Patent Description:
Generally, a compressor is applied to a refrigerant compression type cooling cycle (hereinafter, referred to as a cooling cycle) such as a refrigerator or an air conditioner.

The compressor may be categorized into a reciprocating compressor and a rotary compressor in accordance with a method of compressing a refrigerant, wherein the rotary compressor may include a scroll compressor.

The scroll compressor may be categorized into an upper compression type and a lower compression type in accordance with positions of a driving motor and a compression portion. The upper compression type is that the compression portion is located above the driving motor, and the lower compression type is that the compression portion is located below the driving motor.

That is, the compressor may be called differently depending on relative positions of the driving motor and the compression portion. The compressor may be provided horizontally not vertically. Therefore, the compressor may be called as a more generalized term depending on the relative positions of the driving motor and the compression portion. In accordance with a flow direction of a refrigerant inside the compressor and the position of the driving motor, a compressor for compressing a refrigerant at an upstream of the driving motor and discharging the refrigerant from a downstream of the driving motor may be referred to as an upstream compressor. A compressor for compressing a refrigerant at the downstream of the driving motor and discharging the refrigerant from the downstream of the driving motor may be referred to as a downstream compressor.

The compressor is provided with a bearing portion for rotatably supporting a rotary shaft and a compression portion for compressing a refrigerant. Mechanical friction occurs in the bearing portion and the compression portion, and oil is supplied such that such friction is reduced and the rotary shaft and the compression portion are actively driven. Therefore, active and effective oil supply may continuously be required.

A general oil supply manner is based on a pressure difference between a high pressure and a low pressure. A pressure difference between a lower low oil space which is a high pressure space in a case and a low pressure space of a compression chamber where a refrigerant is compressed is used. That is, an oil path is formed between the lower low oil space and the low pressure space of the compression chamber, whereby oil is supplied due to the pressure difference.

However, if the pressure difference is used, a problem occurs in that it is difficult to continuously maintain effective and active oil supply in a driving area having no great pressure difference, that is, a low pressure ratio driving area.

This problem reduces the possibility of a driving area of a compressor, which may be extended from a low speed to a high speed. This is because that low speed driving may be limited due to the problem of oil supply.

Therefore, a compressor that may provide a wide driving area and enable effective and active oil supply is required.

<CIT> relates to a scroll compressor, including a fixed scroll having a fixed wrap and an orbiting scroll having an orbiting wrap to form a compression chamber by being engaged with the fixed wrap.

<CIT> relates to a scroll compressor having a compression device disposed below a motor.

<CIT> relates to compressors which compresses a refrigerant.

The present invention is defined by the independent claim. Accordingly, the present disclosure is directed to a compressor that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present disclosure is to provide a compressor that solves a problem of a scroll compressor of the related art.

Another object of the present disclosure is to provide a compressor that enables effective and active oil supply even in a low pressure ratio driving area that is lack of a pressure difference, in accordance with one embodiment of the present disclosure.

Another object of the present disclosure is to provide a compressor having a wide driving area through oil supply based on a pressure difference together with oil supply based on a pump. Particularly, another object of the present disclosure is to provide a compressor in which a pump may easily be applied by minimizing a change in components for oil supply based on a pressure difference of the related art.

Another object of the present disclosure is to provide a compressor in which a pump assembly for oil supply may be provided to be exactly matched with a center and its center may stably be fixed.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a compressor according to the present disclosure may comprise a case; a driving motor including a stator provided at an inner side of the case and a rotor rotatably provided at an inner side in a radius direction of the stator; a centrifugation space defined inside the case by a downstream side of the driving motor and the case, enabling centrifugation of a compressed refrigerant and a lubricant oil; a discharge pipe provided in the case, discharging the refrigerant inside the centrifugation space to the outside of the case; a rotary shaft rotated by being coupled to the rotor and provided with an oil supply path; a compression portion provided at an upstream side of the driving motor, compressing the refrigerant through rotation of the rotary shaft; a pump assembly provided below the rotary shaft, pumping oil by being rotated in a single body with the rotary shaft; and an oil pickup forming an oil supply path between the pump assembly and a low oil space formed inside the case.

The compression portion includes a muffler accommodating the compressed refrigerant discharged from the compression portion, provided to guide the compressed refrigerant to the discharge pipe.

The compression portion includes a fixed scroll and an orbiting scroll provided to compress the refrigerant through orbiting movement with respect to the fixed scroll.

