Structure of built-in oil pipe of gearbox

Abstract

The utility model discloses a structure of a built-in oil pipe of a gearbox. The structure comprises a box body and the oil pipe, a box hole is formed in the box body; the device further comprises an oil sleeve. The oil pipe is arranged in the oil sleeve; the oil sleeve is arranged in a box hole in the box body; the oil sleeve is in interference fit with the box hole; the oil pipe is tightened and fixed in the oil sleeve; an oil pipe is tensioned in the pipe sleeve through a hydraulic pipe tensioning machine, the pipe wall of the oil pipe deforms and is clamped in the inner hole ring groove at the position of the inner hole ring groove, oil pipe loosening and inner leakage caused by axial movement of the oil pipe can be prevented, and it is guaranteed that the phenomena of inner leakage and pressure reduction caused by temperature change and vibration in the using process of a gearbox are avoided; therefore, friction plates are prevented from being burnt due to sudden pressure reduction of the gearbox, the reliability of the gearbox is improved, and the gearbox is simple in structural design, free of maintenance, high in reliability, high in operability and low in use cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of gearboxes, and in particular relates to a structure of a gearbox with a built-in oil pipe. Background Art

[0002] Domestic oil fracturing trucks primarily rely on imported power-shift transmissions. These transmissions inevitably include built-in oil pipes. In actual use, statistics show that power-shift transmission failures primarily occur due to friction plate burnout, oil leakage, and loose wiring harness connectors. Friction plate burnout is a key factor causing fracturing trucks to malfunction. Once the friction plates burn out, the transmission ceases to function, causing the fracturing pump to stop operating. This results in reduced flow and pressure in the fracturing pump manifold. Without a backup fracturing truck to provide timely replacement, the oil well could be abandoned, resulting in significant economic losses.

[0003] Therefore, fracturing trucks have very high requirements for the reliability of the transmission system, and the problem of burned friction plates is the core factor affecting reliability. From a large number of fault repairs and disassembly analyses, it was found that part of the cause of burned friction plates is related to the loosening of the built-in oil pipe. Figure 7 As shown, the fundamental reason for the loosening of the built-in oil pipe is that the oil pipe and the box hole are connected through an expansion process, the purpose of which is to create a small amount of interference between the oil pipe and the hole.

[0004] However, in actual use, the fracturing pump's piston moves frequently, and the vibrations generated by pumping the mud-water mixture can impact the internal tubing. Furthermore, due to the different materials of the casing and tubing, their coefficients of thermal expansion are also inconsistent. When the temperature rises above 100°C, the thermal expansion difference between the casing and tubing results in insufficient friction in the tubing, making it unable to withstand the pressure within the tubing, causing it to loosen and leak. Utility Model Content

[0005] In order to solve the technical problems that when the transmission of an oil fracturing vehicle works in a harsh environment (high-frequency vibration), the built-in oil pipe is prone to loosening, internal leakage increases, gear pressure decreases, resulting in friction plate burning, and maintenance is difficult and the reliability is low, the utility model provides a structure for the built-in oil pipe of the transmission.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] A structure for a gearbox with a built-in oil pipe comprises a housing and an oil pipe; a housing is provided with a housing hole; and an oil casing; the oil pipe is arranged inside the oil casing; the oil casing is arranged inside the housing hole on the housing; the oil casing and the housing hole are interference fit; and the oil pipe is tightened and fixed inside the oil casing.

[0008] Furthermore, the box body is provided with a sinking opening corresponding to the box hole, and the sinking opening is a circular structure; an outer convex ring block is fixed to the upper end of the oil casing.

[0009] Furthermore, the outer diameter of the outer convex ring block is slightly larger than the inner diameter of the sinking opening, and the interference error between the outer convex ring block and the sinking opening is 0.01mm-0.05mm.

[0010] Furthermore, the box body is provided with a first chamfer at an inner peripheral position corresponding to the lower portion of the sinking opening, and the angle of the first chamfer is 45°.

[0011] Furthermore, the peripheral edges of the upper and lower sides of the outer convex ring block are both provided with second chamfers, and the angle of the second chamfer is 45°.

[0012] Furthermore, an inner ring groove is provided inside the oil casing, and the upper end surface of the inner ring groove coincides with the lower end surface of the outer convex ring block.

[0013] Furthermore, the outer wall of the upper end of the oil pipe is provided with an outer convex portion corresponding to the inner hole ring groove through the hydraulic pipe expansion process, and the outer convex portion has a circular structure; the inner wall of the upper end of the oil pipe is provided with an inner concave portion corresponding to the inner hole ring groove through the hydraulic pipe expansion process.

[0014] Furthermore, the inner concave portion is a circular structure; the outer convex portion and the inner concave portion have the same specifications, and the outer convex portion and the inner hole ring groove fit together.

[0015] Furthermore, a sleeve portion is provided at the lower end of the oil casing, which has a trapezoidal structure. The inner inclined surface of the trapezoidal structure has an angle of 45° with the inner wall of the oil casing, and the outer inclined surface has an angle of 30° with the outer wall of the oil casing.

