Rotational bending fatigue test device

Abstract

The embodiments of the present invention relate to the field of rotary bending fatigue mechanical property testing of materials at normal low temperatures, and in particular, to a rotary bending fatigue testing device. The rotary bending fatigue testing device comprises: a cooling device, wherein a low-temperature liquid is contained in the cooling device; a heating device, wherein the heating device is arranged in the cooling device; and a driving and adjusting device, wherein a portion of the driving and adjusting device extends into the cooling device and is installed with a sample to be tested, wherein the driving and adjusting device drives the sample to be tested to rotate in the cooling device. The embodiments of the present invention provide a rotary bending fatigue testing device, so as to at least achieve the control of the working environment conditions within a specific temperature range through a cooling device and a heating device.

Description

Technical Field

[0001] The invention relates to the field of rotating bending fatigue mechanical property testing of materials at normal and low temperatures, and in particular to a rotating bending fatigue testing device. Background Art

[0002] Fatigue refers to the phenomenon that damage to materials or structures accumulates until they are destroyed under the action of alternating load cycles. Fatigue phenomena are widely present in all aspects of modern industry. With the development of science and technology, fatigue strength issues have become an important factor affecting the safety and reliability of the engineering field, and have attracted widespread attention from experts and scholars. Rotational bending fatigue, as a typical failure mode of parts, is a complex fatigue coupled with multiple single modes (bending fatigue, tension and compression fatigue, torsion fatigue, etc.). It mainly occurs in rotating shafts (gear shafts, train axles, pulley shafts, etc.) that bear both bending moments and torques during work, posing a major safety hazard to modern transportation equipment, engineering machinery equipment, and engineering equipment. In particular, engineering equipment often serves under extremely harsh working conditions at low temperatures, so the influence of temperature on the mechanical properties of materials cannot be ignored. The mechanical parameters measured at room temperature are inaccurate. It is difficult to guarantee the reliability of the structure if it is designed according to such parameters.

[0003] The existing rotary bending fatigue testing equipment mainly includes a rotary bending fatigue testing machine, but this type of device can only achieve room temperature loading, and it is still difficult to study the rotary bending fatigue mechanical properties of materials at any temperature ranging from low temperature to room temperature (4.2K-300K). Summary of the invention

[0004] In view of the defects existing in the prior art, an embodiment of the present invention provides a rotary bending fatigue testing device, so as to at least control the working environment conditions within a specific temperature range through a cooling device and a heating device.

[0005] According to an embodiment of the present invention, a rotational bending fatigue testing device is provided, comprising: a cooling device, wherein a low-temperature liquid is contained in the cooling device; a heating device, wherein the heating device is arranged in the cooling device; and a driving and adjusting device, wherein a portion of the driving and adjusting device extends into the cooling device and is installed with a sample to be tested, wherein the driving and adjusting device drives the sample to be tested to rotate in the cooling device.

[0006] According to an embodiment of the present invention, the driving and adjusting device includes: a motor, which is arranged outside the cooling device; a rotating shaft, one end of which is connected to the motor shaft of the motor, and the other end extends into the cooling device and is installed with the sample to be tested; and a counter, which is connected to the motor.

[0007] According to an embodiment of the present invention, a sealing structure is provided at a position where the rotating shaft and the cooling device meet.

[0008] According to an embodiment of the present invention, one end of the rotating shaft is connected to the motor shaft via a keyway and a jackscrew bolt, and the other end is locked and connected to the test sample via a self-locking nut.

[0009] According to an embodiment of the present invention, the driving and adjusting device also includes: a low-temperature bearing, which is connected to the sample to be tested; a steel wire rope, one end of which is located in the cooling device and is connected to the low-temperature bearing through a spring, and the other end of which is located outside the cooling device and is connected to a weight; a force sensor, which is located outside the cooling device and is connected in series to the steel wire rope.

[0010] According to an embodiment of the present invention, it further comprises a plurality of fixed pulleys located outside the cooling device, wherein the steel wire rope is wound around the fixed pulleys.

[0011] According to an embodiment of the present invention, the rotation axis is arranged in a horizontal direction, and the spring is arranged in a vertical direction.

[0012] According to an embodiment of the present invention, the heating device comprises a plurality of heaters, and the plurality of heaters are installed on the inner side wall of the cooling device at intervals from each other.

[0013] According to an embodiment of the present invention, the cooling device comprises a cryogenic Dewar tank and a sealing cover arranged on the top of the cryogenic Dewar tank, wherein the sealing cover is provided with a liquid input pipe and an exhaust pipe.

[0014] According to an embodiment of the present invention, the cooling device is configured to have an internal working environment temperature in the range of 4.2K-300K.