A shaft support portion in which the rotary shaft is accommodated by passing therethrough is provided at a center of the fixed scroll, and includes a first boss protruded toward the low oil space.

A pump holder portion recessed toward the driving motor to allow the pump assembly to be arranged therein is formed at a center of the muffler.

A shaft support portion in which the rotary shaft is accommodated by passing therethrough is provided at a center of the pump holder portion, and includes a second boss protruded toward the driving motor.

At least a portion of the first boss is inserted into the second boss, and therefore the first boss and the second boss are overlapped with each other.

The pump assembly may include an oil pump connected to the rotary shaft and pump housings accommodating the oil pump.

The pump housings may include an upper housing inserted into the pump holder portion of the muffler and a lower housing coupled with the upper housing.

The upper housing may be provided with a shaft support portion in which the rotary shaft is accommodated by passing therethrough, and may include a third boss protruded toward the driving motor.

Preferably, at least a portion of the third boss is inserted into the first boss, and therefore the first boss and the third boss are overlapped with each other.

Preferably, the lower housing is provided with an end shaft support portion into which an end of the rotary shaft is inserted and supported.

Preferably, a pumping space in which the oil pump is arranged is formed between the shaft support portion of the upper housing and the end shaft support portion of the lower housing, and the lower housing is provided with a communication portion for communicating the pumping space with the low oil space.

The communication portion may include a pickup arrangement groove into which the oil pickup is inserted and arranged.

The rotary shaft may include a motor coupling portion coupled with the driving motor; a main bearing portion extended from the motor coupling portion; an eccentric portion extended from the main bearing portion and coupled with the orbiting scroll; a sub bearing portion extended from the eccentric portion; and a pump coupling portion extended from the sub bearing portion and coupled with the pump assembly.

Preferably, the rotary shaft is formed in a single body with one bar by mechanical processing of one bar.

Preferably, the motor coupling portion, the main bearing portion, the sub bearing portion and the pump coupling portion have the same shaft, and the pump coupling portion has the smallest outer diameter.

Features of the aforementioned embodiments are complexly applicable to the other embodiments unless contradicted or exclusive.

In accordance with one embodiment of the present disclosure, a compressor, which enables effective and active oil supply even in a low pressure ratio driving area that is lack of a pressure difference, may be provided.

In accordance with one embodiment of the present disclosure, a compressor, in which a pump assembly for oil supply may be provided to be exactly matched with a center and its center may stably be fixed, may be provided.

It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Reference will now be made in detail to the detailed embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

First of all, a compressor applicable to one embodiment of the present disclosure will be described in detail with reference to <FIG>.

<FIG> is a sectional view illustrating an example of a scroll compressor applicable to one embodiment of the present disclosure. Since a compression portion is located below a driving motor, the compressor may be referred to as a lower compression type compressor or an upstream compressor.

For convenience of description, an upper/lower position may be called based on a compressor located vertically. An upstream/downstream position may be called based on a flow of a refrigerant and a position of a driving motor <NUM>. In the compressor, an upper may mean a downstream and a lower may mean an upstream.

The compressor according to the present disclosure includes a case <NUM>, a driving motor <NUM>, a compression portion <NUM>, and a rotary shaft <NUM>.

The case <NUM> may be formed to have an inner space. For example, a low oil space where oil is stored may be provided below the case <NUM>. The low oil space may mean a fourth space V4 which will be described later. That is, the fourth space V4 may be formed as the low oil space.

A refrigerant discharge pipe <NUM> for discharging the compressed refrigerant may be provided at the upstream.

In detail, the inner space of the case <NUM> may include a first space V1 arranged at the upstream of the driving motor <NUM>, a second space V2 arranged between the driving motor <NUM> and the compression portion <NUM>, a third space V3 partitioned by a discharge cover <NUM>, which will be described later, and a fourth space V4 arranged below the compression portion <NUM>.

The first space V1 may be regarded as a space where centrifugation of the compressed refrigerant and lubricant oil is performed. That is, the refrigerant may substantially be discharged to the discharge pipe <NUM> through centrifugation between the refrigerant and oil before the compressed refrigerant is discharged to the outside of the compressor through the discharge pipe <NUM>. This centrifugation space V1 is defined by a downstream side of the driving motor and the case <NUM> inside the case <NUM>.

