Compressor and oil level sensor assembly thereof

Abstract

The present application discloses a kind of compressor and its oil level sensor assembly.The oil level sensor assembly includes: lower shell cover, encapsulated in the bottom of compressor shell, the bottom of the lower shell cover is provided with a first mounting hole.Fixed tube, the first end of the fixed tube is axially disposed in the first mounting hole.Through the fixed tube, it is provided in the fixed tube.Magnetic float, with a through hole that is slidably fitted with the fixed tube.The magnetic float includes a float ball and an inner magnet provided in the float ball.And dust collection magnet, provided on the side of the lower shell cover facing the compressor shell.The dust collection magnet is consistent with the magnetic pole direction of the inner magnet, so that the dust collection magnet and the inner magnet form a magnetic force that repels each other along the axis direction.The oil level sensor assembly of the compressor of the present application can increase the resistance of the magnetic float to the viscosity of the oil film, reduce the influence of the viscosity of the oil film on the magnetic float, and ensure the reliability of the oil level sensor.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment, and more particularly to a compressor and its oil level sensor assembly. Background Technology

[0002] Compressors using oil level sensors are generally used in light commercial or commercial air conditioning systems. They are typically large-displacement compressors with relatively large dimensions. These compressors produce a relatively large amount of iron filings during operation, so a dust-collecting magnet is usually installed at the bottom of the compressor to prevent excessive iron filings from affecting its normal operation. The magnetic float of the oil level sensor floats with the oil level. When the magnetic float approaches the sensing device, it outputs an alarm signal for low oil level detection inside the compressor. Therefore, the magnetic float is usually also located at the bottom of the compressor.

[0003] The oil level sensor is typically fixedly connected to the lower casing of the compressor to form an oil level sensor assembly. During normal operation of the compressor, the bottom of the lower casing accumulates a significant amount of oily substance. This oily substance has a certain degree of adhesion to the magnetic float, and especially when the compressor operates at a low temperature, the magnetic float may become stuck to the bottom of the lower casing due to the oily substance, preventing it from functioning properly.

[0004] To solve the above-mentioned technical problems, existing technologies often add a spring under the float of the magnetic float to ensure the normal operation of the magnetic float. However, in actual use, the spring design does not increase the magnetic float's resistance to the viscosity of the oil film, and may even prevent the magnetic float from falling normally. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a compressor and its oil level sensor assembly to reduce the influence of oil film viscosity on the magnetic float and ensure the reliability of the oil level sensor.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] An oil level sensor assembly for a compressor, comprising:

[0008] The lower cover is encapsulated at the bottom of the compressor housing, and the bottom of the lower cover has a first mounting hole.

[0009] A fixing tube, the first end of which is axially inserted into the first mounting hole.

[0010] A reed switch is located inside the fixed tube.

[0011] A magnetic levitation element has a through hole that slides within the fixed tube. The magnetic levitation element includes a float and an internal magnet disposed within the float.

[0012] A dust-collecting magnet is disposed on the side of the lower cover facing the compressor housing. The magnetic poles of the dust-collecting magnet are aligned with those of the inner magnet, so that a repulsive magnetic force is formed between the dust-collecting magnet and the inner magnet along the axial direction.

[0013] In one embodiment of the present invention, the distance between the central axis of the dust collecting magnet and the central axis of the inner magnet is denoted as L, then:

[0014] L> 3 √[(Br 2 *K0*S) / (F 重力 *10%*2μ0)],where Br is the remanence, K0 is the demagnetization coefficient, S is the cross-sectional area of ​​the magnetic circuit, F 重力 Let μ be the gravity of the magnetic levitation vehicle, and μ0 be the permeability of free space.

[0015] In one embodiment of the present invention, 22mm <L<55mm。

[0016] In one embodiment of the present invention, the dust collecting magnet is annular and coaxially arranged with the compressor housing.

