EP3947971A1

EP3947971A1 - A compressor with improved lubrication performance

Info

Publication number: EP3947971A1
Application number: EP20707051.7A
Authority: EP
Inventors: Melih OZDILEK; Cihan Gunduz; Yasin BATUR
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2019-03-28
Filing date: 2020-02-21
Publication date: 2022-02-09
Also published as: TR201904661A2; WO2020193030A1

Abstract

A compressor (1) comprises: a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a winding holder (12) which supports the motor windings; 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 slit (11) which is provided at the end of the oil suction tube (10) and which extends in the horizontal plane; and a connection member (13) which is seated into the slit (11) along the slit (11) and which is fixed to the winding holder (12) from both ends.

Description

A COMPRESSOR WITH IMPROVED LUBRICATION PERFORMANCE

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 lower 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 order to ensure relative speed in the lubrication system, the oil suction pipe must be kept fixed during the rotational movement of the crankshaft.
In the state of the art United States Patent Application No. US2017204853, it is disclosed that a connection member holding the oil suction tube is attached to the inside of the winding holder.
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 slit which is provided at the end of the oil suction tube and which extends in the horizontal plane, and a connection member which is seated into the slit along the slit and which is fixed to the winding holder from both ends.
By means of the connection member, the oil suction tube is kept fixed in the crankshaft. Thus, the oil is better delivered to the bearings, providing a more efficient oil suction process.
In an embodiment of the present invention, the compressor comprises two locking chambers which enable the connection member to be fixed to the winding holder and which are oppositely disposed on the winding holder, and a locking mechanism which enters the locking chamber, which prevents the connection member from detaching from the winding holder and which has two locking claws on both ends of the connection member. The locking mechanism further comprises a locking extension which extends into the opening at the inlet of the locking chamber and which prevents the locking claw from leaving the locking chamber. By means of the locking mechanism, the connection member is prevented from moving in the horizontal and vertical axes.
In the preferred embodiment of the present invention, the locking claw is in the form of a V. Thus, the locking claw contacts the locking extension and stretches while entering the locking chamber, and returns to the initial position, after entering the locking chamber, since the force exerted by the locking extension is removed. Consequently, when a force is exerted in the vertical axis, the locking claw hits the locking extension and the locking claw is prevented from leaving the locking chamber.
In an embodiment of the present invention, the compressor comprises at least two fixing members which oppositely extend towards each other over the slit extending in the horizontal axis at the base of the oil suction tube and which prevent the connection member seated into the slit from dislodging. In the preferred embodiment of the present invention, a total of four fixing members are provided, two on each wall of the slit.
In the embodiment of the present invention, the connection member is a strip-shaped rod and produced from flexible material.
A compressor realized in order to attain the aim of the present invention is illustrated in the attached figures, where:
Figure 1 - is a cross-sectional view of a compressor.
Figure 2 - is the exploded view of the connection member, the oil suction tube and the winding holder.
Figure 3 - is the view of the cross section A-A in Figure 2.
Figure 4 - is the view of the compressor after the connection member is mounted.
The elements illustrated in the figures are numbered as follows:

Compressor
Motor
Stator
Rotor
Crankshaft
Cylinder block
Bearing
Upper casing
Lower casing
Oil suction tube
Slit
Winding holder
Connection member
Locking mechanism
Locking claw
Locking chamber
Locking extension
Fixing member

The compressor (1) comprises a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a winding holder (12) which supports the motor (2) windings; 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 slit (11) which is provided at the end of the oil suction tube (10) and which extends in the horizontal plane; and a connection member (13) which is seated into the slit (11) along the slit (11) and which is fixed to the winding holder (12) from both ends (Figure 1 and Figure 2).
By means of the connection member (13), the oil suction tube (10) is kept fixed in the crankshaft (5). Thus, the oil is better delivered to the bearings (7), providing a more efficient oil suction process.
In the embodiment of the present invention, the connection member (13) is a strip-shaped rod. In the preferred embodiment of the present invention, the connection member (13) is produced from a flexible material.
In an embodiment of the present invention, the compressor (1) comprises two locking chambers (16) which enable the connection member (13) to be fixed to the winding holder (12) and which are oppositely disposed on the winding holder (12), and a locking mechanism (14) which enters the locking chamber (16), which prevents the connection member (13) from detaching from the winding holder (12) and which has two locking claws (15) on both ends of the connection member (13). The locking mechanism (14) further comprises a locking extension (17) which extends into the opening at the inlet of the locking chamber (16) and which prevents the locking claw (15) from leaving the locking chamber (16). By means of the locking mechanism (14), the connection member (13) is prevented from moving in the horizontal and vertical axes.
In the preferred embodiment of the present invention, the locking claw (15) is in the form of a V. Thus, the locking claw (15) contacts the locking extension (17) and stretches while entering the locking chamber (16), and returns to the initial position, after entering the locking chamber (16), since the force exerted by the locking extension (17) is removed. Consequently, when a force is exerted in the vertical axis, the locking claw (15) hits the locking extension (17) and the locking claw (15) is prevented from leaving the locking chamber (16) (Figure 3).
In an embodiment of the present invention, the compressor (1) comprises at least two fixing members (18) which oppositely extend towards each other over the slit (11) extending in the horizontal axis at the base of the oil suction tube (10) and which prevent the connection member (13) seated into the slit (11) from dislodging. In the preferred embodiment of the present invention, a total of four fixing members (18) are provided, two on each wall of the slit (11) (Figure 4).

Claims

A compressor (1) comprising a motor (2) composed of two main components, namely a stator (3) and a rotor (4); a winding holder (12) which supports the motor (2) windings; 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 slit (11) which is provided at the end of the oil suction tube (10) and which extends in the horizontal plane; and a connection member (13) which is seated into the slit (11) along the slit (11) and which is fixed to the winding holder (12) from both ends.
A compressor (1) as in Claim 1, characterized by the connection member (13) which is a strip-shaped rod.
A compressor (1) as in Claim 1, characterized by two locking chambers (16) which enable the connection member (13) to be fixed to the winding holder (12) and which are oppositely disposed on the winding holder (12), and a locking mechanism (14) which enters the locking chamber (16), which prevents the connection member (13) from detaching from the winding holder (12) and which has two locking claws (15) on both ends of the connection member (13).
A compressor (1) as in Claim 3, characterized by the locking mechanism (14) comprising a locking extension (17) which extends into the opening at the inlet of the locking chamber (16) and which prevents the locking claw (15) from leaving the locking chamber (16).
A compressor (1) as in Claim 3 and Claim 4, characterized by the locking claw (15) which is in the form of a V.
A compressor (1) as in Claim 1, characterized by at least two fixing members (18) which oppositely extend towards each other over the slit (11) extending in the horizontal axis at the base of the oil suction tube (10) and which prevent the connection member (13) seated into the slit (11) from dislodging.