The case <NUM> may be formed in a cylindrical shape. For example, the case <NUM> may include a cylindrical shell <NUM> of which upper and lower ends are opened.

An upper shell <NUM> may be provided at an upper portion of the cylindrical shell <NUM>, and a lower shell <NUM> may be provided at a lower portion of the cylindrical shell <NUM>. For example, the upper and lower shells <NUM> and <NUM> may be coupled to the cylindrical shell <NUM> by welding to form an inner space.

The upper shell <NUM> may be provided with the refrigerant discharge pipe <NUM>. The refrigerant compressed by the compression portion <NUM> may be discharged to the outside through the refrigerant discharge pipe <NUM>. For example, the refrigerant compressed by the compression portion <NUM> may be discharged to the outside through the refrigerant discharge pipe <NUM> after passing through the third space V3, the second space V2 and the first space V1 in due order.

An oil separator or oil returning unit connected with the compressor as a general component is not shown in <FIG>. This means that the compressor according to this embodiment may effectively separate oil so as not to require a separate oil separator.

The lower shell <NUM> may partition the fourth space V4 that is a low oil space where oil may be stored. The fourth space V4 may perform a function as an oil chamber for supplying oil to the compression portion <NUM> such that the compressor may actively operate.

Also, a refrigerant suction pipe <NUM> that is a passage through which the refrigerant which will be compressed enters may be provided at a side of the cylindrical shell <NUM>. The refrigerant suction pipe <NUM> may be provided to pass through a compression chamber S1 along a side of a fixed scroll <NUM> which will be described later.

The driving motor <NUM> may be provided at an inner side of the case <NUM>. For example, the driving motor <NUM> may be arranged above the compression portion <NUM> at the inner side of the case <NUM>.

The driving motor <NUM> includes a stator <NUM> and a rotor <NUM>. The stator <NUM> may have a cylindrical shape, for example, and may be fixed to the case <NUM>. A coil 122a may be wound in the stator <NUM>. Also, a refrigerant path groove 112a may be formed between an outer circumferential surface of the rotor <NUM> and an inner circumferential surface of the stator <NUM> to allow the refrigerant or oil discharged from the compression portion <NUM> to pass therethrough. That is, the refrigerant path groove 112a may be partitioned by the inner circumferential surface of the stator <NUM> and the outer circumferential surface of the rotor <NUM>.

The rotor <NUM> may inwardly be arranged in a radius direction of the stator <NUM>, and may generate a rotation power. That is, as the rotary shaft <NUM> is forcibly inserted into the center of the rotor <NUM>, the rotor <NUM> may be rotated together with the rotary shaft <NUM>. The rotation power generated by the rotor <NUM> may be transferred to the compression portion <NUM> through the rotary shaft <NUM>.

The compression portion <NUM> may be coupled to the driving motor <NUM> to compress the refrigerant. The compression portion <NUM> may be formed to allow the rotary shaft <NUM> connected to the driving motor <NUM> to pass therethrough.

The compression portion <NUM> may include a shaft support portion protruded upwardly and downwardly, and the rotary shaft <NUM> may pass through at least a portion of the shaft support portion. For example, the shaft support portion may include a first shaft support portion upwardly protruded from the compression portion <NUM> and a second shaft support portion downwardly protruded from the compression portion <NUM>, and its detailed description will be given later.

The compression portion <NUM> may include a main frame <NUM>, a fixed scroll <NUM> and an orbiting scroll <NUM>.

In detail, the compression portion <NUM> may further include an Oldham's ring <NUM>. The Oldham's ring <NUM> may be provided between the orbiting scroll <NUM> and the main frame <NUM>. Also, the Oldham's ring <NUM> enables orbiting movement of the orbiting scroll <NUM> on the fixed scroll <NUM> while preventing the orbiting scroll <NUM> from being rotated.

The main frame <NUM> is provided below the driving motor <NUM>, and may form the upper portion of the compression portion <NUM>.

The main frame <NUM> may include a frame end plate (hereinafter, referred to as "first end plate") <NUM> having a circle shape approximately, a frame shaft support (hereinafter, referred to as "first shaft support portion") 132a, which is provided at the center of the first end plate <NUM> and through which the rotary shaft <NUM> passes, and a frame sidewall (hereinafter, referred to as "first sidewall) <NUM> downwardly protruded from an outer circumference of the first end plate <NUM>.

