EP2798218A1

EP2798218A1 - A hermetic compressor comprising an oil sucking member

Info

Publication number: EP2798218A1
Application number: EP12790513.1A
Authority: EP
Inventors: Yusuf Koc
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2011-12-28
Filing date: 2012-11-13
Publication date: 2014-11-05
Also published as: WO2013097973A1; CN104011386A; CN104011386B

Abstract

The present invention relates to a hermetic compressor (1) wherein the oil sucking member (6) is prevented from being deformed inside the crankshaft (5) and wherein the lubrication efficiency thereof is improved.

Description

A HERMETIC COMPRESSOR COMPRISING AN OIL SUCKING MEMBER

The present invention relates to a hermetic compressor comprising an oil sucking member improving the lubrication conditions of the movable members thereof.
In the reciprocating hermetic compressors used in refrigerators, the sliding bearings wherein the crankshaft operates and the other movable members are lubricated with the oil disposed in the compressor casing. In compressors, lubrication provides friction losses of the movable members to be decreased, abrasion to be prevented and heat to be removed by decreasing the temperature of the compressor members. In the compressor lubrication system, the oil at the base of the casing is sucked to be delivered to the bearings and compressor members that are to be lubricated. Generally, the centrifugal force that acts on the oil as a result of the rotation of the crankshaft is utilized for delivering the oil at the base of the casing to the bearings. In variable capacity compressors used in refrigerators, the refrigeration capacity that changes depending on the operating conditions is provided by changing the compressor rotational speed. Since the compressor motor operates at low speed in cases where low capacity is to be met, abrasion may occur in bearings operating in hydrodynamic lubrication conditions. In order to deliver the oil required in cases where the compressor motor operates at low speed, a cylindrical oil sucking member having helical oil transportation grooves is concentrically disposed at the lower end of the crankshaft immersed into oil in the rotation axis of the crankshaft. Vibrations generated due to the operation of the hermetic compressor causes the problem of the oil sucking member not being properly centered inside the crankshaft. The oil sucking member being mounted so as to contact the crankshaft causes the oil sucking member to hit the inner surface of the crankshaft and to be deformed during the operation of the crankshaft. Deformation occurring in the oil sucking member adversely affects the lubrication efficiency of the compressor.
In the state of the art International Document No. WO03012297, a compressor is described, having a bracket that is positioned one above the other with respect to an extension situated on the oil sucking member. The oil sucking member and the bracket are connected to each other by means of a screw.
In the state of the art International Document No. WO03012297, an elastic member is described, that is used in hermetic compressors and located at the base of the oil supply device.
The aim of the present invention is the realization of a hermetic compressor comprising an oil sucking member that provides the lubrication of the movable members and that improves the oil delivery performance.
The hermetic compressor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof comprises a crankshaft that is situated inside a gap opened in the body thereof in the axial direction starting from the lower end, a cylindrical oil sucking member that is placed concentrically with the crankshaft and that delivers the oil in the casing to the crankshaft, a bracket that connects that oil sucking member to the stator and that limits the movement of the oil sucking member during the operation of the motor and two holders, one being mounted to the oil sucking member, the other to the bracket, that provide the oil sucking member to be joined with the bracket and that are joined together in form of a chain.
In an embodiment of the present invention, the holders comprise openings that provide them with movement flexibility with respect to each other when connected to each other. By means of the distance between the holders that remain mounted one within the other during the operation of the compressor, the oil sucking member moves inside the crankshaft. The oil sucking member is prevented from hitting the crankshaft and thus being deformed thanks to its mobility.
In an embodiment of the present invention, the holder is U-shaped. The first holder is mounted to the oil sucking member from both ends, and the second holder to the bracket from both ends. During the operation of the motor, the first holder moves along the openings and provides the oil sucking member with movement flexibility.
In a derivative of this embodiment, both ends of the first holder are fastened to the oil sucking member. Thus, the first holder is provided to be firmly locked with the oil sucking member.
In a derivative of this embodiment, the first holder comprises at least one bend that bears against the base of the oil sucking member and prevents the first holder from detaching from the oil sucking member.
In an embodiment of the present invention, the hermetic compressor comprises the first holder that has at least one extension extending from the free end thereof and the oil sucking member that has at least one housing wherein the extension is snap-fitted.
In a derivative of this embodiment, the first holder is produced from elastic material and has one extension at each of its ends. During the mounting of the first holder to the oil sucking member, the first holder provides the extension to be detachably mounted to the housing. Thus, the first holder is prevented from being detached from the oil sucking member during the operation of the motor unless an external force is applied.
In an embodiment of the present invention, the hermetic compressor comprises the second holder that has at least one protrusion extending from the end thereof and the oil sucking member that has at least one recess wherein the protrusion is snap-fitted.
By means of the present invention, the oil sucking member is prevented from touching and rubbing against the crankshaft during its mounting to the compressor and thus from being deformed as a result of this. The oil sucking member gaining movement flexibility by means of the holders is centered inside the crankshaft during the operation of the motor. Thus, the lubrication efficiency of the compressor increases.
The hermetic compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 – is the schematic view of a hermetic compressor comprising an oil sucking member.
Figure 2 - is the perspective view of an oil sucking member and a bracket.
Figure 3 – is the view of detail A in Figure 2.
Figure 4 - is the perspective view of an oil sucking member and a bracket.
Figure 5 – is the view of detail B in Figure 4.
Figure 6 - is the perspective view of an oil sucking member and a bracket.
Figure 7 – is the view of detail C in Figure 6.
The elements illustrated in the figures are numbered as follows:

Hermetic compressor
Casing
Rotor
Stator
Crankshaft
Oil sucking member
Bracket
108 Holder
109 Opening
Extension
Housing
Bend
Protrusion
Recess

The hermetic compressor (1) comprises a casing (2) supporting the members therein and wherein oil lubricating the movable members is placed, a motor having a rotor (3) and a stator (4), a crankshaft (5) that is snap-fittingly mounted to the core of the rotor (3) in the direction of the rotation axis thereof and that provides the rotational motion of the rotor (3) to be transmitted to the piston, the lower end of which is immersed into the oil in the casing (2) and wherein a gap (B) opening into the body thereof in the axial direction starting from the lower end thereof is arranged, an oil sucking member (6) in cylindrical form, disposed through the lower end of the crankshaft (5) into the interior thereof and concentrically with the crankshaft (5), transferring the oil in the casing (2) to the crankshaft (5), a bracket (7) whereon the oil sucking member (6) is placed, connected to the stator (4) and limiting the movement of the oil sucking member (6) during the operation of the motor and at least two holders (8, 108) that are connected by being inserted one within the other so as to move with respect to each other, one being fastened to the oil sucking member (6), the other to the bracket (7) so as not to be detached from each other (Figure 1).
In household appliances, preferably in cooling devices, the circulation of the refrigerant used for refrigeration is provided by a reciprocating hermetic compressor (1). In these hermetic compressors (1), lubrication is performed for decreasing the friction losses in the movable members of the compressor (1) during operation, for preventing abrasion and removing the heat resulting from friction. The lower end of the crankshaft (5) is immersed into the oil in the casing (2) and the oil in the casing (2) is sucked into the crankshaft (5) by the effect of the centrifugal force. Oil is carried upwards to the gap (B) inside the crankshaft (5) and from this gap (B) to the movable elements on the motor and the sliding bearings by means of the oil sucking member (6) concentrically placed into the crankshaft (5). With the oil being carried upwards, the oil sucking member (6) and the first holder (8) connected to the oil sucking member (6) move upwards. The holders (8, 108) connected so as to move with respect to each other provide the oil sucking member (6) with movement flexibility. Thus, the holders (8, 108) are provided to be connected inseparably so as to move with respect to each other. The oil sucking member (6) inseparably joined with the bracket (7) by means of the holders (8, 108) is centered inside the crankshaft (5) during the operation of the motor and provides the lubrication performance of the compressor (1) to be increased.
In an embodiment of the present invention, the holders (8, 108) comprise openings (9, 109) that enable them to move one within the other. The first holder (8) connected to the oil sucking member (6) move upwards along the openings (9, 109) with the effect of the oil rising from the base of the compressor (1). The holders (8, 108) are connected to each other by moving along the openings (9, 109) in an inseparable manner. During the upward movement of the oil while the motor is operated, the first holder (8) moves upwards along the openings (9, 109) and thus the oil sucking member (6) is centered inside the crankshaft (5) (Figure 2, Figure 3).
In an embodiment of the present invention, the holder (8, 108) is U-shaped. After the second holder (108) is fastened to the bracket (7) from both ends, the first holder (8) is passed through the second holder (108). The first holder (8) joined with the second holder (108) is fastened to the oil sucking member (6) from both free ends. With the motor being started, the first holder (8) moves upwards along the openings (9, 109) and moves away from the second holder (108) connected to the bracket (7). The oil sucking member (6) also moves inside the crankshaft (5) together with the first holder (8) and is centered (Figure 2, Figure 3).
In a derivative of this embodiment, both ends of the first holder (8) are fastened to the oil sucking member (6). Thus, the first holder (8) is provided to be firmly fixed to the oil sucking member (6).
In a derivative of this embodiment, the first holder (8) comprises at least one bend (12) that bears against the base of the oil sucking member (6) and prevents the first holder (8) from detaching from the oil sucking member (6). With the bend (12) being borne against the base of the oil sucking member (6), the holders (8, 108) are prevented from being separated. After the second holder (108) is fastened to the bracket (7), the U-shaped first holder (8) is passed through the second holder (108) to be fastened to the oil sucking member (6) from one end and is bent and borne to the base of the oil sucking member (6) from the other end. Thus, the first holder (8) gains the shape of a ring. Moreover, the end of the first holder (8) that is bent and borne to the base of the oil sucking member (6) is provided to support the oil sucking member (6) (Figure 4, Figure 5).
In an embodiment of the present invention, the hermetic compressor (1) comprises the first holder (8) that has at least one extension (10) situated at the end thereof and the oil sucking member (6) that has at least one housing (11) wherein the extension (10) is seated. After the first holder (8) is passed through the second holder (108) fixed to the bracket (7), the extension (10) is mounted into the housing (11). Thus, the oil sucking member (6) is provided to be detachably mounted to the bracket (7) by means of the holders (8, 108) (Figure 6, Figure 7).
In a derivative of this embodiment, the first holder (8) is produced from elastic material and has one extension (10) at each of its ends. When the first holder (8) is stretched, the distance between the extensions (10) increases. With the extensions (10) being placed into the housings (11), the first holder (8) becomes free. The first holder (8) is compressed again and resumes its normal shape and does not get out of the housings (11) unless an external force is applied. Thus, the first holder (8) is provided to be flexibly attached to and detached from the oil sucking member (6).
In an embodiment of the present invention, the hermetic compressor (1) comprises the second holder (108) that has at least one protrusion (13) situated at the end thereof and the bracket (7) that has at least one recess (14) wherein the protrusion (13) is seated. Thus, the oil sucking member (6) is provided to be detachably mounted to the bracket (7) by means of the holders (8, 108) (Figure 6, Figure 7).
By means of the present invention, the hermetic compressor (1) is disclosed, having the holders (8, 108) enabling the oil sucking member (6) to be mounted to the bracket (7) and to move during the operation of the motor. Thus, the oil sucking member (6) is prevented from contacting the crankshaft (5) during the operation of the motor and thus from being deformed. Moreover, the oil sucking member (6) is easily centered inside the crankshaft (5) by means of its movement flexibility.
It is to be understood that the present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