[0016] Beneficial effects of the utility model:

[0017] 1) The utility model adds an oil casing with an inner ring groove structure that has an interference fit with the case hole, and uses a hydraulic pipe expander to tighten the oil pipe in the pipe casing. The oil pipe wall is deformed at the inner ring groove position and is stuck in the inner ring groove, which can prevent the oil pipe from axial movement and causing loosening of the oil pipe and internal leakage. It ensures that the gearbox will not leak internally due to temperature changes and vibrations during use, causing pressure drop, thereby avoiding the gearbox from burning the friction plate due to sudden pressure drop, thereby improving the reliability of the gearbox. It has a simple structural design, is maintenance-free, has high reliability, strong operability, and low cost.

[0018] 2) The utility model provides a sleeve portion at the lower end of the oil casing. The inner inclined surface of the sleeve portion can be used to easily slide the oil pipe into the oil casing to complete the preliminary assembly; the outer inclined surface of the sleeve portion can be used to easily insert the oil casing together with the oil pipe into the heated box hole to complete the final assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a schematic diagram of the new heavy oil pipe and box hole after assembly;

[0021] Figure 2 It is a cross-sectional view of the utility model;

[0022] Figure 3 It is a cross-sectional view of the box body in the utility model;

[0023] Figure 4 This is a structural diagram of the oil casing of the utility model;

[0024] Figure 5 This is a cross-sectional view of the oil casing of the utility model;

[0025] Figure 6 This is a schematic diagram of the structure of the oil pipe in the utility model;

[0026] Figure 7 This is a cross-sectional view of the oil pipe and the box hole after assembly in the prior art;

[0027] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0028] 1. Box body; 101. Box hole; 102. Sinking mouth; 103. First chamfer; 2. Oil casing; 201. Outer convex ring block; 202. Second chamfer; 203. Inner hole ring groove; 204. Casing part; 3. Oil pipe; 301. Outer convex part; 302. Inner concave part. DETAILED DESCRIPTION

[0029] 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.

[0030] See also Figure 1 - Figure 2As shown, a structure of a gearbox with built-in oil pipes includes a gearbox body 1 of an oil fracturing truck, an oil casing 2, and an oil pipe 3; a box hole 101 is opened on the box body 1; the oil pipe 3 is arranged inside the oil casing 2, and the oil casing 2 is arranged inside the box hole 101 on the box body 1.

[0031] Please refer again Figure 3 As shown, the box body 1 is provided with a sinking opening 102 corresponding to the box hole 101, and the sinking opening 102 is a circular structure; the box body 1 is provided with a first chamfer 103 at the inner peripheral position corresponding to the lower part of the sinking opening 102, and the angle of the first chamfer 103 is 45°.

[0032] Please refer again Figure 4-Figure 5 As shown, an outer convex ring block 201 is fixed to the upper end of the oil casing 2. The outer diameter of the outer convex ring block 201 is slightly larger than the inner diameter of the sinking mouth 102. The interference error between the outer convex ring block 201 and the sinking mouth 102 is 0.01mm-0.05mm. The peripheral positions on the upper and lower sides of the outer convex ring block 201 are both provided with second chamfers 202, and the angle of the second chamfer 202 is 45°.

[0033] An inner ring groove 203 is formed inside the oil casing 2 , and the upper end surface of the inner ring groove 203 coincides with the lower end surface of the outer convex ring block 201 .

[0034] The lower end of the oil casing 2 is provided with a sleeve portion 204, which is a trapezoidal structure. The inner inclined surface of the trapezoidal structure is at an angle of 45° to the inner wall of the oil casing 2, and the outer inclined surface is at an angle of 30° to the outer wall of the oil casing 2.

[0035] Please refer again Figure 2 and Figure 6 As shown, the outer wall of the upper end of the oil pipe 3 is provided with an outer convex portion 301 at a position corresponding to the inner ring groove 203 through the hydraulic pipe expansion process, and the outer convex portion 301 has a circular structure; the inner wall of the upper end of the oil pipe 3 is provided with an inner concave portion 302 at a position corresponding to the inner ring groove 203 through the hydraulic pipe expansion process, and the inner concave portion 302 has a circular structure; the specifications of the outer convex portion 301 and the inner concave portion 302 are consistent, and the outer convex portion 301 and the inner ring groove 203 fit together.

[0036] In order to facilitate understanding of the above technical solution of the present invention, the working principle or operation method of the present invention in actual process is described in detail below:

[0037] In the first step, the oil pipe 3 is inserted into the oil casing 2 from bottom to top (the oil pipe 3 at this time is a pipe structure with the same inner and outer diameters). Then, a hydraulic pipe expansion process is used to tighten and deform the oil pipe 3 at the inner ring groove 203 inside the oil casing 2, so that the oil pipe 3 forms an outer convex portion 301 and an inner concave portion 302 at the inner ring groove 203. In this way, the thickness of the pipe wall can be kept consistent at all locations while the oil pipe 3 is fixed inside the oil casing 2.

