Researchers Submit Patent Application, "Compressor", for Approval (USPTO 20160177933)
By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Lee, Kiyeon (Seoul, KR); Seo, Wonsang (Seoul, KR); Lee, Jongmok (Seoul, KR); Kim, Jinkook (Seoul, KR); Kim, Younghwan (Seoul, KR); Kim, Jaebeum (Seoul, KR); Kim, Kyeongho (Seoul, KR), filed on December 14, 2015, was made available online on June 30, 2016.
The patent's assignee is LG Electronics Inc.
News editors obtained the following quote from the background information supplied by the inventors: "This specification relates to a compressor, and more particularly, a compressor capable of supporting a crankshaft using an angular contact ball bearing.
"A hermetic compressor is a compressor in which a driving motor to generate a driving force and a compression device operating by receiving the driving force from the driving motor are provided in the same casing. Such hermetic compressors may be classified into a reciprocating type, a rotary type, a vane type, a scroll type and the like according to a method of compressing a refrigerant as compressive fluid.
"The reciprocating compressor is a type of compressor that sucks refrigerant, compresses refrigerant and discharges refrigerant by linearly reciprocating a piston in a cylinder. The reciprocating compressors may be classified into a vibration type and a connection type according to a driving method of the piston.
"In the vibration type reciprocating compressor, the piston may reciprocate in the cylinder and vibrate while connected with a mover of a reciprocating motor, thereby compressing a refrigerant. In the connection type reciprocating compressor, a connecting rod is coupled to a crankshaft of a driving motor and a piston is coupled to the connecting rod such that a rotary motion of the driving motor is converted into a linear motion of the piston. The present disclosure relates to the connection type reciprocating compressor, and hereinafter, the connection type reciprocating compressor will be referred to as a reciprocating compressor.
"FIG. 1 is a longitudinal section view of an example of the related art reciprocating compressor.
"As illustrated in FIG. 1, the related art reciprocating compressor includes a frame 2 elastically supported in a casing 1 with an oil storage unit 11, a driving motor 3 supportably disposed at one side of the frame 2 and generating a rotational force, a compression device 4 installed at another side of the frame 2 and receiving the rotational force from the driving motor 3 to compress a refrigerant, and a crankshaft 5 inserted through the frame 2 and having one end coupled to the driving motor 3 and another end coupled to the compression device 4.
"The driving motor 3 includes a stator 31 elastically supported by the frame 2, and a rotor 32 rotatably installed in the stator 31.
"The compression device 4 includes a cylinder 41 defining a compression chamber and integrally formed with or fixedly coupled to the frame 2, a connecting rod 42 rotatably coupled to the crankshaft 5 to convert a rotary motion of the driving motor 3 into a linear motion, a piston 43 rotatably coupled to the connecting rod 42 and compressing a refrigerant by linearly reciprocating in the cylinder 41, a valve assembly 44 coupled to an end of the cylinder 41 and provided with a suction valve and a discharge valve, a suction muffler 45 coupled to a suction side of the valve assembly 44, a discharge cover 46 coupled to accommodate therein a discharge side of the valve assembly 44, and a discharge muffler 47 communicating with the discharge cover 46 to reduce discharge noise of a discharged refrigerant.
"The related art reciprocating compressor having the foregoing configuration operates as follows.
"When power is applied to the stator 31 of the driving motor 3, the rotor 32 is rotated along with the crankshaft 5 by an interaction with the stator 31. The connecting rod 42 coupled to the crankshaft 5 thusly performs an orbiting motion.
"Accordingly, the piston 43 coupled to the connecting rod 42 compresses a refrigerant by linearly reciprocating in the cylinder 41 and discharges the compressed refrigerant to the discharge cover 46. The refrigerant discharged to the discharge cover 46 is discharged out of the compressor via the discharge muffler 47. This series of processes are repeated.
"Simultaneously, in response to the rotation of the crankshaft 5, an oil feeder 6 installed at a lower end of the crankshaft 5 pumps up oil stored in the oil storage unit 11 of the casing 1. Some of the oil is sucked up through an oil passage 55 of the crankshaft 5 to be supplied to each bearing surface, and some of the oil is scattered at an upper end of the crankshaft 5 to be supplied between the cylinder 41 and the piston 43.