A hermetic compressor (1) comprising a casing (2) supporting the members therein and wherein oil lubricating the movable members is placed, a motor having a rotor (3) and a stator (4), a crankshaft (5) that is snap-fittingly mounted to the core of the rotor (3) in the direction of the rotation axis thereof and that provides the rotational motion of the rotor (3) to be transmitted to the piston, the lower end of which is immersed into the oil in the casing (2) and wherein a gap (B) opening into the body thereof in the axial direction starting from the lower end thereof is arranged, an oil sucking member (6) in cylindrical form, disposed through the lower end of the crankshaft (5) into the interior thereof and concentrically with the crankshaft (5), transferring the oil in the casing (2) to the crankshaft (5) and a bracket (7) whereon the oil sucking member (6) is placed, connected to the stator (4) and limiting the movement of the oil sucking member (6) during the operation of the motor, characterized by at least two holders (8, 108) that are connected by being inserted one within the other so as to move with respect to each other, one being fastened to the oil sucking member (6), the other to the bracket (7) so as not to be detached from each other.
A hermetic compressor (1) as in Claim 1, characterized by the holders (8, 108) having openings (9, 109) that enable them to move one within the other.
A hermetic compressor (1) as in Claim 1 or 2, characterized by the U-shaped holders (8, 108).
A hermetic compressor (1) as in Claim 3, characterized by the first holder (8), of which both ends are fastened to the oil sucking member (6).
A hermetic compressor (1) as in any one of the claims 1 to 4, characterized by the first holder (8) having at least one bend (12) that bears against the base of the oil sucking member (6) and that prevents the first holder (8) from being separated from the oil sucking member (6).
A hermetic compressor (1) as in any one of the claims 1 to 5, characterized by the first holder (8) that has at least one extension (10) situated at the end thereof and the oil sucking member (6) that has at least one housing (11) wherein the extension (10) is seated.
A hermetic compressor (1) as in any one of the claims 3 to 6, characterized by the first holder (8) that is produced from elastic material and that has one extension (10) at each of its ends.
A hermetic compressor (1) as in any one of the claims 1 to 6, characterized by the second holder (108) that has at least one protrusion (13) situated at the end thereof and the bracket (7) that has at least one recess (14) wherein the protrusion (13) is seated.