JP7700255B2 - Airtight terminals and compressors - Google Patents

Description

The present disclosure relates to an airtight terminal and a compressor.

Airtight terminals used in refrigerant compressors in refrigerators, air conditioners, etc. are required to withstand high pressure and high voltage because the compressor is placed inside a pressure-resistant container filled with refrigerant.

For example, Patent Document 1 proposes an airtight terminal for a compressor that includes a metal outer ring having a circular top plate portion, a cylindrical portion extending downward from the outer peripheral end of the top plate portion, a flange portion extending from the lower end of the cylindrical portion, and a small cylindrical portion extending inward from the top plate portion and having a lead sealing hole formed therein, a lead sealed to the lead sealing hole of the metal outer ring via sealing glass, and an insulating sleeve fused to the sealing glass on the inner side of the metal outer ring, the insulating sleeve being fused to the sealing glass on the inner side of the metal outer ring so as to extend beyond the small cylindrical portion in parallel to the top plate portion. It also states that the insulating sleeve is made of ceramics such as alumina or forsterite.

Patent Document 2 proposes an airtight terminal comprising a columnar insulator with a through hole formed in the axial direction, a conductor pin inserted into the through hole with both ends protruding, metal joining members that hermetically join the end face of the insulator and the conductor pin, and a metal sleeve joined to the outer circumferential surface of the insulator, at least one of the metal joining members comprising a cylindrical main body portion having a smaller diameter than the insulator and a larger diameter than the conductor pin, a flange portion that is integrally formed on one end of the main body and is joined to the end face of the insulator, and a tubular portion that is integrally formed on the other end of the main body via a step portion and through which the conductor pin is inserted to be joined.

JP 2008-258100 A JP 2002-42920 A

The airtight terminal according to the present disclosure comprises a conductive pin, a cylindrical insulating member having a through hole opening on the high-voltage side and the low-voltage side for inserting the conductive pin, an annular member made of metal surrounding the insulating member, and a brazing portion for fixing the conductive pin to the main surface of the high-voltage side of the insulating member or to the convex surface of a convex portion provided on the main surface. The insulating member comprises a base portion located in the internal space of the annular member, and an extension portion extending from the base portion toward the low-voltage side. The outermost diameter of the base portion is larger than the outermost diameter of the extension portion.

The compressor according to the present disclosure comprises a casing housing a motor for compressing a refrigerant, and the above-mentioned airtight terminal attached to the casing. Electric power from an external power source is supplied to the motor via a conductive pin.

FIG. 2 is a plan view showing a hermetic terminal according to a non-limiting embodiment of the present disclosure, as viewed from the main surface on the low-voltage side of an insulating member. 2 is a plan view of the hermetic terminal shown in FIG. 1 as viewed from a high-voltage side main surface of an insulating member. 3 is a cross-sectional view of the hermetic terminal shown in FIG. 1 and FIG. 2 taken along line III-III. This is the same cross-sectional view as FIG. 4 is an enlarged view of the periphery of an outer surface of an extension portion in the hermetic terminal shown in FIG. 3 . FIG. 2 is a schematic diagram illustrating a compressor according to a non-limiting embodiment of the present disclosure.

When the volume of the insulating sleeve (Patent Document 1) in the inner space of the metal outer ring is large, there is a problem that a higher pressure resistance is required. Also, when fixing with a metal sleeve (Patent Document 2), there is a problem that the insulator is easily peeled off from the metal sleeve due to a shearing action. Also, when exposed to high temperatures, the sealing glass is easily melted, so a structure that can withstand exposure to high temperatures is required.

The present disclosure provides airtight terminals and compressors with high voltage and pressure resistance.

The airtight terminals and compressors disclosed herein have high voltage and pressure resistance.

<Airtight terminal>
Hereinafter, the airtight terminal of the non-limiting embodiment of the present disclosure will be described in detail with reference to the drawings. However, in each of the drawings referred to below, for the convenience of explanation, only the main members necessary for explaining the embodiment are shown in a simplified manner. Therefore, the airtight terminal may include any component member not shown in each of the drawings referred to. In addition, the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components and the dimensional ratios of each component.

