Abstract
A compressor for compressing a refrigerant is described. The compressor comprises a case having at least one curved portion and at least one opening, wherein the opening is located in the at least one curved portion, an electrical terminal arranged within the at least one opening and fixed to the case, wherein the at least one opening is an elliptical opening. Also, an electrical terminal for use with a compressor is described.
Claims
1. A compressor for compressing a refrigerant, the compressor comprising: a case having at least one curved portion and at least one opening, wherein the opening is located in the at least one curved portion; an electrical terminal arranged within the at least one opening and fixed to the case; wherein the at least one opening is an elliptical opening.
2. The compressor according to claim 1, wherein at least a portion of the case forms a hollow cylinder and wherein the curved portion of the case is part of the portion that forms the hollow cylinder, wherein the elliptical opening has an elliptical shape in a lateral surface of the hollow cylinder.
3. The compressor according to claim 1, wherein a projection of the elliptical opening into a two-dimensional projection plane has an elliptical shape.
4. The compressor according to claim 1, wherein a sealed connection is formed between the case and the electrical terminal.
5. The compressor according to claim 4, wherein the sealed connection is formed by placing the electrical terminal in the elliptical opening and welding at least a portion of the electrical terminal to a portion of the case.
6. The compressor according to claim 1, wherein the electrical terminal comprises: a body; at least one connection pin, which is isolated from the body by ease of an insulator; and a protrusion for attaching the electrical terminal to the case, wherein the protrusion extends from the body.
7. The compressor according to claim 6, wherein the body of the electrical terminal has a circular cross-section and wherein the protrusion forms a hollow truncated cone.
8. The compressor according to claim 6, wherein the body has a first outer diameter (d.sub.1,2) and the protrusion has a maximum outer diameter (d.sub.2,2) and wherein the maximum outer diameter (d.sub.2,2) of the protrusion is at least 1.4 times the first outer diameter (d.sub.1,2).
9. The compressor according to claim 6, wherein the body of the terminal comprises a front side and a back side, which form opposing sides of the body, and wherein the protrusion extends from the back side of the body, the terminal further comprising: a recess located at the back side of the body of the terminal.
10. The compressor according to claim 6, wherein the body and the protrusion are formed integrally.
11. An electrical terminal for use with a compressor, wherein the electrical terminal is configured for being fitted into an opening of a case of the compressor, wherein the opening is an elliptical opening.
12. The electrical terminal according to claim 11, comprising: a body; at least one connection pin, which is isolated from the body by ease of an insulator; and a protrusion for attaching the electrical terminal to the case, wherein the protrusion extends from the body.
13. The electrical terminal according to claim 12, wherein the body of the electrical terminal has a circular cross-section and wherein the protrusion forms a hollow truncated cone.
14. The electrical terminal according to claim 12, wherein the body has a first diameter (d.sub.1,2) and the protrusion has a second diameter (d.sub.2,2) and wherein the second diameter (d.sub.2,2) is at least 1.4 times the first diameter (d.sub.1,2).
15. The electrical terminal according to claim 12, wherein the body of the terminal comprises a front side and a back side, which form opposing sides of the body, and wherein the protrusion extends from the back side of the body, the terminal further comprising: a recess located at the back side of the body of the terminal.
Description
DRAWINGS
[0032] In the drawings, like reference characters generally refer to the same parts throughout the different drawings. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
[0033] In the following description, various embodiments of the invention are described with reference to the following drawings, in which:
[0034] FIG. 1 shows a cross-sectional view of an exemplary scroll compressor according to the state of the art.
[0035] FIG. 2a-c show (a) an electrical terminal according to the state of the art, (b) a case according to the state of the art, wherein the case comprises an opening in a flattened portion of the case, and (c) the fitting of the electrical terminal in the opening.
[0036] FIG. 3a-e show (a) an embodiment of the electrical terminal according to the current invention, (b) a case according to the current invention, wherein the case comprises an elliptical opening, (c) an exemplary fitting of the electrical terminal within the elliptical opening of the case, thereby illustrating a gap formed between the body of the electrical terminal and the case, (d) an illustration of the gap size and (e) cross-sectional views of the exemplary fitting of the electrical terminal in the opening.
[0037] FIG. 4 shows another embodiment of the electrical terminal according to the current invention, wherein the electrical terminal comprises a recess for reducing the heat transfer during assembly.
DETAILED DESCRIPTION
[0038] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.
[0039] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs.
