JP7701985B2 - 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 with 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 surface of the metal outer ring, the insulating sleeve being fused to the sealing glass on the inner surface of the metal outer ring so as to extend parallel to the top plate portion beyond the small cylindrical portion.

JP 2008-258100 A

The airtight terminal according to the present disclosure comprises a disk-shaped or cylindrical insulating member having a plurality of conductive pins and a plurality of through holes in the thickness direction for individually inserting the conductive pins, an annular member surrounding the insulating member, and a plurality of brazing portions for respectively fixing the conductive pins to one of the main surfaces of the insulating member. The main surface of the insulating member on the side having the brazing portions has grooves that each define the brazing portions. The shape of the grooves is U-shaped, V-shaped, or isosceles trapezoidal.

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. 2 is a plan view of the hermetic terminal shown in FIG. 1 as viewed from a main surface on the side having a brazing portion. 3 is a cross-sectional view of the hermetic terminal shown in FIG. 1 and FIG. 2 taken along line III-III. 3 is a cross-sectional view of a U-shaped groove, which is an example of a groove in the hermetic terminal shown in FIG. 2 . FIG. 3 is a cross-sectional view of a V-shaped groove, which is an example of a groove in the hermetic terminal shown in FIG. 2 . FIG. 3 is a cross-sectional view of an isosceles trapezoidal groove, showing an example of a groove in the hermetic terminal shown in FIG. 2 . FIG. 3 is a cross-sectional view of an isosceles trapezoidal groove, showing an example of a groove in the hermetic terminal shown in FIG. 2 . FIG. FIG. 7B shows the profile of the groove shown in FIG. 7A. FIG. 3 is a plan view of a hermetic terminal according to a non-limiting embodiment of the present disclosure, viewed from a main surface on a side having a brazing portion, and corresponds to FIG. 2 . FIG. 2 is a schematic diagram illustrating a compressor according to a non-limiting embodiment of the present disclosure.

In the airtight terminal for compressors described in Patent Document 1, a part of the metal outer ring contacts the inner circumference of the lead sealing hole, which means that the creepage distance between adjacent leads cannot be sufficiently secured, making it prone to insulation breakdown.

The present disclosure provides an airtight terminal and compressor that are less susceptible to insulation breakdown.

The airtight terminals and compressors disclosed herein are less susceptible to dielectric breakdown.

<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 in Figures 1 to 3, the airtight terminal 1 comprises a conductive pin 2, an insulating member 3, an annular member 4, and a brazing 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 vessel 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 are multiple conductive pins 2. The number of conductive pins 2 may be 2 or more and 50 or less.

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 is disk-shaped or cylindrical. The example insulating member 3 shown in FIG. 3 is cylindrical. More specifically, the example insulating member 3 shown in FIG. 3 is cylindrical and extends 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 not limited to a specific size. For example, the outer diameter D of the insulating member 3 may be set to about 20 mm or more and 30 mm or less. In addition, the length L of the insulating member 3 in the axial direction S may be set to about 14.5 mm or more and 24.5 mm or less.

The insulating member 3 has a plurality of through holes 31 in the thickness direction for individually inserting the conductive pins 2. The thickness direction may mean the direction of the axis S. The through holes 31 may penetrate the insulating member 3 in the thickness direction.

The number of through holes 31 may be the same as the number of conductive pins 2. 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.

Examples of materials for the annular member 4 include metals. 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 that fixes the plurality of conductive pins 2 to one of the main surfaces of the insulating member 3. The brazing portion 5 may fix the plurality of conductive pins 2 to, for example, the main surface 32 or the convex surface 341 (top surface) 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.

There are multiple brazing portions 5. The number of brazing portions 5 may be the same as the number of conductive pins 2. 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.

