Framework oil seal installation tool

Abstract

The utility model discloses a framework oil seal installation tool which comprises an oil seal seat, a pressing head and a guide pin which are coaxially arranged, a guide hole penetrating through the pressing head and allowing the guide pin to penetrate through is formed in the pressing head, and one end of the pressing head is fixedly connected with a tooth pressing ring used for being embedded into a groove of a framework oil seal. A mounting groove for mounting the framework oil seal is formed in the center of the oil seal seat, a mounting hole penetrating through the oil seal seat and allowing the guide pin to penetrate through is formed in the bottom of the mounting groove, and the diameter of the mounting hole is larger than that of the guide pin. According to the scheme, deviation and inclination of the framework oil seal 10 in the assembling process can be avoided, and oil leakage of the direct-current electric pump caused by sealing failure of the framework oil seal 10 due to framework deformation is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of sealing elements, in particular to a skeleton oil seal installation tool. Background Art

[0002] At present, it is becoming more and more common to use skeleton oil seals as sealing elements for low-cost aviation fuel pumps. As the core component of the fuel pump, the sealing performance of the skeleton oil seal directly affects the sealing performance of the fuel pump. The skeleton oil seal structure consists of a metal skeleton, oil-resistant rubber and an adjustment spring. The metal skeleton is like the steel bars in the concrete component, which plays the role of reinforcing ribs and enables the oil seal to maintain its shape and tension in an L shape. If the force is uneven during assembly, the metal skeleton may be deformed, affecting the sealing performance of the oil seal. When the force is severely uneven, the metal skeleton may damage the rubber parts, causing the oil seal to fail.

[0003] The lip, also called the sealing lip, is naturally formed by an oil-resistant rubber mold. It is a flexible elastic body that can maintain a stable seal under the influence of the pressure fluctuation of the sealing fluid and maintain the stable contact state between the lip and the DC motor shaft surface. Adjusting the spring can increase the pressing force of the sealing lip to the shaft and maintain this pressing force. From the structure of the skeleton oil seal, it can be seen that if effective methods are not taken during the assembly process, it is very easy to cause the sealing performance to fail during the assembly process.

[0004] The current assembly method is to directly press the skeleton oil seal into the oil seal seat, but it is difficult to control the force during the assembly process, which causes uneven force and offset and tilt, and deformation of the skeleton oil seal. After the assembly is completed, a sealing test is carried out, and it is found that the sealing failure is very high. From the previous assembly situation, the proportion of direct sealing failure of the skeleton oil seal caused by this assembly process is as high as more than 50%. If the seal failure is detected, the failed skeleton oil seal needs to be replaced. The value of the skeleton oil seal is relatively high in this low-cost aviation fuel pump, which will directly cause economic losses and increase a lot of unnecessary manufacturing costs. Even greater hidden dangers are that only minor defects are caused to the skeleton oil seal during the assembly process, which cannot be detected in the sealing inspection before the product leaves the factory. During the installation and use process, due to changes in the environment and the continuous changes in stress, it will appear, causing the seal to fail and cause the fuel pump to leak, which will seriously affect flight safety. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, the utility model provides a skeleton oil seal installation tool, which solves the problem in the prior art that the skeleton oil seal assembly easily causes the skeleton oil seal to deform, thereby causing the seal to fail.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] Provided is a skeleton oil seal installation tool, which includes a coaxially arranged oil seal seat, a pressure head and a guide pin, the pressure head is provided with a guide hole penetrating therethrough and for the guide pin to pass through, one end of the pressure head is fixedly connected with a pressure tooth ring for embedding into a groove of the skeleton oil seal; an installation groove for installing the skeleton oil seal is provided at the center of the oil seal seat, a installation hole penetrating the oil seal seat and for the guide pin to pass through is provided at the bottom of the installation groove, and the diameter of the installation hole is larger than the diameter of the guide pin.