An outer circumference of the first sidewall <NUM> may adjoin the inner circumferential surface of the cylindrical shell <NUM>, and its lower end may adjoin an upper end of a fixed scroll sidewall <NUM>, which will be described later.

The first sidewall <NUM> may be provided with a frame discharge hole 131a constituting a refrigerant passage by passing through the inside of the first sidewall <NUM> in a shaft direction. An inlet of the frame discharge hole 131a may be communicated with an outlet of a fixed scroll discharge hole 155a, which will be described later, and its outlet may be communicated with the second space V2. The frame discharge hole 131a and the fixed scroll discharge hole 155a, which are communicated with each other, may be expressed as second discharge holes 131a and 155a.

The frame discharge hole 131a may be provided in a plural number along the circumference of the main frame <NUM>. The fixed scroll discharge hole 155a may be provided in a plural number along the circumference of the fixed scroll <NUM> to correspond to the frame discharge hole 131a.

The first shaft support portion 132a may be formed to be protruded from an upper surface of the first end plate <NUM> to the driving motor <NUM>. Also, the first shaft support portion 132a may be provided with a first bearing formed such that a main bearing portion 126c of the rotary shaft <NUM>, which will be described later, may pass and be supported.

That is, the first shaft support portion 132a, into which the main bearing portion 126c of the rotary shaft <NUM>, which constitutes the first shaft support portion, is rotatably inserted and then supported, may be formed at the center of the main frame <NUM> in a shaft direction to pass through the main frame <NUM>.

An oil pocket 132b that collects oil discharged between the first shaft support portion 132a and the rotary shaft <NUM> may be formed on the upper surface of the first end plate <NUM>.

The oil pocket 132b may be formed to be recessed on the upper surface of the first end plate <NUM>, and may be formed in a ring shape along the circumference of the first shaft support portion 132a. Also, a back pressure chamber S2 may be formed on the bottom of the main frame <NUM> to support the orbiting scroll <NUM> by means of a pressure of a space formed by the fixed scroll <NUM> and the orbiting scroll <NUM>.

For reference, the back pressure chamber S2 may include an intermediate pressure area (that is, intermediate pressure chamber), and an oil supply path 126a provided in the rotary shaft <NUM> may include a high pressure area having a pressure higher than that of the back pressure chamber S2. Therefore, oil may be supplied to each target component through the oil supply path due to a pressure difference between the back pressure chamber and the oil supply path. However, a problem occurs in that such oil supply based on the pressure difference, that is, differential pressure is not sufficient in a low load driving area having low differential pressure. To solve this problem, an embodiment, which will be described later, may be provided.

In order to partition the high pressure area from the intermediate pressure area, a back pressure seal <NUM> may be provided between the main frame <NUM> and the orbiting scroll <NUM>, and may serve as a sealing member, for example.

Also, the main frame <NUM> may be coupled with the fixed scroll <NUM> to form a space where the orbiting scroll <NUM> may pivotally be provided.

The fixed scroll <NUM> may be provided below the main frame <NUM>. That is, the fixed scroll <NUM> constituting a first scroll may be coupled to the bottom of the main frame <NUM>.

The fixed scroll <NUM> may include a fixed scroll end plate (hereinafter, referred to as "second end plate") <NUM> having a circle shape approximately, a fixed scroll sidewall (hereinafter, referred to as "second sidewall") <NUM> protruded from an outer circumference of the second end plate <NUM> to an upper portion of the second end plate <NUM>, a fixed wrap <NUM> protruded from the upper surface of the second end plate <NUM> and engaged with an orbiting wrap <NUM> of the orbiting scroll <NUM> to form a compression chamber S1, and a fixed scroll shaft support portion (hereinafter, referred to as "second shaft support portion") <NUM> formed at the center of a rear surface of the second end plate <NUM> to allow the rotary shaft <NUM> to pass therethrough.

The compression portion <NUM> may include a first discharge hole <NUM> for discharging the compressed refrigerant to the discharge cover <NUM>, and the aforementioned second discharge holes 131a and 155a spaced apart from the first discharge hole <NUM> outside a radius direction of the compression portion <NUM>, guiding the compressed refrigerant toward the refrigerant discharge pipe <NUM>.

In detail, the second end plate <NUM> may be provided with the first discharge hole <NUM> formed to guide the compressed refrigerant from the compression chamber S1 to an inner space of the discharge cover <NUM>. Also, a position of the first discharge hole <NUM> may optionally be set in consideration of a discharge pressure which is required.