"Meanwhile, a bearing portion 21 extends from a central portion of the frame 2 toward the driving motor 3, and a bearing hole 22 is formed through the bearing portion 21, through which the crankshaft 5 is inserted so as to be supported in a radial direction. The bearing portion 21 downwardly protrudes by a predetermined length to have a bearing area, which is large enough to offset an eccentric load by the rotor 32 and the crankshaft 3. A bearing insertion recess 32a in which the bearing portion 21 is partially inserted by a predetermined depth is formed at an upper end portion of the rotor 32.
"An eccentric mass portion 52 is formed at an upper end portion of the crankshaft 5, and a thrust ball bearing 7 supporting the crankshaft 5 in an axial direction is installed between a lower surface of the eccentric mass portion 52 and an upper surface of the frame 2.
"However, in the related art reciprocating compressor, the bearing portion 21 is provided with an increase in length to offset the eccentric load by the rotor 32 and the crankshaft 5; however, such an increased length of the bearing portion 21 results in an increase in a frictional loss between the bearing portion 21 and the crankshaft 5.
"Also, due to the formation of the bearing insertion recess 32a at the rotor 32, a press-fit length between the rotor 32 and the crankshaft 5 is reduced. Accordingly, at a high-speed rotation of the rotor 32, the rotor 32 tilts and thereby causing interference between the stator 31 and the rotor 32.
"The oil that is scattered at the upper end of the crankshaft 5 is not smoothly supplied to a bearing surface as well as the compression device 4, which results in an increased frictional loss and lowered reliability due to the shortage of oil at the compression device 4 and the bearing surface. Specifically, at a low-speed operation, an amount of oil fed is reduced. If an inner diameter of the oil passage 55 is increased to expand the oil passage 55 by taking into account of the reduced amount of oil fed, an outer diameter of the crankshaft 5 increases by the same amount, which causes an increase in a frictional loss between the crankshaft 5 and the bearing portion 21."
As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "Therefore, an aspect of the present disclosure is to provide a compressor that is capable of reducing a frictional loss between a bearing supporting a crankshaft in a radial direction and the crankshaft during rotation of the crankshaft.
"Another aspect of the present disclosure is to provide a compressor that is capable of preventing interference between a rotor and a stator during operation by ensuring a sufficient press-fit length of a crankshaft which is press-fit into the rotor.
"Another aspect of the present disclosure is to provide a compressor that is capable of smoothly supplying oil to a bearing surface as well as a compression device without an increase in a frictional loss even though a diameter of a crankshaft increases to ensure a larger area of an oil passage.
"To achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a compressor including a frame having a shaft hole, a stator coupled to one side surface of the frame, a rotor rotatably inserted into the stator, a crankshaft rotatably coupled through the shaft hole of the frame, the crankshaft having one side coupled to the rotor and another side coupled to a compression device on the basis of the frame, and a bearing member provided between the frame and the crankshaft and supporting the crankshaft with respect to the frame, wherein under assumption that a bearing center of the bearing member is O, a first contact point of the crankshaft which is brought into contact with an inner circumferential surface of the shaft hole when the crankshaft is tilted is P1, a first virtual line connecting the first contact point and the bearing center in a perpendicular state of the crankshaft is L1, a second virtual line connecting the bearing center and one point of the inner circumferential surface of the shaft hole, with which the first contact point is brought into contact when the crankshaft is tilted, is L2, an angle between the first virtual line and the second virtual line based on the bearing center is .alpha.1, and a maximum tilt angle of the bearing member is .alpha.2, a relation of .alpha.1.gtoreq..alpha.2 may be satisfied.
"Here, under assumption that a second contact point on a lower edge of the rotor, which is brought into contact with an inner circumferential surface of the stator when the crankshaft is tilted, is P2, and a third virtual line connecting the second contact point and the bearing center in the perpendicular state of the crankshaft is L3, a fourth virtual line connecting the bearing center and one point of the inner circumferential surface of the stator, with which the second contact point is brought into contact when the crankshaft is tilted, is L4, and an angle between the third virtual line and the fourth virtual line based on the bearing center is .alpha.3, a relation of .alpha.2.ltoreq..alpha.3 may be satisfied.
