WO2014053362A1

WO2014053362A1 - Hermetic compressor with improved oil circulation

Info

Publication number: WO2014053362A1
Application number: PCT/EP2013/069843
Authority: WO
Inventors: Yusuf Koc; Bilgin Hacioglu; Alper Yagci; Arda EYYUBOGLU
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2012-10-05
Filing date: 2013-09-24
Publication date: 2014-04-10
Anticipated expiration: 2015-04-05
Also published as: EP2912313A1

Description

HERMETIC COMPRESSOR WITH IMPROVED OIL CIRCULATION

The present invention relates to a hermetic compressor wherein the circulation of the oil situated therein is improved.

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 should 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.

The oil situated in the casing moves towards the movable members by generating waves around the crankshaft with the effect of the centrifugal force created by the crankshaft. Meanwhile, the oil hitting the bracket rubs against the lower and upper parts of the bracket. Thus, turbulence occurs in the oil situated in the casing, adversely affecting the suction of the oil.

In the International Patent Document No. WO2012062860, a hermetic compressor is disclosed, having a crankshaft immersed into the oil in the casing, an oil sucking member disposed through the lower end of the crankshaft into the interior thereof, a bracket providing the oil sucking member to be fixed to the stator and a barrier fixed to the bracket so as to be around the rotational axis of the crankshaft.

In the Japanese Patent Document No. JP60119389, a hermetic compressor is disclosed, having at least one oil sucking member disposed through the lower end of the crankshaft into the interior thereof and a bracket providing the oil sucking member to be fixed to the stator.

The aim of the present invention is the realization of a hermetic compressor wherein the circulation of the oil situated therein is improved and generation of sound is prevented.

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 mounted to the rotor hub, an oil sucking member disposed through the lower end of the crankshaft into the interior thereof and a bracket whereon the oil sucking member is mounted.

The hermetic compressor of the present invention comprises at least one guiding member situated on the bracket, at least partially immersed into the oil and allowing the oil that hits the bracket during the rotation of the crankshaft to continue its movement in its flow direction. The oil passing through the guiding member during the operation of the compressor continues its movement concentric with the crankshaft. Thus, the oil hitting the crankshaft is prevented from moving in the opposite direction to the movement direction of the crankshaft and from creating a vortex.

In an embodiment of the present invention, the guiding members are arranged one after the other along the bracket. The oil moving during the operation of the motor continuously contacts the bracket. By means of the guiding members, the oil is enabled to be guided along the bracket, providing the flow continuity.

In an embodiment of the present invention, the guiding member has a cambered shape. Thanks to the cambered shape of the guiding member, the flow continuity of the oil is prevented from being deteriorated during the rotation of the crankshaft.

In an embodiment of the present invention, the guiding member transversely extends on the bracket. The lengths of the guiding members arranged one after the other on the bracket are almost equal to the width of the bracket.

In an embodiment of the present invention, the guiding member is shaped like an airfoil. During the movement of the oil over the bracket, the friction force between the oil and the bracket gradually increases. By means of the guiding member with an inclination increasing in the flow direction of the oil, the effect of friction caused by the oil hitting the bracket is decreased. Thus, friction-related sound generation is prevented.

In an embodiment of the present invention, the hermetic compressor comprises the oil sucking member positioned so as to divide the bracket into two, at least one first guiding member remaining at one side of the oil sucking member and at least one second guiding member remaining at the other side of the oil sucking member. By means of the first guiding members and second guiding members situated at the left and right of the oil sucking member, the oil is provided to be guided in its flow direction.

In an embodiment of the present invention, the first guiding member and the second guiding member extend reverse-symmetrically with respect to the oil sucking member. The oil activated by the effect of the rotation of the crankshaft moves on a circular orbit. The angle between the first guiding member and the second guiding member is almost 180 degrees. By means of the first guiding member and the second guiding member extending in the opposite directions with respect to each other, the oil is provided to be guided in a manner conforming to this orbit.

In an embodiment of the present invention, the bracket is shaped like an airfoil. Thus, during the operation of the crankshaft, the bracket is provided to guide the oil so as to maintain its flow continuity.

In an embodiment of the present invention, the guiding member extends upwards from the upper side of the bracket.

In an embodiment of the present invention, the guiding member is shaped like an extension. The guiding member extends from bottom to top on the bracket. The guiding member contributes to the bottom-to-top guiding of the oil moving with the effect of the rotation of the crankshaft.