As the first discharge hole <NUM> is formed toward the lower shell <NUM>, the discharge cover <NUM> for guiding the refrigerant discharged from the compression portion to the fixed scroll discharge hole 155a, which will be described later, may be coupled to the bottom of the fixed scroll <NUM>.

The discharge cover <NUM> may be sealed in and coupled to the lower end of the compression portion <NUM>. The discharge cover <NUM> is formed to guide the refrigerant compressed by the compression portion <NUM> toward the refrigerant discharge pipe <NUM>.

For example, the discharge cover <NUM> may be sealed in and coupled to the bottom of the fixed scroll <NUM> to separate the discharge path of the refrigerant from the fourth space V4.

Also, the discharge cover <NUM> may be provided with a through hole <NUM> coupled to a sub bearing portion <NUM> of the rotary shaft <NUM>, which constitutes a second bearing portion, and formed to allow an oil feeder <NUM> to pass therethrough, wherein at least a portion of the oil feeder <NUM> is immersed in oil stored in the fourth space V4 of the case <NUM>.

Meanwhile, the second sidewall <NUM> may be provided with the fixed scroll discharge hole 155a constituting the refrigerant passage together with the frame discharge hole 131a by passing through the inside of the second sidewall <NUM> in a shaft direction.

The fixed scroll discharge hole 155a may be formed to correspond to the frame discharge hole 131a, and its inlet may be communicated with the inner space of the discharge cover <NUM> and its outlet may be communicated with an inlet of the frame discharge hole 131a.

The fixed scroll discharge hole 155a and the frame discharge hole 131a may communicate the third space V3 with the second space V2 such that the refrigerant discharged from the compression chamber S1 to the inner space of the discharge cover <NUM> may be guided to the second space V2.

A refrigerant suction pipe <NUM> may be provided to be communicated with a suction side of the compression chamber S1 at the second sidewall <NUM>. Also, the refrigerant suction pipe <NUM> may be provided to be spaced apart from the fixed scroll discharge hole 155a.

The second shaft support portion <NUM> may be formed to be protruded from the lower surface of the second end plate <NUM> to the fourth space V4. Also, the second shaft support portion <NUM> may be provided with a second bearing such that a sub bearing <NUM> of the rotary shaft <NUM> may be inserted into and supported in the second bearing.

The second shaft support portion <NUM> may be bent toward a shaft center such that its lower end may constitute a thrust bearing by supporting a lower end of the sub bearing portion <NUM> of the rotary shaft <NUM>.

The orbiting scroll <NUM> may be arranged between the main frame <NUM> and the fixed scroll <NUM> and form a second scroll.

In detail, the orbiting scroll <NUM> may perform orbiting movement by being coupled to the rotary shaft <NUM> and form a pair of compression chambers S1 with the fixed scroll <NUM>. That is, the compression chambers S1 may be formed between the orbiting scroll <NUM> and the fixed scroll <NUM>.

The orbiting scroll <NUM> may include an orbiting scroll end plate (hereinafter, referred to as "third end plate") having a circle shape approximately, an orbiting wrap <NUM> protruded from a lower surface of the third end plate <NUM> and engaged with the fixed wrap <NUM>, and a rotary shaft coupling portion <NUM> provided at the center of the third end plate <NUM> and rotatably coupled to an eccentric portion 126f of the rotary shaft <NUM>.

An outer circumference of the third end plate <NUM> may be located at an upper end of the second sidewall <NUM>, and a lower end of the orbiting wrap <NUM> may be tightly adhered to the upper surface of the second end plate <NUM> and therefore supported in the fixed scroll <NUM>.

For reference, a pocket groove <NUM> for guiding oil discharged through oil holes 128a, 128b, 128d, and 128e, which will be described later, to the intermediate pressure chamber may be formed on the upper surface of the orbiting scroll <NUM>.

In detail, the pocket groove <NUM> may be formed to be recessed on the third end plate <NUM>. That is, the pocket groove <NUM> may be formed on the third end plate <NUM> between the back pressure seal <NUM> and the rotary shaft <NUM>.

Also, one or more pocket grooves <NUM> may be formed at both sides of the rotary shaft <NUM> as shown. The pocket groove <NUM> may be formed in a ring shape on the third end plate <NUM> based on the rotary shaft <NUM> between the back pressure seal <NUM> and the rotary shaft <NUM>.

