EP2724026B1

EP2724026B1 - A hermetic compressor comprising an oil sucking member

Info

Publication number: EP2724026B1
Application number: EP12729654.9A
Authority: EP
Inventors: Husnu Kerpicci; Alper Yagci
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2011-06-27
Filing date: 2012-06-27
Publication date: 2016-05-04
Anticipated expiration: 2032-06-27
Also published as: EP2724026A1; WO2013000963A1; SI2724026T1; CN103620219B; CN103620219A; ES2579607T3

Description

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. Due to the vibrations occurring during the operation of the hermetic compressor, centering of the oil sucking member in the crankshaft causes problems and the oil sucking member becomes deformed by hitting the inner surface of the crankshaft. Deformation occurring in the oil sucking member adversely affects the lubrication efficiency of the compressor.
The oil sucking member cannot be provided to be kept at the same vertical axis in the crankshaft during the operation of the crankshaft and thus lubrication efficiency decreases.
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.
Korean Patent Application KR 2002 0088640 A discloses a hermetic compressor comprising an oil sucking member that is disposed in the end of a rotatable crankshaft and that comprises a housing in which the upper end of a spring is seated. The lower end of the spring is fixed to the bottom of the compressor.
The aim of the present invention is the realization of a hermetic compressor comprising an oil sucking member providing the lubrication of the movable members and the oil transportation performance of which is improved.
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 casing supporting the members therein and wherein oil lubricating the movable members is placed, a motor having a rotor and a stator, a piston providing the refrigerant fluid to be delivered to the cooling system in a pressurized state, a cylinder wherein the piston operates, a crankshaft that is snap-fittingly mounted to the core of the rotor in the direction of the rotation axis thereof and that provides the rotational motion of the rotor to be transmitted to the piston, the lower end of which is immersed into the oil in the casing and wherein a gap opening into the body thereof in the axial direction starting from the lower end thereof is arranged, an oil sucking member in cylindrical form, disposed through the lower end of the crankshaft into the interior thereof and concentrically with the crankshaft, transferring the oil in the casing to the crankshaft, a bracket connecting the oil sucking member to the stator, providing the oil sucking member to be stationary during the operation of the motor and a resilient member disposed on the bracket, placed into the oil sucking member, providing the oil sucking member to remain in the same vertical axis in the crankshaft during the operation of the motor.
In an embodiment of the present invention, the oil sucking member comprises at least one protrusion disposed in the resilient member. The protrusion is located in the resilient member, extending from the oil sucking member towards the bracket. The resilient member surrounds the protrusion, thereby both protecting the protrusion and increasing the movement ability of the oil sucking member during the operation of the hermetic compressor.
In an embodiment of the present invention, the oil sucking member comprises at least one housing wherein the resilient member is located and moves. The resilient member extends from the bracket towards the housing. During the operation of the hermetic compressor, the resilient member is stressed or stretches. Thus, the resilient member provides the elasticity of the oil sucking member to increase and provides the oil sucking member to be centered in the crankshaft.
In an embodiment of the present invention, the protrusion has a diameter smaller than the diameter of the oil sucking member. The oil sucking member serves as a stopper for the resilient member surrounding the protrusion. Thus, the movement of the resilient member around the protrusion and the oil sucking member is limited.
In an embodiment of the present invention, the resilient member at least partially extends in the crankshaft.
In an embodiment of the present invention, the oil sucking member has a diameter larger that the diameter of the resilient member.
In an embodiment of the present invention, the resilient member is disposed in the vicinity of the lower end of the crankshaft. Thus, the opening through which the oil is delivered from the casing to the crankshaft is widened.
In an embodiment of the present invention, the resilient member is spring-shaped. Vibrations occurring during the operation of the compressor are absorbed by means of the spring-shaped resilient member. The spring-shaped resilient member serves as pump and positively affects the rising of the oil in the crankshaft.
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 exploded view of an oil sucking member, a bracket and a resilient member.
Figure 3 - is the perspective view of an oil sucking member, a bracket and a resilient member.
Figure 4 - is the exploded view of a bracket, a resilient member and an oil sucking member having a housing.
Figure 5 - is the front perspective view of a resilient member and a bracket having a spring.
Figure 6 - is the view of detail A in Figure 5.
Figure 7 - is the top perspective view of a resilient member and a bracket having a spring.

The elements illustrated in the figures are numbered as follows:

1. Hermetic compressor
2. Casing
3. Rotor
4. Stator
5. Crankshaft
6. Oil sucking member
7. Bracket
8. Resilient member
9. Protrusion
10. Housing
11. Spring