[0040] FIG. 1 shows a compressor 100 according to the state of the art. The compressor is depicted as a scroll-type compressor for exemplary purposes. The compressor 100 comprises a suction port 102 for receiving a refrigerant from a source, for example a heat accepting heat exchanger of a refrigeration cycle. Further, the compressor boo comprises a means for compressing used to compress the refrigerant. As for compressor 100, which is depicted as a scroll compressor, the means for compressing may be formed by a stationary scroll plate 104 and an orbiting scroll plate 106, which performs an orbiting motion relatively to the stationary scroll plate 104, thereby compressing the refrigerant. After compression, the compressed refrigerant is provided to a discharge port 108, where the compressed refrigerant is discharged from the compressor. Then, the compressed refrigerant may be provided to a heat rejection heat exchanger of the refrigeration cycle.
[0041] Further, the compressor 100 comprises a motor no, which actuates the orbiting scroll plate 106, and a lubricant reservoir 112 used for providing lubricant to the motor no and the scroll plates 104, 106.
[0042] The compressor boo comprises a case 114. In order to provide a connection to an external network, the case 114 of the compressor 100 comprises at least one opening in which an electrical terminal 116 is placed. The electrical terminal 116 comprises connection pins for establishing a connection with an external network.
[0043] An electrical terminal according to the state of the art is depicted in FIG. 2a. FIG. 2a depicts (1) a lateral cross-sectional view of an electrical terminal 200, whereas (2) depicts a front side view of the electrical terminal 200.
[0044] The electrical terminal 200 comprises two portions, namely a body 202 and a protrusion 204. The body 202 forms a hollow cylinder with a first outer diameter d.sub.1,1. The protrusion 204 forms a hollow truncated cone as is depicted in FIG. 2a (1) and extends from the body 202 at its back side. Although the body is depicted as hollow cylinder, it may also be possible that the body forms a disk and the protrusion extends from said disk. The truncated cone has an outer diameter, which increases with respect to an end of the protrusion 204 located at the far side of the body 202. The outer diameter at the far end of the protrusion 204, i.e. at the widest portion of the truncated cone, may be denoted as maximum outer diameter d.sub.2,1. Diameter d.sub.2,1 is greater than diameter d.sub.1,1. The protrusion 204 extends from the body 202 in a rearward direction at an angle from the body 202. Usually, an angle of approximately 45 degree is convenient for the electrical terminal 200 to be fitted into an opening in the case of a compressor. However, other angles are also possible.
[0045] At least one connector pin 208 is attached to the body. In order to insulate the connector pins from the body 202 of the electrical terminal 200, the at least one connector pin 208 is surrounded by an insulator 206, so that the insulator contacts the body 202 directly, while the at least one connector pin 208 does not directly contact the body 202. The insulator 206 may be made from a plastic material, a glass material, or a combination of both. The insulator 206 may have the form of a plate covering the front side of the electrical terminal 200 as is depicted by ease of the circle with the dashed circumference in FIG. 2a (2) and surrounds the connector pins 208 at the locations where these connector pins 208 extend through the body of the electrical terminal 200. As is indicated in the figures, the insulator may have the form of a plate, but the plate may have portions which are thicker, e.g. at the locations where a connector pin extends through an opening in the insulator, and thinner portions. Alternatively, additional insulating elements may be added to the plate or the pins. As depicted in FIG. 2a, the insulator plate may have an outer diameter d.sub.3,1, which is smaller than the outer diameter d.sub.1,1 of the body.
[0046] In the embodiment example depicted in FIG. 2a (2), the protrusion 204 extends from the back side of the body 202 in a rearward direction at an angle with respect to the circular cross-section of the body 202. The outer circumference of the protrusion 204 and the outer circumference of the circular shaped body 202 form concentric circles with diameters d.sub.2,1 and d.sub.1,1, respectively. Further, the circumference of the circular shaped plate of the insulator 206 forms an additional circle with diameter d.sub.3,1, which is also concentric to the aforementioned circles formed by the body 202 and the protrusion 204.
[0047] FIG. 2b depicts a case 300 of a compressor according to the state of the art. The case 300 has a cylindric shape and comprises a flattened surface portion 302. Flattened surface portion 302 may be created by coining the case locally. In the flattened surface portion 302, an opening 304 for receiving an electrical terminal is located. The opening is circular.
[0048] FIG. 2c illustrates the arrangement of an electrical terminal 200 according to the state of the art in a case 300 of a compressor according to the state of the art. In FIG. 2C (1), a cross-sectional side view is shown. Electrical terminal 200 is located within opening 304 of case 300. The body 202 of the electrical terminal 200 is welded to the case 300 in welding area 306. The welding area 306 may be formed by the boundary of the opening 304 and may extend around the circular circumference of body 202 of the electrical terminal 200. During welding, the welding contact is established between the protrusion 204 and the boundary of the opening 304. After welding, there may be a small gap between the body 202 of the electrical terminal 200 and the boundary of the opening 304. By welding the protrusion 204 to the boundary of the opening 304, a sealing is formed between the electrical terminal 200 and the case 300, which allows hermetic separation of the inner volume of the case from the environment. Additionally, FIG. 2c (2) depicts the same embodiment as FIG. 2c (1), but a perspective view instead of a cross-sectional side view.
