Sliding bearing swing test tool
Through the structure of the integral pin shaft and the outer shaft sleeve, the problem of fatigue and fracture of the pin shaft of the sliding bearing rocking test machine is solved, and the accuracy of long-term service life and friction factor detection is achieved, reducing costs.
Patent Information
- Application Number
- CN202421503506.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-27
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2034-06-27
AI Technical Summary
The pin shaft of the existing sliding bearing swing test machine is prone to microcracks at the steps after high-frequency quenching, resulting in fatigue fracture. The friction factor detection results are inaccurate under low-speed heavy load conditions, which cannot meet the long-term service life test requirements.
The integrated pin shaft or pin structure consisting of the shaft core and the outer sleeve is adopted, and the test bushing is fixed with the keyway and nut or elastic snap ring to avoid cracks at the steps, and the connection between the shaft core and the shaft core is optimized through the guidance angle and interference amount to ensure stability.
It improves the service life of the pin, reduces the production cost, ensures the stability of long-term use and the accuracy of friction factor detection, and meets the test needs under low-speed heavy load conditions.
Smart Images
Figure CN223217091U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of sliding bearing swing tests, in particular to a sliding bearing swing test tool. Background Art
[0002] Sliding bearings, such as inlaid bearings and powder metallurgy oil-impregnated bearings, are used in reciprocating rotations and under low and heavy loads. To ensure service life and friction and wear performance, long-term life tests are typically conducted using a swing tester under low-speed, heavy-load conditions. To ensure the proper distance between the test bushings at both ends, existing testing machines utilize a stepped shaft—a larger mating section and a smaller support section. Threaded ends are machined into the shaft, and the test bushings are secured by nuts and mating sections. Life test pins require a hard surface and a soft core, so they are treated with high-frequency quenching. However, due to the different microstructures of the quenched layer and the shaft core, as well as the stepped outer diameters of the mating and support sections, microcracks are easily generated during machining. This can lead to fatigue failure and shaft fracture under high loads, making them inadequate for long-term life testing. Furthermore, to improve shaft life, larger R-angles are machined in the mating and support sections. This introduces transmission lag during testing, resulting in significant wear between the shaft R-angle and the test bushings, distorting the friction coefficient test results for the pin and the sliding bearing. Utility Model Content
[0003] The purpose of the utility model is to provide a sliding bearing swing test fixture to solve the problems raised in the above background technology.
[0004] To achieve the above objectives, the present invention provides the following technical solutions:
[0005] A sliding bearing swing test fixture comprises a pin shaft and support parts located at both ends of the pin shaft;
[0006] The pin shaft includes an axis core, and the axis core is an optical axis structure or an outer axis sleeve is sleeved in the middle of the axis core.
[0007] As a further solution of the present invention: the support part includes a test bushing, the test bushing is sleeved on the end of the pin shaft, the outside of the test bushing is sleeved with a support body through a rolling bearing, and the rolling bearing is fixedly connected to the test bushing through a first nut.
[0008] As a further solution of the present invention: the test bushing and the shaft core are provided with a non-through keyway at the matching position, the test bushing is fixedly connected to the shaft core through a flat key and the non-through keyway, and the end of the shaft core is axially fixedly connected to the test bushing through a second nut
[0009] As a further solution of the present invention: the matching position of the test bushing and the shaft core is provided with a through keyway, the test bushing is fixedly connected to the shaft core through a flat key and a non-through keyway, and the second nut and the elastic retaining ring at the end of the shaft core are axially fixedly connected to the test bushing.
[0010] As a further solution of the present invention: the shaft core includes a fitting section in the middle and support sections at both ends, and the outer sleeve includes a non-quenched layer and a quenched layer arranged outside the non-quenched layer.
[0011] As a further solution of the present invention: an outer sleeve is sleeved on the outside of the fitting section, and the outer sleeve is fixedly connected to the fitting section through a transition fit.