As shown in the example of Figures 1 to 5, the airtight terminal 1 comprises a conductive pin 2, an insulating member 3, an annular member 4, and a brazed portion 5. This airtight terminal 1 can be used, for example, in a compressor. Below, each component of the airtight terminal 1 will be described in order, taking the case where the airtight terminal 1 is for a compressor as an example.

The conductive pin 2 is conductive and can function as a conductive path for inputting and outputting electrical signals to and from the inside and outside of the pressure-resistant container to which the airtight terminal 1 is attached. Examples of materials for the conductive pin 2 include metals with good conductivity, such as copper, such as oxygen-free copper, tough pitch copper, and phosphorus-deoxidized copper, titanium, nickel, austenitic stainless steel (e.g., SUS304), Cu-Ni alloys (e.g., cupronickel), Fe-Co alloys, Fe-Co-C alloys, Fe-Ni alloys, and Fe-Ni-Co alloys. The shape of the conductive pin 2 may be cylindrical or polygonal. There may be one conductive pin 2, or there may be multiple conductive pins 2. When there are multiple conductive pins 2, the number of conductive pins 2 may be 2 to 50.

The insulating member 3 has insulating properties and is capable of holding the conductive pin 2 while electrically insulating it. Examples of materials for the insulating member 3 include electrically insulating materials such as aluminum oxide sintered compacts.

The insulating member 3 has a cylindrical shape. More specifically, the insulating member 3 has a cylindrical shape extending along an axis S. The axis S passes through the centers of each of the two main surfaces 32, 33 of the insulating member 3.

The insulating member 3 is provided with a through hole 31 for inserting the conductive pin 2. The through hole 31 opens to the high pressure side A1 and the low pressure side A2 of the insulating member 3. The high pressure side A1 may mean the side with a relatively high pressure, and the low pressure side A2 may mean the side with a relatively low pressure. When the airtight terminal 1 is used, the high pressure side A1 of the insulating member 3 may be located at a place with a higher pressure than the low pressure side A2 of the insulating member 3. For example, when the airtight terminal 1 is attached to a pressure-resistant container, the main surface 32 of the high pressure side A1 may be located inside the pressure-resistant container, and the main surface 33 of the low pressure side A2 may be located outside the pressure-resistant container. The through hole 31 may open to the main surface 32 of the high pressure side A1 of the insulating member 3 or the convex surface 341 (top surface) of the convex portion 34 provided on the main surface 32, or may open to the main surface 33 of the low pressure side A2 of the insulating member 3.

There may be one through hole 31 or multiple through holes 31. The number of through holes 31 may be the same as the number of conductive pins 2. When there are multiple through holes 31, the multiple through holes 31 may be positioned at equal intervals along the circumferential direction of the insulating member 3. For example, when there are three through holes 31, the three through holes 31 may be positioned so as to be rotationally symmetrical at 120° with respect to the axis S of the insulating member 3.

The conductive pin 2 is inserted into the through hole 31 with both ends protruding. When a device located inside the pressure vessel and a device located outside the pressure vessel are electrically connected to both ends of the conductive pin 2 protruding from the through hole 31, the airtight terminal 1 can function as a terminal that transmits electrical signals between the devices inside and outside the pressure vessel.

The annular member 4 can function as an attachment site for attaching the airtight terminal 1 to the pressure-resistant container. Therefore, the airtight terminal 1 may be attached to the pressure-resistant container via the annular member 4.

The annular member 4 surrounds the insulating member 3. More specifically, the annular member 4 surrounds at least a portion of the insulating member 3. The term "annular" in the annular member 4 is not limited to annular, but is a concept that includes annular or cylindrical shapes as long as it can surround the insulating member 3. Therefore, the shape of the annular member 4 is not limited to annular, but may be annular or cylindrical. For example, as in the example shown in Figure 3, the shape of the annular member 4 may be cylindrical. Furthermore, the outer diameter of the annular member 4 may be constant.

The annular member 4 is made of a metal. Examples of metals include carbon steel for mechanical construction such as S25C, rolled steel for general construction (cold rolled steel) such as SS400, and Fe-Ni-Co alloys.

The brazing portion 5 is a portion for fixing the conductive pin 2 to the main surface 32 of the high-voltage side A1 of the insulating member 3 or to the convex surface 341 of the convex portion 34 provided on the main surface 32. Examples of the brazing material include silver brazing (e.g., Bag-8, Bag-9), etc.