[0017] In one embodiment of the present invention, a first limiting structure is provided at the first axial end of the fixed tube, and the first limiting structure is formed as an annular radial protrusion with a diameter larger than the first mounting hole.

[0018] In one embodiment of the present invention, a second limiting structure is provided at the second end of the fixed tube along the axial direction, and the maximum width of the second limiting structure is greater than the diameter of the end of the through hole away from the first mounting hole.

[0019] In one embodiment of the invention, the float is formed in a cylindrical shape.

[0020] According to another aspect of the invention, a compressor is provided that includes an oil level sensor assembly for a compressor as described above.

[0021] The oil level sensor assembly of the compressor of the present invention can increase the resistance of the magnetic float to oil film viscosity, reduce the influence of oil film viscosity of oily substances on the magnetic float, and ensure the reliability of the oil level sensor. Attached Figure Description

[0022] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the oil level sensor assembly of the compressor in one embodiment of the present invention.

[0024] Figure 2 yes Figure 1 A schematic diagram of the magnetic field distribution of the internal magnet and the dust-collecting magnet.

[0025] Figure 3 yes Figure 1 A 3D view of the magnetic float in the oil level sensor assembly shown.

[0026] Figure Labels

[0027] 1. Lower shell cover

[0028] 2. Fixed tube

[0029] 3 Reed Switches

[0030] 4. Magnetic levitation

[0031] 5 Dust-collecting magnets

[0032] 21 First limiting structure

[0033] 22 Second limiting structure

[0034] 41 Float

[0035] 42 Internal magnets

[0036] 411 Through hole Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0038] Figure 1 This is a schematic diagram of the structure of the oil level sensor assembly of the compressor in one embodiment of the present invention. Figure 2 yes Figure 1 A schematic diagram of the magnetic field distribution of the internal magnet and the dust-collecting magnet. Figure 3 yes Figure 1 A 3D view of the magnetic float in the oil level sensor assembly shown. Figures 1 to 3As shown, this embodiment provides an oil level sensor assembly for a compressor. The oil level sensor assembly includes a lower cover 1, a fixing tube 2, a reed switch 3, a magnetic float 4, and a dust collecting magnet 5. The lower cover 1 is encapsulated at the bottom of the compressor housing, and a first mounting hole is provided at the bottom of the lower cover 1. The first end of the fixing tube 2 passes through the first mounting hole. The reed switch 3 is disposed inside the fixing tube 2. The magnetic float 4 has a through hole 411 that slides with the fixing tube 2. The magnetic float 4 includes a float 41 and an inner magnet 42 disposed in the float 41. The dust collecting magnet 5 is disposed on the side of the lower cover 1 facing the compressor housing. The magnetic poles of the dust collecting magnet 5 and the inner magnet 42 are aligned, so that a repulsive magnetic force is formed between the dust collecting magnet 5 and the inner magnet 42 along the axial direction.

[0039] The oil level sensor assembly of the compressor in this invention can increase the resistance of the magnetic float 4 to oil film viscosity, reduce the influence of oil film viscosity on the magnetic float 4, and ensure the reliability of the oil level sensor. It should be noted that... Figure 2 Only shown Figure 1 The diagram illustrates a magnetic field distribution of the inner magnet 42 and the dust-collecting magnet 5, where both the dust-collecting magnet 5 and the inner magnet 42 may have their N poles pointing upwards. However, this invention is not limited to this; for example, both the dust-collecting magnet 5 and the inner magnet 42 may have their S poles pointing upwards, which can also solve existing technical problems and achieve the corresponding technical effects.

[0040] In this embodiment, the reed switch 3 includes two metal reed contacts made of soft magnetic material that are open when there is no magnetism. In some other embodiments, a third reed can be provided as a normally closed contact. These reed contacts are encapsulated in a glass tube filled with an inert gas (such as nitrogen, helium, etc.) or a vacuum. The ends of the parallel reeds encapsulated inside the glass tube overlap, leaving a certain gap or contacting each other to form the normally open or normally closed contacts of the switch. The magnetic float 4 can control the opening and closing of the reeds as it floats or sinks with the liquid level, thereby affecting the circuit's continuity and realizing the alarm function of the oil level sensor.