[0012] As a further solution of the present invention: the outer side of the mating section is sleeved with an outer shaft sleeve, the outer side of the mating section is provided with a first keyway, the inner wall of the non-quenched layer of the outer shaft sleeve is provided with a second keyway, and the mating section and the outer shaft sleeve are fixedly connected by the first keyway, the second keyway and the connecting key.
[0013] As a further solution of the present invention: the diameter of the supporting segment is smaller than the diameter of the matching segment, and a guide angle is provided at the connection between the supporting segment and the matching segment, and the guide angle is a chamfered angle.
[0014] As a further solution of the present invention: the supporting section is connected to the supporting portion, and a fixing section is provided on the outer side of the supporting section.
[0015] As a further solution of the present invention: the middle portion of the pin shaft is used for a sliding bearing for sleeve belt testing, and the outside of the sliding bearing is connected to a load body through a middle bushing.
[0016] Compared with the prior art, the beneficial effects of the present invention are:
[0017] 1. The pin shaft of the present application uses an integral pin shaft or a pin shaft composed of an axis core and an outer sleeve, which solves the problem of easy fatigue fracture and low service life of the high-frequency quenched step shaft, and meets the requirements of long-term service life testing; the integral pin shaft and the pin shaft composed of an axis core and an outer sleeve will not have the problem of high-frequency quenched step shaft having cracks at the step during quenching, which will cause the pin shaft to be scrapped, thereby reducing the production cost of the pin shaft.
[0018] 2. The present application adopts the method of fixing the position of the test bushing by the inner wall of the keyway and the nut or by the elastic retaining ring and the nut, thereby avoiding the large wear between the R angle and the test bushing in the existing method, and reducing the impact on the test results of the friction factor of the pin shaft and the sliding bearing; the shaft core matching section is provided with a guide angle, and the sleeve is easy to install; the conditions of the swing test are low speed and heavy load, and the torque is very large during the test. The non-guide area of the outer sleeve and the shaft core matching section is selected with a larger interference fit or a key connection to avoid slipping of the outer sleeve and the shaft core during the test. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the structure in which the test bushing and the pin are connected via a nut;
[0020] Figure 2 This is a schematic diagram of the connection structure between the test bushing and the pin shaft through a nut and a spring snap ring;
[0021] Figure 3 This is a schematic diagram of a transition fit pin structure consisting of a shaft core and an outer sleeve;
[0022] Figure 4 This is a schematic diagram of a pin shaft structure consisting of a shaft core and an outer sleeve with two key connections.
[0023] In the figure: 1-pin, 2-middle bushing, 3-sliding bearing, 4-flat key, 5-test bushing, 6-first nut, 7-second nut, 8-elastic snap ring, 9-support body, 10-rolling bearing, 11-load body, 110-shaft core, 111-matching section, 112-support section, 113-fixed section, 114-guide angle, 115-first keyway, 120-outer sleeve, 121-quenching layer, 122-non-quenching layer, 123-second keyway. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0025] See also Figure 1-4A sliding bearing swing test fixture includes a pin shaft 1 and support parts at both ends of the pin shaft 1. The middle part of the pin shaft 1 is used for sleeve-type sliding bearings 3 for belt testing. The outside of the sliding bearing 3 is connected to a load body through a middle bushing 2. The support part includes a test bushing 5, which is sleeved on the end of the shaft core 110. The outside of the test bushing 5 is sleeved with a support body 9 through a rolling bearing 10. The test bushing 5 is fixedly connected to the shaft core 110 through a flat key 4. The end of the shaft core 110 is axially fixedly connected to the test bushing 5 through a second nut 7 or a second nut 7 and an elastic retaining ring 8. The rolling bearing 10 is fixedly connected to the test bushing 5 through a first nut 6.
[0026] The pin shaft 1 includes an axis core 110, which includes a mating section 111 in the middle and support sections 112 at both ends. The support section 112 is connected to the support part, and a fixed section 113 is provided on the outside of the support section 112. The axis core 110 is an optical axis structure or an outer shaft sleeve 120 is sleeved in the middle of the axis core 110.
