EP1488105B1

EP1488105B1 - Hermetic compressor

Info

Publication number: EP1488105B1
Application number: EP03715914A
Authority: EP
Inventors: Sitki Bi Er; Tolga Yaroglu
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2002-03-21
Filing date: 2003-03-21
Publication date: 2009-02-25
Anticipated expiration: 2023-03-21
Also published as: ATE423904T1; TR200402387T1; ES2321499T3; WO2003081044A1; AU2003219647A1; DE60326325D1; DK1488105T3; EP1488105A1

Abstract

This invention is related to a hermetic compressor (1), used in domestic appliances, preferably in the refrigerators, efficiency of which is improved by preventing the oil used for lubricating the bearings, to proceed to the plastic suction muffler (10) area and thereon towards to the cylinder hole.

Description

This invention is related to a compressor, which is preferably used in refrigerators, and efficiency of which is increased by preventing the oil that provides the lubrication and cooling of the bearings inside it to reach the area where the suction muffler is located.
Hermetic compressors with pistons and plastic suction mufflers that are preferably used in refrigerators use oil for lubricating the bearings in the compressor during their operation and this oil proceeds to the plastic suction muffler area and then to the cylinder hole due to insufficient sealing. As oil reaches the cylinder hole, it reduces the performance of the system when pumped to the system. Besides this, when the quantity of the oil in the hermetic compressor is reduced, lubrication efficiency of the oil is reduced as well and thus compressor life is also decreased.
Lubrication of the bearing in the hermetic compressors with pistons is provided by the rotation of the crankshaft at high speeds. The lubrication is done by the oil transmitted through the oil suction tube placed at the lower part of the crankshaft. The main purpose of the presence of oil in the compressor is to lubricate the bearings and to discharge the heat of the compressor through the upper housing.
However centrifuged oil from top in order to discharge the heat of the compressor, causes the lubrication of all parts along with the upper housing. Therefore, some of the hurled oil goes to the plastic suction muffler and cylinder head. The cooling gas, that enters into the housing during the operation of the compressor, passes through the cylinder hole by being sucked together with the oil at the nozzle of the plastic suction muffler and is then pumped to the cooling system through the outlet pipe. Furthermore, the suction muffler sucks the oil when the sealing between the cylinder head and the plastic suction muffler is not sufficient. Thus, this causes the compressor to pump oil as well, whereas its main function is to pump cooling gas to the cooling system.
The most common known method to solve this problem is keeping the centrifuged oil level below the body cylinder hole level. Thus, the centrifuged oil contacts the cylinder hole and cannot not reach the cylinder head area.
However, in that case, the oil cannot reach the upper areas of the housing and thus cannot provide sufficient expelling of the compressor heat.
In another known application, oil is prevented to enter the nozzle area by placing barriers on the muffler. However, said barriers fail to prevent oil flow due to high viscosity of oil at high temperatures. Therefore, some oil is pumped to the system along with the cooling gas.
In the state of the art, in WO. 0077400 , making a cast protrusion over the cylinder area on the body prevents the oil to reach the cylinder head. However, as oil reaches that area at high speed, said barrier cannot duly perform its function as the barrier cannot be as high as desired because of the lack of sufficient space in the housing.
The object of this invention is to develop a compressor with high efficiency that presents the mixing of the cooling and lubricating oil with the cycling fluid pumped to the system.
The compressor realized in order to attain the objects of the present invention has been illustrated in the drawings, wherein :

Figure 1- is the a perspective view of a deflector
Figure 2 - is the a bottom view of the upper housing
Figure 3 - A side section view of a compressor which has a centrifuge pipe on its suction muffler side
Figure 4 - A side section view of a compressor which has a centrifuge pipe on the opposite side of the muffler

The components shown in the drawings have been separately enumerated as listed below :

1.: Compressor
2.: Lower Housing
3.: Cylinder
4.: Piston
5.: Crankshaft
6.: Connecting rod
7.: Piston Pin
8.: Cylinder Head
9.: Upper Housing
10.: Suction muffler
11.: Counterweight
12.: Suction pipe
13.: Centrifuge pipe
14.: Deflector
15.: Inlet nozzle
16.: Tail
17.: Cavity
18.: Recess
19.: Protrusion

