Nitrogen charging device for a compressor

Abstract

The application provides a nitrogen filling device of a compressor, which comprises a nitrogen filling needle, a driving module and a detection module. Two ends of the nitrogen filling needle are a needle tail and a needle tip, respectively. The driving module drives the nitrogen filling needle to move from an initial position to a nitrogen filling position in the direction from the needle tail to the needle tip to pierce a blocking member of the compressor, and drives the nitrogen filling needle to move in the direction from the needle tip to the needle tail to reset. The detection module comprises an inductive unit and an alarm unit. The inductive unit is arranged at the initial position of the needle tip. The inductive unit is configured to trigger the alarm unit to generate an alarm signal when the nitrogen filling needle is located outside the inductive range of the inductive unit in the axial direction. Compared with the prior art, the application can accurately determine whether the nitrogen filling needle is broken or bent, greatly reduces the misjudgment rate of the broken needle, avoids the rusting of the compressor caused by the nitrogen leakage, avoids the broken needle left in the compressor from scratching the inner wall of the compressor, and improves the starting rate of the automatic nitrogen filling equipment of the compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a nitrogen filling device of a compressor. BACKGROUND

[0002] The existing automatic nitrogen filling mode of the compressor is that a double-shaft air cylinder is pressed down, a needle is fixed at one end of the shaft, the needle penetrates through a rubber plug when the air cylinder is pressed down, so as to perform vacuumizing treatment on the cavity of the compressor, and then nitrogen filling operation is performed. However, since the needle has a certain service life, if the needle breaks during the nitrogen filling process, if the needle opening is not completely closed, the equipment cannot alarm to remind the device, it is defaulted that the nitrogen filling is successful, the line body is normally released, the nitrogen leakage is prone to occur, and the needle is also prone to bending and scratching the inner wall of the copper pipe, causing the defective product in the cavity to flow out.

[0003] The root cause of the above phenomenon is that the current mainly relies on the vacuum degree to judge, the false alarm rate is high, and the automatic equipment starting rate is affected. SUMMARY

[0004] The purpose of the present application is to provide a nitrogen filling device of a compressor, so as to solve the problem that the false judgment rate is high in the prior art by judging whether the nitrogen filling needle breaks by the vacuum degree, thereby affecting the starting rate of the compressor.

[0005] To solve the above technical problems, the present application provides a nitrogen filling device of a compressor, which comprises:

[0006] a nitrogen filling needle, two ends of the nitrogen filling needle are a needle tail and a needle tip respectively;

[0007] a driving module, the driving module drives the nitrogen filling needle to move from an initial position to a nitrogen filling position in the direction from the needle tail to the needle tip to pierce a blocking member of the compressor, and the driving module drives the nitrogen filling needle to move in the direction from the needle tip to the needle tail to reset;

[0008] a detection module, the detection module comprises an induction unit and an alarm unit, the induction unit is arranged at the initial position of the needle tip, and the induction unit is configured to trigger the alarm unit to generate an alarm signal when the nitrogen filling needle is located outside the induction range of the induction unit in the axial direction.

[0009] Optionally, the induction unit comprises a ring-shaped electromagnetic coil, and the ring-shaped electromagnetic coil is penetrable by the nitrogen filling needle.

[0010] Optionally, the alarm signal comprises at least one of a sound signal and a visual signal.

[0011] Optionally, the nitrogen filling device comprises a mounting shaft assembly, the mounting shaft assembly has a needle channel, the nitrogen filling needle and the sensing unit are arranged in the needle channel; when the needle tip is in the initial position, the needle tip is located in the needle channel; when the needle tip is in the nitrogen filling position, the needle tip extends out of the needle channel.

[0012] Optionally, the nitrogen filling device comprises a needle sleeve, one end of the needle sleeve is connected with the driving module, and the other end of the needle sleeve is connected with the needle tail of the nitrogen filling needle.

[0013] Optionally, the mounting shaft assembly comprises a first mounting shaft and a second mounting shaft which are detachably connected with each other, at least part of the driving module is located in the corresponding needle channel of the first mounting shaft, and at least part of the nitrogen filling needle is located in the corresponding needle channel of the second mounting shaft; the sensing unit is arranged on the second mounting shaft.

