Device for determining a twisting play

Abstract

A device (100) for determining a twisting clearance, with an inclinometer (10) designed to determine the inclination of a surface relative to a reference plane, a measuring lever (20), wherein the inclinometer is arranged on a surface of the measuring lever, and a centering clamp (30) arranged non-rotatably on the measuring lever, which is designed to be arranged at least partially in a rotatable machine element, wherein the centering clamp has several clamping jaws (32) and at least one centering piece (34) with several contact surfaces (35).

Description

[0001] Herein lies a device for determining a twisting play, in particular for measuring a twisting play of a hollow shaft.

[0002] Devices for determining the backlash of a shaft are known. These are typically designed to be attached to or coupled with a stationary shaft—that is, a shaft that is not driven at the time of the backlash measurement—using a (plug-in) adapter. After attaching the (plug-in) adapter to the shaft, the shaft is rotated manually or automatically, first in one direction and then in the opposite direction, as far as its backlash allows. The extent of the backlash, i.e., the maximum rotational range of the undriven shaft, is usually determined using an angle measuring device coupled to the backlash measurement device.

[0003] One technical problem here is that the accuracy of determining the backlash of the shaft is limited by the backlash of the adapter relative to the shaft and by the backlash of the angle or inclination measuring device relative to the adapter itself.

[0004] Therefore, there is a need for an improved device for determining backlash.

[0005] Such an improved device is defined by claim 1. Embodiments of the improved device are defined by the dependent claims.

[0006] The device for determining backlash includes an inclinometer configured to determine the inclination of a surface relative to a reference plane. The device further includes a measuring lever, with the inclinometer arranged on or attached to a surface of the measuring lever. A centering clamp, fixed to the measuring lever, is configured to be at least partially mounted in a rotatable machine element, for example, in a (hollow) shaft. The centering clamp has several clamping jaws and at least one centering element with multiple, in particular planar, contact surfaces. These contact surfaces can be designed to bear flat against the clamping jaws or against clamping jaw contact surfaces. This reference plane can be, for example, a horizontal, a vertical, or another spatially oriented plane.

[0007] Because the inclinometer is mounted on the measuring lever, and because the measuring lever is mounted on the centering clamp, rotation of the measuring instrument relative to the centering clamp is at least substantially prevented. Because the clamping jaws of the centering clamp bear at least partially flat against the centering element of the centering clamp, rotation of the individual components of the centering clamp relative to each other is at least substantially prevented. Furthermore, the clamping jaws of the centering clamp can be brought into contact with an (inner) surface of the rotating machine element and / or pressed against this (inner) surface of the rotating machine element, thereby at least substantially preventing rotation of the centering clamp relative to the machine element.

[0008] Compared to known devices where an inclinometer is coupled to a rotatable machine element via a (plug-in) adapter, this device exhibits a significantly reduced (overall) play between the inclinometer and the rotatable machine element. This improves measurement accuracy and operator-independent reproducibility of the measurement process.

[0009] Furthermore, the centering clamp can have a centering cylinder with several, in particular flat, contact surfaces. These contact surfaces can be designed to bear in contact with the clamping jaws or with the clamping jaw contact surfaces of the clamping jaws.

[0010] One advantage of this design is that the jaws of the centering clamp can also bear at least a partial, flat contact surface against the clamping cylinder, further hindering rotation of the measuring instrument relative to the centering clamp, particularly relative to the clamping jaws of the centering clamp. Furthermore, improved force transmission between the clamping cylinder and the jaws reduces any torsional play of the centering clamp relative to the rotating machine element. Both of these factors—the reduction of torsional play of the inclinometer relative to the centering clamp and the reduction of torsional play of the centering clamp relative to the rotating machine element—contribute to improved accuracy in determining the torsional play of the rotating machine element.

[0011] The centering clamp can also have a threaded spindle designed to engage an internal thread of the centering piece and to change the distance between the centering piece and the centering cylinder by rotating it around a spindle axis. By changing the distance between the centering piece and the centering cylinder, the clamping jaws can be brought into contact with an (inner) surface of the rotating machine element and / or pressed against this (inner) surface. To bring the clamping jaws into contact with an (inner) surface of the rotating machine element and / or to press the clamping jaws against this (inner) surface, the distance between the centering piece and the centering cylinder can be reduced.

