receiving slot 752 will get smaller when the component interfacing fixture 740 is affixed to the block body 712 and a load is applied to the tapered portion 762 by tightening the fastener 704. The load may pull the tapered portion 762 further into the block tapered bore 722 and into an interference condition with the block tapered bore wall 724 which may push the sections 758 closer together causing the diameter of the receiving slot 752 to get smaller and clamp onto a root 816 of the component 800. To fit within the receiving slot 752 of this embodiment, the root 816 may be a portion of the component 800, such as a shaft.
The compressor 200 includes a compressor rotor assembly 210, compressor stationary vanes (stators) 250, and inlet guide vanes 255. The compressor rotor assembly 210 mechanically couples to shaft 120. As illustrated, the compressor rotor assembly 210 is an axial flow rotor assembly. The compressor rotor assembly 210 includes one or more compressor disk assemblies 220. Each compressor disk assembly 220 includes a compressor rotor disk that is circumferentially populated with compressor rotor blades 222. Stators 250 axially follow each of the compressor disk assemblies 220. Each compressor disk assembly 220 paired with the adjacent stators 250 that follow the compressor disk assembly 220 is considered a compressor stage. Some of the stators 250 may be variable guide vanes 253. Compressor 200 includes multiple compressor stages. Inlet guide vanes 255 axially precede the compressor stages. The variable guide vanes 253 and the inlet guide vanes 255 may rotate about a shaft so that the position of their airfoils may be changed depending on the operating conditions of the gas turbine engine 100.
The combustor 300 includes a combustion chamber 320 and one or more fuel injectors 310. The fuel injectors 310 may be upstream of the combustion chamber 320 and may be annularly arranged about the axis of the gas turbine engine 100.
The turbine 400 includes a turbine rotor assembly 410 and turbine nozzles 450. The turbine rotor assembly 410 mechanically couples to the shaft 120. In the embodiment illustrated, the turbine rotor assembly 410 is an axial flow rotor assembly. The turbine rotor assembly 410 includes one or more turbine disk assemblies 420. Each turbine disk assembly 420 includes a turbine disk that is circumferentially populated with turbine blades 422. Turbine nozzles 450 axially precede each of the turbine disk assemblies 420. Each turbine disk assembly 420 paired with the adjacent turbine nozzles 450 that precede the turbine disk assembly 420 is considered a turbine stage. Turbine 400 includes multiple turbine stages.
The exhaust 500 includes an exhaust diffuser 510 and an exhaust collector 520. The power output coupling 50 may be located at an end of shaft 120.
Components for industrial machines, such as the rotating components and the components within the flow path through the gas turbine engine 100 described above, often operate under extreme heat and pressure. Failure of these components may result in a catastrophic failure of the industrial machine. Thus, these components need to be tested so that owners, operators, and manufacturers know when to replace them.
Fixtures used for testing components are often large and heavy. These fixtures may be difficult to move around, require a significant amount of storage space, and may take time to develop. Further, the upper limit of force that a shaker table can provide may limit the size and weight of the components that can be tested on it. The majority of the weight of the testing fixture 700 is separated into the fixture block 710 and the component interfacing fixture 740. This separation may significantly reduce the weight that an operator needs to lift at any given time.
The component interfacing fixture 740 may be a modular part. The fixture block 710 may be standardized to mate with multiple component interfacing fixtures 740 designed for holding a number of different components 800 for multiple industrial machines. This may allow the fixture block 710 to remain affixed to the mounting plate 620 of the testing mechanism 600 no matter which of the components 800 will be tested. Only the component interfacing fixture 740 needs to be changed to accommodate a different component 800. This modular set up also reduces the amount of storage required, since only the component interfacing fixtures 740 need to be stored.
The method may also include selecting a component interfacing fixture 740 from a plurality of component interfacing fixtures 740 at step 920. When a new component 800 is developed, step 920 may include modeling and forming the component interfacing fixture 740. To save time, blanks may include a preformed stem 760 and an interfacing portion 750 that has not been formed yet. The component interfacing fixture 740 may then be formed by machining the interfacing portion 750 to include receiving slot 752 and other features needed to secure the new component 800 to the component interfacing fixture 740. Having blanks with preformed stems 760 may save time between design and testing and help speed up the overall design process of a component 800.
The method may further include inserting a portion of the component 800, such as the root 816, into the receiving slot 752 at step 930. If the testing fixture 700 was previously used, a previously tested component 800 may need to be removed prior to step 930.
