Flat belt tester with moving endless support member

Abstract

To provide a testing machine, and a method of supporting a test specimen for rotation.SOLUTION: A testing machine for rotating test specimens comprises: a frame; and a roadway assembly. The roadway assembly includes an endless belt that provides a surface for engaging with the test specimen, is supported by rollers, and rolls on the roller. An endless support member supported by the frame is disposed between the rollers, and engages with the endless belt from below. The endless support member moves with, or is synchronized with the endless belt so as to have the same velocity as the endless belt. The endless support member provides a flat reaction structure for a load from the test specimen placed on the endless belt, and is of size corresponding to that needed by a contact patch of the test specimen on the endless belt. Since the endless support member moves at the same velocity as the endless belt, no forces are generated between the endless support member and the endless belt.SELECTED DRAWING: Figure 1

Description

Background Art

[0001] Background The following discussion is provided only for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.

[0002] Testing machines having an endless belt simulating a roadway surface are known and are used to test various tire and wheel assemblies. The testing machine includes a frame that supports a test sample on the endless belt. The endless belt is supported on and rotates around a pair of drums or rollers. Typically, one of the pair of drums or rollers is driven. Because the belt is flexible, a central support positioned under the endless belt between the drums provides a reaction structure on the opposite side of the test sample to keep the belt flat. Generally, the upper surface of the central support contains lubricating oil that uses hydrodynamic principles to react to the load applied to the belt from the test sample. The testing machine is suitable for testing tires, wheels, and assemblies at highway speeds, but is not suitable for all test samples.

Summary of the Invention

[0003] Summary This summary and abstract in this specification are provided to introduce, in simplified form, selected concepts that are further described below in the detailed description. This summary and abstract are not intended to identify key or essential features of the claimed subject matter, nor are they intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all of the disadvantages described in the background art.

[0004] The first disclosed embodiment is a testing machine for testing a rotating test specimen. The testing machine comprises a frame and a roadway assembly. The roadway assembly comprises a first roller and a second roller, each joined to the frame. An endless belt provides a surface for engaging with the test specimen, is supported by the first and second rollers, and rolls on the first and second rollers. An endless support member, supported by the frame, is positioned between the first and second rollers and engages with the endless belt from below. The endless support member moves together with or synchronized with the endless belt at the same speed. The endless support member provides a flat reaction structure against loads from the test specimen placed on the endless belt, and is sized to correspond to the required size of the contact surface of the test specimen with respect to the endless belt. Because the endless support member moves at the same speed as the endless belt, no force is generated between the endless support member and the endless belt.

[0005] The testing machine may have one or more of the following features: The endless support member may include a first rotatable member and a second rotatable member to support the endless support member for rotation. Typically, a first drive unit is coupled to at least the first rotatable member and drives the first rotatable member. Generally, the testing machine includes a second drive unit operably coupled to a first roller and driving the first roller and, consequently, the endless belt. A control unit is operably coupled to the first drive unit so that the speed of the endless support member matches the speed of the endless belt. A suitable speed sensor provides input signals corresponding to the speeds of the endless belt and the endless support member.

[0006] A fixed support can be positioned between the first roller and the second roller. The fixed support supports the endless support member from below, if necessary. To reduce friction, a bearing can be positioned between the fixed support and the surface of the endless support member facing the fixed support. The bearing may comprise multiple rotatable support elements, such as rollers extending transversely to the direction of movement of the endless support member. The bearing may also comprise a fluid positioned between the endless support member and the fixed support. The fixed support may be fluidically coupled to a pressurized fluid source and may comprise multiple outlets for discharging the fluid to the endless support member. The fluid may include a liquid or a gas. The pressurized gas source may include a pump.

[0007] The endless support member may comprise a plurality of interconnecting elements. In one embodiment, the interconnecting elements may include interconnecting plates, each plate extending in a direction transverse to the direction of movement of the endless belt.

[0008] Another comprehensive embodiment includes a method for supporting a test specimen for rotation. This method also includes supporting the test specimen with an endless belt rotating beneath it, and supporting the endless belt with an endless support member on the side of the endless belt opposite to the side of the endless belt that engages with the test specimen, wherein the speed of the endless support member beneath the test specimen matches the speed of the endless belt beneath the test specimen. The above-described features of the endless support member can be incorporated to support a test specimen in rotation. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the testing machine.

[0010] [Figure 2] This is a perspective view of the testing machine.

