CROSS-REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of the earlier filing date and the right of priority to Korean Patent Application No. 10-2020-0073806, filed on Jun. 17, 2020, the contents of which are incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present disclosure relates to a linear compressor, and more particularly, a silencer.

BACKGROUND

A linear compressor can include a linear motor installed inside a sealed shell, and a piston connected to the linear motor. The linear compressor can perform suctioning, compressing, and discharging refrigerant while the piston is linearly reciprocating inside a cylinder.

Like other compressors, a linear compressor may generate noise including vibrational noise during operation of the compressor. The noise may be transmitted outwardly of the shell and lead to an increase of noise of products such as refrigerators including linear compressors therein.

In some cases, the linear compressor may include elements to suppress or reduce noise of the compressor. For example, a suction muffler may be installed in an inner space of a shell to reduce suction noise, and a discharge cover may be installed in an inner space of a shell to reduce discharge noise.

However, in some cases, despite the installation of the suction muffler or the discharge cover, some noise may not be canceled. For example, there are limits in effectively attenuating noise in 800 Hz band (seeFIG. 10).

In some cases, a silencer may be additionally installed inside the shell. However, the silencer may increase material costs as the number of separate components as well as assemblers increases, and therefore, the overall manufacturing cost of the compressor may be increased.

In some cases, when a separate silencer is installed inside the shell, an internal volume of the shell may be increased, and therefore, an overall size or weight of the compressor may be increased.

In some cases, silencers of various standards may be installed in order to offset noise in various bands generated inside the shell.

SUMMARY

An aspect of the present disclosure is to provide a linear compressor capable of effectively canceling noise generated inside a shell.

Another aspect of the present disclosure is to provide a linear compressor capable of effectively canceling noise generated inside the shell by using existing members without additionally installing a silencer inside the shell.

Further, another aspect of the present disclosure is to provide a linear compressor capable of effectively canceling noise in various frequency bands generated inside a shell.

According to one aspect of the subject matter described in this application, a linear compressor includes a shell that defines an inner space therein, a motor that is disposed in the inner space of the shell and includes a mover configured to perform a reciprocating motion in an axial direction, a cylinder disposed in the inner space of the shell, a piston coupled to the mover of the motor and configured to reciprocate in the cylinder, a spring that supports the piston in the axial direction, and a spring cap that is inserted into and supports an end portion of the spring. The spring cap defines a space portion that is defined inside the spring cap and has a volume separate from the inner space of the shell, and a passage portion that extends through an axial side surface of the spring cap and is configured to provide communication between the space portion and the inner space of the shell.

Implementations according to this aspect can include one or more of the following features. For example, the linear compressor can further include a spring supporter coupled to the piston or the mover of the motor and configured to move together with the piston or the mover of the motor, where the spring supporter defines a cap support hole that receives the spring cap, and the spring cap passes through the cap support hole. In some examples, the spring cap can include a first cap inserted into a first side of the cap support hole, and a second cap inserted into a second side of the cap support hole opposite to the first side in the axial direction, where the first cap and the second cap are in communication with each other through the cap support hole and define the space portion inside the first cap and the second cap.

In some implementations, the spring supporter can be configured to move together with the piston or the mover of the motor and define a cap support hole that receives the spring cap, where an axial length of the space portion is greater than an axial length of the cap support hole of the spring supporter. In some implementations, the spring cap includes a first cap that is inserted into a first side of the cap support hole and defines a first space portion therein, and a second cap that is inserted into a second side of the cap support hole opposite to the first side in the axial direction, the second cap defining a second space portion therein. In some implementations, a volume of the first space portion can be equal to a volume of the second space portion. In some implementations, the volume of the first space portion can be different from the volume of the second space portion.

In some implementations, the spring cap includes a first cap that is inserted into a first side of the cap support hole, and a second cap that is inserted into a second side of the cap support hole opposite to the first side in the axial direction, where one of the first cap or the second cap has a first axial side surface that is blocked, and another of the first cap or the second cap has a second axial side surface that is at least partially opened and defines the passage portion.

In some implementations, the spring cap includes a first cap that is inserted into a first side of the cap support hole, and a second cap that is inserted into a second side of the cap support hole opposite to the first side in the axial direction, where the passage portion includes a first passage portion defined at one surface of the first cap, and a second passage portion defined at one surface of the second cap.