[0008] The utility model has the following beneficial effects: when in use, the oil seal seat is passed through the guide pin, and the pressure gear ring is inserted into the groove of the skeleton oil seal, and the guide pin is inserted into the guide hole, and then pressure is applied to the top of the pressure head to press the skeleton oil seal into the installation groove, and the skeleton oil seal and the installation groove are interference fit. Then the pressed oil seal seat and the skeleton oil seal are installed in the DC motor.

[0009] Since the oil seal seat, pressure head and guide pin are all coaxial, the concentricity of the skeleton oil seal during assembly can be ensured through the auxiliary guidance of the guide pin and guide hole, avoiding the deviation and tilt of the skeleton oil seal during assembly, and avoiding the failure of the skeleton oil seal due to skeleton deformation, thereby causing oil leakage of the DC electric pump. The use of this installation tool is fast, simple, reliable and effective, and the assembly qualification rate of the skeleton oil seal at the factory has been increased from 50% to 100%. In the process of user use, the feedback is good and no oil leakage failure occurs.

[0010] Preferably, a fixed support is further included, the bottom of the guide pin is fixedly connected to the fixed support, and the fixed support is cylindrical; the guide pin is perpendicular to the plane of the fixed support and coaxial with the fixed support. The fixed support can ensure the stability of the guide pin during press-fitting and avoid press-fitting failure caused by the guide pin being tilted by force.

[0011] Preferably, a disc-shaped positioning boss is provided at the center of the top surface of the fixed support, and a positioning groove matching the size of the positioning boss is provided at the bottom of the oil seal seat; when in use, the positioning groove is matched and connected with the positioning boss. This arrangement can ensure the concentricity of the oil seal seat and the guide shaft during press-fitting, and avoid shaking of the oil seal seat or axis deviation.

[0012] Preferably, the pressure head is in a "T" shape, including a cylindrical shaft and a force-bearing part, the force-bearing part and the shaft are an integrated structure; the diameter of the force-bearing part is larger than the diameter of the shaft; the pressure tooth ring is arranged at one end away from the force-bearing part. During press-fitting, pressure is applied to the surface of the force-bearing part, and the force-bearing part can increase the force-bearing area of ​​the pressure head and increase the pressure head's ability to withstand external forces.

[0013] Preferably, the guide hole and the guide pin are clearance-matched, with a single-side clearance of ≤0.05 mm; the roughness of the guide hole is not inferior to Ra3.2. The concentricity is ensured while the pressure head slides smoothly on the guide pin, and no positional deviation occurs during the sliding process.

[0014] Preferably, the roughness of the end surface of the pressure tooth ring in contact with the skeleton seal is not less than Ra3.2; the inner and outer rings of the pressure tooth ring are both rounded to avoid damaging the rubber surface during the assembly of the skeleton oil seal.

[0015] Preferably, the height of the pressure tooth ring is greater than or equal to the depth of the installation groove, and the cross-sectional dimension of the pressure tooth ring matches the cross-sectional dimension of the skeleton oil seal groove.

[0016] The beneficial effects of the above technical solution are: ensuring that the pressure tooth ring can touch the bottom of the installation groove, so that the bottom of the skeleton oil seal is fully in contact with the bottom of the installation groove, ensuring that it can be installed in place. The cross-sectional thickness of the pressure tooth ring should be infinitely close to the thickness of the skeleton oil seal groove to ensure that the force area is maximized during the assembly process, while ensuring that the metal skeleton of the skeleton oil seal does not deform. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the skeleton oil seal installation tooling in use;

[0018] Figure 2 This is a schematic diagram of the skeleton oil seal being pressed into the oil seal seat;

[0019] Figure 3 This is a schematic diagram of the steps for removing the skeleton oil seal after installation;

[0020] Among them, 10, skeleton oil seal; 20, oil seal seat; 21, installation groove; 22, positioning groove; 30, pressure head; 31, guide hole; 32, pressure gear ring; 33, column body; 34, force-bearing part; 40, guide pin; 50, fixed support; 51, positioning boss. DETAILED DESCRIPTION

[0021] The specific implementation methods of the utility model are described below to facilitate technical personnel in this technical field to understand the utility model, but it should be clear that the utility model is not limited to the scope of the specific implementation methods. For ordinary technical personnel in this technical field, as long as various changes are within the spirit and scope of the utility model defined and determined by the attached claims, these changes are obvious, and all utility model creations using the concept of the utility model are protected.

