Test shaft for testing multiple flexible thin-wall bearings

Abstract

The invention discloses a test shaft for testing a plurality of flexible thin-wall bearings, which comprises a connecting element, a test shaft positioning device and a plurality of bearing fixing elements, and is characterized in that the connecting element comprises a main shaft element, and a square table is arranged at one end of the main shaft element and is used for being connected and matched with the bearing fixing elements; each bearing fixing element comprises a bearing mounting seat, a square table and a square groove are arranged at the two ends of each bearing mounting seat respectively, the adjacent bearing fixing elements are matched through the square tables and the square grooves, and the bearing fixing element closest to the main shaft element is matched with the square table of the main shaft element through the square groove. According to the invention, the square groove and the square table are matched for transmission, so that not only can the movement be transmitted while the radial force and the axial force are borne, but also the requirement on the mounting precision is low, the square table and the square groove are matched more tightly, the transmission gap is small, and the power loss is low.

Description

Technical Field

[0001] The present invention belongs to the field of mechanical design, and particularly relates to a test shaft part for multiple flexible thin-wall bearing tests. Background Art

[0002] As a core component of industrial robots, the harmonic reducer has the characteristics of high precision, high load-bearing capacity, large transmission ratio, etc. The flexible thin-wall bearing is one of the core components of the harmonic reducer and plays a crucial role in the overall performance of the harmonic reducer. Under normal working conditions, the flexible thin-wall bearing has to bear both the elastic deformation with the elliptical wave generator and the alternating stress generated by its own characteristics. In addition, under non-ideal conditions, it also has to bear the static or dynamic load from the outside. Therefore, during the research and development process of the flexible thin-wall bearing, its stability, accuracy, and service life should be tested, and only after all performance indicators meet the requirements can it be put into industrial production, thus solving the industrialization problem of domestic industrial robots.

[0003] As a key component of the harmonic reducer, the rotational accuracy and stability of the flexible thin-wall bearing under different working conditions play an important role in the overall performance of the harmonic reducer. The flexible thin-wall bearing deforms from the original circular cross-section to an elliptical cross-section. Therefore, when simulating the performance of the flexible thin-wall bearing under actual working conditions, the flexible thin-wall bearing needs to be fixed on an elliptical camshaft. Li Weiguang et al. disclosed a drive shaft assembly for sequential tests of flexible thin-wall bearings in Chinese invention patent CN108692940A. The drive shaft assembly includes a power connection member, a clamping device, and a number of bearing mounting kits connected in sequence. The power connection member includes a spindle tool holder and a pull stud threadedly connected to the front end of the spindle tool holder. A conical frustum connected to the bearing mounting kit is provided at the rear end of the spindle tool holder, and a threaded hole is provided at the center of the rear end. The bearing mounting kit includes a hollow bearing mounting socket, a rear retaining ring, a front retaining ring, a bearing locking bolt, and a set screw nut. A tapered hole is provided at the front end of the bearing mounting socket, a conical frustum is provided at the rear end, and an elliptical shoulder for press-fitting and mounting a thin-wall bearing is provided on the outer peripheral wall of the middle part. The tapered hole and the conical frustum are respectively an elliptical tapered hole and an elliptical conical frustum with an elliptical cross-section. This technical solution realizes connection and transmission through the elliptical conical frustum and the elliptical tapered hole. However, although the elliptical conical frustum can better transmit rotational power, its bearing capacity for radial and axial forces is limited, and at the same time, the requirement for installation accuracy is relatively high. Summary of the Invention

[0004] In order to solve at least one of the problems existing in the prior art, the present invention provides a test shaft member for testing multiple flexible thin-wall bearings. Through the cooperation of a square groove and a square platform for transmission, it can not only transmit motion while bearing radial and axial forces, but also has relatively low requirements for installation accuracy. The cooperation between the square platform and the square groove is tight, with a small transmission clearance and low power loss. When using the test shaft member of the present invention for testing, it is efficient, convenient, flexible, stable and highly reliable, and can be applied to simulate the actual working conditions of a series of deformations of flexible thin-wall bearings in a harmonic reducer, so as to simulate various tests on them.

[0005] The present invention can test multiple flexible thin-wall bearings simultaneously. In addition, it is convenient to test various performances of the bearings.