In some examples, the first passage portion can be defined at a first side of the spring cap, and the second passage portion can be defined at a second side of the spring cap opposite to the first side in the axial direction. A cross-sectional area of the first passage portion can be different from a cross-sectional area of the second passage portion, or an axial length of the first passage portion can be different from an axial length of the second passage portion.

In some implementations, the passage portion can include a first passage portion that is defined at a first side of the spring cap and extends along a first axial line, and a second passage portion that is defined at a second side of the spring cap opposite to the first side in the axial direction, the second passage portion extending along a second axial line different from the first axial line. In some implementations, the passage portion extends from one surface of the spring cap in the axial direction.

In some implementations, the spring cap can be one of a plurality of spring caps that are arranged in a circumferential direction, where each of the plurality of spring caps defines a space portion and a passage portion. In some examples, shapes of the space portions are identical to one another, and shapes of the passage portions are identical to one another. In some examples, a shape of at least one of the space portions is different from a shape of another of the space portions, and a shape of at least one of the passage portions can be different from a shape of another of the passage portions.

In some implementations, the first cap can be coupled to a first axial side surface of the spring supporter, and the second cap can be coupled to a second axial side surface of the spring supporter. The first cap can include a first hole insertion portion inserted from a first side surface of the spring supporter into a first side of the cap support hole, a first cap support portion that has a flange shape extending from an outer circumferential surface of the first hole insertion portion and is supported by the first side surface of the spring supporter in the axial direction, and a first spring insertion portion that extends from the first cap support portion away from the first hole insertion portion. The second cap can include a second hole insertion portion inserted from a second side surface of the spring supporter into a second side of the cap support hole, a second cap support portion that has a flange shape extending from an outer circumferential surface of the second hole insertion portion and is supported by the second side surface of the spring supporter in the axial direction, and a second spring insertion portion that extends from the second cap support portion away from the second hole insertion portion. An end portion of the first hole insertion portion can face and be in communication with an end portion of the second hole insertion portion to thereby define the space portion inside the first cap and the second cap. An axial side surface of the first spring insertion portion or an axial side surface of the second spring insertion portion can be at least partially opened and define the passage portion.

In some implementations, the first cap includes a hole penetrating portion that is inserted from a first side surface of the spring supporter into the cap support hole and penetrates the cap support hole in the axial direction, a first cap support portion that has a flange shape extending from an outer circumferential surface of the hole penetrating portion and is supported by the first side surface of the spring supporter in the axial direction, and a first spring insertion portion that extends from the first cap support portion away from the hole penetrating portion. The second cap can include a cap coupling portion disposed at a second side surface of the spring supporter and coupled to a part of the hole penetrating portion outside the cap support hole, a second cap support portion that has a flange shape extending from an outer circumferential surface of the cap coupling portion and is supported by the second side surface of the spring supporter in the axial direction, and a second spring insertion portion that extends from the cap coupling portion away from the first spring insertion portion.

In some implementations, the first cap can be coupled to a first axial side surface of the spring supporter and include a first spring insertion portion that extends in the axial direction. The second cap can be coupled to a second axial side surface of the spring supporter and include a second spring insertion portion that extends in the axial direction. An inner diameter of at least one of the first spring insertion portion or the second spring insertion portion can be constant along the axial direction.

In some implementations, a cross-sectional area of at least one of the first spring insertion portion or the second spring insertion portion can decrease as the at least one of the first spring insertion portion or the second spring insertion portion extends away from the spring supporter along the axial direction. In some implementations, the spring cap can pass through opposite axial side surfaces of the spring supporter and be coupled to the spring supporter, and an axial side surface of the spring cap can be at least partially opened and defines the passage portion.

In some implementations, the linear compressor can further include a stator cover and a rear cover that are disposed at one side of the motor and support opposite ends of the spring, respectively, where the spring cap is disposed at the stator cover or the rear cover. In some implementations, the spring can include a front spring and a rear spring that are arranged along the axial direction, where the spring cap is disposed between the front spring and the rear spring and connects the front spring and the rear spring to each other.