The outer circumference of the rotary shaft coupling portion <NUM> is connected to the orbiting wrap <NUM> and serves to form the compression chamber S1 together with the fixed wrap <NUM> during a compression process.

The fixed wrap <NUM> and the orbiting wrap <NUM> may be formed in an involute shape. The involute shape may mean a curved line corresponding to a track drawn by an end of a thread wound around a base source having a random radius when the thread is unwound.

Also, the eccentric portion 126f of the rotary shaft <NUM> may be inserted into the rotary shaft coupling portion <NUM>. The eccentric portion 126f inserted into the rotary shaft coupling portion <NUM> may be overlapped with the orbiting wrap <NUM> or the fixed wrap <NUM> in a radius direction of the compressor.

In this case, the radius direction may mean a direction (that is, left and right direction) orthogonal to the shaft direction (that is, up and down direction).

As described above, if the eccentric portion 126f of the rotary shaft <NUM> is overlapped with the orbiting wrap <NUM> in a radius direction by passing through the third end plate <NUM>, a repulsive force and a compressive force of the refrigerant may be given to the same plane based on the third end plate <NUM> and therefore counterbalanced with each other.

Also, the rotary shaft <NUM> may be coupled to the driving motor <NUM>, and may include the oil supply path 126a for guiding the oil stored in the fourth space V4 that is a low oil space of the case <NUM>, to the upper portion.

In detail, an upper portion of the rotary shaft <NUM> may be forcibly inserted into the center of the rotor <NUM> and its lower portion may be coupled to the compression portion <NUM> and therefore supported in a radius direction.

The rotary shaft <NUM> may transfer a rotary force of the driving motor <NUM> to the orbiting scroll <NUM> of the compression portion <NUM>. As a result, the orbiting scroll <NUM> eccentrically coupled to the rotary shaft <NUM> may perform orbiting movement with respect to the fixed scroll <NUM>.

The main bearing portion 126c may be formed below the rotary shaft <NUM> and therefore inserted into the first shaft support portion 132a of the main frame <NUM> and supported in a radius direction. Also, the sub bearing portion <NUM> may be formed below the main bearing portion 126c and therefore inserted into the second shaft support portion <NUM> of the fixed scroll <NUM> and supported in a radius direction. The eccentric portion 126f may be formed between the main bearing portion 126c and the sub bearing portion <NUM> and therefore inserted into and coupled to the rotary shaft coupling portion <NUM> of the orbiting scroll <NUM>.

The main bearing portion 126c and the sub bearing portion <NUM> may be formed on the same shaft line to have the same shaft center, and the eccentric portion 126f may be formed to be eccentric with respect to the main bearing portion 126c or the sub bearing portion <NUM> in a radius direction.

The eccentric portion 126f may be formed to have an outer diameter smaller than that of the main bearing portion 126c and greater than that of the sub bearing portion <NUM>. In this case, it may be favorable to couple the rotary shaft <NUM> to the eccentric portion 126f by passing through each of the shaft support portions 132a and <NUM> and the rotary shaft coupling portion <NUM>.

The oil supply path 126a for supplying oil of the fourth space V4 that is a low oil space to the outer circumference of each of the bearing portions 126c and <NUM> and the outer circumference of the eccentric portion 126f may be formed inside the rotary shaft <NUM>. The oil holes 128a, 128b, 128d and 128e passing from the oil supply path 126a to the outside of a radius direction of the rotary shaft <NUM> may be formed in the bearing portions 126c and <NUM> and the eccentric portion 126f of the rotary shaft <NUM>.

In detail, the oil holes may include the first oil hole 128a, the second oil hole 128b, the third oil hole 128d, and the fourth oil hole 128e.

First of all, the first oil hole 128a may be formed to pass through the outer circumference of the main bearing portion 126c. The first oil hole 128a may be formed to pass from the oil supply path 126a to the outer circumference of the main bearing portion 126c.

Also, the first oil hole 128a may be formed to pass through, but not limited to, an upper portion of the outer circumferential surface of the main bearing portion 126c. If the first oil hole 128a includes a plurality of holes, each hole may be formed at the upper portion or the lower portion of the outer circumferential surface of the main bearing portion 126c, or may be formed at each of the upper portion and the lower portion of the outer circumferential surface of the main bearing portion 126c.