[0022] like Figure 1 and Figure 2As shown, the skeleton oil seal installation tool of the present scheme includes a coaxially arranged oil seal seat 20, a pressure head 30 and a guide pin 40. The outer diameter of the guide pin 40 is consistent with the shaft diameter of the skeleton oil seal 10 installation shaft in the DC motor, and the outer circle roughness of the guide pin 40 is controlled to be no worse than Ra1.6, ensuring that the skeleton oil seal 10 does not generate contact wear with the rubber lip of the skeleton oil seal 10 during the assembly process and the removal process.

[0023] The center of the oil seal seat 20 is provided with a mounting groove 21 for mounting the skeleton oil seal 10, and the bottom of the mounting groove 21 is provided with a mounting hole that penetrates the oil seal seat 20 and is passed by the guide pin 40, and the diameter of the mounting hole is larger than the diameter of the guide pin 40. When in use, the oil seal seat 20 and the skeleton oil seal 10 are both sleeved on the outside of the guide pin 40, and the skeleton oil seal 10 is located above the oil seal seat 20; after assembly, the skeleton oil seal 10 is press-fitted into the mounting groove 21.

[0024] A guide hole 31 is provided at the center of the pressure head 30, which penetrates the pressure head 30 itself and is passed through by the guide pin 40. When in use, the guide pin 40 extends into the guide hole 31. Through the auxiliary guidance of the guide pin 40 and the guide hole 31, it can be ensured that the pressure head 30 moves linearly along the guide pin 40 when moving downward, thereby ensuring the concentricity during the assembly process of the skeleton oil seal 10. A pressure tooth ring 32 for embedding into the groove of the skeleton oil seal 10 is fixedly connected to one end of the pressure head 30. When in use, the pressure tooth ring 32 is in close contact with the groove wall of the skeleton oil seal 10 to prevent the skeleton oil seal 10 and the pressure tooth ring 32 from generating relative movement.

[0025] As a preferred embodiment of the utility model, the utility model further includes a fixed support 50, the bottom of the guide pin 40 is fixedly connected to the fixed support 50, and the fixed support 50 is cylindrical; the guide pin 40 is perpendicular to the plane of the fixed support 50 and is coaxial with the fixed support 50. The fixed support 50 can ensure the stability of the guide pin 40 during press-fitting, and avoid the failure of press-fitting caused by the guide pin 40 being tilted by force. The pressure head 30, the guide pin 40 and the fixed support 50 are all made of metal materials with high strength.

[0026] The verticality of the guide pin 40 and the surface of the fixed support 50 should be controlled within 0.02mm as much as possible, and the concentricity of the contact surface of the guide pin 40 and the fixed support 50 should be controlled within Φ0.02mm as much as possible to ensure the guidance and concentricity of the skeleton oil seal 10 during the installation process. The guide pin 40 and the fixed support 50 can be processed and formed as one piece, and can also be divided into two independent parts. The fixed support 50 is provided with a mounting hole running through it, and the guide pin 40 is pressed into the inner hole of the fixed support 50 to be fixed as a whole. The mounting holes of the guide pin 40 and the fixed support 50 are interference fit.

[0027] Specifically, a disc-shaped positioning boss 51 is provided at the center of the top surface of the fixed support 50, and a positioning groove 22 matching the size of the positioning boss 51 is provided at the bottom of the oil seal seat 20; when in use, the positioning groove 22 is matched and connected with the positioning boss 51. This arrangement can ensure the concentricity of the oil seal seat 20 and the guide shaft 10 during press-fitting, and avoid the oil seal seat 20 from shaking or axis deviation. In addition, the diameter of the through hole of the oil seal seat 20 is allowed to be larger than the diameter of the guide pin 40, so that the oil seal seat 20 and the guide pin 40 are easy to separate.