The brazing portion 5 may be one or more. The number of brazing portions 5 may be the same as the number of conductive pins 2. When there are multiple brazing portions 5, the multiple brazing portions 5 are located apart from each other.

2, when the number of brazing parts 5 is three, the three brazing parts 5 may be conveniently designated as the first brazing part 51, the second brazing part 52, and the third brazing part 53. The same applies to the conductive pin 2 and the through hole 31.

3 and 4, the insulating member 3 includes a base 35 located in the internal space of the annular member 4, and an extension 36 extending from the base 35 toward the low-voltage side A2. The outermost diameter D1 of the base 35 is greater than the outermost diameter D2 of the extension 36. In these cases, the spatial distance and creepage distance between the conductive pin 2 and the annular member 4 on the low-voltage side A2 are longer, so that the withstand voltage can be increased. In addition, the low-voltage side A2 of the base 35 can be attached directly to the metal annular member 4 by brazing or the like, so that the withstand voltage can be increased.

In addition, the outermost diameter D1 and the outermost diameter D2 are not limited to a specific value. For example, the outermost diameter D1 may be set to about 20 mm or more and 30 mm or less. Furthermore, the outermost diameter D2 may be set to about 15 mm or more and 20 mm or less.

The length L1 (mm) of the extension 36 in the axial direction S may be 1/400 or more times the potential difference (V/mm) between the annular member 4 and the conductive pin 2. In this case, the spatial distance and creepage distance between the outer circumferential surface of the conductive pin 2 exposed to the low-voltage side A2 and the surface of the annular member 4 closest to the outer circumferential surface of the conductive pin 2 can be increased, thereby further increasing the withstand voltage.

The length L1 (mm) of the extension 36 in the axial direction S may be 1/100 or more times the potential difference (V/mm) generated between the annular member 4 and the conductive pin 2. The potential difference (V/mm) may be measured, for example, by a voltage resistance tester.

The length L1 of the extension 36 in the axial direction S may be 7 mm or more. In this case, the spatial distance and creepage distance between the outer peripheral surface of the conductive pin 2 exposed to the low-voltage side A2 and the surface of the annular member 4 closest to the outer peripheral surface of the conductive pin 2 can be increased, thereby further increasing the withstand voltage. The upper limit of the length L1 may be 12 mm.

The length L1 of the extension 36 in the axial direction S may be longer than the length L2 of the base 35 in the axial direction S. In this case, the spatial distance and creepage distance between the conductive pin 2 and the annular member 4 on the low-voltage side A2 are longer, so that the withstand voltage can be increased. Note that the length L2 is not limited to a specific value. For example, the length L2 may be set to approximately 7 mm or more and 12 mm or less.

As shown in the example of FIG. 5, the outer surface 361 of the extension portion 36 may be inclined toward the low-voltage side A2. In other words, the outer surface 361 of the extension portion 36 may be an inclined surface that inclines toward the axis S of the insulating member 3 toward the main surface 33 of the low-voltage side A2. The angle θ between the outer surface 361 of the extension portion 36 and the axis S of the insulating member 3 may be an acute angle. In these cases, for example, when the insulating member 3 is produced by uniaxial press molding, cold isostatic pressing (CIP) molding, or the like, demolding becomes easy, and cracks are less likely to occur when the molded body is removed. Therefore, even if the temperature is increased and decreased repeatedly, the extension of the cracks is suppressed.

The angle θ is not limited to a specific value. For example, the angle θ may be set to about 2° or more and 3° or less. When evaluating the angle θ, a virtual axis S' parallel to the axis S may be used as a reference.

The outer surface 361 of the extension portion 36 may have a smaller average value of the cut level difference (Rδc), which represents the difference between the cut level at a load length ratio of 25% on the roughness curve and the cut level at a load length ratio of 75% on the roughness curve, than the main surface 32 of the high-pressure side A1 of the insulating member 3.

If the average value of the cut level difference (Rδc) of the outer surface 361 is smaller than the average value of the cut level difference (Rδc) of the main surface 32, when the outer surface 361 is held by a holding member (not shown), the detachment of particles that is likely to occur due to holding can be reduced. Here, the particles refer to a plurality of solid fine particles that are formed when an aluminum oxide sintered body or the like is used as the insulating member 3, and part of the crystals constituting the sintered body detach into the space. Since the detachment of such particles is reduced, the floating of the detached particles in the space (e.g., vacuum space) of the low-pressure side A2 is suppressed. On the other hand, since the average value of the cut level difference (Rδc) of the main surface 32 is larger than the average value of the cut level difference (Rδc) of the outer surface 361, the extension distance between the conductive pins 2 becomes longer, and the risk of insulation breakdown is reduced.