[0014] Optionally, the nitrogen filling device comprises a limiting piece, the limiting piece is arranged on the mounting shaft assembly, and the limiting piece abuts against the sensing unit to constrain the axial position of the sensing unit along the needle channel.

[0015] Optionally, the nitrogen filling device comprises a fine adjustment assembly, the fine adjustment assembly abuts against the mounting shaft assembly, and the fine adjustment assembly is used for adjusting the radial position of the mounting shaft assembly along the nitrogen filling needle.

[0016] Optionally, the fine adjustment assembly comprises a mounting head, a snap ring and a thrust ball bearing, the mounting head is fixed relative to the mounting shaft assembly in the axial direction of the nitrogen filling needle, the thrust ball bearing is arranged in the mounting head and sleeves the mounting shaft assembly, the snap ring sleeves and is fixed on the mounting shaft assembly, and the snap ring abuts against the thrust ball bearing in the axial direction.

[0017] Optionally, the nitrogen filling device comprises a spring, the spring sleeves the mounting shaft assembly, and the spring is fixed in the axial position along the needle channel.

[0018] In summary, in the nitrogen charging device of the compressor provided by the application, the nitrogen charging device comprises a nitrogen charging needle, a driving module and a detection module, two ends of the nitrogen charging needle are a needle tail and a needle tip respectively, the driving module drives the nitrogen charging needle to move from an initial position to a nitrogen charging position in the direction from the needle tail to the needle tip to pierce the blocking member of the compressor, and the driving module drives the nitrogen charging needle to move in the direction from the needle tip to the needle tail to reset; the detection module comprises an induction unit and an alarm unit, the induction unit is arranged at the initial position of the needle tip, and the induction unit is configured to trigger the alarm unit to generate an alarm signal when the nitrogen charging needle is located outside the induction range of the induction unit in the axial direction. In this way, after the movement of the nitrogen charging needle makes the nitrogen charging needle pierce the blocking member of the compressor, nitrogen can be injected into the cavity of the compressor through the nitrogen charging needle, thereby solving the problem of rusting of the internal structure of the compressor, and after the movement of the nitrogen charging needle is reset, if the nitrogen charging needle is detected within the induction range of the induction unit, no alarm signal will be generated by the alarm signal, indicating that the nitrogen charging needle is normal and can still be used subsequently, if the alarm unit generates an alarm signal after the nitrogen charging needle is reset, it indicates that the needle tip of the nitrogen charging needle is not within the induction range of the induction unit, so that the nitrogen charging needle is broken or bent, and the operator can manually replace the nitrogen charging needle or directly perform a gas supplementing operation on the cavity of the compressor based on the generation of the alarm signal. Compared with the prior art, the application can accurately judge whether the nitrogen charging needle is broken or bent, greatly reduces the misjudgment rate of the broken needle, avoids rusting of the compressor caused by nitrogen leakage, avoids scratching of the inner wall of the compressor caused by the broken needle left in the compressor, and improves the starting rate of the automatic nitrogen charging equipment of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0019] Those skilled in the art should understand that the provided drawings are used to better understand the application, and do not constitute any limitation on the scope of the application. Among them:

[0020] Figure 1 is a front view of the nitrogen charging device of an embodiment of the application;

[0021] Figure 2 is Figure 1 is a sectional view along the A-A direction;

[0022] Figure 3 is Figure 2 is an enlarged view of part B in

[0023] Figure 4 is a schematic view of the nitrogen charging needle of the nitrogen charging device of an embodiment of the application;

[0024] Figure 5 is a schematic view of the connecting rod of the nitrogen charging device of an embodiment of the application;

[0025] Figure 6 is a schematic view of the first mounting shaft of the nitrogen charging device of an embodiment of the application;

[0026] Figure 7 is a schematic view of a second mounting shaft of the nitrogen filling device according to an embodiment of the present application;

[0027] Figure 8 is a schematic view of a nitrogen injection head of the nitrogen filling device according to an embodiment of the present application.