Here, the main surface 32 on the side having the brazing portion 5 has grooves 321 that define the brazing portion 5. As shown in the example in Figures 4 to 6, the grooves 321 are U-shaped grooves (hereinafter, a U-shaped groove is referred to as a U-groove) 322, V-shaped grooves (hereinafter, a V-shaped groove is referred to as a V-groove) 323, or isosceles trapezoid grooves (hereinafter, an isosceles trapezoid groove is referred to as an isosceles trapezoid groove) 324. By having the grooves 321 that define the brazing portion 5 on the main surface 32 on the side having the brazing portion 5, the creepage distance between adjacent conductive pins 2 is increased, thereby reducing the risk of insulation breakdown. Furthermore, when the groove 321 is a U-groove 322, a V-groove 323, or an isosceles trapezoidal groove 324, the insulating member 3 can be easily demolded in the molding process of uniaxial press molding, cold isostatic pressing (CIP), or the like, compared with the case where the groove 321 is rectangular, and microcracks are less likely to occur around the bottom surface 321a of the groove 321. Therefore, the airtight terminal 1 can be used for a long period of time even if the temperature is repeatedly raised and lowered.

4 to 6 are cross-sectional views perpendicular to the extension direction of the groove 321 (in FIG. 2, the direction from the axis S of the insulating member 3 toward the outer periphery, the same below). As shown in an example in FIG. 4, the U-groove 322 may mean a groove formed in a U-shape in a cross section perpendicular to the extension direction of the groove 321. As shown in an example in FIG. 5, the V-groove 323 may mean a groove formed in a V-shape in a cross section perpendicular to the extension direction of the groove 321. As shown in an example in FIG. 6, the isosceles trapezoidal groove 324 may have an opening width larger than the width of the bottom surface 321a in a cross section perpendicular to the extension direction of the groove 321. The U-groove 322 does not need to be strictly U-shaped, and may include a slight curvature as long as the effect is obtained. This is the same for the V-groove 323 and the isosceles trapezoidal groove 324.

Groove 321 is not limited to a specific size. For example, the width of the opening of groove 321 in a direction perpendicular to the extension direction of groove 321 may be set to about 0.5 mm or more and 2 mm or less. In addition, the depth of groove 321 may be set to about 0.5 mm or more and 2 mm or less.

As shown in FIG. 7A, the groove 321 may have an isosceles trapezoidal shape, and the bottom surface 321a of the groove 321 may be convexly curved in the depth direction of the groove 321 from the main surface 32 side having the brazing portion 5 toward the bottom surface 321a side.

When the bottom surface 321a is convexly curved as described above, the creepage distance between adjacent conductive pins 2 is longer than in the case of an isosceles trapezoid in which the bottom surface 321a is flat, thereby further enhancing the effect of suppressing the risk of insulation breakdown.

In this case, the radius of curvature of the bottom surface 321a is preferably not less than 300 μm and not more than 350 μm.
When the radius of curvature of bottom surface 321a is 300 μm or more, the curvature of bottom surface 321a becomes small, and the occurrence of cracks originating from bottom surface 321a can be suppressed.
If the radius of curvature of the bottom surface 321a is 350 μm or less, the groove 321 becomes deep, and the effect of suppressing the risk of dielectric breakdown is further increased.

Figure 7B is a diagram showing an example of the profile of the groove shown in Figure 7A, and the curvature of the bottom surface 321a is 319 μm. The profile of the groove 321 can be measured using a shape analysis laser microscope (Keyence Corporation's "VK-X1100" or its successor model). Here, the profile of the groove 321 includes the width of the opening of the groove 321, the depth of the groove 321, the radius of curvature of the bottom surface 321a of the groove 321, and the shortest length along the surface of the groove 321. As the measurement conditions, the illumination method is set to coaxial epi-illumination, the magnification is set to 120 times, and the range including the groove 321 is set to, for example, 2781 μm (longitudinal direction of the groove 321) × 2090 μm per location, and three locations are selected. Then, a line perpendicular to the longitudinal direction of the groove 321 is drawn, and the profile measurement is performed using this line as the measurement target.

The bottom surface 321a of the groove 321 may have an average cutting level difference (Rδc), which represents the difference between the cutting level at a load length ratio of 25% on the roughness curve and the cutting level at a load length ratio of 75% on the roughness curve, of 1 μm or more and 2.2 μm or less, or may have an average cutting level difference (Rδc) of 1 μm or more and 2.2 μm or less, or may have an average cutting level difference (Rδc) of 1.3 μm or more and 2.2 μm or less.