[0049] FIG. 3a (1) illustrates a lateral cross-sectional view of an electrical terminal 40o according to the current invention, whereas (2) depicts a front side view of the electrical terminal 400.
[0050] The electrical terminal 400 comprises two portions, namely a protrusion 404 and a body 402. The body 402 may comprise a cylindric body with a first outer diameter d.sub.1,2. The protrusion 404 forms a hollow truncated cone as is depicted in FIG. 3a (1) and extends from the body 402 at its back side. The truncated cone has a variable outer diameter, which increases with respect to an end of the protrusion 404, which does not contact the body 402, i.e. the far side of the body 402. The outer diameter at the far end of the protrusion 404, i.e. at the widest portion of the truncated cone, may be denoted as maximum outer diameter d.sub.2,2. Diameter d.sub.2,2 is greater than diameter d.sub.1,2. The protrusion 404 extends from the body 402 in a rearward direction at an angle from the body 402. Usually, an angle of 45 degree is convenient for the electrical terminal 400 to be fitted into an opening in the case of a compressor. However, other angles are also possible. Preferably, angles of 30, 45, 60, or 75 degrees are used.
[0051] Compared to the protrusion 204 of the electrical terminal 200 according to the state of the art depicted in FIG. 2a, the size of the protrusion 404 is increased. This means that if the outer diameter of the bodies of the electrical terminals is equal d.sub.1,1=d.sub.1,2, the maximum outer diameter d.sub.2,2 of the protrusion 404 of electrical terminal 400 is greater than the maximum outer diameter d.sub.2,1 of the protrusion 204 of electrical terminal 200. The maximum outer diameter d.sub.2,2 of the protrusion 404 may be at least 1.4 times the first outer diameter d.sub.1,2 of the body 402. This increased size of the protrusion 404 allows for placing the electrical terminal in an elliptical opening in the case of a compressor, while the elliptical opening is entirely closed by contact between at least a portion of the protrusion 404 of the electrical terminal 400 and the case of the compressor. If an electrical terminal according to the state of the art would be placed in an elliptical opening in a case of a compressor, at least a portion of the elliptical opening may not be closed by the shorter protrusion and the body. Even if the protrusion of a state of the art terminal would close the entire elliptical opening, the protrusion would not be long enough to provide for a sufficient welding contact and therefore, the elliptical opening could not be sealed.
[0052] The protrusion 404 and the cylindrical body 402 may be formed integrally. Alternatively, the protrusion may be a separate element and may be attached to the body. In this case, an insulating layer may be added between the body and the protrusion. Such an insulating layer may reduce heat transfer from the protrusion to the body during welding. Further, the protrusion and/or the body may be made of metal.
[0053] At least one connector pin 408 and an insulator 406 are attached to the body 402. The at least one connector pin 408 and the insulator 406 with outer diameter d.sub.3,2 are similar to the at least one connector pin 208 and the insulator 206 of the electrical terminal 200 depicted in FIG. 2a. Therefore, they will not be described in detail again.
[0054] In the embodiment example depicted in FIG. 3a (2), the protrusion 404 extends from the back side of the body 402 in a rearward direction at an angle with respect to the circular cross-section of the body 402. Although the body is depicted as hollow cylinder, it may also be possible that the body forms a disk and the protrusion extends from said disk. The outer circumference of the protrusion 404 and the outer circumference of the circular shaped body 402 form concentric circles with diameters d.sub.2,2 and d.sub.1,2, respectively. Further, the circumference of the circular shaped plate of the insulator 406 forms an additional circle with diameter d.sub.3,2 which is concentric to the aforementioned circles formed by the body 402 and the protrusion 404. Again, compared to the protrusion 204 of the electrical terminal 200 with diameter d.sub.2,1, the protrusion 404 has an increased diameter d.sub.2,2.
[0055] FIG. 3b depicts a case 500 of a compressor according to the current invention. The case 500 has a cylindric shape and comprises an opening 504 for receiving an electrical terminal. The opening 504 is an elliptical opening with a minor axis 506 and a major axis 508. The minor axis 506 is oriented along the cylinder axis z of the compressor case 500, whereas the major axis is oriented perpendicular to the cylinder axis z. While FIG. 3b (1) shows a projection of the elliptical opening 504 into a plane, different shapes of the elliptical opening may be possible, which are all encompassed by the current application. For example, the elliptical opening 504 itself may be curved, because it is formed in a surface, which is flat along the minor axis 506, but curved along the major axis 508. Further, the shape of the elliptical opening may be adjusted to match a specific design of the protrusion of the terminal in case the axial cross-section of the protrusion of the terminal deviates from the straight profile as shown in the illustrative figures.