The average value of the cut level difference (Rδc) of the main surface 32 may be 1 μm or more and 2.2 μm or less, or may be 1 μm or more and 1.9 μm or less.

The difference (ΔRδc) between the average value of the cutting level difference (Rδc) of the outer surface 361 and the average value of the cutting level difference (Rδc) of the main surface 32 is, for example, 0.2 μm or more and 0.7 μm or less.

The cut level difference (Rδc) may be measured, for example, in accordance with JIS B 0601:2001, by drawing four lines to be measured at approximately equal intervals in each of three measurement ranges on each of the outer side surface 361 and the main surface 32, and performing line roughness measurement, as described below, and calculating an average value of 12 measured values on each of the outer side surface 361 and the main surface 32. The measurement conditions may be set, for example, as follows.
Measuring instrument: Shape analysis laser microscope (Keyence Corporation's "VK-X1100" or its successor model)
Illumination: Coaxial epi-illumination Cutoff value λs: None Cutoff value λc: 0.08 mm
Cutoff value λf: None End effect correction: Yes Measurement magnification: 240x (10x24)
Surface shape correction: Waviness removal Correction strength: 5
Height threshold setting: Ignoring minute areas (103.34 μm ² ) Measurement locations: Three locations on each of the outer surface 361 and the main surface 32 Measurement range: 1428 μm×1071 μm/location Length of lines to be measured: 1280 μm/line

The shape of the extension 36 may be a truncated cone. For example, if the extension 36 is a truncated pyramid, stress concentration is likely to occur on the side edges. However, if the extension 36 is a truncated cone, there are no side edges, so stress concentration is unlikely to occur. Therefore, the extension 36 is less likely to break.

The base 35 may include a small diameter portion 351 and a large diameter portion 352. The small diameter portion 351 may be located on the high pressure side A1. The large diameter portion 352 may be located on the low pressure side A2. More specifically, the large diameter portion 352 may be located on the lower pressure side A2 than the small diameter portion 351. In addition, the outer diameter D4 of the large diameter portion 352 may be larger than the outer diameter D3 of the small diameter portion 351.

When the base 35 has the small diameter portion 351 and the large diameter portion 352 described above, a step surface 353 is formed that connects the outer circumferential surface of the small diameter portion 351 to the outer circumferential surface of the large diameter portion 352. In other words, the base 35 has a step surface 353 that connects the outer circumferential surface of the small diameter portion 351 to the outer circumferential surface of the large diameter portion 352. Due to the presence of this step surface 353, the creeping distance between the conductive pin 2 and the annular member 4 on the high voltage side A1 is increased, so that the withstand voltage can be increased. The outer diameter D4 of the large diameter portion 352 may be the outermost diameter D1 of the base 35. The outer diameter D3 of the small diameter portion 351 may be larger than the outermost diameter D2 of the extension portion 36. When the outer diameter D3 is larger than the outermost diameter D2, the strength of the base 35 is high.

The length L3 of the small diameter portion 351 in the axial direction S may be shorter than the length L4 of the large diameter portion 352 in the axial direction S. In this case, the length L4 of the large diameter portion 352 in the axial direction S is relatively long, so that the strength of the base portion 35 is high.

<Compressor>
Next, a compressor according to a non-limiting embodiment of the present disclosure will be described with reference to the drawings, taking as an example a case in which the compressor includes the above-described airtight terminal 1 .

As shown in the example in FIG. 6, the compressor 100 comprises a casing 101 (pressure-resistant container) and an airtight terminal 1. The casing 101 houses a motor 102 for compressing the refrigerant. The airtight terminal 1 is attached to the casing 101. Power from an external power source 103 is supplied to the motor 102 via the conductive pin 2. In these cases, the compressor 100 comprises an airtight terminal 1 with high voltage and pressure resistance, enabling stable operation over a long period of time.