[0028] Preferably, the pressure head 30 is in a "T" shape, including a cylindrical shaft portion 33 and a force-bearing portion 34, both of which are cylindrical. The force-bearing portion 34 and the shaft portion 33 are an integrated structure; the diameter of the force-bearing portion 34 is larger than the diameter of the shaft portion 33; and the pressure tooth ring 32 is arranged at one end away from the force-bearing portion 34. During press-fitting, pressure is applied to the surface of the force-bearing portion 34. The force-bearing portion 34 can increase the force-bearing area of ​​the pressure head 30 and reduce the pressure per unit area of ​​the pressure head 30, thereby increasing the pressure head 30's ability to withstand external forces. The parallelism between the surface of the force-bearing portion 34 and the bottom surface of the pressure tooth ring 32 should be controlled within 0.02 mm, and the verticality between the guide hole 31 and the bottom surface of the pressure tooth ring 32 should be controlled within 0.02 mm as much as possible.

[0029] As a preferred embodiment of the utility model, the guide hole 31 and the guide pin 40 are clearance-matched, and the single-side clearance is ≤0.05mm; the roughness of the guide hole 31 is not inferior to Ra3.2. (The smaller the surface roughness, the smoother the surface, and the smaller the value, the smoother the surface. The roughness is not inferior to Ra3.2 means that it cannot be higher than this value.) Ensure that the pressure head 30 slides smoothly on the guide pin 40 while ensuring concentricity and ensuring that no position deviation occurs during the sliding process. The single-side clearance should be optimally controlled within 0.03mm.

[0030] The roughness of the end surface of the pressing tooth ring 32 in contact with the skeleton seal 2 is not less than Ra3.2; the inner and outer rings of the pressing tooth ring 32 are both chamfered to avoid damaging the rubber surface during the assembly of the skeleton oil seal 10. At the same time, in order to ensure the effective contact area with the skeleton oil seal 10, the fillet should not be too large, and is generally controlled within R0.2.

[0031] The height of the pressing tooth ring 32 is greater than or equal to the depth of the installation groove 21, and the cross-sectional dimensions of the pressing tooth ring 32 match the cross-sectional dimensions of the groove of the skeleton oil seal 10. Ensure that the pressing tooth ring 32 can touch the bottom of the installation groove 21, so that the bottom of the skeleton oil seal 10 is fully in contact with the bottom of the installation groove 21, and ensure that it can be installed in place. And the cross-sectional thickness of the pressing tooth ring 32 should be infinitely close to the thickness of the groove of the skeleton oil seal 10, to ensure that the force area is maximized during the assembly process, and at the same time ensure that the metal skeleton of the skeleton oil seal 10 does not deform.

[0032] The specific installation steps of the utility model are:

[0033] 1. Place the fixed support 50 with the guide pin 40 on the table of the spinning machine; 2. Pass the oil seal seat 20 through the guide pin 40, and make the positioning boss 51 cooperate with the positioning groove 22; 3. Apply a proper amount of grease to the inner and outer circles of the skeleton oil seal 10, insert the guide pin 40, and place it on the top of the oil seal seat 20; 4. Insert the guide hole 31 into the guide pin 40, and embed the pressure gear ring 32 into the groove of the skeleton oil seal 10; 5. Adjust the force position of the plane force head of the spinning machine so that it is located at the surface center of the force-bearing part 34, and slowly apply pressure until the skeleton oil seal 10 is installed in place.

[0034] During the installation process, the displacement end point of the spinning machine should be determined in advance according to the size of the skeleton oil seal 10 and the installation tooling to ensure that the spinning machine moves to the preset position and releases pressure to ensure that the skeleton oil seal 10 is installed in place without excessive pressure.

