Connecting structure of flat key to spline

Abstract

The utility model relates to the technical field of mechanical connection structures, in particular to a flat key-to-spline connection structure, which mainly solves the technical problem that the connection effect and the structural strength cannot be both considered when an existing shaft with a smaller outer diameter is connected by adopting a flat key. The connecting structure of the flat key to the spline comprises a shaft and a connecting shaft, wherein the shaft comprises a main body shaft section, a mounting shaft section and a connecting shaft section of which the diameters are sequentially reduced; the spline wheel sleeves the outer side of the mounting shaft section and is positioned through a flat key; the fastening assembly is screwed and fixed on the connecting shaft section and is used for pressing the spline wheel on the shaft shoulder between the main body shaft section and the mounting shaft section along the axial direction; the shaft sleeve is connected to the outer side of the spline wheel in a sleeving mode and positioned through a spline. The connecting structure can overcome key groove deformation caused by stress concentration of flat key connection, so that the connecting effect is guaranteed, meanwhile, key grooves do not need to be additionally formed in the gear shaft, and the structural strength of the gear shaft can also be guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical connection structures, in particular to a connection structure of a flat key to a spline. Background Art

[0002] The connection method of a certain existing lubricating oil pump product and a test device is as follows: the gear shaft of the lubricating oil pump and the shaft sleeve of the test device are connected through a flat key to transmit torque.

[0003] This connection structure will generate a large stress concentration at the end of the flat keyway on the gear shaft, so the keyway of the gear shaft is prone to deformation, resulting in loose connection and affecting the connection effect. To overcome this defect, people in this field have tried to use a connection method of double flat keys symmetrically distributed or splines, but both double flat keys symmetrically distributed and splines require adding keyways on the gear shaft, and the outer diameter of the gear shaft is small. Adding a keyway easily leads to a decrease in the structural strength of the gear shaft, so it is not feasible.

[0004] Therefore, there is an urgent need for a connection structure that can avoid keyway deformation while ensuring the structural strength of the gear shaft. Utility Model Content

[0005] In order to overcome the technical defect that the connection effect and the structural strength cannot be taken into account at the same time when the shaft with a smaller outer diameter is connected by a flat key, the utility model provides a flat key to spline connection structure.

[0006] The utility model provides a flat key to spline connection structure, comprising:

[0007] A shaft, comprising a main shaft section, a mounting shaft section and a connecting shaft section with successively decreasing diameters, wherein the mounting shaft section is provided with a first flat keyway, and the connecting shaft section is provided with an external thread;

[0008] A spline wheel, whose inner circumference is provided with a second flat key groove adapted to the first flat key groove, the spline wheel is sleeved on the outer side of the mounting shaft section and positioned by a flat key embedded in the first flat key groove and the second flat key groove, and an outer circumference of the spline wheel is provided with an external spline;

[0009] A fastening assembly, which is threadedly fixed on the connecting shaft section and is used to axially press the spline wheel onto the shaft shoulder between the main shaft section and the mounting shaft section;

[0010] The inner circumference of the shaft sleeve is provided with an internal spline matched with the external spline. The shaft sleeve is sleeved on the outer side of the spline wheel and is positioned by the external spline and the internal spline.

[0011] Optionally, the axial length of the mounting shaft segment is smaller than the axial length of the spline wheel.

[0012] Optionally, the axial length of the inner spline is greater than the axial length of the outer spline.

[0013] Optionally, the outer peripheral surface diameter of the spline wheel is larger than the diameter of the main shaft section.

[0014] Optionally, the fastening assembly includes a fastening nut and a flat washer, the fastening nut is threaded on the connecting shaft section, and the flat washer is pressed between the fastening nut and the spline wheel.

[0015] Optionally, the fastening assembly further includes a spring washer, and the spring washer is pressed between the flat washer and the fastening nut.

[0016] Optionally, the shaft is a gear shaft of a lubricating oil pump, and the shaft sleeve is a shaft sleeve of a test device.

[0017] Compared with the prior art, the technical solution provided by the utility model has the following advantages:

[0018] The flat key-to-spline connection structure provided by the utility model is designed with a spline wheel, and the spline wheel is fixed on the installation shaft section by using a fastening assembly to cooperate with the external thread of the connecting shaft section, so that the spline wheel and the gear shaft form an integral structure that is jointly stressed. The formed integral structure is spline-connected with the sleeve of the test equipment, which can overcome the deformation of the keyway caused by the stress concentration of the flat key connection, thereby ensuring the connection effect. At the same time, there is no need to open an additional keyway on the gear shaft, and the structural strength of the gear shaft can also be ensured. In addition, since the gear shaft and the spline wheel form an integral structure, there will be no axial relative displacement between the gear shaft and the spline wheel, so this structure can also avoid wear on the outer peripheral surface of the gear shaft; and since the spline structure has good guiding performance, the wear between the spline wheel and the sleeve is also small. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings herein are incorporated in and constitute a part of the specification, illustrate embodiments consistent with the present utility model, and together with the description, are used to explain the principles of the present utility model.

