EP2212557A1

EP2212557A1 - A compressor

Info

Publication number: EP2212557A1
Application number: EP08844942A
Authority: EP
Inventors: Erkan Ozkan; Bora Abdik; Umit Fidan; Sedat Samut; Huseyin Kayar
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2007-11-02
Filing date: 2008-10-28
Publication date: 2010-08-04
Also published as: CN101842592A; BRPI0819247A2; CN101842592B; WO2009056529A1

Abstract

The present invention relates to a compressor (1) comprising a motor (2) composed of two main components, a stator (3) and a rotor (4), a crankshaft (5) that transmits the motion received from the motor (2) and an oil suction pipe (6) secured to the end of the crankshaft (5) for aspirating the oil that prevents the friction and heating of the movable components in the compressor (1).

Description

A COMPRESSOR

[0001] The present invention relates to a compressor for which ease of production is provided.

[0002] In household appliances, preferably cooling devices, the circulation of the refrigerant used for cooling is provided by a compressor (1 '). In hermetic compressors (1 ') used in cooling devices, the motor (2') is comprised of two main components, the stator (3') and the rotor (4'). The magnetic field created in the motor (2') rotates the rotor (4') and the crankshaft (5') secured press-fittingly on the rotor (4') also rotates. The rotational motion of the crankshaft (5') is transmitted to the piston by the piston rod and the crankpin, providing the back and forth motion of the piston. The compressor (1 ') furthermore comprises an oil suction pipe (6') secured at the end of the crankshaft (5') (Figure 1).

[0003] However, during the production of the compressor, some difficulties are encountered in securing the rotor press-fittingly to the crankshaft. During the press-fitting process, the rotor air gap has to be adjusted properly. Moreover, while securing the rotor to the crankshaft, various damages can be formed on the rotor and the crankshaft. There are various implementations in the technique for facilitating the securing of the rotor to the crankshaft and to provide ease of production.

[0004] In the state of the art Japanese Patent Application No JP10061553, a compressor comprising a motor is explained having a rotor that is press-fittingly secured to the crankshaft and the oil suction pipe.

[0005] In the conventional technique, the rotor has to be selected to be suitable with the diameter of the crankshaft since crankshafts with different diameters are used in different types of compressors having variable powers and since the rotor is secured press-fittingly to the crankshaft made of casting material. This creates difficulties in both production and assembly and also in storage.

[0006] Moreover, during the production of the compressor, the rotor has to be dismounted from the crankshaft in order to repair the disorders of the rotor or crankshaft, piston rod and the crankpin. During this process, damages may occur, mainly in the crankshaft and the other components. [0007] The aim of the present invention is the realization of a compressor for which ease of production and assembly is provided. [0008] The compressor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a rotor that is secured press-fittingly to the oil suction pipe without being in contact with the crankshaft. [0009] In the compressor, the only mechanical connection of the rotor is with the oil suction pipe. The length of the crankshaft can be shortened by means of the rotor being press-fittingly secured to the oil suction pipe without being in contact with the crankshaft. This provides to reduce cost of the crankshaft, that is produced of cast material and having a higher cost than the oil suction pipe. [0010] Moreover, the rotor, secured on the oil suction pipe independently from the crankshaft, is enabled to be used in different types of compressors without modification. By means of the present invention, advantages are provided for the producer in production and storage since the same rotor can be used with the crankshafts of variable diameters. [0011] In addition to this, mounting the rotor more easily during the assembly of the compressor allows the demounting process, which can result from adversaries on the rotor or the crankshaft, to be performed easily. [0012] In another embodiment of the present invention, the length of the crankshaft can be shortened to remain in the bearing. [0013] In another embodiment of the present invention, the oil suction pipe is mounted inside the crankshaft press-fittingly. [0014] In another embodiment of the present invention, the oil suction pipe is mounted press-fittingly on the crankshaft from outside the crankshaft. [0015] In another embodiment of the present invention, the oil suction pipe is mounted on the crankshaft from outside the crankshaft by means of a fastening element. [0016] In another embodiment of the present invention, the oil suction pipe is inserted into the crankshaft and secured on the crankshaft by screwing from outside the crankshaft. [0017] In another embodiment of the present invention, the oil suction pipe is mounted on the crankshaft by screwing. [0018] By means of the present invention, the same type of rotor can be used in different types of compressors. Moreover, the length of the crankshaft can be shortened to provide cost advantage. In addition to this, the air gap between the rotor and stator can be adjusted more conveniently. By means of the present invention, not only ease of production and assembly is provided but also the cost of storage is reduced. [0019] A compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