[0028] In the drawings:

[0029] 10 - nitrogen filling needle; 11 - nitrogen filling channel; 12 - air hole; 20 - driving module; 21 - first air cylinder; 22 - connecting rod; 23 - guide plate; 30 - sensing unit; 40 - needle cover; 50 - mounting shaft assembly; 51 - first mounting shaft; 52 - second mounting shaft; 521 - limiting hole section; 53 - nitrogen injection head; 531 - guide hole section; 60 - limiting member; 71 - mounting head; 72 - snap ring; 73 - thrust ball bearing; 81 - spring; 82 - first mounting plate; 83 - second mounting plate; 84 - third mounting plate; 85 - second air cylinder; 86 - butterfly screw. DETAILED DESCRIPTION

[0030] In order to make the objects, advantages and features of the present application clearer, the following will further describe the present application in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are very simplified and not drawn according to scale, and are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the present application. In addition, the structures shown in the drawings are often a part of the actual structures. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0031] As used in the present application, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. The term "or" is generally employed in its sense of "and / or" unless the context clearly dictates otherwise. The term "plurality" is generally employed in its sense of "at least one" unless the context clearly dictates otherwise. The term "at least two" is generally employed in its sense of "two or more" unless the context clearly dictates otherwise. In addition, the terms "first," "second," "third," etc. are used only to describe a particular object and do not imply or suggest relative importance or imply a specific number of the recited technical features. Thus, features defined with "first," "second," "third," etc. can explicitly or implicitly include one or at least two of the features. The terms "one end" and "the other end" and "proximal" and "distal" generally refer to two parts corresponding to each other, which not only include end points, and the terms "mounting," "connecting," and "connecting" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrated; can be mechanically connected, can be electrically connected; can be directly connected, or indirectly connected through an intermediate element; can be internal communication or interaction between two elements. In addition, as used in the present application, a component disposed in another component generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two components, and the two components can be directly or indirectly connected, coupled, cooperated or transmitted through an intermediate component, and cannot be understood as indicating or suggesting the spatial positional relationship between the two components, i.e. one component can be in any orientation inside, outside, above, below or one side of another component, unless the context clearly indicates otherwise. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] Figure 1 is the front view of the nitrogen filling device of an embodiment of the present application, Figure 2 is Figure 1 is a sectional view along the direction of A-A, Figure 3 is Figure 2 is an enlarged view of the middle B part. As Figures 1 to 3As shown, an embodiment of the present application schematically provides a nitrogen charging device for a compressor, which includes a nitrogen charging needle 10, a driving module 20 and a detection module. Two ends of the nitrogen charging needle 10 are a needle tail and a needle tip respectively, and the nitrogen charging needle 10 can introduce nitrogen into the compressor. The driving module 20 is connected with the nitrogen charging needle 10, specifically connected with the needle tail of the nitrogen charging needle 10, so as to drive the nitrogen charging needle 10 to move in the axial direction of the nitrogen charging needle 10, including driving the nitrogen charging needle 10 to move from an initial position to a nitrogen charging position in the direction from the needle tail to the needle tip to pierce a blocking member (such as a rubber plug) of the compressor, so as to introduce nitrogen into the compressor, and driving the nitrogen charging needle 10 to move from the nitrogen charging position to the initial position in the direction from the needle tip to the needle tail to reset. Understandably, after resetting, the nitrogen charging needle 10 will exit the blocking member. The detection module includes a sensing unit 30 and an alarm unit, the alarm unit is connected with the sensing unit 30, and the sensing unit 30 is arranged at the initial position of the needle tip. The sensing unit 30 is configured to trigger the alarm unit to generate an alarm signal when the nitrogen charging needle 10 is located outside the sensing range of the sensing unit 30 in the axial direction. It should be noted that, Figure 2 and Figure 3 The nitrogen charging needle 10 shown in

[0033] Specifically, the sensing unit 30 is located at the initial position of the needle tip. When the nitrogen charging needle 10 is located at the initial position as a whole, the sensing unit 30 can sense and detect the needle tip, and at this time, no alarm signal will be generated. When the nitrogen charging needle 10 moves to pierce the blocking member and in the process of piercing, the part of the nitrogen charging needle 10 between the needle tip and the needle tail is always located within the sensing range of the sensing unit 30 in the axial direction, and at this time, no alarm signal will be generated. After the gas pressure value of the introduced nitrogen detected by the gas pressure sensor reaches a threshold value, the driving module 20 drives the nitrogen charging needle 10 to reset. When the needle tip has not reset to the initial position, the part of the nitrogen charging needle 10 between the needle tip and the needle tail is always located within the sensing range of the sensing unit 30 in the axial direction, and at this time, no alarm signal will be generated. When the needle tip resets to the initial position, if the needle tip appears a broken needle condition, or the needle tip appears a bending condition, the needle tip will be located outside the sensing range of the sensing unit 30 in the axial direction, and at this time, the sensing unit 30 triggers the alarm unit to generate an alarm signal. The operator can obtain the broken needle or bending condition of the nitrogen charging needle 10 according to the alarm signal, so as to manually replace the nitrogen charging needle 10. If no alarm signal is generated after the needle tip resets, it means that the nitrogen charging needle 10 can still be used for the work of charging nitrogen.