The circulation of the cycling fluid for providing the cooling, in domestic appliances, preferably in refrigerators, is provided by a hermetic compressor (1). The cooling gas is used as cycling fluid, in the preferred embodiment.
The compressor (1) comprises of a lower housing (2) to hold the parts in it, an upper housing (9), placed on the lower housing (2), a cylinder (3) placed in the upper (9) and lower housing (2) to provide pumping the cooling gas in it, a piston (4) placed above the cylinder (3) to provide the cooling gas to be compressed into the cylinder orifice, a crankshaft (5), to transmit the motor motion, a connecting rod (6), to transmit the motion from the crankshaft to the piston (4), a piston pin (7) that connects the connecting rod (6) to the piston (4), a counterweight (11) which cancels the offsets of the center of gravity, in reference to the axis of rotation of the crankshaft (5) and parts like crankshaft, connecting rod (6) and piston (4), a suction muffler (10) preferably made of plastic material to convey the cooling gas to the cylinder area without getting hot and to prevent the noise caused by the cooling gas and a cylinder head (8), which connects the suction muffler (10) and the cylinder (3).
Preferably, a fluid, is used in the compressor to facilitate the movement of the compressor parts and to transfer the heat emerging inside the compressor (1) to outside. In the preferred embodiment, oil is used as fluid.
The compressor (1), comprises a suction tube (12) to provide the oil in the lower housing (2) to be sucked and transmitted to the crankshaft (5), a centrifuge pipe (13) fixed at an angle to the rotation axis of the crankshaft (5) that centrifuges oil coming from the crankshaft (5), by rotating together with the crankshaft (5) lubricating the bearings to the upper housing (13) and a deflector (14) which directs the oil centrifuged from the pipe (13) over to the connecting rod (6), piston (4) and piston pin (7) by preventing the oil to reach the cylinder area.
The oil deflector (14) comprises a suction nozzle (15) onto which the oil centrifuged by the centrifuge pipe (13) contacts first and which prevents the oil to reach the suction muffler (10) and provides the oil to be transferred onto the movable parts, a tail (16), to prevent the oil to reach from the suction muffler (10), and a cavity (17) to provide the accelerated oil to drop onto the upper housing (2) or directly onto the compressor (1) parts by sliding over the upper housing (9).
The oil sucked by the suction pipe (12) is centrifuged into the compressor (1) over the crank eccentric, by passing through the crankshaft (5). Thus the heat of the oil, heated in the bearings and in the motor is transferred to the upper housing (9). Hence, the deflector (14) prevents the oil, having high viscosity and velocity to reach the area of the cylinder head (8) and the suction muffler (10) without preventing the oil to impact the upper housing (9) in the compressor (1) and to prevent the mixing of the oil to the cooling gas in cylinder (3).
In the preferred embodiment, the deflector (14) is fixed onto the upper housing (9), preferably by point welding. The deflector (14) is located at a point, where it may prevent the centrifuged oil to enter into the side of the suction muffler (10) and where it may provide the centrifuged oil to come over the piston pin (7), when the piston (4) is in its lower dead point and where it will be in an area in between the centrifuge pipe (13) and the cylinder head (8). Thus, centrifuged oil is transmitted onto the piston pin (7) and the piston bearings and the better lubrication of these areas are hence provided, while the passing of the centrifuged oil which is centrifuged horizontally over the centrifuge pipe (13) to the suction muffler (10) area is prevented. The length of the centrifuge tube (13) is sufficient enough so as not to touch the upper housing (9) while rotating together with the crankshaft (5) in order to provide the transfer of the heat of the oil centrifuged from the centrifuge tube (13) to the upper housing (9). Thus, the deflector (14) is fixed to the upper housing (9) instead of placing over the parts in the compressor.
The deflector (14) located to be sufficiently distant from the moving parts in the compressor (1) has a form to eliminate collision to the moving parts. Because there is the danger of colliding of the moving parts to the deflector (14) due to the deflections that happen during the starting and the stopping of the compressor (1).
Closer the deflector (14) to the centrifuge pipe (13), more successful is the prevention of the oil to reach the suction muffler. The limitation in getting closer to the thrower tube (13), is being at a distance, which is just as much that the hitting of the deflector (14) to the movable parts will be prevented. Due to this reason, the deflector (14) has one or more recesses (18) at its side, which is closer to the movable parts in such a manner and quantity that it will be prevented from hitting the movable parts and the deflector (14) has one or more protrusions that will not hit the movable parts and that will provide the oil to get closer as much as possible to the parts.
In the preferred embodiment, a deflector (14), in the form of a hook is used. The entrance nozzle (15) of the deflector (14), which is preferably in linear form, is located just before the cylinder (3), in accordance with the direction of rotation of the centrifuge pipe (13), and this prevents the oil to reach the suction muffler (10). The oil directed by the entrance nozzle (15) of the deflector (14) goes away the suction muffler (10) by the help of the jet flow of the tail (16) part of the deflector (14), in the form of a chord, and is then directed towards the desired directions. Whereas, the cavity outside the entrance nozzle (15) and the tail (16) part of the deflector (14) is for preventing the accumulation of oil within the deflector (14) which remains in between the sidewalls of the deflector (14) To provide this, the deflector (14) is located in such a way to be in the center of the geometrical axis (E1) of the upper housing (9) and in order not to hit the projection of the circular centrifuge rotation forming a circle which assumes the axis of rotation (E2) of the crankshaft (5).
Oil centrifuged by the centrifuge tube (13), drops onto the lower housing or directly onto the compressor (1) parts sliding over the upper housing (9). Thus, cooling of the movable parts which are heated as they move are provided by contacting them with oil while the heat of the oil is transferred to the upper housing (9) and the travel of the oil to the suction muffler (10) area is prevented.
Hence, oil pumping over to the suction muffler (10) and to the cylinder orifice through the cylinder head and there onwards to the cooling system is prevented and oil hitting the deflector (14) is transmitted to the bearing in between the piston pin (7) and connecting rod hole and the piston pin (7) by directed over the piston pin (7) and hence the lubrication in this bearing is improved.
The heat transfer from the oil to the cooling gas inside the suction muffler (10) is eliminated by preventing the hot oil to reach the suction muffler (10). Thus, the inlet temperature of the cooling gas entering the cylinder hole is lowered and the columetric efficiency of the compressor (1) is increased.
The deflector (14) does not prevent taking out the parts in the compressor (1) during transportation.