The second oil hole 128b may be formed between the main bearing portion 126c and the eccentric portion 126f. The second oil hole 128b may include a plurality of holes unlike the shown drawing.

The third oil hole 128d may be formed to pass through the outer circumferential surface of the eccentric portion 126f. In detail, the third oil hole 128d may be formed to pass from the oil supply path 126a to the outer circumferential surface of the eccentric portion 126f.

The fourth oil hole 128e may be formed between the eccentric portion 126f and the sub bearing portion <NUM>.

The oil guided to the upper portion through the oil supply path 126a may be discharged through the first oil hole 128a and then supplied to the outer circumferential surface of the main bearing portion 126c.

Also, the oil guided to the upper portion through the oil supply path 126a may be discharged through the second oil hole 128b and then supplied to the upper surface of the orbiting scroll <NUM>, and may be discharged through the third oil hole 128d and then supplied to the outer circumferential surface of the eccentric portion 126f.

Also, the oil guided to the upper portion through the oil supply path 126a may be discharged through the fourth oil hole 128e and then supplied to the outer circumferential surface of the sub bearing portion <NUM> or between the orbiting scroll <NUM> and the fixed scroll <NUM>.

The oil feeder <NUM> for pumping the oil stored in the fourth space V4 may be coupled to the lower end of the rotary shaft <NUM>, that is, the lower end of the sub bearing portion <NUM>. The oil feeder <NUM> may be formed to supply the oil stored in the fourth space V4 to the aforementioned oil holes 128a, 128b, 128d and 128e.

The oil feeder <NUM> may include an oil supply pipe <NUM> inserted into the oil supply path 126a of the rotary shaft <NUM> and coupled to the oil supply path 126a, and an oil suction member <NUM> inserted into the oil supply pipe <NUM>, sucking the oil.

The oil supply pipe <NUM> may be provided to be immersed in the fourth space V4 by passing through the through hole <NUM> of the discharge cover <NUM>, and the oil suction member <NUM> may serve as a propeller.

The oil suction member <NUM> may be provided with a spiral groove 174a extended along a length direction of the oil suction member <NUM>. The spiral groove 174a may be formed in the circumference of the oil suction member <NUM>, and may be extended toward the aforementioned oil holes 128a, 128b, 128d and 128e.

If the oil feeder <NUM> is rotated together with the rotary shaft <NUM>, the oil stored in the fourth space V4 may be guided to the oil holes 128a, 128b, 128d and 128e along the spiral groove 174a.

A balance weight <NUM> for restraining noise vibration may be coupled to the rotor <NUM> or the rotary shaft <NUM>. The balance weight <NUM> may be provided in the second space V2 between the driving motor <NUM> and the compression portion <NUM>.

Subsequently, the operation process of the scroll compressor according to the embodiment of the present disclosure will be described.

If a power source is applied to the driving motor <NUM> to generate a rotational force, the rotary shaft <NUM> coupled to the rotor <NUM> of the driving motor <NUM> is rotated. Then, while the orbiting scroll <NUM> eccentrically coupled to the rotary shaft <NUM> performs orbiting movement with respect to the fixed scroll <NUM>, the compression chamber S1 is formed between the orbiting wrap <NUM> and the fixed wrap <NUM>. The compression chamber S1 may be formed in various steps with a volume narrower toward a center direction.

Then, the refrigerant supplied from the outside of the case <NUM> through the refrigerant suction pipe <NUM> may directly enter the compression chamber S1. This refrigerant may be compressed while moving toward a discharge chamber of the compression chamber S1 in accordance with orbiting movement of the orbiting scroll <NUM> and then discharged to the third space V3 through the first discharge hole <NUM> of the fixed scroll <NUM>.

Afterwards, the compressed refrigerant discharged to the third space V3 has been discharged to the inner space of the case <NUM> through the fixed scroll discharge hole 155a and the frame discharge hole 131a and then discharged to the outside of the case <NUM> through the refrigerant discharge pipe <NUM>. A series of these processes are repeated.

While the compressor is being driven, the oil stored in the fourth space V4 may be guided to the upper portion through the rotary shaft <NUM> and then actively supplied to the bearing portion, that is, bearing surface through the plurality of oil holes 128a, 128b, 128d and 128e, whereby the bearing portion may be prevented from being worn out.