[0006] To achieve the purpose of the present invention, a test shaft member for testing multiple flexible thin-wall bearings provided by the present invention includes a connecting element, a test shaft positioning device and a plurality of bearing fixing elements. The plurality of bearing fixing elements are located between the connecting element and the test shaft positioning device. The test shaft positioning device penetrates through each bearing fixing element and is connected to the connecting element; the connecting element includes a main shaft element, and one end of the main shaft element is provided with a square platform for connecting and cooperating with the bearing fixing element;

[0007] Each bearing fixing element includes a bearing mounting seat. Square platforms and square grooves are respectively arranged at both ends of the bearing mounting seat. Adjacent bearing fixing elements are cooperated through the square platform and the square groove, and the bearing fixing element closest to the main shaft element is cooperated with the square platform of the main shaft element through the square groove.

[0008] For a further improvement of the present invention, the test shaft positioning device includes a clamping bolt. A threaded hole is concavely arranged on the square platform of the main shaft element. The clamping bolt sequentially penetrates through each bearing fixing element and is connected and fixed to the main shaft element through the threaded hole.

[0009] For a further improvement of the present invention, the connecting element further includes a connecting piece, and the connecting piece is connected to the other end of the main shaft element.

[0010] Preferably, the connecting piece is a blind rivet.

[0011] Preferably, a threaded hole is also arranged at the other end (head) of the main shaft element, and the connecting piece is threadedly connected to the head of the conical shaft.

[0012] Preferably, the front part of the main shaft element is a conical shaft.

[0013] Preferably, the threaded hole is located on the central axis of the main shaft element, and each bearing mounting seat is provided with a central hole. During assembly, the threaded hole and the central hole are located on the same straight line.

[0014] For a further improvement of the present invention, a trapezoidal groove facilitating assembly and disassembly is provided on the main shaft element.

[0015] For a further improvement of the present invention, an oval shoulder for positioning a flexible thin-wall bearing is provided on the bearing mounting seat.

[0016] Preferably, the oval shoulder is provided at the middle section of the bearing mounting seat.

[0017] For a further improvement of the present invention, the thickness of the oval shoulder is 0.01 - 0.03 mm greater than the inner ring thickness of the flexible thin-wall bearing.

[0018] For a further improvement of the present invention, the bearing fixing element further includes a front side retaining ring, a rear side retaining ring, a locking bolt and a set screw. The front side retaining ring and the rear side retaining ring are respectively arranged on both sides of the oval shoulder on the bearing mounting seat and are fixed by the locking bolt and the set screw.

[0019] Furthermore, the oval shoulder, the front side retaining ring and the rear side retaining ring are all provided with bolt holes distributed circumferentially for cooperating with the locking bolt.

[0020] For a further improvement of the present invention, a step facilitating fixation is provided on one side of the rear side retaining ring that fits with the flexible thin-wall bearing.

[0021] For a further improvement of the present invention, the cross-sections of the square groove and the square platform are both square. The mutual cooperation of the square groove and the square platform can achieve a larger torque transmission and concentric positioning with the bearing fixing element.

[0022] Furthermore, the gradient ratio of the square groove and the square platform is 1:2.

[0023] For a further improvement of the present invention, the test shaft positioning device further includes a gasket and a spring washer. The clamping bolt sequentially passes through each bearing fixing element, the gasket and the spring washer and is threadedly connected to the threaded hole at the rear of the main shaft element to form an integral body.

[0024] For a further improvement of the present invention, the rear part of the main shaft element is a conical shaft with a taper ratio of 1:3.

[0025] For a further improvement of the present invention, a conical hole for positioning is provided at the center of the rear part of the clamping bolt.

[0026] For a further improvement of the present invention, the taper ratio of the conical hole of the clamping bolt is 1:4.

[0027] Compared with the prior art, the present invention can at least achieve the following beneficial effects:

[0028] (1) The present invention uses a square groove and a square platform for cooperative transmission, which can not only transmit motion while bearing radial force and axial force, but also has relatively low requirements for installation accuracy. The cooperation between the square platform and the square groove is closer, with a small transmission clearance and low power loss.

[0029] (2) The present invention can achieve the installation and fixation of several flexible thin-walled bearings, is suitable for simulating the actual situation of flexible thin-walled bearings in a harmonic reducer, and further tests them. At the same time, the bearing fixing element adopts a modular design, and the number of elements for fixing bearings can be increased or decreased according to test requirements, increasing the flexibility and accuracy of the test. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. It should be noted that: Similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Among them:

[0031] Figure 1 Is an isometric structural schematic diagram of a test shaft part for testing multiple flexible thin-walled bearings provided by an embodiment of the present invention.

[0032] Figure 2 Is a front view schematic diagram of a test shaft part for testing multiple flexible thin-walled bearings provided by an embodiment of the present invention.