When the average value of the cutting level difference (Rδc) of the bottom surface 321a of the groove 321 is equal to or greater than the lower limit described above, the contact angle with pure water is small. Therefore, when dirt adhering to the bottom surface 321a is washed with pure water, the dirt can be easily removed. Furthermore, when the average value of the cutting level difference (Rδc) of the bottom surface 321a of the groove 321 is equal to or less than the upper limit described above, the surface quality is good, so that large shedding is unlikely to occur, and even if such shedding does occur, it is unlikely to float or scatter and cause adverse effects.
The bottom surface 321a of the groove 321 is, for example, a ground surface or a fired surface.

The bottom surface 321a of the groove 321 may have a ratio R2/R1 of the average value R2 of the average length (RSm) to the average value R1 of the arithmetic mean roughness (Ra) in the roughness curve, which is 5 or more.

The average length (RSm) represents the average period of the unevenness of the surface being measured. As the ratio R2/R1 increases, the average period of the unevenness of the surface being measured becomes longer and the average depth of the concave portions of the unevenness becomes shallower. If the ratio R2/R1 is 5 or more, even if the temperature is repeatedly raised and lowered, there are few deep concave portions on the bottom surface 321a, so the occurrence of microcracks can be suppressed.

The ratio R2/R1 may be less than 30.

The main surface 32 on the side having the brazing portion 5 may have an average cutting level difference (Rδc) of 1 μm or more and 2.2 μm or less, or may be 1 μm or more and 1.9 μm or less.

When the average value of the cut level difference (Rδc) of the main surface 32 on the side having the brazed portion 5 is equal to or greater than the above-mentioned lower limit, the contact angle with pure water is small. Therefore, when dirt adhering to the main surface 32 is washed with pure water, the dirt can be easily removed. Furthermore, when the average value of the cut level difference (Rδc) of the main surface 32 is equal to or less than the above-mentioned upper limit, the surface quality is good, so that large grains are unlikely to fall off, and even if such grains do fall off, they are unlikely to float or scatter and cause adverse effects.
The main surface 32 is, for example, a fired surface.

The cut level difference (Rδc), arithmetic mean roughness (Ra) and average length (RSm) 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 as shown below, measuring the line roughness, and calculating the average value of 12 measured values for each. 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)
Measurement locations: 3 locations on bottom surface 321a of groove 321 and main surface 32 Measurement range: 1428 μm×1071 μm/1 location Length of line to be measured: 1280 μm/1 line

The grooves 321 may be provided radially from the axis S of the insulating member 3 toward the outer periphery. In this case, dirt is easily discharged from the axis S toward the outer periphery during cleaning. The grooves 321 may reach the outer periphery of the insulating member 3.

The grooves 321 may be arranged in a honeycomb shape. In the example of the airtight terminal 1' shown in FIG. 8, the grooves 321 are arranged in a honeycomb shape. In this case, the degree of freedom in arranging the conductive pins 2 is increased. The honeycomb shape may mean that the grooves 321 are composed of a plurality of polygons in a plan view. Examples of polygons include a hexagon and an octagon. The grooves 321 may be arranged so as to surround each of the brazing portions 5.

As shown in the example of FIG. 2, the shape of the groove 321 in plan view may be linear. Note that the shape of the groove 321 in plan view is not limited to linear. The shape of the groove 321 in plan view may be, for example, curved, or a combination of linear and curved shapes. The shape of the groove 321 may be zigzag, serpentine, comb-tooth, or wavy. If it has any of these shapes, it may have an irregular or regular pattern.

As shown in the example of FIG. 3, the main surface 32 on the side having the brazing portion 5 may be located on the high pressure side A1, and the other main surface 33 on the side not having the brazing portion 5 may be located on the low pressure side A2. 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 using the airtight terminal 1, the main surface 32 on the side having the brazing portion 5 may be located at a place where the pressure is higher than that of the other main surface 33. For example, when the airtight terminal 1 is attached to a pressure-resistant container, the main surface 32 on the side having the brazing portion 5 may be located inside the pressure-resistant container, and the other main surface 33 may be located outside the pressure-resistant container. The position of the main surface 32 on the side having the brazing portion 5 is not limited to the high pressure side A1, and may be the low pressure side A2.

