EP3111090A1

EP3111090A1 - Hermetic reciprocating compressor with improved vibration damping facility

Info

Publication number: EP3111090A1
Application number: EP14708836.3A
Authority: EP
Inventors: Ismail YESILAYDIN; Erhan Kasapoglu; Zafer OYAR
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2014-02-28
Filing date: 2014-02-28
Publication date: 2017-01-04
Also published as: WO2015127998A1

Abstract

The present invention relates to a hermetic reciprocating compressor (1) comprising a compressor-kit, a casing which accommodates the compressor-kit, a damping means for damping vibrations of the compressor-kit. In the hermetic reciprocating compressor (1) of the present invention, the damping means includes a compression coil spring (7) which is coaxially arranged with respect to the stator (6) and configured to support the compressor-kit. A lower end of the spring (7a) is coupled to a bottom of the casing and an upper end (7b) of the spring (7) is circumferentially coupled to a peripheral portion (6a) of the stator (6).

Description

HERMETIC RECIPROCATING COMPRESSOR WITH IMPROVED VIBRATION DAMPING FACILITY

The present invention relates to a hermetic reciprocating compressor for use in a refrigeration appliance, in particular a domestic refrigerator. The present invention more particularly relates to a damping facility for damping vibrations generated by a compressor-kit accommodated inside a casing.
It is generally desirable to reduce a size and a weight of a compressor to save manufacturing and transportation costs. A compact compressor increases the utilizable volume of the refrigeration appliance. This is also an important factor for improving customer benefit. However, design limitations and operational constraints generally prevent attaining a significant reduction in the size and the weight of the compressor.
Fig. 1 shows a conventional reciprocating compressor (1´). The conventional reciprocating compressor (1´) has a compressor-kit, a casing which accommodates the compressor-kit and a damping mechanism for damping vibrations of the compressor-kit. The compressor-kit includes: a cylinder block (2´) which has a compression chamber, a cylinder head (3´), a valve assembly which is arranged between the cylinder block (2´) and the cylinder head (3´), a piston head which is reciprocatingly arranged inside the compression chamber, a piston rod which is coupled to the piston head, a crank shaft (4´) which is rotatably arranged into the cylinder block (2´) and eccentrically coupled to the piston rod, a rotor (5´) which is fixed on the crank shaft (4´) and an annular shaped stator (6´) which is arranged coaxially around the rotor (5´) and fixed to the cylinder block (2´). The damping mechanism includes four springs (7´) which are respectively coupled to the pillar-like supports and the lower part of the casing. The above-mentioned constituent parts of the compressor-kit are not-exhaustive. Other constituent parts are well known in the art.
A problem with the reduction of the size of the constituent parts of the compressor is that such modifications generally result in a significant amount of loss of the refrigeration capacity and/or degradation in the compressor performance.
An objective of the present invention is to provide a hermetic reciprocating compressor which overcomes the aforementioned problems of the prior art and which has a damping mechanism that enables a reduction in size without compromising a compressor performance, in particular a damping performance
This objective has been achieved by the hermetic reciprocating compressor according to the present invention as defined in claim 1 and the refrigeration appliance according to the present invention as defined in claim 9. Further achievements have been attained by the subject-matters respectively defined in the dependent claims.
In the hermetic reciprocating compressor of the present invention, the damping means includes a compression coil spring which is coaxially arranged with respect to the stator and which supports the compressor kit. A lower end of the spring is coupled to a bottom of the casing and an upper end of the spring is circumferentially coupled to a peripheral portion of the stator.
In an embodiment, the hermetic reciprocating compressor comprises a pair of separate coupling means which are utilized to respectively couple the casing and the stator via the compression coil spring. In a version of this embodiment, both coupling means have an annular-shaped frame structure which match the shape of the opposing ends of compression coil spring.
In an alternative embodiment, the coupling means between the stator and the compression coil spring is dispensed with. In this embodiment, the upper end of the spring is directly fitted around the peripheral portion of the stator and is retained in place with its own clamping force. In a version of this embodiment, the peripheral portion of the stator is formed by a plurality of steel laminations which are insulated by an insulating material. The upper end of the spring is directly fitted around the insulated steel laminations.
In another embodiment, the damping means includes a single compression coil spring.
By virtue of the damping facility of the present invention, the compressor-kit has been coupled to the bottom of the casing through a centered compression coil spring, namely a compression coil spring which is coaxially aligned with the stator and the rotational axis of the rotor and the crank shaft. As the centered compression coil spring is circumferentially coupled to a peripheral portion of the stator, a stable configuration with a low center of mass has been attained. Thereby, a height of the compressor has been reduced so that a smaller casing can be utilized. In this configuration, the centered compression coil spring has a diameter which is larger than that of the conventional springs shown in Fig. 1. The centered compression coil spring has a sufficient stuffiness to support the compressor-kit and absorbs the vibrations more smoothly. Thereby, a damping performance has been improved. With the damping facility of the present invention, the number of separate contacts to be established between the casing and the compressor-kit during an assembly process has been reduced. This configuration substantially simplifies the assembly process and saves costs.
Additional advantages of the hermetic reciprocating compressor of the present invention and the refrigeration appliance of the present invention will become apparent with the detailed description of the embodiments with reference to the accompanying drawings in which:
Figure 1 – is a schematic cross sectional view of a conventional hermetic reciprocating compressor, taken along a vertical direction,
Figure 2 – is a schematic partial side view of a hermetic reciprocating compressor according to an embodiment of the present invention prior to mounting a crank shaft together with a rotor to a cylinder block,
Figure 3 – is a schematic exploded perspective view of the hermetic reciprocating compressor shown in Fig. 2,
Figure 4 – is a schematic partial side view of a hermetic reciprocating compressor according to another embodiment of the present invention prior to mounting the crank shaft together with the rotor to the cylinder block,
Figure 5 – is a schematic exploded perspective view of the hermetic reciprocating compressor shown in Fig. 4.
The reference signs appearing on the drawings relate to the following technical features.