[0033] Figure 3 Is Figure 2 A cross-sectional schematic diagram in the A-A direction in

[0034] Figure 4 Is Figure 2 A cross-sectional schematic diagram in the B-B direction in

[0035] Figure 5 Is Figure 2 A cross-sectional schematic diagram in the C-C direction in

[0036] Figure 6 Is a front view schematic diagram of the bearing fixing element provided by an embodiment of the present invention.

[0037] As shown in the figure: 1 - connecting piece, 2 - main shaft element, 3 - set screw, 4 - front side retaining ring, 5 - bearing mounting seat, 6 - flexible thin-walled bearing, 7 - rear side retaining ring, 8 - locking bolt, 9 - gasket, 10 - spring washer, 11 - clamping bolt. Detailed implementation mode

[0038] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the meaning of order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0040] As Figures 1 to 6 shown, a test shaft member for multiple flexible thin-wall bearing tests provided by an embodiment of the present invention includes a connecting element, a test shaft positioning device, and a plurality of bearing fixing elements. The plurality of bearing fixing elements are located between the connecting element and the test shaft positioning device. The test shaft positioning device passes through the central holes of the bearing fixing elements and is connected to the connecting element, connecting the connecting element, the test shaft positioning device, and the plurality of bearing fixing elements into an integrated body.

[0041] The connecting element includes a main shaft element 2 and a connecting member 1. The rear part of the main shaft element 2 is a square platform for connecting and cooperating with the bearing fixing element. A threaded hole is provided at the center of the rear part of the main shaft element 2. The connecting member 1 is threadedly connected to the head of the main shaft element 2, and the connecting member 1 is used to connect to an external input device.

[0042] Each of the bearing fixing elements includes a bearing mounting seat 5. Square platforms and square grooves are respectively provided at both ends of the bearing mounting seat 5. Adjacent bearing fixing elements are matched through the square platforms and the square grooves. The bearing fixing element closest to the spindle element 2 is matched with the square platform on the spindle element 2 through the square groove. The flexible thin-walled bearing 6 will bear radial force and axial force simultaneously during the test. Through the cooperation of the square platform and the square groove, it can better bear radial and axial forces while transmitting motion.

[0043] In one embodiment of the present invention, the connecting member 1 is a blind rivet. The front part of the connecting member 1 is a conical shaft, and the blind rivet is connected by thread to the head of the conical shaft.

[0044] In one embodiment of the present invention, the rear part of the spindle element 2 is a conical shaft with a taper ratio of 1:3.

[0045] In one embodiment of the present invention, a trapezoidal groove for easy installation and disassembly is provided in the middle of the spindle element 2.

[0046] In one embodiment of the present invention, each of the bearing fixing elements further includes a front side retaining ring 4, a rear side retaining ring 7, a locking bolt 8 and a set nut 3. A square groove is provided at the front part of the bearing mounting seat 5, a square platform is provided at the rear part of the bearing mounting seat 5, and an oval shoulder for positioning the flexible thin-walled bearing 6 is provided in the middle of the bearing mounting seat 5. The front side retaining ring 4 and the rear side retaining ring 7 are fixed by the locking bolt 8 and the set nut 3, and the front side retaining ring 4 and the rear side retaining ring 7 are respectively arranged on both sides of the oval shoulder on the bearing mounting seat 5. The axial movement of the flexible thin-walled bearing 6 is restricted through the cooperation of the front side retaining ring 4 and the rear side retaining ring 7.

[0047] In one embodiment of the present invention, the thickness of the oval shoulder is 0.01 - 0.03 mm larger than the inner ring thickness of the flexible thin-walled bearing 6.

[0048] In one embodiment of the present invention, the square platform and the square hole are both a square platform and a square groove with a square cross-section. The gradient ratio of the square groove and the square platform is 1:2. The cooperation of the square platform and the square groove can achieve larger torque transmission and concentric positioning with the bearing fixing element.

[0049] In one embodiment of the present invention, a step for easy fixing is provided on the side of the rear side retaining ring 7 that is in contact with the flexible thin-walled bearing 6 to prevent the cage of the flexible thin-walled bearing 6 from slipping during the test.

[0050] In one embodiment of the present invention, six bolt holes distributed circumferentially for cooperating with the locking bolt 8 are provided on the elliptical shoulder, the front retaining ring 4, and the rear retaining ring 7.

[0051] In one embodiment of the present invention, the test shaft positioning device includes a gasket 9, a spring washer 10, and a clamping bolt 11. The clamping bolt 11 sequentially passes through the spring washer 10, the gasket 9, and each of the bearing fixing elements, and the front part of the clamping bolt 11 is integrally connected to the threaded hole at the rear of the main shaft element 2 by threading.