[0011] [Figure 3] This is a front view of the testing machine. [Modes for carrying out the invention]

[0012] Detailed description of the illustrated embodiment Figures 1 to 3 show a testing machine 10 suitable for testing specimens that move at a slower speed than conventional tire and wheel assemblies on a vehicle and / or have a larger road surface contact area than conventional tires on a vehicle. The testing machine 10 comprises a frame 11 and a movable roadway assembly 13 supported by the frame 11.

[0013] The roadway assembly 13 comprises a first roller 14 and a second roller 16 that support an endless belt 12 on rollers 14 and 16 for rotation. Generally, the endless belt 12 is made of steel, but can be made of any material suitable for the test to be performed. Similarly, the endless belt 12 can be smooth or have surfaces configured for the test specimen under test. Generally, at least one of the rollers 14 and 16 is driven by a suitable drive unit 15. The drive unit 15 can be powered electrically or by a hydraulic fluid, etc. An actuator 17 can be provided to change the distance between the rotatable axes of the rollers 14 and 16, for example, to allow the installation of the endless belt 12.

[0014] The testing machine 10 described herein is suitable for testing test specimens having a larger contact area than a typical tire and wheel assembly and / or rotating on an endless belt 12 at a slower speed than a conventional tire and wheel assembly. As an example, Figure 1 schematically shows a track assembly 20 used on a vehicle such as a tractor, skid steer loader, or tank, which houses a test specimen. The track assembly 20 is mounted on a support structure 22 of a frame 11 to hold the track assembly 20 in place on the endless belt 12. Generally, the support structure 22 is equipped with various actuators, one of which is shown as 24, and provides a downward force to the track assembly 20, for example. The support structure 22 can take many forms depending on the test specimen under test and will not be further described as they are not relevant to the testing machine 10.

[0015] The test specimen 24 is supported on the endless belt 12 as the endless belt 12 rotates on the endless support member 26. The endless support member is supported by the frame 11 and is positioned between the first roller 14 and the second roller 16. The endless support member 26 engages with the endless belt 12 from below and moves with the endless belt 12 for at least the portion of the endless belt 12 that engages with the test specimen 24, so as to form the endless belt 12 as a flat surface. The endless support member 26 provides support to the endless belt 12 in order to react to the force exerted by the large contact surface of the test specimen 24. Furthermore, the endless support member 26 provides such support at a linear speed of the endless belt 12 that is slower than the linear speed of a conventional flat belt tester, which uses a lubricating film and hydrodynamic principles to generate support for the endless belt via a lubricating fluid, as described in the background art. At the lower speeds required to test test specimens such as a track assembly 20, the lubricating film and hydrodynamic principles do not provide the necessary support.

[0016] Typically, the endless support member 26 comprises rigid interconnection elements 30, such as support plates. The interconnection elements 30 may be connected together, for example, by a swivel link, or the elements 30 may be fixed to an element support member 31, such as a belt or chain. A first rotatable member 32 and a second rotatable member 34 are provided to allow continuous rotation of the endless support member 26. The first rotatable member 32 and the second rotatable member 34 are configured to engage with the endless support member 26 and to drive the endless support member 26 by a drive device 33. The first rotatable member 32 and the second rotatable member 34 may depend on the structure of the element support member 31 used to interconnect the elements 30. For example, if the element support member 31 includes an endless belt, the first rotatable member 32 and the second rotatable member 34 may include drums, each having substantially cylindrical surfaces, for frictional engagement with and driving the element support member 31. Similarly, the first rotatable member 32 and the second rotatable member 34 may include, for example, gears having teeth that engage with openings in the element support member 31 if the element support member 31 includes a chain. In Figures 2 and 3, the inclined portions of the endless support member 26 relative to the first rotatable member 32 and the second rotatable member 34 have been removed.

[0017] A fixed support 38 is typically positioned between a first rotatable member 32 and a second rotatable member 34, and reacts to the load generated by the test specimen 24 through the endless belt 12 and portion of the endless support member 26 beneath the test specimen 24. Generally, a bearing 40 is positioned between the upper surface 42 of the fixed support 38 and the lower surface 44 of the endless support member 26 during rotation. The bearing 40 can take on numerous forms. For example, in Figure 1, the bearing 40 comprises a rotatable element 46, such as a roller, that contacts the endless support member 26 from below, and the rotatable element 46 is supported for rotation by the fixed support 38 or the frame 11. The rotatable element 46 may include, for example, a roller having a width and a longitudinal axis that transverses the linear motion of the endless support member 26 beneath the test specimen. The rotatable element 46 may extend across the entire width of the endless support member 26 or only a portion thereof.