[0012] One advantage here is that the centering clamp can easily be arranged or attached inside a rotatable machine element, especially inside a (hollow) shaft.

[0013] The threaded spindle can be specifically designed to be turned or rotated with a torque wrench.

[0014] One advantage of this is that the contact force applied to the (inner) surface of the rotating machine element can be precisely selected or set for each measurement process, regardless of the operator. This particularly improves the reproducibility of the measurement results.

[0015] Optionally, the centering piece can have more than two contact surfaces. Alternatively or additionally, the centering cylinder can also have more than two contact surfaces.

[0016] In particular, at least part of the centering piece and / or at least part of the centering cylinder can have a cross-sectional area that is at least approximately polygonal.

[0017] One advantage of this is that the force transmission between the clamping jaws and the centering piece and / or the force transmission between the clamping jaws and the centering cylinder is further improved. This also makes it more difficult for the clamping jaws of the centering clamp to rotate relative to the clamping piece and / or the clamping cylinder.

[0018] Optionally, at least part of the centering piece can have a cross-sectional area that is at least approximately square. Alternatively or additionally, at least part of the centering cylinder can also have a cross-sectional area that is at least approximately square.

[0019] In one variant, at least part of the centering piece can have the shape of a truncated pyramid. Alternatively or additionally, at least part of the centering cylinder can have the shape of a truncated pyramid.

[0020] One advantage of this is that a force from the centering piece and / or the centering cylinder can be transferred evenly in four different spatial directions to the clamping jaws of the centering clamp.

[0021] Optionally, each jaw of the centering clamp can be configured to engage with one contact surface of the centering piece and / or one contact surface of the centering cylinder. The centering piece and / or the centering cylinder can each have as many contact surfaces as the centering clamp has jaws. Each contact surface of the centering piece and each contact surface of the centering cylinder can be configured to engage with exactly one clamping jaw or with exactly one clamping jaw contact surface of a clamping jaw.

[0022] One advantage of this is that the force transmission between the clamping jaws and the centering piece and / or the force transmission between the clamping jaws and the centering cylinder is further improved. This also makes it more difficult for the clamping jaws of the centering clamp to rotate relative to the clamping piece and / or the clamping cylinder.

[0023] Furthermore, the centering clamp may have at least one spring element designed to push the clamping jaws towards the threaded spindle.

[0024] One advantage of this is that it improves the removal of the centering clamp from a rotating machine element, such as a (hollow) shaft, after the backlash measurement has been completed. For example, after the backlash measurement has been completed, the distance between the centering piece and the centering cylinder can be increased, for example using the threaded spindle, so that a space is created between the centering piece and the centering cylinder into which the spring element can press the clamping jaws.

[0025] The centering clamp can be arranged essentially perpendicular to the measuring lever. Furthermore, the inclinometer can be configured to determine the inclination of the measuring lever's surface relative to the Earth's surface.

[0026] One advantage of this is that the backlash of the rotatable machine element can be determined in this way with an inclinometer without having to calculate an angle correction.

[0027] A procedure for determining a twisting play includes the following steps: - At least partial arrangement of a centering clamp inside a rotatable machine element, for example in a (hollow) shaft, wherein the centering clamp has several clamping jaws and at least one centering element with several contact surfaces, and wherein a measuring lever is arranged non-rotatably on the centering clamp, and wherein an inclinometer, configured to determine the inclination of a surface relative to a horizontal, is arranged on or at a surface of the measuring lever; and - Fixing the centering clamp inside a rotatable machine element by bringing the clamping jaws into contact with an (inner) surface of the machine element, in particular by reducing the distance between the centering piece and a centering cylinder using a rotatable threaded spindle; - Rotation of the rotatable machine element in a first direction of rotation as far as a twisting action of the rotatable machine element allows; - Determining a first inclination angle of the measuring lever using the inclinometer; - Rotating the rotatable machine element in a second direction of rotation, which is opposite to the first direction of rotation, insofar as a twisting action of the rotatable machine element is permitted; - Determining a second inclination angle of the measuring lever using the inclinometer; and - Determining a twisting angle of the rotatable machine element based on the previously determined first tilt angle of the measuring lever and based on the previously determined second tilt angle of the measuring lever.