The airtight terminal 1 may be attached to the casing 101, for example, by welding. The motor 102 may be, for example, a three-phase motor. The external power source 103 may be, for example, a three-phase AC power source. The motor 102 and the external power source 103 may be electrically connected to the conductive pin 2 via wiring 104.

The compressor 100 may include a compression mechanism 105, a suction pipe 106, and a discharge pipe 107. The compression mechanism 105 is housed in a casing 101. The suction pipe 106 and the discharge pipe 107 are attached to the casing 101. The suction pipe 106 and the discharge pipe 107 may be attached to the casing 101 by, for example, welding.

The compression mechanism 105 is driven by the motor 102 and compresses the refrigerant. The suction pipe 106 sends the refrigerant to the compression mechanism 105. The discharge pipe 107 discharges the refrigerant compressed by the compression mechanism 105 and sends it to the refrigerant circulation system.

When the compressor 100 includes the compression mechanism 105, the suction pipe 106, and the discharge pipe 107, power is supplied from the external power source 103 to the motor 102 via the airtight terminal 1, and the compression mechanism 105 can compress the refrigerant by driving the motor 102. The refrigerant also flows from the suction pipe 106 into the compression mechanism 105, and the compressed refrigerant flows out of the discharge pipe 107 and is sent to the refrigerant circulation system.

Although the above provides examples of embodiments of the present disclosure, it goes without saying that the present disclosure is not limited to the above embodiments and may be any embodiment without departing from the gist of the present disclosure.

For example, in the above embodiment, the airtight terminal 1 is used for a compressor in a refrigerator, but the airtight terminal 1 can be used for other purposes. Examples of other uses include sensor units, aluminum electrolytic capacitors, relay contact devices, medical equipment, storage devices, and compressors driven by electric motors used in hybrid and electric vehicles.

REFERENCE SIGNS LIST 1: Airtight terminal 2: Conductive pin 3: Insulating member 31: Through hole 32: Main surface on high pressure side 33: Main surface on low pressure side 34: Convex portion 341: Convex surface 35: Base 351: Small diameter portion 352: Large diameter portion 353: Step surface 36: Extension portion 361: Outer surface 4: Annular member 5: Brazed portion 51: First brazed portion 52: Second brazed portion 53: Third brazed portion 100: Compressor 101: Casing 102: Motor 103: External power source 104: Wiring 105: Compression mechanism 106: Suction pipe 107: Discharge pipe S: Shaft A1: High pressure side A2: Low pressure side

Claims (7)

A conductive pin;
a cylindrical insulating member having through holes opening on a high voltage side and a low voltage side and into which the conductive pin is inserted;
a metal annular member surrounding the insulating member;
a brazing portion for fixing the conductive pin to a main surface of the high voltage side of the insulating member or a convex surface of a convex portion provided on the main surface,
The insulating member is
A base portion located in an internal space of the annular member;
an extension portion extending from the base portion toward the low pressure side,
The outermost diameter of the base portion is larger than the outermost diameter of the extension portion,
a side surface of the extension portion facing the annular member is spaced from the annular member;
a distance between the side surface and the annular member is longer than a distance between the side surface and the conductive pin;
The base portion is
A small diameter portion located on the high pressure side;
a large diameter portion located on the low pressure side and having an outer diameter larger than that of the small diameter portion,
An airtight terminal , wherein the small diameter portion has an outermost diameter larger than the outermost diameter of the extension portion . The airtight terminal according to claim 1, wherein the axial length (mm) of the extension is 1/400 or more times the potential difference (V/mm) generated between the annular member and the conductive pin. The airtight terminal according to claim 1 or 2, wherein the axial length of the extension is 7 mm or more. The airtight terminal according to claim 1 or 2, wherein the outer surface of the extension is inclined toward the low-voltage side and forms an acute angle with the axis of the insulating member. The airtight terminal according to claim 1 or 2, in which the outer surface of the extension has a smaller average value of the cut level difference (Rδc) representing the difference between the cut level at a load length ratio of 25% on the roughness curve and the cut level at a load length ratio of 75% on the roughness curve than the main surface on the high-voltage side of the insulating member. The airtight terminal according to claim 1 or 2, wherein the extension portion has a truncated cone shape. a casing housing a motor for compressing a refrigerant;
and the hermetic terminal according to claim 1 or 2 attached to the casing,
A compressor that supplies power from an external power source to the motor through the conductive pin.

Images