The hermetic compressor (1) comprises a casing (2) carrying the members therein and wherein oil lubricating the movable members is placed, a motor having a rotor (3) and a stator (4), a piston providing the refrigerant fluid to be delivered to the cooling system in a pressurized state, a cylinder wherein the piston operates, 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), providing the oil sucking member (6) to be stationary during the operation of the motor and at least one resilient member (8) disposed on the bracket (7), that surrounds the end of the oil sucking member (6) seated onto the bracket (7) or that is seated into the end of the oil sucking member (6) seated onto the bracket (7), providing the oil sucking member (6) to be centered in the crankshaft (5) (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 components of the compressor (1) during operation, prevent abrasion and to remove 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).
The resilient member (8) provides the oil sucking member (6) to be centered in the crankshaft (5) during the movement of the motor. The oil sucking member (6) is seated into the resilient member (8) to enter into the crankshaft (5). On the one hand, the resilient member (8) prevents the oil sucking member (6) from hitting the inner surface of the crankshaft (5) by moving in synchronization with the vibrations formed by the crankshaft (5) in the radial direction and on the other hand absorbs the vibration movements of the motor since it is connected to the stator (4) by means of the bracket (7). Moreover, the resilient member (8) prevents the oil sucking member (6) from breaking during the transportation or the mounting of the bracket (7).
The resilient member (8) whereto the end of the oil sucking member (6) seated onto the bracket (7) is functionally connected stretches during the movement of the motor and provides the oil sucking member (6) to be centered.
In an embodiment of the present invention, the oil sucking member (6) comprises at least one protrusion (9) in cylindrical form, that is seated onto the bracket (7) and that is surrounded by the resilient member (8). The protrusion (9) facilitates the mounting of the oil sucking member (6) into the resilient member (8) and lubrication intake into the crankshaft (5). The outer surface of the oil sucking member (6) except for the protrusion (9) is helical. Thus, the oil is provided to be delivered in a controlled manner (Figure 2 and Figure 3).
In an embodiment of the present invention, the oil sucking member (6) comprises at least one housing (10) wherein the resilient member (8) is seated. The resilient member (8) provides the oil sucking member (6) to be centered in the crankshaft (5) by stretching or being stressed in the housing (10) (Figure 4).
The protrusion (9) has a diameter smaller than the diameter of the oil sucking member (6). The diameter of the resilient member (8) that surrounds the protrusion (9) is smaller than the diameter of the oil sucking member (6). Consequently, the oil sucking member (6) serves as a stopper for the resilient member (8).
In an embodiment of the present invention, the resilient member (8) is at least partially disposed in the crankshaft (5). By means of the resilient member (8), the oil sucking member (6) is prevented from hitting the walls of the crankshaft (5) and the oil sucking member (6) is provided to remain at the same vertical axis in the crankshaft (5) by absorbing the vibrations of the crankshaft (5) in the radial direction.
In an embodiment of the present invention, the resilient member (8) extends from the bracket (7) towards the vicinity of the lower end of the crankshaft (5). With a gap between the crankshaft (5) and the bracket (7), oil transfer into the crankshaft (5) is facilitated.
In an embodiment of the present invention, the resilient member (8) is shaped as a cone narrowing from the bottom to the top. The resilient member (8) in conical form facilitates the oil intake into the crankshaft (5) during the oil sucking by the crankshaft (5) and positively affects the movement of the oil in the crankshaft (5).
In another embodiment of the present invention, the resilient member (8) is produced from rubber material.
In another embodiment of the present invention, the resilient member (8) is produced from spiral spring. During the transfer of the oil by means of the oil sucking member (6), the resilient member (8) in spring form serves as a helical channel and provides the oil in the crankshaft (5) to rise (Figure 2, Figure 3 and Figure 4).
In an embodiment of the present invention, the bracket (7) comprises at least one spring (11) that provides the resilient member (8) to be mounted to the bracket (7). Thus, the movement ability of the resilient member (8) and the oil sucking member (6) is improved (Figure 5, Figure 6 and Figure 7).
By means of the present invention, a hermetic compressor (1) is realized, comprising a resilient member (8) that provides the oil sucking member (6) to remain at the same vertical axis in the crankshaft (5) and that improves the lubrication efficiency thereof. By means of the resilient member (8), the friction losses of the movable parts are decreased, abrasion is prevented and the heat is removed by decreasing the temperature of the members of the hermetic compressor (1). By means of the resilient member (8), the mounting of the bracket (7) to the crankshaft (5) is facilitated.
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) carrying the members therein and wherein oil lubricating the movable members is placed,

- a motor having a rotor (3) and a stator (4),

- a piston providing the refrigerant fluid to be delivered to the cooling system in a pressurized state,

- a cylinder wherein the piston operates,

- 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),

- at least one resilient member (8),
characterized by
a bracket (7) whereon the oil sucking member (6) is placed, connected to the stator (4), providing the oil sucking member (6) to be stationary during the operation of the motor,
wherein the at least one resilient member (8) is disposed on the bracket (7) and either surrounds the end of the oil sucking member (6) seated onto the bracket (7) or is seated into the end of the oil sucking member (6) seated onto the bracket (7), providing the oil sucking member (6) to be centered in the crankshaft (5).
The hermetic compressor (1) as in Claim 1, characterized by the oil sucking member (6) having at least one protrusion (9) in cylindrical form, that is seated onto the bracket (7) and that is surrounded by the resilient member (8).
The hermetic compressor (1) as in Claim 1, characterized by the oil sucking member (6) having at least one housing (10) wherein the resilient member (8) is seated.
The hermetic compressor (1) as in Claim 2, characterized by the protrusion (9) having a diameter which is smaller than the diameter of the oil sucking member (6).
The hermetic compressor (1) as in any one of the Claims 1 to 4, characterized by the resilient member (8) that is at least partially disposed in the crankshaft (5).
The hermetic compressor (1) as in any one of the Claims 1 to 4, characterized by the resilient member (8) that extends from the bracket (7) towards the vicinity of the lower end of the crankshaft (5).
The hermetic compressor (1) as in any one of the above claims, characterized by the resilient member (8) that is in form of a cone narrowing from bottom to top.
The hermetic compressor (1) as in any one of the above claims, characterized by the resilient member (8) that is produced from rubber material.
The hermetic compressor (1) as in any one of the Claims 1 to 7, characterized by the resilient member (8) that is produced from spiral spring.
The hermetic compressor (1) as in any one of the above claims, characterized by at least one spring (11) that provides the resilient member (8) to be mounted to the bracket (7).