EP2798219A1

EP2798219A1 - A compressor comprising an oil sucking member

Info

Publication number: EP2798219A1
Application number: EP12812938.4A
Authority: EP
Inventors: Bilgin Hacioglu; Cihan Gunduz
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2011-12-27
Filing date: 2012-12-18
Publication date: 2014-11-05
Also published as: CN104169581B; WO2013098126A1; CN104169581A

Abstract

The present invention relates to a compressor (1) comprising a casing (2) wherein the oil lubricating the movable members is placed, a body (3) situated in the casing (2), four feet (4) whereon the body (3) is seated, a support member (5) that connects the two feet (4), a motor (6) situated on the body (3), a crankshaft (7) that transmits the movement of the motor (6) to the piston and that has an opening (8) extending from the lower end thereof to the upper end and an oil sucking member (9) that provides the oil to be delivered to the other movable members and that is placed at the lower end of the crankshaft (7) so that one end thereof enters into the opening (8) and the other into the oil at the base of the casing (2), and wherein the lubrication efficiency is improved.

Description

A COMPRESSOR COMPRISING AN OIL SUCKING MEMBER

The present invention relates to a hermetic compressor comprising an oil sucking member, the lubrication efficiency of which 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 temperature to be decreased by removing the heat on 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. 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 disposed at the lower end of the crankshaft immersed into oil. The oil sucking member is disposed at the rotational axis of the crankshaft in a manner concentric with the crankshaft. The oil sucking member disposed so as to extend inside the crankshaft increases the lubrication efficiency of the compressor. The lubrication efficiency decreases as the eccentricity between the axes of the oil sucking member and the crankshaft increases, sufficient oil cannot be delivered to the movable parts such as piston rod-crankpin, piston-cylinder.
In some of the state of the art compressors, the oil sucking members are produced integrated with the feet of the body. During the production of this member that directly affects the position of the oil sucking member with respect to the crankshaft, only small tolerances can be allowed. However, problems sometimes occur while centering the oil sucking member just at the middle point of the feet. Consequently, the axial eccentricity between the crankshaft and the oil sucking member increases and this causes decrease in the lubrication efficiency. In case that the oil sucking member touches the inner surface of the crankshaft, the compressor loses power and also the oil sucking member wears out. The particles breaking off the oil sucking member damage the compressor and sometimes even cause it to break down. Moreover, even if the crankshaft and the oil sucking member are properly centered during assembly, vibrations occurring during the operation of the compressor may cause axial eccentricity.
In the state of the art United States of America Patent Document No. US6716001, a compressor is disclosed, comprising two support brackets located between the diagonal feet of the body and an oil sucking member disposed at a point where the support brackets intersect.
In the state of the art International Patent Application No. WO03012297, a compressor is described, comprising flexible members at the base of the oil sucking member. The oil sucking member can move inside the crankshaft thanks to the structure at the base thereof. In this embodiment, there is also a member that prevents the oil sucking member from rotating.
The aim of the present invention is the realization of a compressor of which the lubrication performance is improved.
The compressor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof comprises at least one support member that connects the two adjacent feet of the body. A connection rod extends from the support member towards the opening at the base of the crankshaft and the oil sucking member is placed to the free end of the connection rod. Since one end of the connection rod is free, the connection rod serves as a spring during the operation of the compressor and absorbs the vibrations acting on the oil sucking member.
In an embodiment of the present invention, the connection rod is produced from elastic material. Thus, the vibrational movements in the vertical direction are more easily absorbed and the oil sucking member is prevented from touching the crankshaft.
In an embodiment of the present invention, the compressor comprises an extension that joins the oil sucking member and the connection rod by one end thereof being mounted to the oil sucking member and the other end to the connection rod. The extension provides a height difference between the members it joins. Accordingly, the oil sucking member is positioned at a lower level with respect to the connection rod. The oil sucking member being closer to the base of the casing increases the lubrication performance thereof.
In an embodiment of the present invention, the support member has a stationary portion that is connected to the feet and a movable portion that moves with respect to the stationary part.
In a derivative of this embodiment, the connection rod is fastened onto the movable portion. The oil sucking member, thanks to the movable portion whereto it is connected, withstands the centripetal forces that the crankshaft is subjected to due to the rotational movement and remains concentric with the crankshaft during the movement. This provides the oil sucking member to suck more oil in unit time and to direct it to other movable members.
In an embodiment of the present invention, the stationary portion is shaped as a flat rod that connects the two feet. Before the stationary portion is mounted to the feet, the movable portion is mounted over the stationary portion by means of the slot located at the center thereof. Afterwards, the stationary portion grouped with the movable portion is mounted to the feet. In this embodiment, the movable portion moves over the stationary portion and along the stationary portion.
In another embodiment of the present invention, the stationary portion comprises two hollow arms that extend from the two feet towards each other so as not to contact with each other. On the other hand, the movable portion comprises a connector and two legs mounted to its two sides. The legs are placed into the arms so as to move backwards and forwards and move the connector whereto they are connected in the direction between the feet. During the movement, while one of the legs enters into an arm, the other leg leaves the other arm. In this embodiment, the connection rod is mounted onto the connector and the oil sucking member moves in a direction parallel to the connector.
In an embodiment of the present invention, the connection rod serving as a bridge between the movable portion and the oil sucking member provides the distance between the support member and the oil sucking member to be changed by shortening and lengthening. Thus, the oil sucking member moves in two directions almost perpendicular to each other, thereby the movement accuracy thereof is increased.
In an embodiment of the present invention, helical recesses extending along the oil sucking member are arranged on the outer surface of the oil sucking member. The oil moves upwards inside the oil sucking member by moving in these recesses and moves towards the other movable members after leaving the oil sucking member.
By means of the present invention, the occurrence of axial eccentricity between the oil sucking member and the crankshaft is prevented during the operation of the compressor and thus the lubrication process is provided to be performed in an efficient manner.
The compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 – is the partial view of a compressor.
Figure 2 – is the perspective view of the body and the feet.
Figure 3 – is the exploded view of the support member, the oil sucking member, the connection rod, the extension and the feet related to an embodiment of the present invention.
Figure 4 – is the perspective view of the support member, the oil sucking member, the connection rod, the extension and the feet related to an embodiment of the present invention.
Figure 5 – is the perspective view of the support member, the oil sucking member, the connection rod, the extension and the feet related to another embodiment of the present invention.
Figure 6 – is the perspective view of the body, the support member, the oil sucking member, the connection rod, the extension, the body and the feet related to another embodiment of the present invention.
The elements illustrated in the figures are numbered as follows:

Compressor
Casing
Body
Foot
Support member
Motor
Crankshaft
Opening
Oil sucking member
, 110. Stationary portion
, 111. Movable portion
Slot
Arm
Connector
Leg
Connection rod
Extension

The compressor (1) comprises a casing (2) wherein the oil lubricating the movable members is placed, a body (3) situated in the casing (2), four feet (4) whereon the body (3) is seated, a motor (6) situated on the body (3), a crankshaft (7) that transmits the movement of the motor (6) to the piston and that has an opening (8) extending from the lower end thereof to the upper end and an oil sucking member (9) that provides the oil to be delivered to the other movable members and that is placed at the lower end of the crankshaft (7) so that one end thereof enters into the opening (8) and the other into the oil at the base of the casing (2) (Figure 1, Figure 2).
With the operation of the compressor (1), the rotor of the motor (6) that has a rotor and a stator starts to rotate and transmits its movement to the crankshaft (7). Depending on the rotation speed of the crankshaft (7), the oil at the lower portion of the crankshaft (7) is moved and taken into the crankshaft (7) through the opening (8). The oil sucking member (9) that is placed to the crankshaft (7) from the lower end of the crankshaft (7) so that at least some portion thereof hangs downwards from the crankshaft (7) and that is closer to the oil surface than the crankshaft (7) provides the receiving of more oil into the crankshaft (7) and the delivery thereof to the upper points inside the crankshaft (7). The feet (4) form a rectangle so that the projection of the opening (8) is at the center of this rectangle.
The compressor (1) of the present invention furthermore comprises a support member (5) that connects the two adjacent feet (4) and a connection rod (16) that is connected to the support member (5) from one end, that extends from the support member (5) towards under the opening (8) and to the other end of which the oil sucking member (9) is placed. In this embodiment, there is no member between the oil sucking member (9) and the oil surface. Thus, the oil sucking member (9) sucks more oil in unit time, thereby increasing the lubrication efficiency of the compressor (1). Moreover, since one end of the connection rod (16) whereon the oil sucking member (9) is situated is free, it oscillates in the vertical axis and improves the lubrication efficiency (Figure 3, Figure 4, Figure 5, Figure 6).
In an embodiment of the present invention, the connection rod (16) is produced from elastic material. Thus, the oil sucking member (9) easily moves in the vertical direction during the operation of the compressor (1) and absorbs the generated vibrations.
In an embodiment of the present invention, the compressor (1) comprises an extension (17) that connects the support member (5) and the oil sucking member (9) so that there is a height difference therebetween. By means of the height difference between the two ends of the extension (17), the oil sucking member (9) is positioned lower than the support member (5). Thus, while the support member (5) remains above the oil surface, the oil sucking member (9) is immersed into the oil or gets much closer to the oil surface. This provides the lubrication to be realized in an efficient manner without splashing oil onto the support member (5) and the members there around (Figure 3, Figure 4, Figure 5, Figure 6).
In an embodiment of the present invention, the support member (5) comprises a stationary portion (10, 110) connected to the two feet (4), and a movable portion (11, 111) whereon the oil sucking member (9) is connected and that moves along the line connecting the feet (4) over the stationary portion (10, 110). In this embodiment, the movable portion (11, 111) can move in both directions along the line between the two feet (4) (Figure 3, Figure 4, Figure 5, Figure 6).
In a derivative of this embodiment, the connection rod (16) is fastened onto the movable portion (11, 111). The oil sucking member (9) connected to the movable portion (11, 111) by means of the connection rod (16) is subjected to the centripetal forces during the rotation of the crankshaft (7) and balances these forces by displacing thanks to the movement of the movable portion (11, 111). Thus, the oil sucking member (9) is always concentric with the crankshaft (7) during the rotation of the crankshaft (7), thereby the lubrication performance thereof is prevented from decreasing (Figure 3, Figure 4, Figure 5, Figure 6).
In a derivative of this embodiment, the support member (5) comprises a stationary portion (10) that continuously connects the two feet (4) and the movable portion (11) that has a slot (12) located at the centre thereof, providing the movable portion (11) to be slidably mounted onto the stationary portion (10). In this embodiment, the stationary portion (10) is mounted to the feet (4) after the movable portion (11) is mounted thereover. After the stationary portion (10) is mounted to the feet (4), the movable portion (11) cannot be detached from the stationary portion (10) and linearly moves over the stationary portion (10) (Figure 3, Figure 4).