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A cross-sectional view showing a connection structure of a flat key to a spline in an embodiment of the utility model;

[0022] Figure 2 A schematic diagram showing the structure of the shaft in the embodiment of the utility model;

[0023] Figure 3A schematic diagram showing the structure of a spline wheel in an embodiment of the utility model;

[0024] Figure 4 A schematic diagram showing the structure of a shaft sleeve in an embodiment of the utility model is shown.

[0025] In the figure:

[0026] 1. Shaft; 11. Main shaft section; 12. Mounting shaft section; 121. First flat keyway; 13. Connecting shaft section; 2. Spline wheel; 21. Second flat keyway; 22. Flat key; 23. External spline; 3. Fastening assembly; 31. Fastening nut; 32. Flat washer; 33. Spring washer; 4. Bushing; 41. Internal spline. DETAILED DESCRIPTION

[0027] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the scheme of the utility model will be further described below. It should be noted that the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

[0028] In the description, it should be noted that the terms “first” and “second” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] The specific embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0031] Reference Figure 1 This embodiment provides a flat key to spline connection structure, including a shaft 1, a spline wheel 2, a fastening assembly 3 and a sleeve 4. Among them, the shaft 1 includes a main shaft section 11, a mounting shaft section 12 and a connecting shaft section 13 with successively decreasing diameters, the mounting shaft section 12 is provided with a first flat key groove 121, and the connecting shaft section 13 is provided with an external thread; the inner circumference of the spline wheel 2 is provided with a second flat key groove 21 adapted to the first flat key groove 121, the spline wheel 2 is sleeved on the outer side of the mounting shaft section 12 and is positioned by a flat key 22 embedded in the first flat key groove 121 and the second flat key groove 21, and the outer circumference of the spline wheel 2 is provided with an external spline 23; the fastening assembly 3 is threadedly fixed on the connecting shaft section 13 and is used to axially press the spline wheel 2 on the shoulder between the main shaft section 11 and the mounting shaft section 12; the inner circumference of the sleeve 4 is provided with an internal spline 41 adapted to the external spline 23, the sleeve 4 is sleeved on the outer side of the spline wheel 2 and is positioned by the external spline 23 and the internal spline 41.

[0032] Specifically, the shaft 1 and the sleeve 4 adopt the following structure: the shaft 1 is the gear shaft 1 of the lubricating oil pump, and the sleeve 4 is the sleeve 4 of the test equipment. The gear shaft 1 is fixed with a gear on the main shaft section 11, and the sleeve 4 of the test equipment is divided into a double-cavity structure, that is, two cavities with different diameters are provided, the small-diameter cavity is provided with an internal spline 41 and cooperates with the installation shaft section 12, and the large-diameter cavity is used to connect the main shaft 1 of the experimental equipment. Of course, the connection structure of the flat key to the spline is not limited to this, and can also be used for connections in other scenarios. For example, the shaft 1 is a stepped shaft 1 of four or more levels and the main shaft section 11, the installation shaft section 12 and the connecting shaft section 13 are located in adjacent three-level shaft 1 sections, and the sleeve 4 is a single-cavity or three-cavity or more cavity structure.

[0033] Specifically, the relative lengths of the installation shaft section 12 and the spline wheel 2 are designed as follows: the axial length of the installation shaft section 12 is less than the axial length of the spline wheel 2. When the spline wheel 2 is sleeved on the installation shaft section 12, one axial end of the spline wheel 2 abuts against the shoulder between the main shaft section 11 and the installation shaft section 12, and the other end protrudes outward from the installation shaft section 12, which is more conducive to the clamping of the spline wheel 2 by the fastening component 3. Of course, the axial length of the installation shaft section 12 can also be equal to or greater than the axial length of the spline wheel 2, but the fastening component 3 needs to be equipped with a washer or other structure to make up for the length difference between the installation shaft section 12 and the spline wheel 2, so as to achieve the purpose of clamping the spline wheel 2.

[0034] Specifically, the relative lengths of the inner spline 41 and the outer spline 23 are designed as follows: the axial length of the inner spline 41 is greater than the axial length of the outer spline 23. It should be noted that the gear shaft 1 will be subjected to a certain axial force during the test, and the spline wheel 2 with the outer spline 23 and the gear shaft 1 have formed an integral structure through the fastening assembly 3, so the length of the inner spline 41 is designed to be greater than the length of the outer spline 23, which is more conducive to the axial movement of the overall structure; at the same time, the remaining space except for the space occupied by the inner spline 41 and the outer spline 23 can also be used to accommodate the fastening assembly 3, avoiding the influence of the fastening assembly 3 placed outside the inner spline 41 on the installation of other structures.

