EP3770430A1

EP3770430A1 - A compressor with improved lubrication performance

Info

Publication number: EP3770430A1
Application number: EP20187449.2A
Authority: EP
Inventors: Melih OZDILEK; Bilgin Hacioglu; Sitki Bicer
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2019-07-26
Filing date: 2020-07-23
Publication date: 2021-01-27
Anticipated expiration: 2040-07-23
Also published as: PL3770430T3; EP3770430B1

Abstract

The present invention relates to a compressor (1) comprising a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a crankshaft (5) which transmits the motion received from the motor (2) and which enables the delivery of the oil; a cylinder block (6); a bearing (7) which enables the crankshaft (5) to be borne in the radial direction to the cylinder block (6); an upper casing (8) which covers the movable components; a lower casing (9) at the base of which the oil is disposed; an oil suction tube (10) which is attached to the end of the crankshaft (5); a reservoir (11) which is disposed between the oil suction tube (10) and the crankshaft (5) and which extends along the diameter of the (5) crankshaft in the horizontal axis; and at least one channel (12) with one end opening into the reservoir (11), which is arranged in the crankshaft (5).

Description

The present invention relates to a compressor comprising an oil suction tube which moves together with the crankshaft.
In cooling devices, the circulation of the refrigerant liquid used for refrigeration is provided by a compressor. Especially in compressors used in the cooling devices, the delivery of the oil to the bearings formed by the movable surfaces is provided by means of an oil suction tube. In the lubrication process in the compressor, the oil on the base of the lower casing is sucked and delivered to the bearings to be lubricated and to compressor components to be cooled down. In the compressors, the centrifugal force acting on the oil as a result of the rotation of the crankshaft is used to deliver the oil on the base of the casing to the bearings. In state of the art embodiments, the oil first enters through the lower hole of the oil suction tube. The oil moving over the inner surface of the crankshaft reaches the helical channel arranged on the outer surface of the crankshaft. The oil moving through the helical channel is finally discharged from the channel which is arranged on the crankshaft and which opens into the compressor. However, the oil in the oil suction tube at the idle time of the compressor trickles down to the lower casing with the effect of gravity. In particular in inverter compressors when the speed is low, the effect of the centrifugal force decreases and sufficient amount of oil for lubrication cannot be provided. Moreover, when the compressor starts operating, a certain period of time elapses for the oil to be sucked from the base of the casing and delivered to the bearings. During said period of time, sufficient amount of oil cannot be delivered to the bearings. This situation results in, when the compressor operates again, the lack of sufficient oil in the oil suction tube and in mechanical losses and dry friction in the bearings until the oil suction tube sucks the oil in the lower casing again and delivers to the bearings. Furthermore, since sufficient amount of oil cannot be sucked by the oil suction tube at low compressor speeds, the required lubrication cannot be provided in the movable components of the compressor and in the bearings. This is one of the important factors which affect the lifespan and the efficiency of the compressor. Since the centrifugal force effect decreases during the low speed operation of the compressor, the problem encountered during the delivery of sufficient amount of oil to the bearings is eliminated, ensuring that sufficient amount of oil is delivered to the bearings even at low speeds due to the relative speed between the crankshaft and the lubrication screw by means of the oil suction tube. On the other hand, the use of the oil suction tube, which is advantageous for lubrication at low speeds, becomes a disadvantage at high speeds. Excessive oil delivered to the system may cause the compressor to become unlubricated. Moreover, the high-speed oil sent from the cam journal of the crankshaft causes an increase in the noise of the compressor.
In the state of the art United States Patent Application No. US2002170779 , an oil suction tube is disclosed, that is rotated in the reverse direction of the crankshaft by means of the gears.
Another state of the art embodiment is explained in the Swedish Patent Application No. SE422699 . In this application, a separator is disclosed, that is fixed in the crankshaft and that moves together with the crankshaft.
The aim of the present invention is the realization of a compressor with improved lubrication performance.
The compressor realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises an oil suction tube which is attached to the end of the crankshaft; a reservoir which is disposed between the oil suction tube and the crankshaft and which extends along the diameter of the crankshaft in the horizontal axis; and at least one channel with one end opening into the reservoir, which is arranged in the crankshaft.
By means of the reservoir disposed between the crankshaft and the oil suction tube, an efficient oil suction process is realized. The oil received from the reservoir is directed towards the channel with a smaller diameter than the reservoir which is arranged in the crankshaft, and the flow rate of the oil sucked by the oil suction tube is regulated such that the amount of oil leaving the crankshaft at high speeds is decreased and problems such as lack of oil in the compressor and increase in noise are prevented.
By means of the reservoir disposed between the crankshaft and the oil suction tube and the channel with one end opening into the reservoir, the flow rate of the oil is regulated, and the performance at high speeds is improved. Moreover, by means of the reservoir and the channel, the oil suction tube is enabled to stay in the crankshaft with a larger diameter in a stable manner and the oil performance is increased.
In an embodiment of the present invention, the compressor comprises two channels which are symmetrical to the central axis of the crankshaft and which open into the reservoir from one end each and outside the crankshaft from the other end.
In another embodiment of the present invention, the channel is cylindrical and the channels are inclined from the center of the crankshaft towards the edge thereof. Thus, in case the centrifugal force is not sufficient at low speeds, the volume of the crankshaft is divided into two, enabling the oil to be carried more efficiently. Consequently, the effect of capillarity is increased, and the centrifugal force can be used more efficiently, and the oil can be delivered in particular to the components to be cooled or lubricated at low speeds.
By means of the present invention, thanks to the reservoir disposed between the crankshaft and the oil suction tube, the oil received from the reservoir is directed towards the channel with a smaller diameter than the reservoir which is arranged in the crankshaft, and the flow rate of the oil sucked by the oil suction tube is regulated such that the amount of oil leaving the crankshaft at high speeds is decreased and an efficient oil suction process is realized while problems such as lack of oil in the compressor and increase in noise are prevented.
A compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the cross-sectional view of a compressor.
Figure 2 - is the cross-sectional view of the crankshaft, and the oil suction tube.