"A press-fit length that the crankshaft is press-fit into the rotor may be the same as a height of the rotor in an axial direction of the rotor.
"A boss portion may be formed around the shaft hole of the frame and extend toward the rotor. Here, under assumption that a third contact point of the crankshaft which is brought into contact with the inner circumferential surface of the boss portion when the crankshaft is tilted is P3, a fifth virtual line connecting the third contact point and the bearing center in the perpendicular state of the crankshaft is L5, a sixth virtual line connecting the bearing center and one point of the inner circumferential surface of the boss portion, with which the third contact point is brought into contact when the crankshaft is tilted, is L6, and an angle between the fifth virtual line and the sixth virtual line based on the bearing center is .alpha.4, a relation of .alpha.4.gtoreq..alpha.2 may be satisfied.
"Under assumption that a second contact point on a lower edge of the rotor, which is brought into contact with an inner circumferential surface of the stator when the crankshaft is tilted is P2, and a third virtual line connecting the second contact point and the bearing center in the perpendicular state of the crankshaft is L3, a fourth virtual line connecting the bearing center and one point of the inner circumferential surface of the stator, with which the second contact point is brought into contact when the crankshaft is tilted, is L4, and an angle between the third virtual line and the fourth virtual line based on the bearing center is .alpha.3, a relation of .alpha.4.ltoreq..alpha.3 may be satisfied.
"A boss insertion recess in which the boss portion is inserted may be formed at one side surface of the rotor. Here, under assumption that a fourth contact point of the boss portion, which is brought into contact with an inner circumferential surface of the boss insertion recess when the crankshaft is tilted is P4, a seventh virtual line connecting the fourth contact point and the bearing center in the perpendicular state of the crankshaft is L7, an eighth virtual line connecting the bearing center and one point of the inner circumferential surface of the boss portion, with which the fourth contact point is brought into contact when the crankshaft is tilted, is L8, and an angle between the seventh virtual line and the eighth virtual line based on the bearing center is .alpha.5, a relation of .alpha.4.ltoreq..alpha.5 may be satisfied.
"To achieve the objective of the present invention, a compressor according to another exemplary embodiment may include a frame having a shaft hole, a stator coupled to one side surface of the frame, a rotor rotatably inserted into the stator, a crankshaft rotatably coupled through the shaft hole of the frame, the crankshaft having one side coupled to the rotor and another side coupled to a compression device on the basis of the frame, and a bearing member provided between the frame and the crankshaft and supporting the crankshaft with respect to the frame in a radial direction and an axial direction of the crankshaft, the bearing member being located out of a range in an axial direction of the rotor.
"Here, under assumption that a bearing center of the bearing member is O, a first contact point of the crankshaft which is brought into contact with an inner circumferential surface of the shaft hole when the crankshaft is tilted is P1, a first virtual line connecting the first contact point and the bearing center in a perpendicular state of the crankshaft is L1, a second virtual line connecting the bearing center and one point of the inner circumferential surface of the shaft hole, with which the first contact point is brought into contact when the crankshaft is tilted, is L2, an angle between the first virtual line and the second virtual line based on the bearing center is .alpha.1, and a maximum tilt angle of the bearing member is .alpha.2, a relation of .alpha.1.gtoreq..alpha.2 may be satisfied.
"Under assumption that a second contact point on a lower edge of the rotor, which is brought into contact with an inner circumferential surface of the stator when the crankshaft is tilted, is P2, and a third virtual line connecting the second contact point and the bearing center in the perpendicular state of the crankshaft is L3, a fourth virtual line connecting the bearing center and one point of the inner circumferential surface of the stator, with which the second contact point is brought into contact when the crankshaft is tilted, is L4, and an angle between the third virtual line and the fourth virtual line based on the bearing center is .alpha.3, a relation of .alpha.2.ltoreq..alpha.3 may be satisfied.