[0015] In the rotary bending fatigue test device provided in the embodiment of the invention, the driving and adjusting device can drive the sample to be tested to rotate in the cooling device, the cooling device contains a cryogenic liquid and the heating device is arranged in the cooling device for heating. Thus, the test working environment temperature of the sample to be tested in the cooling device can be controlled within a specific temperature range (for example, 4.2K-300K). Therefore, the rotary bending fatigue test device of the present invention can test the rotary bending fatigue mechanical properties at any temperature ranging from low temperature to normal temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of an embodiment of a rotary bending fatigue testing device of the present invention.

[0018] Reference numerals:

[0019] 100: Rotary bending fatigue test device; 102: Cooling device; 104: Heating device; 106: Test sample; 108: Motor; 110: Rotating shaft; 112: Counter; 114: Sealing structure; 116: Low-temperature bearing; 118: Wire rope; 120: Force sensor; 122: Spring; 124: Weight; 126: Fixed pulley; 128: Low-temperature Dewar tank; 130: Sealing cover. DETAILED DESCRIPTION

[0020] The following will further describe the embodiments of the present invention in detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0022] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0023] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] See now Figure 1 , the rotary bending fatigue test device provided by the embodiment of the present invention is described. It should be understood that the following description is only an illustrative embodiment of the present invention and does not constitute any special limitation to the present invention.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a rotary bending fatigue test device 100. Specifically, the rotary bending fatigue test device 100 includes a cooling device 102, a heating device 104 and a driving adjustment device.

[0027] The cooling device 102 contains cryogenic liquid (such as liquid helium or liquid nitrogen), the heating device 104 is arranged in the cooling device 102, and a part of the driving and adjusting device extends into the cooling device 102 and is installed with the sample to be tested 106. Specifically, the driving and adjusting device drives the sample to be tested 106 to rotate in the cooling device 102.

[0028] According to the above embodiments, in the rotary bending fatigue test device 100 provided in the embodiment of the invention, the driving and adjusting device can drive the sample to be tested 106 to rotate in the cooling device 102, the cooling device 102 contains a cryogenic liquid and the heating device 104 is arranged in the cooling device 102 for heating. Thus, the test working environment temperature of the sample to be tested 106 in the cooling device 102 can be controlled within a specific temperature range (for example, 4.2K-300K). Therefore, the rotary bending fatigue test device 100 of the present invention can test the rotary bending fatigue mechanical properties at any temperature ranging from low temperature to normal temperature.

[0029] Continue to see Figure 1 In one embodiment of the present invention, the driving and adjusting device may include a motor 108 , a rotating shaft 110 , and a counter 112 .

[0030] Specifically, Figure 1 As shown, the motor 108 is disposed outside the cooling device 102, one end of the rotating shaft 110 is connected to the motor shaft of the motor 108, and the other end extends into the cooling device 102 and is installed with the test sample 106 as described above. In addition, the counter 112 is connected to the motor 108.

[0031] In one embodiment, a sealing structure 114 may be provided at the position where the rotating shaft 110 is connected to the cooling device 102. In addition, one end of the rotating shaft 110 may be connected to the motor shaft via a keyway and a jackscrew bolt, and the other end of the rotating shaft 110 may be locked and connected to the sample to be tested 106 via a self-locking nut.

[0032] Continue to see Figure 1 In one embodiment of the present invention, the driving and adjusting device may further include a cryogenic bearing 116 , a steel wire rope 118 and a force sensor 120 .

[0033] Specifically, the cryogenic bearing 116 can be connected to the test sample 106, one end of the wire rope 118 can be located in the cooling device 102 and connected to the cryogenic bearing 116 through the spring 122, and the other end of the wire rope 118 can be located outside the cooling device 102 and connected to the weight 124. In addition, the force sensor 120 can be located outside the cooling device 102 and connected in series to the wire rope 118. Further, in one embodiment, the rotary bending fatigue test device 100 can also include a plurality of fixed pulleys 126 located outside the cooling device 102, and the wire rope 118 can be wound on the fixed pulleys 126. Figure 1 As shown, in one embodiment of the present invention, the rotating shaft 110 is arranged in the horizontal direction, and the spring 122 is arranged in the vertical direction. In other words, the extending direction of the rotating shaft 110 and the setting direction of the spring 122 are perpendicular to each other.

[0034] Continue to see Figure 1 In one embodiment of the present invention, the heating device 104 may include a plurality of heaters, and the plurality of heaters may be installed on the inner side wall of the cooling device 102 at intervals from each other.