In a derivative of this embodiment, the support member (5) comprises the stationary portion (110) that has two hollow arms (13) extending towards each other from the two feet (4) and the movable portion (111) that has a connector (14) and two legs (15) with one end each thereof being fixed to one edge of the connector (14) and the other end each being borne into each of the arms (13) so as to make telescopic movement together with the arms (13). In this embodiment, the legs (15) moves backwards and forwards inside the arms (13) and provides the connector (14) to change position between the feet (4). By means of the telescopic structure of the legs (15) and the arms (13), the movement accuracy of the oil sucking member (9) connected to the connector (14) by means of the connection rod (16) is increased. Consequently, this provides the axial eccentricity between the oil sucking member (9) and the crankshaft (7) to be minimized (Figure 5, Figure 6).
In an embodiment of the present invention, the connection rod (16) enables the distance between the support member (5) and the oil sucking member (9) to be changed. Thus, the oil sucking member (9) can move in two different directions in the same plane and the oil sucking member (9) is more precisely centered with the crankshaft (7). In this embodiment, the connection rod (16) has preferably a telescopic structure (Figure 5, Figure 6).
By means of the present invention, the oil sucking member (9) gains ease of movement and is provided to be positioned concentrically with the crankshaft (7) during the operation time of the compressor (1). Thus, the oil in the casing (2) is more efficiently distributed inside the compressor (1). Moreover, since the oil sucking member (9) is prevented from touching the inner surface of the crankshaft (7), the oil sucking member (9) is prevented from losing its efficiency by being worn out in course of time.
It is to be understood that the present invention is not limited to 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 compressor (1) comprising a casing (2) wherein the oil lubricating the movable members is placed, a body (3) situated in the casing (2), four feet (4) whereon the body (3) is seated, a motor (6) situated on the body (3), a crankshaft (7) that transmits the movement of the motor (6) to the piston and that has an opening (8) extending from the lower end thereof to the upper end and an oil sucking member (9) that provides the oil to be delivered to the other movable members and that is placed at the lower end of the crankshaft (7) so that one end thereof enters into the opening (8) and the other into the oil at the base of the casing (2), characterized by the support member (5) that connects the two adjacent feet (4) and a connection rod (16) that is connected to the support member (5) from one end, that extends from the support member (5) towards under the opening (8) and to the other end of which the oil sucking member (9) is placed.
A compressor (1) as in Claim 1, characterized by the connection rod (16) that is produced from elastic material.
A compressor (1) as in Claim 1 or 2, characterized by an extension (17) that connects the support member (5) and the oil sucking member (9) so that there is a height difference therebetween.
A compressor (1) as in any one of the above claims, characterized by the support member (5) that comprises a stationary portion (10, 110) connected to the two feet (4), and a movable portion (11, 111) whereon the oil sucking member (9) is connected and that moves along the line connecting the feet (4) over the stationary portion (10, 110).
A compressor (1) as in Claim 4, characterized by the connection rod (16) that is mounted onto the movable portion (11, 111).
A compressor (1) as in Claim 4 or 5, characterized by a stationary portion (10) that continuously connects the two feet (4) and the movable portion (11) that comprises a slot (12) located at the centre thereof, providing the movable portion (11) to be slidably mounted onto the stationary portion (10).
A compressor (4) as in Claim 4 or 5, characterized by the stationary portion (110) that has two hollow arms (13) extending towards each other from the two feet (4) and the movable portion (111) that has a connector (14) and two legs (15) with one end each thereof being fixed to one edge of the connector (14) and the other end each being borne into each of the arms (13) so as to make telescopic movement together with the arms (13).
A compressor (1) as in any one of the above claims, characterized by the connection rod (16) that enables the distance between the support member (5) and the oil sucking member (9) to be changed.