The elements illustrated in the figures are numbered as follows:

1. Compressor
2. Motor
3. Stator
4. Rotor
5. Crankshaft
6. Cylinder block
7. Bearing
8. Upper casing
9. Lower casing
10. Oil suction tube
11. Reservoir
12. Channel

The compressor (1) comprises a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a crankshaft (5) which transmits the motion received from the motor (2) and which enables the delivery of the oil; a cylinder block (6); a bearing (7) which enables the crankshaft (5) to be borne in the radial direction to the cylinder block (6); an upper casing (8) which covers the movable components; a lower casing (9) at the base of which the oil is disposed; an oil suction tube (10) which is attached to the end of the crankshaft (5); a reservoir (11) which is disposed between the oil suction tube (10) and the crankshaft (5) and which extends along the diameter of the (5) crankshaft in the horizontal axis; and at least one channel (12) with one end opening into the reservoir (11), which is arranged in the crankshaft (5) (Figure 1).
By means of the reservoir (11) disposed between the crankshaft (5) and the oil suction tube (10), an efficient oil suction process is realized. The oil received from the reservoir (11) is directed towards the channel (12) with a smaller diameter than the reservoir (11) which is arranged in the crankshaft (5), and the flow rate of the oil sucked by the oil suction tube (10) is regulated such that the amount of oil leaving the crankshaft (5) at high speeds is decreased and problems such as lack of oil in the compressor (1) and increase in noise are prevented.
In an embodiment of the present invention, the cross-section of the reservoir (11) is quadrilateral.
In household appliances, preferably in cooling devices, the circulation of the refrigerant fluid used for refrigeration is provided by the compressor (1). The rotational movement of the motor (2) is transmitted to the piston by means of the crank-connecting rod-crankpin mechanism, thus realizing the reciprocating movement of the piston. By means of the reciprocating movement of the piston, the refrigerant fluid in the cylinder hole is compressed. As the suction leaf on the valve table opens into the cylinder hole, the gas entering the suction valve is compressed and pressurized to the desired level and passes through the exhaust port with the opening of the exhaust leaf on the valve table, thus the high-pressure gas is delivered to the exhaust chamber of the cylinder head and the refrigerant fluid is delivered after the exhaust chamber. By means of the reservoir (11) disposed between the crankshaft (5) and the oil suction tube (10) and the channel (12) with one end opening into the reservoir (11), the flow rate of the oil is regulated, and the performance at high speeds is improved. Moreover, by means of the reservoir (11) and the channel (12), the oil suction tube (10) is enabled to stay in the crankshaft (5) with a larger diameter in a stable manner and the oil performance is increased.
In an embodiment of the present invention, the compressor (1) comprises two channels (12) which are symmetrical to the central axis of the crankshaft (5) and which open into the reservoir (11) from one end each. In this embodiment of the present invention, one end of the channels (12) opens into the reservoir while the other ends thereof open outside the crankshaft (5) (Figure 2).
In another embodiment of the present invention, the channel (12) is cylindrical. In this embodiment, the channels (12) are inclined from the center of the crankshaft (5) towards the edge thereof. In this embodiment of the present invention, the crankshaft (5) and the oil suction tube (10) fixed to the end thereof move together. Thus, in case the centrifugal force is not sufficient at low speeds, the volume of the crankshaft (5) is divided into two, enabling the oil to be carried more efficiently. Thus, the effect of capillarity is increased, and the centrifugal force can be used more efficiently, and the oil can be delivered in particular to the components to be cooled or lubricated at low speeds.
By means of the present invention, thanks to the reservoir (11) disposed between the crankshaft (5) and the oil suction tube (10), the oil received from the reservoir (11) is directed towards the channel (12) with a smaller diameter than the reservoir (11) which is arranged in the crankshaft (5), and the flow rate of the oil sucked by the oil suction tube (10) is regulated such that the amount of oil leaving the crankshaft (5) at high speeds is decreased and an efficient oil suction process is realized while problems such as lack of oil in the compressor (1) and increase in noise are prevented.

Claims

A compressor (1) comprising a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a crankshaft (5) which transmits the motion received from the motor (2) and which enables the delivery of the oil; a cylinder block (6); a bearing (7) which enables the crankshaft (5) to be borne in the radial direction to the cylinder block (6); an upper casing (8) which covers the movable components; a lower casing (9) at the base of which the oil is disposed; and an oil suction tube (10) which is attached to the end of the crankshaft (5), characterized by a reservoir (11) which is disposed between the oil suction tube (10) and the crankshaft (5) and which extends along the diameter of the (5) crankshaft in the horizontal axis; and at least one channel (12) with one end opening into the reservoir (11), which is arranged in the crankshaft (5).
A compressor (1) as in Claim 1, characterized by the channel (12) which has a smaller diameter than the reservoir (11).
A compressor (1) as in Claim 1, characterized by two channels (12) which are symmetrical to the central axis of the crankshaft (5) and which open into the reservoir (11) from one end each.
A compressor (1) as in any one of the Claims 1 to 3, characterized by the channel (12) which opens into the reservoir (11) from one end and which opens outside the crankshaft (5) from another end.
A compressor (1) as in any one of the above claims, characterized by the channel (12) which is cylindrical.
A compressor (1) as in any one of the above claims, characterized by the channel (12) which is inclined from the center of the crankshaft (5) towards the edge thereof.