Compressor
Cylinder block
Cylinder head
Crank shaft
Rotor
Stator

6a. Peripheral portion
7. Spring
7a. Lower end
7b. Upper end
8. Lower coupling means
9. Upper coupling means
10. Laminations
The hermetic reciprocating compressor (1) comprises a compressor-kit which includes a cylinder block (2) which has a compression chamber, a cylinder head (3), a valve assembly which is arranged between the cylinder block (2) and the cylinder head (3), a piston head which is reciprocatingly arranged within the compression chamber, a piston rod which is coupled to the piston head, a crank shaft (4) which is rotatably arranged into the cylinder block (2) and eccentrically coupled to the piston rod, a rotor (5) which is fixed on the crank shaft (4) and an annular shaped stator (6) which is coaxially arranged around the rotor (5) and fixed to the cylinder block (2), a casing which accommodates the compressor-kit and a damping means for damping vibrations of the compressor-kit (Figs. 2 to 5).
In the hermetic reciprocating compressor (1) of the present invention, the damping means includes a compression coil spring (7) which is coaxially arranged with respect to the stator (6) and configured to support the compressor-kit. A lower end (7a) of the spring (7) is coupled to a bottom of the casing and an upper end (7b) of the spring (7) is circumferentially coupled to a peripheral portion (6a) of the stator (6) (Figs. 2 to 5).
In an embodiment, the hermetic reciprocating compressor (1) comprises a lower coupling means (8) which is firmly attached to the bottom of the casing and configured to circumferentially hold the lower end (7a) of the spring (7) (Figs. 2 to 5). In a version of this embodiment, the lower coupling means (8) has an annular-shaped frame which matches the shape of the lower end (7a) of the compression coil spring (7). In another version of this embodiment, the lower coupling means (8) is made from plastic.
In another embodiment, the hermetic reciprocating compressor (1) comprises an upper coupling means (9) which is circumferentially attached to the peripheral portion (6a) of the stator (6) and configured to circumferentially hold the upper end (7b) of the spring (7) (Figs. 2 and 3). In a version of the embodiment, the upper coupling means (9) has also an annular-shaped frame which matches the shape of the compression coil spring (7) and a peripheral portion (6a) of the stator (6) so that the annular-shaped frame can be sleeved onto the peripheral portion (6a) while firmly holding the upper end (7b) of the spring (7).
In another version of this embodiment, the upper coupling means (9) is also made from plastic.
In an alternative embodiment, the upper coupling means (9) is not used. In this embodiment, the upper end (7b) of the spring (7) is directly fitted around the peripheral portion (6a) of the stator (6). Herein, an inner diameter of the spring (7) is configured to be slightly smaller than an outer diameter of the peripheral portion (6a) of the stator (6). Thereby, in a fitted state, a clamping force is exerted to the stator (6) by the spring (7) (Figs. 4 and 5). In a version of this alternative embodiment, the peripheral portion (6a) of the stator (6) is formed by a plurality of steel laminations (10). In addition, an insulating material (not shown) is provided between the upper end (7b) of the spring (7) and the steel laminations (10) (Figs. 4 and 5).
In another embodiment, the damping means includes a single compression coil spring (7) (Figs. 2 to 5). In a version of this embodiment, the single compression coil spring (7) is made of one piece.
The present invention also provides a refrigeration appliance (not shown) which comprises the hermetic reciprocating compressor (1). In another embodiment, the refrigeration appliance is provided as a domestic refrigerator (not shown).
The present invention provides a hermetic reciprocating compressor (1) which has a damping facility that stably supports the compressor-kit. Due to the low center of mass of the above-described configuration, a height of the compressor (1) has been reduced and, thus, a smaller casing can be utilized. This configuration substantially simplifies the assembly process and saves costs. Also due to the coaxially arranged compression coil spring (7) the vibrations can be absorbed more smoothly. The damping facility of the present invention is particularly suited for use in compact compressors (1) in which the constituent parts have a relatively low weight and, thus, generate less vibrations.