The method may yet further include applying a load to the component 800 inserted into the receiving slot 752 to secure the component 800 to the component interfacing fixture 740 at step 940. The load may be applied by a loading mechanism 780, such as by inserting a spanner 784 below the receiving slot 752 and pressing the spanner 784 against the root 816 of the component 800 by threading a set screw 782 into the threaded portion 774. The load applied may retain the root 816 in the receiving slot 752. The spanner 784 may press the root 816 away from the stem 760 and into the root retention feature 753 of the receiving slot 752 to simulate the loading of the component 800, such as a rotary blade during operation of a rotary machine. Simulating the load applied to the component 800 while the industrial machine is operating may improve the accuracy of the material test.
The method may still further include inserting the stem 760 of the component interfacing fixture 740 into the block tapered bore 722 at step 950. If the testing fixture 700 was previously used, a previously used component interfacing fixture 740 may need to be removed prior to step 930.
The method may also include orienting the component 800 in an optimal position by rotating the component 800 and the component interfacing fixture 740 relative to the fixture block 710 at step 960. The optimal position of the component 800 may be a predetermined position of the component 800 relative to the fixture block 710 or relative to the mounting plate 620. The optimal position may be predetermined using a variety of methods including solid modeling, mathematical determinations, empirical observations, and combinations thereof. Orienting the component 800 in an optimal position may reduce the amount of forces needed to perform the material test and may allow heavier objects to be tested at the upper limits of the forces that the testing mechanism is capable of supplying.
The method may further include securing the component interfacing fixture 740 to the fixture block 710 to prevent relative motion there between at step 970. Step 970 may include securing a fastener 704 to the fastening portion 764 and tightening the fastener 704 on the back side of the block tapered bore wall 724 to bring the tapered portion 762 into an interference condition with the block tapered bore wall 724, and to increase the friction between the block tapered surface 725 and the stem tapered surface 765. The back side of the block tapered bore wall 724 may be at the block back surface 718 or may be at the annular surface 721 in the interior of the block counterbore 720. The fastener 704 may tighten against the block back surface 718 or the annular surface 721.
The method may yet further include conducting a material test of the component 800 after step 970 is completed at step 980. In some embodiments, the mounting plate 620 is affixed to a high cycle fatigue testing mechanism 610, such as a shaker table, and step 980 includes performing a high cycle fatigue test on the component 800. In other embodiments, step 980 includes affixing a modal testing mechanism 630 to the interfacing portion 750 of the component interfacing fixture 740, and step 980 includes performing a modal test on the component 800. Affixing the modal testing mechanism 630 to the interfacing portion 750 may reduce the number of times the forces from the modal testing mechanism 630 are transferred between objects and may reduce the distance between the component 800 and the modal testing mechanism 630. Such reductions may reduce losses in the transferred forces and may increase the accuracy of the modal test.
It is understood that the steps disclosed herein (or parts thereof) may be performed in the order presented or out of the order presented, unless specified otherwise. For example, steps 930 and 950 may be performed in any order. Likewise, it is understood that multiple steps may be performed concurrently or combined into a single step. For example, in the embodiment described in accordance with
Further, it is understood that single steps may be subdivided. A subdivided step may be performed partially before and partially after another step. For example, step 970 may be performed in two parts. Securing the fastener 704 to the fastening portion 764 may be performed prior to the step of orienting the component 800 in the optimal position, while tightening the fastener 704 on the back side of the block tapered bore wall 724 to prevent relative rotation between the block tapered bore wall 724 and the tapered portion 762 may be performed afterward so as to secure the component 800 in the optimal position. It is also understood that some steps may be omitted or may only need to be performed once when conducting multiple tests using the method disclosed herein.
The preceding detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. The described embodiments are not limited to use in conjunction with components of a particular type of industrial machine. Although the present disclosure, for convenience of explanation, depicts and describes particular embodiments of the testing mechanism and the testing fixture, it will be appreciated that the testing mechanism and testing fixture in accordance with this disclosure can be implemented in various other configurations, and can be used to test components of other types of machines. Any explanation in connection with one embodiment applies to similar features of other embodiments, and elements of multiple embodiments can be combined to form other embodiments. Furthermore, there is no intention to be bound by any theory presented in the preceding background or detailed description. It is also understood that the illustrations may include exaggerated dimensions to better illustrate the referenced items shown, and are not consider limiting unless expressly stated as such.