[0028] Further features, properties, advantages, and possible variations will become clear to a person skilled in the art from the following description, which refers to the accompanying drawings. All features described and / or illustrated, individually or in any combination, depict the object disclosed herein. The dimensions and proportions of the devices and components shown in the figures are not to scale. Fig. Figure 1 shows an example of a device for determining backlash. Fig. Figure 2 shows a schematic representation of a device for determining a twisting play in a top view. Fig. Figures 3 to 5 each show a schematic view of a centering clamp for a device for determining backlash. Fig. Figure 6 schematically shows a centering piece of a centering clamp from different views. Fig. Figure 7 schematically shows a centering cylinder of a centering clamp from different views.

[0029] Comparable, identical, or equivalent components and features are identified by the same reference symbols in the figures. For clarity, reference symbols for individual features and components have sometimes been omitted in the figures, although these features and components are already identified by reference symbols in other figures. Components and features not described again in relation to the other figures are similar in form and function to the corresponding components and features shown in the other figures.

[0030] The Fig. Figure 1 shows an example of a device 100 for determining backlash. Fig. Figure 2 shows a schematic representation of the device 100 for determining a twisting clearance in a top view.

[0031] The in the Fig. 1 and Fig. The device shown in Figure 2 comprises a centering clamp 30, a measuring lever 20 fixed to the centering clamp 30, and an inclinometer 10 arranged on a surface of the measuring lever 20. The inclinometer 10 is configured to measure the inclination of the surface of the measuring lever 20, on which it is arranged, relative to a horizontal. The centering clamp 30 is configured to be arranged, at least partially, inside a rotatable machine element, for example, in a (hollow) shaft.

[0032] The Fig. Figures 3 to 5 each show different details of the centering clamp 30.

[0033] As in the Fig. As shown schematically in Figure 3, the centering clamp 30 has a centering cylinder 36, a centering piece 34 and several clamping jaws 32.

[0034] How to proceed schematically in the Fig. As shown in Figure 4, a threaded spindle 38, rotatable about a spindle axis X, with an external thread, is arranged inside the centering clamp 30. The threaded spindle 38 engages with its external thread in a corresponding internal thread of the centering piece 34, so that by rotating the threaded spindle 38 the distance between the centering piece 34 and the centering cylinder 36 can be changed, i.e., decreased or increased.

[0035] A reduction in the distance between the centering piece 34 and the centering cylinder 36 causes the clamping jaws 32 arranged between the centering piece 34 and the centering cylinder 36 to be forced radially outwards. If the centering clamp 30 is at least partially located inside a rotatable machine element, the clamping jaws 32 are thus forced into contact with an inner surface of the rotatable machine element and / or pressed against this inner surface, so that the centering clamp 30 is attached to or within the rotatable machine element.

[0036] How to proceed schematically in the Fig. As shown in Figure 5, the centering clamp has at least one spring element 39 that presses the clamping jaws 32 towards the threaded spindle 38. If the centering clamp 30 is to be released from a rotatable machine element after determining its backlash, the distance between the centering piece 34 and the centering cylinder 36 can be increased by rotating the threaded spindle 38 accordingly, so that the spring element 38 presses the clamping jaws 32 into the space thus released between the centering piece 34 and the centering cylinder 36, and the clamping jaws 32 are released from contact with an inner surface of the rotatable machine element.

[0037] To improve the accuracy of determining the backlash of a rotatable machine element, it is advantageous to prevent, or at least make as difficult as possible, a rotation of components of the device 100 relative to each other, in particular a rotation of the centering piece 34 and the centering cylinder 36 relative to the clamping jaws 32.

[0038] As in the Fig. 6 and Fig. As shown schematically in Figure 7, the centering piece 34 and / or the centering cylinder can therefore each have several contact surfaces on which the clamping jaws 32 of the centering clamp 30 can each bear in contact over a flat area.

[0039] The Fig. Figure 6 shows the centering piece 34 schematically from two different views. The centering piece 34 shown is at least partially truncated pyramidal in shape and therefore has a polygonal cross-sectional area, square in the example shown, and four contact surfaces 35. However, this is not necessarily the case for all embodiments of the device 100; embodiments with multiple contact surfaces 35 but no polygonal cross-sectional area are also possible.

[0040] Will, as with reference to the Fig. As described in section 4, the distance between the centering piece 34 and the centering cylinder 36 is reduced, and the contact surfaces 35 with correspondingly shaped clamping jaw contact surfaces of the clamping jaws 32 come into contact over a flat area.