[0038] In order to ensure the sealing between the oil casing 2 and the oil pipe 3, the inner diameter of the oil casing 2 and the outer diameter of the oil pipe 3 are in a transitional fit state (that is, the inner diameter of the oil casing 2 or the outer diameter of the oil pipe 3 has a tolerance within the allowable range, and the inner diameter of the oil casing 2 may be slightly larger than the outer diameter of the oil pipe 3, or may be slightly smaller than the outer diameter of the oil pipe 3). At this time, a sleeve portion 204 is provided at the lower end of the oil casing 2. The inner inclined surface of the sleeve portion 204 can easily slide the oil pipe 3 into the oil casing 2 to complete the preliminary assembly.

[0039] In the second step, the inside of the box hole 101 on the box body 1 is first heated to cause it to expand due to heat, and then the oil casing 2 and the oil pipe 3 are inserted into the box hole 101. After the box hole 101 gradually cools down, the box hole 101 with a slightly smaller inner diameter squeezes the oil casing 2 with a slightly larger outer diameter into the box hole 101, so that there is an interference fit between the box hole 101 and the oil casing 2.

[0040] The outer convex ring block 201 and the sinking hole 102 cooperate with each other to directly limit the position of the oil casing 2 inside the box hole 101, which not only prevents the oil casing 2 from falling into the box body 1 during assembly, but also facilitates the removal of the oil casing 2 during subsequent maintenance.

[0041] Among them, since the inner diameter of the box hole 101 is slightly small and the outer diameter of the oil casing 2 is slightly large, by providing a sleeve portion 204 at the lower end of the oil casing 2, the oil casing 2 together with the oil pipe 3 can be easily inserted into the heated box hole 101 by utilizing the outer inclined surface of the sleeve portion 204 to complete the final assembly.

[0042] The utility model adds an oil casing 2 with an inner ring groove 203 structure that is interference-fitted with the box hole 101, and uses a hydraulic pipe expander to tighten the oil pipe 3 in the casing. At the position of the inner ring groove 203, the wall of the oil pipe 3 is deformed and stuck in the inner ring groove 203, which can prevent the oil pipe 3 from axial movement and loosening, causing internal leakage, and ensure that the gearbox will not leak internally due to temperature changes and vibrations during use, causing pressure reduction, thereby avoiding the gearbox from burning the friction plate due to a sudden drop in pressure, thereby improving the reliability of the gearbox. The utility model has a simple structural design, is maintenance-free, has high reliability, strong operability, and low cost.

[0043] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0044] The above content is merely an example and explanation of the structure of the present utility model. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should fall within the scope of protection of the present utility model.

Claims

1. A structure for a gearbox with a built-in oil pipe, comprising a housing (1) and an oil pipe (3); a housing hole (101) is provided on the housing (1); and the structure is characterized in that: An oil casing (2) is provided between the box hole (101) and the oil pipe (3); The oil casing (2) is arranged inside the box hole (101); and the oil pipe (3) is arranged inside the oil casing (2).

2. The structure of a gearbox with a built-in oil pipe according to claim 1, characterized in that: The box body (1) is provided with a sinking opening (102) corresponding to the box hole (101), and the sinking opening (102) is a circular structure; an outer convex ring block (201) is fixed to the upper end of the oil casing (2).

3. The structure of a gearbox with a built-in oil pipe according to claim 2, characterized in that: The outer diameter of the outer convex ring block (201) is slightly larger than the inner diameter of the sinking opening (102).

4. The structure of a gearbox with a built-in oil pipe according to claim 2, characterized in that: The box body (1) is provided with a first chamfer (103) at an inner peripheral edge position corresponding to the lower portion of the sinking opening (102).

5. The structure of a gearbox with a built-in oil pipe according to claim 2, characterized in that: Second chamfers (202) are provided at the peripheral positions of the upper and lower sides of the outer convex ring block (201).

6. The structure of a gearbox with a built-in oil pipe according to claim 1, characterized in that: An inner ring groove (203) is provided inside the oil casing (2), and the upper end surface of the inner ring groove (203) coincides with the lower end surface of the outer convex ring block (201).

7. The structure of a gearbox with a built-in oil pipe according to claim 1, characterized in that: An outer convex portion (301) is provided on the outer wall of the upper end of the oil pipe (3) at a position corresponding to the inner hole annular groove (203), and the outer convex portion (301) is in a circular structure; an inner concave portion (302) is provided on the inner wall of the upper end of the oil pipe (3) at a position corresponding to the inner hole annular groove (203).

8. The structure of a gearbox with a built-in oil pipe according to claim 7, characterized in that: The inner concave portion (302) is a circular structure; the outer convex portion (301) and the inner concave portion (302) have the same specifications, and the outer convex portion (301) and the inner hole ring groove (203) fit each other.

9. The structure of a gearbox with a built-in oil pipe according to claim 1, characterized in that: The lower end of the oil casing (2) is provided with a sleeve portion (204), and the sleeve portion (204) is in a trapezoidal structure.

Images