[0027] When the outer sleeve 120 is sleeved on the middle part of the shaft core 110, the outer sleeve 120 is sleeved on the outside of the mating section 111, and the outer sleeve 120 is fixedly connected to the mating section 111 through a transition fit. The outer sleeve 120 is sleeved on the outside of the mating section 111, and a first keyway 115 is provided on the outside of the mating section 111. The outer sleeve 120 includes a non-quenched layer 122 and a quenched layer 121 arranged outside the non-quenched layer 122. The inner wall of the non-quenched layer 122 of the outer sleeve 120 is provided with a second keyway 123. The mating section 111 and the outer sleeve 120 are fixedly connected by the first keyway 115, the second keyway 123 and the connecting key. The diameter of the support section 112 is smaller than the diameter of the mating section 111. A guide angle 114 is provided at the connection between the support section 112 and the mating section 111, and the guide angle 114 is a chamfered corner.
[0028] Example 1
[0029] An assembly for a sliding bearing swing test includes a test bushing 5, a pin 1, a flat key 4, a sliding bearing 3 to be tested, a middle bushing 2, a rolling bearing 10, a load body 11, and a support body 9. The sliding bearing 3 is pressed into the middle bushing 2, with the sliding bearing 3 and the middle bushing 2 having a transitional fit. The middle bushing 2 is fastened to the load body 11 via a pin. The test bushing 5 has a slight transitional fit with the rolling bearing 10, which is fastened to the test bushing 5 using a first nut 6. The rolling bearing 10 has a transitional fit with the support body 9. The pin 1 passes through the test bushing 5, and the bearing hole of the rolling bearing 10 is connected to the test bushing 5 via a flat key 4. A non-through keyway is machined in the test bushing 5, and the position of the test bushing 5 is fixed by the inner wall of the keyway and the nut 6.
[0030] Pin 1 is an integral optical shaft. The outer diameter of the integral optical shaft matching section and the supporting section is 70mm. It is first tempered and then high-frequency quenched. The tempered hardness is 290-320HBW, the quenched layer hardness is 55-60HRC, and the quenched layer thickness is 1.5mm.
[0031] Example 2
[0032] An assembly for a sliding bearing swing test includes a test bushing 5, a pin 1, a flat key 4, a test sliding bearing 3, a middle bushing 2, a rolling bearing 10, a load body 11, and a support body 9. The test sliding bearing 3 is pressed into the middle bushing 2, with the test sliding bearing 3 and the middle bushing 2 having a transitional fit. The middle bushing 2 is fastened to the load body 11 via a pin. The test bushing 5 has a slight transitional fit with the rolling bearing 10, which is fastened to the test bushing 5 using a nut 6. The rolling bearing 10 has a transitional fit with the support body 9. The pin 1 passes through the test bushing 5, the bearing hole of the rolling bearing 10, and is connected to the test bushing via a flat key. A through keyway and a snap ring groove are machined on the test bushing 5. The test bushing is fixed in place by the inner wall of the keyway and a nut, or by an elastic snap ring and nut.
[0033] The pin 1 consists of a shaft core 110 and an outer sleeve 120. The outer diameter of the mating section 111 of the shaft core 110 is 61 mm, and the outer diameter of the supporting section 112 of the shaft core 110 is 55 mm. A 40° guide angle is provided at both ends of the mating section 111. The axial distance of the guide angle is 3 mm, the guide part has a smooth transition, and the support section 112 is provided with a keyway; the thickness of the outer sleeve is 9 mm, the thickness of the quenching layer is 1.5 mm, the hardness of the quenching layer is 55-60 HRC, and the width of the outer sleeve is 70 mm.
[0034] Comparative Example 1
[0035] The mating shaft is an integral type, including a mating section and a supporting section. The mating shaft is subjected to advanced quenching and tempering treatment, with a quenching and tempering hardness of 290-320HBW. The mating section is then subjected to high-frequency quenching treatment, with a quenching layer thickness of 1.5mm and a quenching layer hardness of 55-60HRC.