[0034] In an embodiment, in the axial direction of the nitrogen charging needle 10, the sensing range of the sensing unit 30 is 2mm-3mm. Further, referring to Figure 4The nitrogen filling needle 10 has a nitrogen filling channel 11 inside, the nitrogen filling channel 11 extends along the axial direction of the nitrogen filling needle 10, the needle tip of the nitrogen filling needle 10 has a gas hole 12, one end of the gas hole 12 communicates with the nitrogen filling channel 11, and the other end of the gas hole 12 penetrates the nitrogen filling needle 10 along the radial direction of the nitrogen filling needle 10. The cooperation of the nitrogen filling channel 11 and the gas hole 12 can fill nitrogen into the compressor or perform air extraction treatment on the cavity of the compressor.

[0035] In an embodiment, referring to Figure 2 and Figure 5 The driving module 20 includes a first cylinder 21, a connecting rod 22 and a guide plate 23, the first cylinder 21 is connected with the connecting rod 22, the connecting rod 22 is connected with the needle tail of the nitrogen filling needle 10, and the first cylinder 21 drives the nitrogen filling needle 10 to move in the axial direction. The guide plate 23 is fixed on the external device, and the guide plate 23 is connected with the first cylinder 21 to guide the movement of the first cylinder 21, so that the first cylinder 21 does not shake greatly during the movement of driving the nitrogen filling needle 10. In the actual scene, the axial direction of the nitrogen filling needle 10 is parallel to the direction of gravity. Further, the nitrogen filling device includes a needle sleeve 40, one end of the needle sleeve 40 is sleeved and fixed on the connecting rod 22 of the driving module 20, and the other end of the needle sleeve 40 is sleeved on the needle tail of the nitrogen filling needle 10.

[0036] The nitrogen filling device as above, the driving module 20 drives the nitrogen filling needle 10 to move so that the nitrogen filling needle 10 pierces the blocking member of the compressor, and then nitrogen can be injected into the cavity of the compressor through the nitrogen filling needle 10, thereby solving the problem of rusting of the internal structure of the compressor. After the nitrogen filling needle 10 is reset, if the nitrogen filling needle 10 is detected within the sensing range of the sensing unit 30, no alarm signal will be generated, indicating that the nitrogen filling needle 10 is normal and can still be used subsequently. If the nitrogen filling needle 10 is reset and the alarm unit generates an alarm signal, it indicates that the needle tip of the nitrogen filling needle 10 is not within the sensing range of the sensing unit 30, so the nitrogen filling needle 10 is broken or bent. The operator can manually replace the nitrogen filling needle 10 or directly perform air supplementing operation on the cavity of the compressor based on the generation of the alarm signal. Compared with the prior art, the present application can accurately determine whether the nitrogen filling needle 10 is broken or bent, greatly reduces the misjudgment rate of broken needle, avoids rusting of the compressor due to nitrogen leakage, avoids scratching of the inner wall of the compressor by the broken needle left in the compressor, and improves the starting rate of the compressor automatic nitrogen filling equipment.

[0037] The material of the nitrogen filling needle 10 is metal, the sensing unit 30 includes a ring-shaped electromagnetic coil, the ring-shaped electromagnetic coil is penetrated by the nitrogen filling needle 10, and preferably, the ring-shaped electromagnetic coil and the nitrogen filling needle 10 are coaxially arranged. When the nitrogen filling needle 10 is in the ring-shaped electromagnetic coil, the ring-shaped electromagnetic coil detects the metal, so that the alarm unit connects the corresponding circuit loop, thereby generating an alarm signal.

[0038] Alarm signals can be at least one of sound signals and visual signals; when they are combined, they form an audiovisual signal. Sound signals can take the form of voice prompts or musical prompts, while visual signals can be indicated by changes in graphics on a display or changes in the color of an indicator light.