[0035] Accordingly, the cooling device 102 may include a cryogenic dewar 128 and a sealing cover 130 disposed on the top of the cryogenic dewar 128. Specifically, in one embodiment, a liquid input pipe and an exhaust pipe may be disposed on the sealing cover 130. Furthermore, the cooling device 102 may be configured to have an internal working environment temperature within a range of 4.2K-300K.

[0036] During actual operation, the motor 108 is used to drive the rotating shaft 110 and the test sample 106 to rotate. The rotating shaft 110 is connected to the motor shaft of the motor 108, and the rotating shaft 110 and the motor shaft are fixed by a keyway and a top screw bolt to prevent the rotating shaft 110 and the motor shaft from rotating and slipping. The test sample 106 is locked and connected to the rotating shaft 110 by a self-locking nut. In addition, the sealing structure 114 is used to prevent the leakage of cryogenic liquid and frostbite the motor 108. The test sample 106 is connected to the connecting line of the load application through a cryogenic bearing 116 to ensure that the sample can rotate freely during the load application process.

[0037] Furthermore, if Figure 1 As shown, the spring 122 is used to adjust the direction of the applied load after the sample to be tested 106 is bent and deformed during the test. The wire rope 118 is used to transfer the load to the sample to be tested 106. The cryogenic dewar tank 128 is used to store cryogenic liquid and provide a low temperature environment for the sample to be tested 106. In addition, the heater of the heating device 104 is used to cooperate with the cryogenic cold source to achieve temperature control during the test. The force sensor 120 is used to measure the load applied to the sample to be tested 106 during the test. The fixed pulley 126 is used to support the weight 124 that applies the load to the sample to be tested 106. The sealing cover 130 is designed with a liquid helium delivery pipeline and a helium exhaust pipe (i.e., a liquid input pipe and an exhaust pipe), which are respectively used to transport / discharge the helium or nitrogen volatilized from liquid helium or liquid nitrogen when measuring the mechanical properties of the sample in the temperature range of 4.2-300K. Further, the weight 124 is used to provide a load for the sample to be tested 106. The counter 112 is used to record the number of cycles of the sample during the rotation bending test.

[0038] In summary, in the rotational bending fatigue testing device 100 provided by the present invention, the testing of materials under any temperature environment in the temperature range of 4.2K-300K is realized through the coordinated work of the cooling device 102 and the heating device 104. The test sample 106 is driven to rotate by the driving adjustment device, and a low-temperature bearing 116 is applied to the shaft end of the test sample 106, so that the sample can rotate freely. The rotational bending fatigue mechanical properties of the material at normal and low temperatures can be accurately and efficiently detected through the counter 112.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotating bending fatigue testing device, characterized in that: include: a cooling device containing a cryogenic liquid; A heating device, wherein the heating device is arranged in the cooling device; A driving and adjusting device, a portion of which extends into the cooling device and is provided with a sample to be tested, Wherein, the driving and adjusting device drives the sample to be tested to rotate in the cooling device; The drive adjustment device comprises: A motor, wherein the motor is arranged outside the cooling device; A rotating shaft, one end of which is connected to the motor shaft of the motor, and the other end of which extends into the cooling device and is installed with the sample to be tested; A counter connected to the motor; The drive adjustment device also includes: A low-temperature bearing, the low-temperature bearing being connected to the sample to be tested; A steel wire rope, one end of which is located in the cooling device and connected to the cryogenic bearing through a spring, and the other end of which is located outside the cooling device and connected to a weight; A force sensor, the force sensor is located outside the cooling device and is connected in series to the steel wire rope; A sealing structure is provided at a position where the rotating shaft and the cooling device are connected; The rotation shaft is arranged in a horizontal direction, and the spring is arranged in a vertical direction.

2. The rotary bending fatigue testing device according to claim 1, characterized in that: One end of the rotating shaft is connected to the motor shaft through a keyway and a jackscrew bolt, and the other end is locked and connected to the sample to be tested through a self-locking nut.

3. The rotary bending fatigue testing device according to claim 1, characterized in that: It also includes a plurality of fixed pulleys located outside the cooling device, wherein the steel wire rope is wound around the fixed pulleys.

4. The rotary bending fatigue testing device according to claim 1, characterized in that: The heating device includes a plurality of heaters installed on an inner side wall of the cooling device at intervals from each other.

5. The rotary bending fatigue testing device according to claim 1, characterized in that: The cooling device comprises a low-temperature Dewar tank and a sealing cover arranged on the top of the low-temperature Dewar tank, wherein the sealing cover is provided with a liquid input pipe and an exhaust pipe.

6. The rotary bending fatigue testing device according to claim 1, characterized in that: The cooling device is configured such that the internal working environment temperature is within the range of 4.2K-300K.

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