[0036] The outer diameter of the supporting section of the mating shaft is 55mm, the outer diameter of the mating section is 70mm, and a 40° guide angle is set at both ends of the mating section. The axial distance of the guide angle is 3mm, the guide part has a smooth transition, and the support section is provided with a keyway; the width of the non-guide area of the mating section is 70mm.
[0037] Comparing the service life of Example 1, Example 2, and Comparative Example 1, the service life of the mating shaft was tested on a swing tester under the following test conditions: load 65 MPa, swing angle ±90°, cycle number 2.5 times / min, test time 100h, and the test results are as follows:
[0038] Is the mating shaft broken? Mating shaft fracture time Example 1 no - Example 2 no - Comparative Example 1 yes 36h
[0039] The test results show that the life of the mating shaft in Example 1 is at least 1.7 times longer than that in Comparative Example 1.
[0040] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.
[0041] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
Claims
1. A sliding bearing swing test fixture, characterized in that: It comprises a pin shaft (1) and support parts located at both ends of the pin shaft (1); The pin shaft (1) comprises a shaft core (110), wherein the shaft core (110) is an optical shaft structure or an outer shaft sleeve (120) is sleeved in the middle of the shaft core (110); The support portion includes a test bushing (5), the test bushing (5) is sleeved on the end of the pin shaft (1), the outside of the test bushing (5) is sleeved with a support body (9) via a rolling bearing (10), and the rolling bearing (10) is fixedly connected to the test bushing (5) via a first nut (6).
2. A sliding bearing swing test fixture according to claim 1, characterized in that: A non-through keyway is provided at the matching position of the test bushing (5) and the shaft core (110); the test bushing (5) is fixedly connected to the shaft core (110) via a flat key (4) and the non-through keyway; and the end of the shaft core (110) is axially fixedly connected to the test bushing (5) via a second nut (7).
3. The sliding bearing swing test fixture according to claim 1, characterized in that: A through keyway is provided at the matching position of the test bushing (5) and the shaft core (110); the test bushing (5) is fixedly connected to the shaft core (110) via a flat key (4) and a non-through keyway; a second nut (7) and an elastic retaining ring (8) at the end of the shaft core (110) are axially fixedly connected to the test bushing (5).
4. The sliding bearing swing test fixture according to claim 1, characterized in that: The shaft core (110) includes a matching section (111) in the middle and supporting sections (112) at both ends; the outer sleeve (120) includes a non-quenched layer (122) and a quenched layer (121) arranged outside the non-quenched layer (122).
5. The sliding bearing swing test fixture according to claim 4, characterized in that: An outer shaft sleeve (120) is sleeved on the outside of the fitting section (111), and the outer shaft sleeve (120) is fixedly connected to the fitting section (111) through transition fitting.
6. The sliding bearing swing test fixture according to claim 4, characterized in that: The outer sleeve (120) is sleeved on the outside of the mating section (111), a first keyway (115) is provided on the outer side of the mating section (111), a second keyway (123) is provided on the inner wall of the non-quenched layer (122) of the outer sleeve (120), and the mating section (111) and the outer sleeve (120) are fixedly connected via the first keyway (115), the second keyway (123) and a connecting key.
7. The sliding bearing swing test fixture according to claim 4, characterized in that: The diameter of the supporting section (112) is smaller than the diameter of the matching section (111); a guide angle (114) is provided at the connection between the supporting section (112) and the matching section (111); and the guide angle (114) is a rounded angle.
8. The sliding bearing swing test fixture according to claim 4, characterized in that: The supporting section (112) is connected to the supporting portion, and a fixing section (113) is provided on the outer side of the supporting section (112).
9. The sliding bearing swing test fixture according to claim 1, characterized in that: The middle part of the pin shaft (1) is used for sleeve-jointing a sliding bearing (3) for belt testing, and the outside of the sliding bearing (3) is connected to a load body (11) via a middle bushing (2).