[0039] Further, see Figure 2 The nitrogen filling device includes a mounting shaft assembly 50, which has a needle channel. The nitrogen filling needle 10 and the sensing unit 30 are both disposed within the needle channel. The needle channel can be understood as an internal hole in the mounting shaft assembly 50. The drive module 20 drives the nitrogen filling needle 10 to move within the needle channel of the mounting shaft assembly 50. When the needle tip is in the initial position, it is located within the needle channel; when the needle tip is in the nitrogen filling position, it extends outside the needle channel.

[0040] Furthermore, see Figure 2 , Figure 6 and Figure 7 The mounting shaft assembly includes a first mounting shaft 51 and a second mounting shaft 52 that are detachably connected to each other, for example, via a wing screw 86. Figure 1 As shown, the first mounting shaft 51 and the second mounting shaft 52 are detachably connected, with the wing screw 86 perpendicular to the axial direction of the nitrogen filling needle 10. At least a portion of the drive module 20 is located within the needle channel corresponding to the first mounting shaft 51, that is, the first connecting rod 22 is located within the needle channel corresponding to the first mounting shaft 51, and at least a portion of the nitrogen filling needle 10 is located within the needle channel corresponding to the second mounting shaft 52; the sensing unit 30 is disposed on the second mounting shaft 52.

[0041] For further implementation details, please refer to Figure 7 The needle channel of the second mounting shaft 52 has a limiting hole section 521. The limiting hole section 521 is adapted to the shape of the needle sleeve 40. After the driving module 20 drives the nitrogen filling needle 10 to move so that the needle sleeve 40 is in the limiting hole section 521, the limiting hole section 521 abuts against the needle sleeve 40 to prevent the needle sleeve 40 from moving along the needle tail towards the needle tip. At this time, it can also be considered that the nitrogen filling needle 10 has moved from the initial position to the nitrogen filling position.

[0042] Preferably, see Figure 8 The mounting shaft assembly 50 also includes a nitrogen injection head 53 connected to the second mounting shaft 52. The needle channel of the nitrogen injection head 53 has a guide hole section 531, which is located at the end of the nitrogen injection head 53 away from the second mounting shaft 52, and the guide hole section 531 is flared in the direction from the needle tail to the needle tip. In this way, the nitrogen injection head 53, through the setting of the guide hole section 531, can attach to and cover different sealing parts, thereby guiding the operation of the nitrogen filling needle 10.

[0043] Preferably, see Figure 2 and Figure 3The nitrogen filling device comprises a limiting member 60, which is arranged on the mounting shaft assembly and abuts against the induction unit 30 to restrict the axial position of the induction unit 30 along the needle channel. The limiting member 60 is arranged to ensure that the induction unit 30 is always located at the initial position of the needle tip. The limiting member 60 can be an elastic retaining ring, for example.

[0044] Preferably, the device comprises a fine adjustment assembly, which abuts against the mounting shaft assembly 50 and is used to adjust the radial position of the mounting shaft assembly 50 along the nitrogen filling needle 10. In actual scenarios, the nitrogen filling needle 10 is parallel to the direction of gravity, and the fine adjustment assembly is arranged to fine-tune the position of the mounting shaft assembly 50 in the horizontal direction, so that the position of the nitrogen filling needle 10 in the horizontal direction can be finely adjusted to meet the actual requirements of the nitrogen injection position. In an embodiment, referring to Figure 2 The fine adjustment assembly comprises a mounting head 71, a snap ring 72 and a thrust ball bearing 73. The mounting head 71 is fixed relative to the mounting shaft assembly in the axial direction of the nitrogen filling needle 10. The thrust ball bearing 73 is arranged in the mounting head 71, and the snap ring 72 is arranged on and fixed to the mounting shaft assembly. The snap ring 72 abuts against the thrust ball bearing 73 in the axial direction. In this way, the horizontal position of the mounting shaft assembly can be achieved by the sliding fit between the snap ring 72 and the ball of the thrust ball bearing 73.

[0045] Preferably, the nitrogen filling device comprises a spring 81, which is arranged on the mounting shaft assembly, specifically on the first mounting shaft 51, and is fixed in the axial position along the needle channel. During the movement of the driving module 20 to drive the nitrogen filling needle 10, the spring 81 can reduce vibration and improve the coaxiality of the entire device, so that the position of the device on the plane will not be offset.