"A boss portion may be formed around the shaft hole of the frame and extend toward the rotor. Here, under assumption that a third contact point of the crankshaft which is brought into contact with the inner circumferential surface of the boss portion when the crankshaft is tilted is P3, a fifth virtual line connecting the third contact point and the bearing center in the perpendicular state of the crankshaft is L5, a sixth virtual line connecting the bearing center and one point of the inner circumferential surface of the boss portion, with which the third contact point is brought into contact when the crankshaft is tilted, is L6, and an angle between the fifth virtual line and the sixth virtual line based on the bearing center is .alpha.4, a relation of .alpha.4.gtoreq..alpha.2 may be satisfied.
"To achieve the objective of the present disclosure, a compressor according to another exemplary embodiment may include a frame having a shaft hole, a stator coupled to one side surface of the frame, a rotor rotatably inserted into the stator, a crankshaft rotatably coupled through the shaft hole of the frame, the crankshaft having one side coupled to the rotor and another side coupled to a compression device on the basis of the frame, and a bearing member provided between the frame and the crankshaft and supporting the crankshaft with respect to the frame in a radial direction and an axial direction of the crankshaft, wherein a gap between an inner circumferential surface of the shaft hole and an outer circumferential surface of the crankshaft may be greater than or equal to a bearing gap in a radial direction of the bearing member.
"The gap between the inner circumferential surface of the shaft hole and the outer circumferential surface of the crankshaft may be smaller than or equal to a gap between the stator and the rotor.
"A boss portion may be formed around the shaft hole of the frame and extends toward the rotor, and a gap between an inner circumferential surface of the boss portion and the outer circumferential surface of the crankshaft may be greater than or equal to the bearing gap in the radial direction of the bearing member and smaller than or equal to a gap between the stator and the rotor.
"A boss insertion recess in which the boss portion is inserted may be formed at one side surface of the rotor, and a gap between an outer circumferential surface of the boss portion and an inner circumferential surface of the boss insertion recess may be greater than or equal to a gap between the inner circumferential surface of the boss portion and the outer circumferential surface of the crankshaft.
"A reciprocating compressor according to the present disclosure may include a bearing member located out of a range in an axial direction of a rotor. Accordingly, the bearing member and the rotor cannot overlap each other so as to reduce a bearing area. This may result in reducing a frictional loss of the compressor and ensuring a press-fit length of the rotor, so as to prevent interference between the rotor and a stator. Also, an area of an oil passage can be increased without an increase in the frictional loss, resulting in an increase in an amount of oil supplied.
"Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
"The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the invention. In the drawings:
"FIG. 1 is a longitudinal view of an example of the related art reciprocating compressor;
"FIG. 2 is a longitudinal view of an example of a reciprocating compressor in accordance with the present disclosure;
"FIG. 3 is an enlarged view of a part 'A' of FIG. 2;
"FIG. 4 is an enlarged view of a part 'B' of FIG. 2;
"FIG. 5 is a schematic view comparing a gap between a bearing gap of a bearing member and a shaft hole in the compressor according to FIG. 2;
"FIG. 6 is a graph illustrating a comparison result of frictional losses of the related art compressor and the compressor according to FIG. 2;
"FIG. 7 is a longitudinal view illustrating another embodiment of a boss portion in a reciprocating compressor in accordance with the present disclosure;
"FIG. 8 is an enlarged view of surroundings of the boss portion of FIG. 7; and
"FIG. 9 is a schematic view illustrating a gap between the boss portion and a crankshaft and a gap between the boss portion and a boss insertion recess in FIG. 7."
For additional information on this patent application, see: Lee, Kiyeon; Seo, Wonsang; Lee, Jongmok; Kim, Jinkook; Kim, Younghwan; Kim, Jaebeum; Kim, Kyeongho. Compressor. Filed December 14, 2015 and posted June 30, 2016. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5511&p=111&f=G&l=50&d=PG01&S1=20160623.PD.&OS=PD/20160623&RS=PD/20160623
Keywords for this news article include: LG Electronics Inc, Electronic Equipment Companies.
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