[0035] During the pressing-in process of the skeleton oil seal 10, since the skeleton oil seal 10 and the mounting groove 21, as well as the skeleton oil seal 10 and the guide pin 40 are interference fit, a balanced upward friction force will be generated during the pressing-in process. Therefore, during the pressing-in process of the skeleton oil seal 10, the force is always balanced, thereby ensuring the assembly performance of the skeleton oil seal 10.

[0036] like Figure 3 As shown, after the skeleton oil seal 10 is assembled, the pressure head 30 is taken out along the guide pin 40, and then the oil seal seat 20 assembled with the skeleton oil seal 10 is taken out along the guide pin 40 to obtain a complete oil seal seat 20 with the skeleton oil seal 10. When the DC electric pump is assembled, the oil seal seat 20 with the skeleton oil seal 10 pressed is directly installed on the motor shaft of the DC motor 4.

[0037] In summary, this solution can ensure that the skeleton seal 10 moves linearly along the guide pin 40 during assembly, avoid the skeleton oil seal 10 from offsetting or tilting, and avoid oil leakage in the DC electric pump caused by sealing failure of the skeleton oil seal 10 due to skeleton deformation.

Claims

1. A skeleton oil seal installation tool, characterized in that: The invention comprises an oil seal seat (20), a pressure head (30) and a guide pin (40) which are coaxially arranged. The pressure head (30) is provided with a guide hole (31) which passes through the pressure head and is provided for the guide pin (40) to pass through. One end of the pressure head (30) is fixedly connected with a pressure tooth ring (32) which is used to be embedded in the groove of the skeleton oil seal (10). The center of the oil seal seat (20) is provided with a mounting groove (21) for mounting the skeleton oil seal (10). The bottom of the mounting groove (21) is provided with a mounting hole which passes through the oil seal seat (20) and is provided for the guide pin (40) to pass through. The diameter of the mounting hole is larger than the diameter of the guide pin (40).

2. The skeleton oil seal installation tool according to claim 1, characterized in that: It also includes a fixed support (50), the bottom of the guide pin (40) is fixedly connected to the fixed support (50), and the fixed support (50) is cylindrical; the guide pin (40) is perpendicular to the plane of the fixed support (50) and coaxial with the fixed support (50).

3. The skeleton oil seal installation tool according to claim 2 is characterized in that: A disc-shaped positioning boss (51) is arranged at the center of the top surface of the fixed support (50), and a positioning groove (22) matching the size of the positioning boss (51) is opened at the bottom of the oil seal seat (20); when in use, the positioning groove (22) is matched and connected with the positioning boss (51).

4. The skeleton oil seal installation tool according to claim 1, characterized in that: The pressure head (30) is in a "T" shape, and comprises a cylindrical shaft portion (33) and a force-bearing portion (34), both of which are cylindrical. The force-bearing portion (34) and the shaft portion (33) are an integrated structure. The diameter of the force-bearing portion (34) is larger than the diameter of the shaft portion (33). The pressure tooth ring (32) is arranged at an end away from the force-bearing portion (34).

5. The skeleton oil seal installation tool according to claim 1, characterized in that: The guide hole (31) and the guide pin (40) are clearance-matched, and the single-side clearance is ≤0.05 mm; the roughness of the guide hole (31) is not inferior to Ra3.

2.

6. The skeleton oil seal installation tool according to claim 1, characterized in that: The roughness of the end surface of the pressure tooth ring (32) in contact with the skeleton seal (2) is not less than Ra3.2; the inner and outer rings of the pressure tooth ring (32) are both chamfered.

7. The skeleton oil seal installation tool according to claim 1, characterized in that: The height of the pressing tooth ring (32) is greater than or equal to the depth of the installation groove (21), and the cross-sectional dimensions of the pressing tooth ring (32) match the cross-sectional dimensions of the groove of the skeleton oil seal (10).

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