[0035] Specifically, the relative diameters of the spline wheel 2 and the main shaft section 11 are designed as follows: the outer diameter of the spline wheel 2 is larger than the diameter of the main shaft section 11. It should be noted that since the gear shaft 1 is subjected to a certain axial force during the test, the gear shaft 1 and the sleeve 4 will move axially, so the shoulder between the main shaft section 11 and the installation shaft section 12 in the existing connection structure is prone to frequent contact with the sleeve 4 to cause wear. In this structure, the outer diameter of the spline wheel 2 is designed to be larger than the diameter of the main shaft section 11, so that even if there is axial movement between the gear shaft 1 and the sleeve 4, the sleeve 4 will not contact the shoulder, thereby avoiding wear on the shoulder.

[0036] Specifically, the fastening assembly 3 adopts the following structure: the fastening assembly 3 includes a fastening nut 31 and a flat washer 32, the fastening nut 31 is threaded on the connecting shaft section 13, and the flat washer 32 is pressed between the fastening nut 31 and the spline wheel 2. It is easy to understand that the flat washer 32 can increase the pressing area of ​​the fastening nut 31, making the fixation more secure.

[0037] Furthermore, the fastening assembly 3 is provided with the following improved structure: the fastening assembly 3 further comprises a spring washer 33, which is pressed between the flat washer 32 and the fastening nut 31. The spring washer 33 can provide an axial pre-tightening force for the fastening nut 31, thereby preventing the fastening nut 31 from loosening.

[0038] The working principle of the flat key to spline connection structure of this embodiment is as follows:

[0039] When in use, first connect the spline wheel 2 to the mounting shaft section 12 through the flat key 22, then install the flat washer 32 and the spring washer 33 in sequence, then screw the fastening nut 31 onto the connecting shaft section 13 and press the spline wheel 2, and finally match the spline wheel 2 with the sleeve 4 through the external spline 23 and the internal spline 41.

[0040] The above is only a specific implementation of the utility model, so that those skilled in the art can understand or implement the utility model. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A flat key to spline connection structure, characterized in that: include: A shaft (1) comprising a main shaft section (11), a mounting shaft section (12) and a connecting shaft section (13) of successively decreasing diameters, wherein the mounting shaft section (12) is provided with a first flat keyway (121), and the connecting shaft section (13) is provided with an external thread; A spline wheel (2), the inner circumference of which is provided with a second flat key groove (21) adapted to the first flat key groove (121); the spline wheel (2) is sleeved on the outer side of the mounting shaft section (12) and positioned by a flat key (22) embedded in the first flat key groove (121) and the second flat key groove (21); and the outer circumference of the spline wheel (2) is provided with an external spline (23); A fastening assembly (3) which is threadedly fixed on the connecting shaft section (13) and is used to axially press the spline wheel (2) onto the shaft shoulder between the main shaft section (11) and the mounting shaft section (12); The shaft sleeve (4) has an inner circumferential surface provided with an inner spline (41) adapted to the outer spline (23); the shaft sleeve (4) is sleeved on the outer side of the spline wheel (2) and positioned by the outer spline (23) and the inner spline (41).

2. The flat key to spline connection structure according to claim 1, characterized in that: The axial length of the installation shaft section (12) is smaller than the axial length of the spline wheel (2).

3. The flat key to spline connection structure according to claim 1, characterized in that: The axial length of the internal spline (41) is greater than the axial length of the external spline (23).

4. The flat key to spline connection structure according to claim 1, characterized in that: The diameter of the outer peripheral surface of the spline wheel (2) is greater than the diameter of the main shaft section (11).

5. The flat key to spline connection structure according to claim 1, characterized in that: The fastening assembly (3) comprises a fastening nut (31) and a flat washer (32); the fastening nut (31) is threaded onto the connecting shaft section (13); and the flat washer (32) is pressed between the fastening nut (31) and the spline wheel (2).

6. The flat key to spline connection structure according to claim 5, characterized in that: The fastening assembly (3) further comprises a spring washer (33), wherein the spring washer (33) is pressed between the flat washer (32) and the fastening nut (31).

7. The flat key to spline connection structure according to any one of claims 1 to 6, characterized in that: The shaft (1) is a gear shaft (1) of a lubricating oil pump, and the shaft sleeve (4) is a shaft sleeve (4) of a test device.

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