[0056] FIG. 3c illustrates how the electrical terminal 400 is placed in the opening 504 and welded to the case 500 of the compressor. In FIG. 3c (i), a front view is depicted, which illustrates how the electrical terminal 400 can be welded to the case 500. Exemplary, two welding areas 510a, 510b are shown, wherein welding area 510a is along the minor axis 506 of the elliptical opening 504, wherein the welding area 510b is along the major axis 508 of the elliptical opening 504. In both welding areas 510a, 510b, the welding contact is established between the case 500 and the protrusion 404 of the electrical terminal 400.
[0057] Hence, there is a gap x formed between the case and the body 402 of the electrical terminal 400. In welding area 510a, the gap x is smaller than in welding area 510b. If the electrical terminal 400 is formed with a cylindrical body 402 as depicted in FIG. 3c (i) and is placed symmetrically in the center of the elliptical opening 504, the gap x is minimal in welding area 510a and maximal in welding area 510b. In such a case, for example, when starting at the minor axis (e.g. welding area 510a), the gap x will increase with increasing in-plane angle γ as depicted in FIG. 3c (2) until it reaches its maximum for γ=90°. Then, the gap x will decrease for further increasing angle γ until it reaches its minimum for γ=180° and will again increase until it reaches its maximum for γ=270° and again its minimum for γ=360°=0°. As is depicted in FIG. 3c (2), r denotes the radius of the circular body of the electrical terminal, a denotes the semi-major axis and b denotes the semi-minor axis of the elliptical opening. s(γ) is the distance of the boundary of the elliptical opening (e.g. the welding contact) from the center of the elliptical opening and depends on the angle γ, so that the gap size x(γ) is given as a function of the angle γ as follows:
[00001]
[0058] Accordingly, the gap size is minimal for welding areas 510a along the minor axis of the elliptical opening, i.e. x.sub.min=x(γ=0°)=x(γ=180°)=b−r, whereas the gap size is maximal for welding areas 510b along the major axis of the elliptical opening, i.e. x.sub.max=x(γ=90°)=x(γ=270°)=a−r. FIG. 3d illustrates the dependency of the gap size x(γ) on the in-plane angle γ.
[0059] FIGS. 3e (1) and (2) illustrate the welding contact between the protrusion of the electrical terminal and the boundary of the elliptical opening of the case in more detail. FIG. (1) illustrates a cross-sectional view along the minor axis 506, while (2) illustrates a cross-sectional view along the major axis 508. In the respective welding areas 510a, 510b, the case 500 and the protrusion 504 are welded together, wherein the section indicated as black triangles represents the portions where the welding contact is established or in other words, the portions that will be welded together.
[0060] FIG. 4 depicts another embodiment of an electrical terminal according to the invention. The electrical terminal 600 depicted in FIG. 4 is similar to electrical terminal 400 depicted in FIG. 3a. Accordingly, electrical terminal 600 comprises a body 602, a protrusion 604, an insulator 606 and at least one connector pin 608, which all are essentially similar to their counterparts body 402, protrusion 404, insulator 406 and connector pin 408 of electrical terminal 400 in FIG. 3a.
[0061] However, electrical terminal 600 comprises a recess 610 at the backside of the body 602. In this regard, backside of the body 602 means that this side faces the inner portion of the case when the electrical terminal is assembled in the opening of the case. The recess 610 may be circular and may have a diameter d.sub.4,3, which is smaller than the diameter d.sub.1,3 of the body 602, but greater than the diameter d.sub.3,3 of the insulator. Although it is depicted in this way in FIG. 4, it may also be possible that the diameter d.sub.4,3 of the recess may be smaller than diameter d.sub.3,3 of the insulator. In any case, the recess bio improves the welding process, because it can interrupt heat transfer from the protrusion 604 to the insulator 608, which may occur during the welding process, when heat is applied to the protrusion 604 and the case of the compressor and subsequently dissipates from the protrusion into the body of the electrical terminal. Interrupting the heat transfer protects the insulator from harm or overheating, because if too much heat acts on the insulator, the insulator may break. The person skilled in the art will appreciate that more than one insulator may be used. The more than one insulators may at least partially be made of different non-metal materials. In a preferred embodiment, three insulators are used, one made of rubber, one made of glass and one made of a ceramic. Using different insulators may provide additional improvements. For example, a glass insulator may not only provide insulating properties but additionally also provide for hermetically sealing the opening in the body of the terminal where the at least one connection pin extends through the body.
[0062] What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the scope of the appended claims.