In an embodiment of the present invention, the guiding member is shaped like a cavity. The guiding member is formed on the bracket by the cut-out method.

In an embodiment of the present invention, the guiding members are positioned on the bracket at equal intervals.

By means of the present invention, the flow of the oil in the casing while the crankshaft sucks oil is improved. The oil moving in the casing during the rotation of the crankshaft is prevented from hitting the bracket and generating a turbulence.

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.

Figure 2 – is the perspective view of a bracket related to an embodiment of the present invention.

Figure 3 – is the partial view of the bracket.

Figure 4 – is the perspective view of a bracket related to another embodiment of the present invention.

The elements illustrated in the figures are numbered as follows:

Hermetic compressor
Casing
Rotor
Stator
Crankshaft
Oil sucking member
Bracket
, 108 Guiding member

The hermetic compressor (1) comprises a casing (2) supporting the members therein and wherein the 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 hub of the rotor (3) in the direction of the rotation axis thereof, an oil sucking member (6) disposed through the lower end of the crankshaft (5) into the interior thereof and a bracket (7) whereon the oil sucking member (6) is mounted (Figure 1).

The hermetic compressor (1) of the present invention comprises at least one guiding member (8, 108) situated on the bracket (7), at least partially immersed into the oil and allowing the oil that hits the bracket (7) during the rotation of the crankshaft (5) to continue its movement without changing its flow direction (Figure 1, Figure 2).

Being fixed to the stator (4) by means of the bracket (7), the oil sucking member (6) remains stationary in the gap (B) in the crankshaft (5) during the operation of the motor. 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). The end of the crankshaft (5) where the oil sucking member (6) is placed rotates in the oil. The oil in the casing (2) moves towards the inner surface of the casing (2) by creating waves around the crankshaft (5) with the effect of the centrifugal force generated by the crankshaft (5). The said waves created with the movement of the oil extend almost to the point where the bracket (7) is connected to the stator (4). Upon hitting the bracket (7), the oil moving around the crankshaft (5) in the casing (2) continues its movement without turning back by means of the guiding member (8, 108). By means of the guiding member (8, 108), a channel forms on the bracket (7) in the flow direction of the oil and generation of unwanted turbulences or vortexes in the oil is prevented. Thus, the circulation of the oil is improved. By means of the guiding members (8, 108), the movement of the oil in the casing (2) around the center of the crankshaft (5) continues in an ordered manner. Moreover, the oil is prevented from changing its flow direction by hitting the bracket (7), thereby preventing generation of sound.

In an embodiment of the present invention, the guiding members (8, 108) are arranged one after the other on the bracket (7). The oil moving during the operation of the motor continuously contacts the bracket (7). By means of the guiding members (8, 108), the oil is enabled to be guided along the bracket (7), maintaining the flow continuity.

In an embodiment of the present invention, the guiding member (8, 108) is in inclined form. The highest friction force, exerted by the oil onto the bracket (7) due to its movement while the oil moving in the casing (2) during the operation of the hermetic compressor (1) contacts the bracket (7), gradually increases from the first point it contacts the bracket (7) to the last point. Thanks to the inclined shape of the bracket (7), resistance against friction increases. Thus, by means of the guiding member (8, 108), the oil is enabled to pass by around the bracket (7) without creating a turbulence, maintaining the flow continuity. The oil is prevented from changing the flow direction.

In an embodiment of the present invention, the guiding member (8, 108) transversely extends on the bracket (7). The length of the guiding member (8, 108) is almost equal to the width of the bracket (7). The end of the crankshaft (5) where the oil sucking member (6) is placed rotates in the oil. The oil in the casing (2) moves towards the inner surface of the casing (2) by creating waves around the crankshaft (5) with the effect of the centrifugal force generated by the crankshaft (5). The said waves generated around the oil in the casing (2) create partial rings around the oil sucking member (6). By means of its shape, the guiding member (8, 108) provides the oil to move in its flow path during the operation of the hermetic compressor (1) (Figure 2).

In an embodiment of the present invention, the transversal cross-section of the guiding member (8, 108) widens in the flow direction of the oil. In an embodiment of the present invention, the guiding member (8, 108) is at least partially shaped like an airfoil. Thus, during operation of the compressor (1) the continuity of the oil flow is maintained.

In an embodiment of the present invention, the hermetic compressor (1) comprises the oil sucking member (6) positioned so as to divide the bracket (7) into two, at least one first guiding member (8) remaining at one side of the oil sucking member (6) and at least one second guiding member (108) remaining at the other side of the oil sucking member (6). By means of the first guiding member (8) and the second guiding member (108), the oil is provided to be guided in its flow direction.