[0041] The distance between the central axis of the dust collecting magnet 5 and the central axis of the inner magnet 42 can be denoted as L, then: L> 3 √[(Br 2 *K0*S) / (F 重力 *10%*2μ0)],where Br is the remanence, K0 is the demagnetization coefficient, S is the cross-sectional area of ​​the magnetic circuit, F 重力 Let μ be the gravity of the magnetic levitation 4, and μ0 be the vacuum permeability. Specifically, due to the repulsive magnetic force F between the dust collecting magnet 5 and the inner magnet 42... 磁 Much smaller than the weight F of buoy 41 重力The liquid level tolerance for the magnetic levitation 4 to rise or sink is expected to be within ±2mm, and the repulsive magnetic force F 磁 This causes the magnetic levitation element 4 to float upwards in advance, changing the positional relationship between the actual oil level and the expected alarm oil level. Based on extensive experimental data, it can be seen that the F... 磁 The proportion must be at least less than 4 times the gravity F of the magnetic levitation. 重力 10%, that is, F 磁 <F 重力 *10%.

[0042] According to Maxwell's formula for suction force F 磁 = (B 2 S) / (2μ0). Where B is the magnetic flux density (Wb / m2), and S is the cross-sectional area of ​​the magnetic circuit (m²). 2 μ0 is the free permeability, μ0 = 1.25 * 10⁻⁶ -6 (H / m). Furthermore, the magnetic force between the dust-collecting magnet 5 and the inner magnet 42 is almost inversely proportional to the cube of the horizontal distance between them. Therefore, combining existing technology, F 磁 =(Br 2 *K0*S) / [L 3 *(2μ0)], where Br is the remanence, K0 is the demagnetization coefficient, and K0=1.6*10 9 Therefore, L> 3 √[(Br 2 *K0*S) / (F 重力 *10%*2μ0)].

[0043] Table 1

[0044]

[0045] Table 1 shows the relevant experimental data. As can be seen from Table 1, when L is less than 22 mm, the early alarm height of the oil level sensor exceeds the expected liquid level tolerance (±2 mm), and the ratio of magnetic force to gravity is >10%, which obviously does not meet the design requirements.

[0046] Furthermore, to ensure the reliability of the oil level sensor, L > 22mm is preferable. Of course, considering that the maximum radius of the compressor housing is generally 55mm, the distance L between the central axis of the dust collecting magnet 5 and the central axis of the inner magnet 42 should naturally satisfy: L < 55mm.

[0047] The inner magnet 42 can be multiple cylindrical magnets arranged in a ring around the through hole 411. Alternatively, the inner magnet 42 can be at least one annular magnet, coaxially arranged with the through hole 411. The inner magnet 42 can be located inside the float 41. Furthermore, the through hole 411 can pass through the center of gravity of the magnetic float 4. This reduces the resistance of the magnetic float 4 as it fluctuates with the oil surface, improving the sensitivity of the oil level sensor. Further, the openings at both ends of the through hole 411 are the same size. Therefore, this oil level sensor assembly does not require a mounting structure for installing a buoyancy spring or related components. This further reduces the resistance of the magnetic float 4 as it fluctuates with the oil surface, thereby improving the sensitivity of the oil level sensor.

[0048] Please see Figure 1 The dust-collecting magnet 5 can be annular and coaxially arranged with the compressor housing. This effectively adsorbs iron filings generated during compressor operation, preventing excessive iron filings from affecting the normal operation of the compressor. The fixing tube 2 is vertically arranged at the bottom of the lower cover 15. This allows for more accurate monitoring of the lubricating oil level in the compressor. The first axial end of the fixing tube 2 can typically be provided with a first limiting structure 21, which is formed as an annular radial protrusion with a diameter larger than the first mounting hole. This first limiting structure 21 can both prevent the magnetic float 4 from directly contacting the lower cover 1 and facilitate a stable connection between the fixing tube 2 and the lower cover 1.