[0020] Figure 1 - is the schematic view of a compressor in the conventional art. [0021] Figure 2 - is the schematic view of the compressor in the present invention. [0022] Figure 3 - is the cross-sectional view of the oil suction pipe and the rotor mounted to each other press-fittingly. [0023] Figure 4 - is the cross-sectional view of another version of the embodiment in Figure 3. [0024] Figure 5 - is the cross-sectional view of the oil suction pipe and the crankshaft secured to each other by using a fastening element. [0025] Figure 6 - is the cross-sectional view of another version of the embodiment in Figure 5. [0026] Figure 7 - is the cross-sectional view of the oil suction pipe and the crankshaft secured to each other by screwing. [0027] Figure 8 - is the cross-sectional view of another version of the embodiment in Figure 7. [0028] The elements illustrated in the figures are numbered as follows:

1. Compressor

2. Motor

3. Stator

4. Rotor

5. Crankshaft

6. Oil suction pipe

7. Cylinder block 8. Bearing

[0029] The compressor (1) comprises a motor (2) composed of two main components, a stator (3) and a rotor (4), a crankshaft (5) that transmits the motion received from the motor (2), a cylinder block (7) and a bearing (8) for the crankshaft (5) to bear on the cylinder block (7) in the radial direction and an oil suction pipe (6) secured to the end of the crankshaft (5) for aspirating the oil.

[0030] In the compressor (1) of the present invention, the rotor (4) is secured to the oil suction pipe (6) without being in contact with the crankshaft (5) (Figure 2). The rotor (4) is secured on the oil suction pipe (6), preferably by press-fitting, and such that the only physical connection thereof is with the oil suction pipe (6). Thus, the rotational motion of the rotor (4) is transmitted to the crankshaft (5), not in contact with the rotor (4), by means of the oil suction pipe (6) whereon the rotor (4) is secured.

[0031] While the crankshaft (5) is secured in place, the rotor (4) is mounted to the oil suction pipe (6) coaxially. The assembly of the rotor (4) is completed by securing the oil suction pipe (6), with the rotor (4) thereon, to the end of the crankshaft (5). The magnetic field created in the motor (2) rotates the rotor (4) and thus the oil suction pipe (6) press-fittingly secured to the rotor (4) and the crankshaft (5) to which it is mounted, also rotates. The rotation of the crankshaft (5) is transmitted to the piston by the piston rod and the crankpin, moving the piston back and forth thereby operating the compressor (1).

[0032] The length of the crankshaft (5) is shortened by mounting the rotor (4) to the oil suction pipe (6) instead of the crankshaft (5). Shortening the length of the crankshaft (5) allows reducing the cost of the crankshaft (5) which is preferably produced of cast material.

[0033] Moreover, the same rotor (4) can be used in different types of compressors (1) wherein crankshafts (5) with different diameters are used by mounting the rotor (4) to the oil suction pipe (6). This provides both production and storage advantages. For example, in compressors (1) wherein a crankshaft (5) with a 16 mm. diameter is used, when the rotor (4) is mounted to the oil suction pipe (6), the oil suction pipe (6) is secured on the crankshaft (5) from outside the crankshaft (5). By means of the present invention, the same rotor (4) can be used in a compressor (1) having a 19 mm. crankshaft (5), by inserting the oil suction pipe (6) into the crankshaft (5) (The wall thickness of the oil suction pipe (6) is 1 ,5 mm.).

[0034] In addition to this, the air gap between the rotor (4) and the stator (3) can be adjusted more properly and conveniently. Moreover, the damages incurred during mounting the rotor (4) to the crankshaft (5) can be prevented.