1 to 8, an airtight terminal in which the main surface 32 has the groove 321 has been described as an example. Instead of the groove 321, the main surface 32 may have linear protrusions (not shown) that each divide the brazing portion 5, and the shape of the protrusions may be U-shaped, V-shaped, or isosceles trapezoidal. These shapes of the protrusions are shapes in a cross section perpendicular to the direction in which the protrusions extend (the longitudinal direction of the protrusions). By providing protrusions that each divide the brazing portion 5, the creepage distance between adjacent conductive pins 2 is increased, thereby reducing the risk of dielectric breakdown. In addition, when the protrusions are U-shaped, V-shaped, or isosceles trapezoidal, demolding is easier than when the protrusions are rectangular when forming the insulating member 3 by uniaxial press molding, cold isostatic pressing (CIP) molding, or the like, and microcracks are less likely to occur around the top surface of the protrusions. Therefore, the airtight terminal can be used for a long period of time even if the temperature is repeatedly increased and decreased.

In a cross section perpendicular to the direction in which the protrusion extends, the width of the isosceles trapezoidal protrusion that intersects with the main surface may be greater than the width of the top surface. Note that the U-shaped protrusion does not need to be strictly U-shaped, and may include a slight curvature as long as the effect is obtained. This is the same for the V-shaped protrusion and the isosceles trapezoidal protrusion.

The protrusion is not limited to a specific size. For example, in a cross section perpendicular to the direction in which the protrusion extends, the width of the protrusion intersecting the main surface may be set to about 0.5 mm or more and 2 mm or less. The height of the protrusion may be set to about 0.5 mm or more and 2 mm or less.

The protrusion may have an isosceles trapezoidal shape, and the top surface of the protrusion may be convexly curved in the height direction of the protrusion from the main surface 32 side having the brazing portion 5 toward the top surface side of the protrusion.

When the top surface is convexly curved as described above, the creepage distance between adjacent conductive pins 2 is longer than in the case of an isosceles trapezoid with a flat top surface, thereby further increasing the effect of suppressing the risk of insulation breakdown.

In this case, the radius of curvature of the top surface is preferably 300 μm or more and 350 μm or less.
When the radius of curvature of the top surface is 300 μm or more, the curvature of the top surface becomes small, and the occurrence of cracks originating from the top surface can be suppressed.
If the radius of curvature of the top surface is 350 μm or less, the protrusion becomes high, and the effect of suppressing the risk of dielectric breakdown is further increased.

The top surface of the protrusion may have an average cutting level difference (Rδc), which represents the difference between the cutting level at a load length ratio of 25% on the roughness curve and the cutting level at a load length ratio of 75% on the roughness curve, of 1 μm or more and 2.2 μm or less, or may be 1.3 μm or more and 2.2 μm or less.

When the average value of the cut level difference (Rδc) of the top surface of the protrusion is equal to or greater than the lower limit described above, the contact angle with pure water is small. Therefore, when dirt adhering to the top surface is washed with pure water, the dirt can be easily removed. Furthermore, when the average value of the cut level difference (Rδc) of the top surface of the protrusion is equal to or less than the upper limit described above, the surface quality is good, so that large shedding is unlikely to occur, and even if such shedding does occur, it is unlikely to float or scatter and cause adverse effects.
The top surface of the protrusion is, for example, a polished surface, a ground surface, or a fired surface.

The top surface of the protrusion may have a ratio R4/R3 of the average value R4 of the average length (RSm) to the average value R3 of the arithmetic mean roughness (Ra) in the roughness curve, which is 5 or more.

When R4/R3 is large, the average period of the unevenness on the top surface becomes longer and the average depth of the concaves of the unevenness becomes shallower. If the ratio R4/R3 is 5 or more, even if the temperature is repeatedly raised and lowered, there are few deep concaves on the top surface, so the occurrence of microcracks can be suppressed.

The ratio R4/R3 may be less than 30.