[0049] Furthermore, such as Figure 1 As shown, a second limiting structure 22 is provided at the second axial end of the fixed pipe 2. This second limiting structure 22 can also be designed with reference to the first limiting structure 21, as long as the maximum width of the first limiting structure 21 is greater than the inner diameter of the through hole 411. This can prevent the magnetic float 44 from detaching from the fixed pipe 2 and ensure the reliability of the oil level sensor in monitoring the lubricating oil level in the compressor.

[0050] like Figure 3 As shown, the float 41 is formed in a cylindrical shape. However, the float 41 can also be formed in a spherical or other regular shape; this invention is not limited to this. This simplifies the manufacturing process of the float 41, facilitates the assembly of the oil level sensor assembly, reduces the resistance of the magnetic float 4 as the oil surface fluctuates, and improves the sensitivity of the oil level sensor.

[0051] In summary, the oil level sensor assembly of the compressor of the present invention can increase the resistance of the magnetic float 4 to oil film viscosity, reduce the influence of oil film viscosity of oily substances on the magnetic float 4, and ensure the reliability of the oil level sensor.

[0052] Furthermore, according to another aspect of the present invention, a compressor is also provided, which includes the oil level sensor assembly described above. For the specific structure of the oil level sensor assembly and its corresponding technical advantages, please refer to... Figures 1 to 3 As described above. In summary, the oil level sensor assembly of the compressor of the present invention can increase the resistance of the magnetic float 4 to oil film viscosity, reduce the influence of oil film viscosity of oily substances on the magnetic float 4, and ensure the reliability of the oil level sensor.

[0053] It should be noted that, in this embodiment, the compressor also includes other components from the prior art besides the oil level sensor assembly, such as a motor, pump body, and housing. Since these are not the innovative aspects of this invention, their specific structures can be designed with reference to existing technologies. Therefore, this invention does not limit them, nor will it elaborate on them here.

[0054] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. An oil level sensor assembly for a compressor, characterized in that, include: The lower cover is encapsulated at the bottom of the compressor housing, and the bottom of the lower cover is provided with a first mounting hole; A fixing tube, wherein the first end of the fixing tube is axially disposed through the first mounting hole; A reed switch is disposed inside the fixed tube; A magnetic float having a through hole that slides with the fixed tube, the magnetic float comprising a float ball and an inner magnet disposed in the float ball; A dust-collecting magnet is located on the side of the lower cover facing the compressor housing. The magnetic poles of the dust-collecting magnet are aligned with those of the inner magnet, creating an axially repulsive magnetic force between them. This magnetic force is less than 10% of the weight of the magnetic levitation buoy. Let L be the distance between the central axis of the dust-collecting magnet and the central axis of the inner magnet. Where Br is the remanence, Ko is the demagnetization coefficient, and S is the cross-sectional area of ​​the magnetic circuit. ρ is the gravity of the magnetic levitation vehicle, and µo is the permeability of free space.

2. The oil level sensor assembly according to claim 1, characterized in that, 22mm <L<55mm。 3. The oil level sensor assembly according to claim 1, characterized in that, The dust collection magnet is ring-shaped and coaxially arranged with the compressor housing.

4. The oil level sensor assembly according to claim 1, characterized in that, The first end of the fixed tube along the axial direction is provided with a first limiting structure, which is formed as an annular radial protrusion with a diameter larger than the first mounting hole.

5. The oil level sensor assembly according to claim 1, characterized in that, The second end of the fixed tube is provided with a second limiting structure, and the maximum width of the second limiting structure is greater than the diameter of the end of the through hole away from the first mounting hole.

6. The oil level sensor assembly according to claim 1, characterized in that, The buoy is formed in a cylindrical shape.

7. A compressor, characterized in that, Includes the oil level sensor assembly as described in any one of claims 1-6.

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