[0046] Further, referring to Figure 1 and Figure 2 The nitrogen filling device further comprises a first mounting plate 82, a second mounting plate 83, a third mounting plate 84 and a second air cylinder 85. The first mounting plate 82 is fixed to an external device. The second air cylinder 85 is connected to the first mounting plate 82 and can be a double-shaft air cylinder. The second air cylinder 85 is connected to the second mounting plate 83, which is connected to the third mounting plate 84. The third mounting plate 84 is connected to the mounting head 71. In this way, the second air cylinder 85 can adjust the position of the entire device in the horizontal and vertical directions.

[0047] Although the present application has been disclosed with reference to the preferred embodiments thereof, it is to be understood that the application is not limited to the above-described embodiments, but encompasses any and all modifications within the scope of the present application. Therefore, any simple modification, equivalent change and modification of the above-described embodiments made according to the technical spirit of the present application without departing from the scope of the present application should be construed as falling within the scope of the present application.

Claims

1. A nitrogen charging device for a compressor, characterized by, The nitrogen filling device comprises: a nitrogen filling needle, two ends of the nitrogen filling needle being a needle tail and a needle tip respectively; a driving module, which drives the nitrogen filling needle to move from an initial position to a nitrogen filling position in a direction from the needle tail to the needle tip to pierce a blocking member of a compressor, and drives the nitrogen filling needle to move in a direction from the needle tip to the needle tail to reset; a detection module, which comprises a sensing unit and an alarm unit, the sensing unit being arranged at the initial position of the needle tip, and the sensing unit being configured to trigger the alarm unit to generate an alarm signal when the nitrogen filling needle is located outside the sensing range of the sensing unit in the axial direction; a mounting shaft assembly, which has a needle channel, the nitrogen filling needle and the sensing unit being arranged in the needle channel, the needle tip being located in the needle channel when the needle tip is in the initial position, and the needle tip extending out of the needle channel when the needle tip is in the nitrogen filling position.

2. The nitrogen charging device of the compressor according to claim 1, characterized by The sensing unit comprises a ring-shaped electromagnetic coil, and the ring-shaped electromagnetic coil is available for the nitrogen filling needle to pass through.

3. The nitrogen charging device of the compressor according to claim 1, characterized by The alarm signal comprises at least one of a sound signal and a visual signal.

4. The nitrogen charging device of the compressor according to claim 1, characterized by The nitrogen filling device comprises a needle sleeve, one end of the needle sleeve being connected with the driving module, and the other end of the needle sleeve being connected with the needle tail of the nitrogen filling needle.

5. The nitrogen charging device for a compressor according to claim 1, characterized by The mounting shaft assembly comprises a first mounting shaft and a second mounting shaft which are detachably connected with each other, at least part of the driving module being located in the corresponding needle channel of the first mounting shaft, and at least part of the nitrogen filling needle being located in the corresponding needle channel of the second mounting shaft; and the sensing unit is arranged on the second mounting shaft.

6. The nitrogen charging device of the compressor according to claim 1, characterized by The nitrogen filling device comprises a limiting piece, the limiting piece being arranged on the mounting shaft assembly, and the limiting piece abutting against the sensing unit to restrict the axial position of the sensing unit along the needle channel.

7. The nitrogen charging device for a compressor according to claim 1, wherein The nitrogen filling device comprises a fine adjustment assembly, the fine adjustment assembly abutting against the mounting shaft assembly, and the fine adjustment assembly being used to adjust the radial position of the mounting shaft assembly along the nitrogen filling needle.

8. The nitrogen charging device of the compressor according to claim 7, characterized by The fine adjustment assembly comprises a mounting head, a snap ring and a thrust ball bearing, the mounting head being fixed relative to the mounting shaft assembly in the axial direction of the nitrogen filling needle, the thrust ball bearing being arranged in the mounting head and sleeving the mounting shaft assembly, the snap ring sleeving and being fixed on the mounting shaft assembly, and the snap ring abutting against the thrust ball bearing in the axial direction.

9. The nitrogen charging device for a compressor according to claim 1, characterized by The nitrogen filling device comprises a spring, the spring sleeving the mounting shaft assembly, and the spring being fixed in the axial position along the needle channel.

Images