Claims

A hermetic reciprocating compressor (1) comprising

- a compressor-kit which includes a cylinder block (2) which has a compression chamber, a cylinder head (3), a valve assembly which is arranged between the cylinder block (2) and the cylinder head (3), a piston head which is reciprocatingly arranged inside the compression chamber, a piston rod which is coupled to the piston head, a crank shaft (4) which is rotatably arranged into the cylinder block (2) and eccentrically coupled to the piston rod, a rotor (5) which is fixed on the crank shaft (4) and an annular shaped stator (6) which is coaxially arranged around the rotor (5) and fixed to the cylinder block (2),

- a casing which accommodates the compressor kit,

- a damping means for damping vibrations of the compressor kit,

characterized in that

- the damping means includes a compression coil spring (7) which is coaxially arranged with respect to the stator (6) and configured to support the compressor kit, wherein a lower end (7a) of the spring (7) is coupled to a bottom of the casing and an upper end (7b) of the spring (7) is circumferentially coupled to a peripheral portion (6a) of the stator (6).
The hermetic reciprocating compressor (1) according to claim 1, characterized in that a lower coupling means (8) which is firmly attached to the bottom of the casing and configured to circumferentially hold the lower end (7a) of the spring (7).
The hermetic reciprocating compressor (1) according to claim 2, characterized in that the lower coupling means (8) is made from plastic.
The hermetic reciprocating compressor (1) according to claim 2 or 3, characterized in that an upper coupling means (9) which is circumferentially attached to the peripheral portion (6a) of the stator (6) and configured to circumferentially hold the upper end (7b) of the spring (7).
The hermetic reciprocating compressor (1) according to claim 4, characterized in that the upper coupling means (9) is made from plastic.
The hermetic reciprocating compressor (1) according to claim 2 or 3, characterized in that the upper end (7b) of the spring (7) is directly fitted around the peripheral portion (6a) of the stator (6), wherein an inner diameter of the spring (7) is slightly smaller than an outer diameter of the peripheral portion (6a) of the stator (6) so as to exert, in fitted state, a clamping force to the stator (6).
The hermetic reciprocating compressor (1) according to claim 6, characterized in that the peripheral portion (6a) of the stator (6) is formed by a plurality of steel laminations (10), wherein an insulating material is provided between the upper end (7b) of the spring (7) and the steel laminations (10).
The hermetic reciprocating compressor (1) according to any one of claims 1 to 7, characterized in that the damping means includes a single compression coil spring (7).
A refrigeration appliance, in particular a domestic refrigerator comprising a hermetic reciprocating compressor (1) according to any one of claims 1 to 8.