[0018] In the embodiment shown in Figure 2, the bearing 40 is formed by pressurized fluid released from a fixed support 38 to contact a portion of the endless support member 26 beneath the test specimen and drive this portion upward. The fixed support 38 may be provided with an opening or outlet 48 from which the fluid is released. A suitable fluid conduit 50 is provided from a pressurized fluid source 52, which is typically a pump, to each of the openings 48. The fluid may optionally contain a gas such as air or a liquid, and the pump 52 is configured to pressurize the fluid depending on whether the fluid is a gas or a liquid.

[0019] The endless support member 26 is driven to synchronize with the speed of the endless belt 12 beneath the test specimen 24. In this way, support for the test specimen is provided across the desired contact surface at the speed at which the test specimen is moving. However, because the endless support member 26 moves with the endless belt 12 at the same linear speed as the endless belt 12, friction between the endless belt and the endless support member is substantially minimized or nonexistent. Therefore, the endless support member 26 provides support without generating undesirable forces on the test specimen 24. The endless support member 26 can be driven by a suitable electric or fluid drive device. Speed ​​sensors monitor the speed of the endless belt 12 and / or the endless support member 26 either directly, optically, or indirectly via the rotation of the first roller 14 and the second roller 16 and / or the first rotatable member 30 and the second rotatable member 32. The control device 54 receives inputs indicating the speed of the endless belt 12 and the endless support member 26 via the speed sensor, and controls the drive device of the endless support member 26 to match the speed of the endless belt 12.

[0020] While the subject matter has been described in terms of specific environments, structural features, and / or methodological actions, it should be understood that the subject matter as defined in the attached claims is not limited to the aforementioned environments, specific features, or actions, as has been determined by the courts. Rather, the aforementioned environments, specific features, and actions are disclosed as exemplary forms that implement the claims.

Claims

1. A testing machine, The frame and 1. A roadway assembly comprising: a first roller joined to the frame; a second roller joined to the frame; an endless belt supported by the first roller and the second roller and rolling on the first roller and the second roller; an endless support member supported by the frame, disposed between the first roller and the second roller, engaging the endless belt from below and moving together with the endless belt; a roadway assembly comprising: A testing machine comprising:

2. 10. The testing machine of claim 1, further comprising a first rotatable member and a second rotatable member, the endless support member being supported for rotation by the first rotatable member and the second rotatable member.

3. 3. The testing machine according to claim 1, further comprising a fixed support disposed between the first roller and the second roller, the fixed support supporting the endless support member from below.

4. 4. The testing machine of claim 3, further comprising a bearing disposed between the fixed support and a surface of the endless support member facing the fixed support, the bearing preferably comprising one of a plurality of support rollers or a fluid disposed between the endless support member and the fixed support, the fixed support comprising a plurality of outlets fluidly coupled to a source of pressurized fluid, the plurality of outlets configured to release the fluid, the fluid preferably comprising a liquid or a gas, and the source of pressurized fluid comprising a pump.

5. 3. The testing machine of claim 2, further comprising a drive coupled to the first rotatable member to drive the first rotatable member, and in a further embodiment, a second drive operably coupled to the first roller to drive the first roller.

6. 6. The testing machine of claim 5, further comprising a controller operatively coupled to the drive so that the speed of the endless support member matches the speed of the endless belt.

7. 3. The testing machine of claim 1 or 2, wherein the endless support member comprises a plurality of interconnecting elements.

8. The testing machine of claim 7 , wherein the interconnection element comprises an interconnection plate.

9. 8. The testing machine of claim 7, wherein the interconnecting elements include interconnecting plates, each plate extending in a direction transverse to the direction of movement of the endless belt.

10. 1. A method of supporting a test sample for rotation, comprising: supporting the test sample using an endless belt that rotates beneath the test sample; supporting the endless belt with an endless support member on a side of the endless belt opposite to the side engaging the test specimen, wherein the speed of the endless support member below the test specimen matches the speed of the endless belt below the test specimen; A method comprising:

11. 11. The method of claim 10, wherein supporting the endless belt with the endless support member comprises driving the endless support member so that the speed of the endless support member below the test sample matches the speed of the endless belt below the test sample.

12. The method of claim 10 or 11, wherein the endless support member comprises a plurality of interconnecting elements.

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