[0035] As a result of mounting the rotor (4) to the oil suction pipe (6), the length of the crankshaft (5) is shortened to remain inside the bearing (8). Thus, the bending of the crankshaft (5) inside the bearing (8) is minimized. Since the crankshaft (5) is prevented from leaning against the bearing (8) from one direction, the forces acting on the crankshaft (5) during the operation of the compressor (1) are reduced.

[0036] The oil suction pipe (6) can be fastened to the crankshaft (5) either press-fittingly, by using a fastening element or by screwing for transmitting the rotational motion of the rotor (4), mounted to the oil suction pipe (6), to the piston rod and the piston.

[0037] In another embodiment of the present invention, the oil suction pipe (6) is partially inserted into the crankshaft (5) and secured press-fittingly to the crankshaft (5). In this embodiment, the diameter of the crankshaft (5) does not change (Figure 4).

[0038] In another embodiment of the present invention, the oil suction pipe (6) is secured press-fittingly to the crankshaft (5) such that the end of the crankshaft (5) is partially encircled (Figure 3).

[0039] In yet another embodiment of the present invention, the oil suction pipe (6) is inserted into the crankshaft (5) and is secured to the crankshaft (5) by using a fastening element (screw etc.) from above the portion of the crankshaft (5) corresponding to the place wherein the oil suction pipe (6) is inserted (Figure 6).

[0040] In another embodiment of the present invention, the oil suction pipe (6) is secured to the crankshaft (5), partially surrounding the crankshaft (5), by using a fastening element from above the portion surrounding the crankshaft (5) (Figure 5).

[0041] In another embodiment of the present invention, grooves are opened on the oil suction pipe (6) and on the inner and outer surfaces of the crankshaft (5). The oil suction pipe (6) is secured inside or outside the crankshaft (5) by screwing via these grooves (Figure 7 and Figure 8).

[0042] The length of the crankshaft (5) is shortened by driving in the rotor (4) to the oil suction pipe (6). Besides, the same type of rotor (4) is enabled to be utilized in compressors (1) wherein crankshafts (5) with different diameters are used by driving in the rotor (4) to the oil suction pipe (6). In addition to this, ease of mounting and dismounting the compressor (1) is provided, minimizing the damages to the crankshaft (5) and the rotor (4) during these processes. Again by means of the present invention, the time period required for the process of adjusting the air gap between the rotor (4) and the stator (3) is reduced, providing ease of assembly.

Claims

1. A compressor (1) that comprises a motor (2) composed of two main components, a stator (3) and a rotor (4), a crankshaft (5) that transmits the motion received from the motor (2), a cylinder block (7) and a bearing (8) for the crankshaft (5) to bear on the cylinder block (7) in the radial direction and an oil suction pipe (6) secured to the end of the crankshaft (5) for aspirating the oil and characterized by a rotor (4) secured to the oil suction pipe (6) without being in contact with the crankshaft (5).

2. A compressor (1) as in Claim 1 , characterized by a rotor (4) that is mounted press-fittingly to the oil suction pipe (6).

3. A compressor (1) as in Claim 1 , characterized by a crankshaft (5) that entirely remains inside the bearing (8).

4. A compressor (1) as in any one of the above Claims, characterized by an oil suction pipe (6) press-fittingly secured to the crankshaft (5) by partially inserting into the crankshaft (5).

5. A compressor (1) as in any one of the Claims 1 to 3, characterized by an oil suction pipe (6) press-fittingly secured to the crankshaft (5) by partially surrounding the end of the crankshaft (5).

6. A compressor (1) as in any one of the Claims 1 to 3, characterized by an oil suction pipe (6) partially inserted into the crankshaft (5) and secured to the crankshaft (5) by using a fastening element from above the portion corresponding to the place of insertion.

7. A compressor (1) as in any one of the Claims 1 to 3, characterized by an oil suction pipe (6) secured to the crankshaft (5), partially surrounding the crankshaft (5), and by using a fastening element from above the portion surrounding the crankshaft (5).

8. A compressor (1) as in any one of the Claims 1 to 3, characterized by an oil suction pipe (6) and a crankshaft (5) having grooves on the inner and outer surfaces and secured inside or outside the crankshaft (5) by screwing via these grooves.