[0041] If the centering clamp 30 is arranged at least partially inside a rotatable machine element, the contact surfaces 35 are pressed flat against the correspondingly shaped clamping jaw contact surfaces of the clamping jaws 32, so that a twisting of the clamping piece 34 relative to the clamping jaws 32 is considerably more difficult compared to centering clamps with a conically shaped, i.e. conical or frustoconical, centering piece.

[0042] The Fig. Figure 7 shows one corresponding to the one in the Fig. Figure 6 schematically shows the centering cylinder 36 formed by the centering element 34 from two different views. The centering cylinder 36 shown is at least partially truncated pyramidal in shape and therefore has a polygonal cross-sectional area, square in the example shown, and four contact surfaces 37. However, this is not necessarily the case for all embodiments of the device 100; embodiments are also possible that have several contact surfaces 37 but no polygonal cross-sectional area.

[0043] Will, as with reference to the Fig.As described in section 4, when the distance between the centering element 34 and the centering cylinder 36 is reduced, the contact surfaces 37, with their correspondingly shaped clamping jaw contact surfaces of the clamping jaws 32, also come into full contact. If the centering clamp 30 is arranged at least partially inside a rotatable machine element, the contact surfaces 37 are also pressed flat against the correspondingly shaped clamping jaw contact surfaces of the clamping jaws 32, so that rotation of the centering cylinder 36 relative to the clamping jaws 32 is considerably more difficult compared to centering clamps with a conically shaped, i.e., conical or frustoconical, centering cylinder.

[0044] It is understood that the exemplary embodiments described above are not exhaustive and do not limit the subject matter disclosed herein. In particular, it is evident to the person skilled in the art that they can combine the described features in any way they wish and / or omit various features without deviating from the subject matter disclosed herein.

Claims

[1] A device (100) for determining a twisting clearance, with an inclinometer (10) designed to determine the inclination of a surface relative to a reference plane, a measuring lever (20), wherein the inclinometer is arranged on a surface of the measuring lever, and a centering clamp (30) arranged non-rotatably on the measuring lever, which is designed to be arranged at least partially in a rotatable machine element, wherein the centering clamp has several clamping jaws (32) and at least one centering piece (34) with several contact surfaces (35). [2] The device according to claim 1, wherein the centering clamp (30) further comprises a centering cylinder (36) with several contact surfaces (37). [3] The device (100) according to claim 2, wherein the centering clamp (30) further comprises a threaded spindle (38) which is configured to engage in an internal thread of the centering piece (34) and to change the distance of the centering piece from the centering cylinder (36) by rotating it about a spindle axis (X). [4] The device (100) according to any one of claims 1 to 3, wherein the centering piece (34) has more than two contact surfaces (35), and / or the centering cylinder (36) has more than two contact surfaces (37). [5] The device (100) according to any one of claims 1 to 4, wherein at least part of the centering piece (34) has a polygonal cross-sectional area, and / or at least part of the centering cylinder (36) has a polygonal cross-sectional area. [6] The device (100) according to any one of claims 1 to 5, wherein at least part of the centering piece (34) has a square cross-sectional area, and / or at least part of the centering cylinder (36) has a square cross-sectional area. [7] The device (100) according to any one of claims 1 to 6, wherein at least part of the centering piece (34) has the shape of a truncated pyramid, and / or at least part of the centering cylinder (36) has the shape of a truncated pyramid. [8] The device (100) according to any one of claims 1 to 7, wherein Each clamping jaw (32) is designed to be brought into contact with a contact surface (35) of the centering piece (34) and / or with a contact surface (37) of the centering cylinder (36), and / or The centering piece and / or the centering cylinder each have as many contact surfaces as the centering clamp (30) has clamping jaws, wherein each contact surface of the centering piece and each contact surface of the centering cylinder is designed to be brought into contact with exactly one clamping jaw. [9] The device (100) according to any one of claims 3 to 8, wherein the centering clamp (30) has at least one spring element (39) which is configured to push the clamping jaws (32) in the direction of the threaded spindle. [10] The device (100) according to any one of claims 1 to 9, wherein the centering clamp (30) is arranged substantially perpendicular to the measuring lever (20) and / or the inclinometer (10) is configured to determine the inclination of the surface of the measuring lever relative to the Earth's surface.

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