In an embodiment of the present invention, the first guiding member (8) and the second guiding member (108) extend reverse-symmetrically with respect to the oil sucking member (6). The first guiding member (8) and the second guiding member (108) arranged on the oil sucking member (6) at equal intervals are reverse-symmetrical. During the operation of the hermetic compressor (1), the oil moves on an orbit. The first guiding member (8) and the second guiding member (108) provide the oil to move properly on this orbit (Figure 3).

In an embodiment of the present invention, the transversal cross-section of the bracket (7) widens in the flow direction of the oil. Thus, the bracket (7) is provided to guide the oil so as to maintain its flow continuity.

In an embodiment of the present invention, the guiding member (8, 108) is disposed on the upper side of the bracket (7). The oil sucked from the lower end of the crankshaft (5) is carried upwards to the gap (B) inside the crankshaft (5) and from here to the movable members on the motor such as cylinder, piston, piston rod and sliding bearings by means of the helical grooves on the oil sucking member (6) concentrically placed into the crankshaft (5). The guiding members (8, 108) situated at the upper side of the bracket (7) supports the upwards-guiding of the oil with the rotation of the crankshaft (5).

In an embodiment of the present invention, the guiding member (8, 108) is shaped as a protrusion. The guiding member (8, 108) extends from bottom to top on the bracket (7). The guiding member (8, 108) is shaped as a triangle so that the inclination thereof increases in the flow direction of the oil (Figure 2).

In an embodiment of the present invention, the guiding member (8, 108) is shaped as a recess. The guiding member (8, 108) can be formed on the bracket (7) by the cut-out method afterwards or can be formed on the bracket (7) during the production of the bracket (7). By means of the channel-shaped guiding members (8, 108), the area of the friction surface between the oil and the bracket (7) is decreased and the oil is guided in its flow direction while passing through the guiding member (8, 108). The guiding member (8, 108) is shaped as a triangle so that the inclination thereof increases in the flow direction of the oil (Figure 4).

In an embodiment of the present invention, the guiding members (8, 108) are situated in parallel on the bracket (7). Thus, the oil is provided to be guided in an ordered manner in conformity with its flow on the bracket (7).

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 the 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 hub of the rotor (3) in the direction of the rotation axis thereof, an oil sucking member (6) disposed through the lower end of the crankshaft (5) into the interior thereof and a bracket (7) whereon the oil sucking member (6) is mounted, characterized by at least one guiding member (8, 108) situated on the bracket (7), at least partially immersed into the oil and allowing the oil that hits the bracket (7) during the rotation of the crankshaft (5) to continue its movement without changing its flow direction.
The hermetic compressor (1) as in Claim 1, characterized by more than one guiding member (8, 108) arranged one after the other along the bracket (7).
The hermetic compressor (1) as in Claim 1 or 2, characterized by the guiding member (8, 108) shaped in an inclined manner.
The hermetic compressor (1) as in any one of the Claims 1 to 3, characterized by the guiding member (8, 108) extending transversely on the bracket (7).
The hermetic compressor (1) as in any one of the Claims 1 to 4, characterized by the guiding member (8, 108), the transverse cross-section of which widens in the flow direction of the oil.
The hermetic compressor (1) as in any one of the above claims, characterized by the oil sucking member (6) positioned so as to divide the bracket (7) into two, at least one first guiding member (8) remaining at one side of the oil sucking member (6) and at least one second guiding member (108) remaining at the other side of the oil sucking member (6).
The hermetic compressor (1) as in Claim 6, characterized by the first guiding member (8) and the second guiding member (108) extending reverse-symmetrically with respect to the oil sucking member (6).
The hermetic compressor (1) as in any one of the above claims, characterized by the bracket (7), the transverse cross-section of which widens in the flow direction of the oil.
The hermetic compressor (1) as in any one of the above claims, characterized by the guiding member (8, 108) situated at the upper side of the bracket (7).
The hermetic compressor (1) as in any one of the above claims, characterized by the protrusion-shaped guiding member (8, 108).
The hermetic compressor (1) as in any one of the Claims 1 to 10, characterized by the recess-shaped guiding member (8, 108).
The hermetic compressor (1) as in any one of the above claims, characterized by the guiding members (8, 108) situated in parallel on the bracket (7).