Claims

A compressor (1) which is used in domestic appliances, preferably in refrigerators, comprising a lower housing (2) carrying the parts inside it and an upper housing (9) placed over the lower housing (2) characterized by a deflector (14) fixed into the upper housing (9) in a form so as not to allow hitting the moving parts, to prevent the oil used to lubricate the bearings during its operation to reach the suction muffler (10) and the cylinder (3) orifice during the spraying of the oil to the upper housing (9) for cooling.
A compressor (1) as defined in Claim 1, characterized with the deflector (14), which includes an entrance nozzle (15), to which the oil centrifuged by the centrifuge pipe (13) touches first and which prevents the oil to reach to the suction muffler (10) and which transmits the oil onto the movable parts.
A compressor (1) as defined in Claims 1 and 2, characterized with the deflector (14) which includes a tail (16) to keep the oil away from the suction muffler (10).
A compressor (1) as defined in Claims 1 to 3, characterized with the deflector (14), including a cavity (17) to provide the oil centrifuged by the centrifuge tube (13) to drop upon the lower housing (2) sliding over the upper housing (9) or to drop directly onto the compressor (1) parts.
A compressor (1) as defined in Claims 1 to 4, characterized with the deflector (14) which includes one or more protrusion (19), having a form that will not collide with the movable parts and that will provide the oil to approach the parts as close as possible.
A compressor (1) as defined in Claims 1 to 5, characterized with the deflector (14), having one or more recesses (18) to prevent the collision of the deflector to the movable parts on the side close to the movable parts.