[0052] In one embodiment of the present invention, a tapered hole with a taper ratio of 1:4 is provided at the center of the rear part of the clamping bolt 11 to facilitate quick and accurate positioning, increasing the accuracy and stability of the test.

[0053] In the foregoing embodiments of the present invention, the number of the bearing fixing elements can be increased or decreased according to actual test requirements, and the clamping bolt 11 can also be processed into different specifications of lengths according to the number of the bearing fixing elements, which is applicable to different test schemes. As Figure 3 shown, during installation, two adjacent bearing mounts 5 are connected end to end by interference fit, and the cooperation between the square hole and the square platform can realize the synchronous rotation of several bearing fixing elements. The elliptical shoulder can sequentially fix each flexible thin-walled bearing 6 on the corresponding bearing fixing element, thereby simulating the actual working conditions of the flexible thin-walled bearing and adapting to different test requirements.

[0054] The foregoing embodiments of the present invention are applicable to the test of flexible thin-walled bearings, can be connected with an electric spindle in a matching manner, are convenient for installation and disassembly, and are safe and reliable in operation. At the same time, the number of bearing fixing elements can be flexibly increased or decreased according to actual needs to meet the test requirements under different conditions, increasing the applicability and reliability of the test.

[0055] In the foregoing embodiments of the present invention, by fixing the flexible thin-walled bearing 6 on the elliptical shoulder of the bearing mount 5, it is applicable to simulating the actual working conditions of the flexible thin-walled bearing in a harmonic reducer. The structure of this test shaft part is simple and compact, convenient for installation and disassembly, and increases the flexibility and accuracy of the test.

[0056] The above embodiments are only preferred examples of the present invention, and are not limitations on the implementation manners of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention are all included within the protection scope of the claims of the present invention.

Claims

1. A test shaft component for multiple flexible thin-walled bearing tests, comprising a connecting element, a test shaft positioning device, and a plurality of bearing fixing elements. The plurality of bearing fixing elements are located between the connecting element and the test shaft positioning device. The test shaft positioning device penetrates through each bearing fixing element and is connected to the connecting element; characterized in that, The connecting element described above includes a spindle element (2), and one end of the spindle element (2) is provided with a square platform for connecting and cooperating with the bearing fixing element; Each bearing fixing element includes a bearing mounting seat (5). Square platforms and square grooves are respectively arranged at both ends of the bearing mounting seat (5). Adjacent bearing fixing elements are cooperated through the square platforms and the square grooves, and the bearing fixing element closest to the spindle element (2) is cooperated with the square platform of the spindle element (2) through the square groove.

2. The test shaft part for testing multiple flexible thin-wall bearings according to claim 1, characterized in that, The test shaft positioning device includes a clamping bolt (11). A threaded hole is concavely arranged on the square platform of the spindle element (2). The clamping bolt (11) sequentially penetrates through each bearing fixing element and is connected and fixed to the spindle element (2) through the threaded hole.

3. The test shaft part for testing multiple flexible thin-walled bearings according to claim 1, characterized in that, The connecting element described above further includes a connecting piece (1), and the connecting piece (1) is connected to the other end of the spindle element (2).

4. A test shaft member for testing multiple flexible thin-walled bearings according to claim 1, characterized in that, Trapezoidal grooves facilitating assembly and disassembly are arranged on the spindle element (2).

5. A test shaft member for testing multiple flexible thin-walled bearings according to claim 1, characterized in that Oval shoulders are arranged on the bearing mounting seat (5).

6. A test shaft member for testing multiple flexible thin-wall bearings according to claim 5, characterized in that, The thickness of the oval shoulder is 0.01 - 0.03 mm larger than the inner ring thickness of the flexible thin-wall bearing (6).

7. A test shaft member for testing multiple flexible thin-wall bearings according to claim 5, characterized in that, The bearing fixing element further includes a front side retaining ring (4), a rear side retaining ring (7), a locking bolt (8) and a set nut (3). The front side retaining ring (4) and the rear side retaining ring (7) are respectively arranged on both sides of the oval shoulder on the bearing mounting seat (5) and are fixed through the locking bolt (8) and the set nut (3).

8. A test shaft member for multiple flexible thin-wall bearing tests according to claim 7, characterized in that, A step facilitating fixation is arranged on one side of the rear side retaining ring (7) that fits the flexible thin-wall bearing (6).

9. A test shaft member for testing multiple flexible thin-walled bearings according to any one of claims 1-8, characterized in that: The cross-sections of the square groove and the square platform are both squares.

10. A test shaft member for testing multiple flexible thin-wall bearings according to claim 9, characterized in that: The gradient ratio of the square hole and the square platform is 1:2.

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