The measurement conditions for the cut level difference (Rδc), arithmetic mean roughness (Ra) and average length (RSm) of the top surface of the protrusion are the same as those described above, except that the bottom surface 321a is replaced with the top surface of the protrusion.

The protrusions may be arranged radially from the axial core S of the insulating member 3 toward the outer periphery.

The protrusions may be arranged in a honeycomb pattern.

<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. 9, 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 that is less susceptible to insulation breakdown, 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 having brazed portion 321: Groove 321a: Bottom surface 322: U-groove 323: V-groove 324: Equal-legged trapezoidal groove 33: Other main surface 34: Convex portion 341: Convex 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: Axis A1: High pressure side A2: Low pressure side

Claims (11)

A plurality of conductive pins;
a disk-shaped or cylindrical insulating member having a plurality of through holes in a thickness direction for inserting the conductive pins individually;
an annular member surrounding the insulating member;
A hermetic terminal comprising: a plurality of brazing portions each fixing the conductive pin to one of the main surfaces of the insulating member;
the main surface of the insulating member on the side having the brazing portion has grooves that define the brazing portions,
The groove has a U-shape, a V-shape, or an isosceles trapezoidal shape;
the insulating member includes, in order from the main surface side including the brazing portion in a direction along an axis of the insulating member, a small diameter portion and a large diameter portion having an outer diameter larger than that of the small diameter portion,
An airtight terminal, wherein the groove is arranged radially from the axis of the insulating member toward the outer periphery, extends to the outer periphery of the small diameter portion, and is in contact with the space located between the side of the small diameter portion facing the annular member and the annular member without contacting the annular member. The airtight terminal according to claim 1, wherein the groove is an isosceles trapezoid and the bottom surface of the groove is convexly curved in the depth direction. The hermetic terminal according to claim 2, wherein the bottom surface of the groove has an average cut level difference (Rδc) of 1 μm or more and 2.2 μm or less, 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. The airtight terminal according to claim 2 or 3, wherein the ratio R2/R1 of the average value R2 of the average length (RSm) to the average value R1 of the arithmetic mean roughness (Ra) in the roughness curve of the bottom surface of the groove is 5 or more. The airtight terminal according to claim 1 or 2, wherein the grooves are arranged in a honeycomb pattern. A plurality of conductive pins;
a disk-shaped or cylindrical insulating member having a plurality of through holes in a thickness direction for inserting the conductive pins individually;
an annular member surrounding the insulating member;
A hermetic terminal comprising: a plurality of brazing portions each fixing the conductive pin to one of the main surfaces of the insulating member;
the main surface of the insulating member on the side including the brazing portion includes linear projections that define the brazing portions,
The linear protrusions have a U-shape, a V-shape, or an isosceles trapezoidal shape,
the insulating member includes, in order from the main surface side including the brazing portion in a direction along an axis of the insulating member, a small diameter portion and a large diameter portion having an outer diameter larger than that of the small diameter portion,
An airtight terminal, wherein the linear protrusions are arranged radially from the axis of the insulating member toward the outer periphery, extend to the outer periphery of the small diameter portion, and are in contact with the space located between the side of the small diameter portion facing the annular member and the annular member without contacting the annular member. The airtight terminal according to claim 6, wherein the linear protrusion has an isosceles trapezoid shape, and the top surface of the linear protrusion is curved convexly in the height direction. The airtight terminal according to claim 7, wherein the top surface of the linear protrusion has an average cut level difference (Rδc) of 1 μm or more and 2.2 μm or less, 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. The airtight terminal according to claim 7 or 8, wherein the top surface of the linear protrusion has a ratio R4/R3 of the average length (RSm) to the average arithmetic mean roughness (Ra) in the roughness curve, R4, of 5 or more. The airtight terminal according to claim 1 or 6, wherein the main surface on the side having the brazing portion has an average cut level difference (Rδc) of 1 μm or more and 2.2 μm or less, 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. a casing housing a motor for compressing a refrigerant;
and the hermetic terminal according to claim 1 or 6 attached to the casing,
A compressor that supplies power from an external power source to the motor through the conductive pin.

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