Also, the oil discharged through the plurality of oil holes128a, 128b, 128d and 128e may form an oil film between the fixed scroll <NUM> and the orbiting scroll <NUM> to maintain an airtight state in the compression portion.

For this reason, the oil may be mixed with the refrigerant compressed in the compression portion <NUM> and then discharged to the first discharge hole <NUM>. Hereinafter, for convenience of description, the refrigerant mixed with the oil may be referred to as an oil mixture refrigerant.

The oil mixture refrigerant is guided to the first space V1 by passing through the second discharge holes 131a and 155a, the second space V2 and the refrigerant path groove 112a. The refrigerant of the oil mixture refrigerant guided to the first space V1 may be discharged to the outside of the compressor through the refrigerant discharge pipe <NUM> and the other oil may return to the fourth space V4 through an oil returning path 112b.

For example, the oil returning path 112b may be arranged at the outmost in a radius direction inside the case <NUM>. In detail, the oil returning path 112b may include a path between the outer circumferential surface of the stator <NUM> and the inner circumferential surface of the cylindrical shell <NUM>, a path between the outer circumferential surface of the main frame <NUM> and the inner circumferential surface of the cylindrical shell <NUM>, and a path between the outer circumferential surface of the fixed scroll <NUM> and the inner circumferential surface of the cylindrical shell <NUM>.

Meanwhile, since the discharge cover <NUM> is coupled to the lower end of the compression portion <NUM>, a fine gap may exist between the lower end of the compression portion <NUM> and the upper end of the discharge cover <NUM>. This fine gap may be a cause of refrigerant leakage.

That is, when the refrigerant is discharged to the third space V3 through the first discharge hole <NUM> of the compression portion <NUM> and then guided to the second discharge holes 131a and 155a, the refrigerant may leak out to the gap that may exist between the compression portion <NUM> and the discharge cover <NUM>.

Also, a problem occurs in that leakage of the refrigerant may deteriorate compression efficiency of the compressor. This problem may be solved through sealing members provided between the compression portion <NUM> and the discharge cover <NUM> (a coupling portion of the compression portion <NUM> and the discharge cover <NUM>) and a coupling structure of the compression portion <NUM> and the discharge cover <NUM>.

The compressor applicable to one embodiment of the present disclosure has been described as above. Particularly, the scroll compressor has been described, and the basic structure for supplying oil due to a differential pressure has been described.

Hereinafter, an embodiment in which oil is supplied through an oil pump embodied complexly with the aforementioned oil supply structure based on the differential pressure will be described in detail.

In this embodiment, the oil pump <NUM> is provided using the discharge cover or the muffler <NUM> and the fixed scroll <NUM>, which are shown in <FIG>. That is, the oil pump <NUM> may additionally be arranged, and shapes of the rotary shaft <NUM>, the muffler <NUM> and the fixed scroll <NUM> may be changed for arrangement of the oil pump <NUM>. Also, an oil pickup <NUM> may be added for supply of the oil. The oil pickup may be the same as or similar to the oil feeder <NUM> that includes the oil supply pipe <NUM> or the oil suction member <NUM> shown in <FIG>.

<FIG> illustrates a section that the fixed scroll <NUM>, the muffler <NUM> and a pump assembly <NUM> are coupled to one another. <FIG> illustrates a section of the fixed scroll <NUM> shown in <FIG>, and <FIG> illustrates a section of the muffler <NUM> shown in <FIG>. <FIG> illustrates an exploded section of the oil pump assembly <NUM> shown in <FIG>.

First of all, the fixed scroll <NUM> and the muffler <NUM> may be coupled to each other by assembly. Both the fixed scroll <NUM> and the muffler <NUM> may be fixed with robustness by such assembly coupling. Particularly, based on the muffler <NUM>, the muffler <NUM> and the fixed scroll <NUM> may be coupled to each other by assembly at the outside in a radius direction of the muffler <NUM>.

Next, the muffler <NUM> and the pump assembly <NUM> may be coupled to each other by assembly. The pump assembly <NUM> may include pump housings <NUM> and <NUM> forming an external appearance and accommodating the oil pump <NUM> therein. At least a portion of the pump housings <NUM> and <NUM> may be inserted into the muffler <NUM>, whereby the pump housings <NUM> and <NUM> and the muffler <NUM> may be coupled to each other.

Particularly, the pump housings <NUM> and <NUM> may include an upper housing <NUM> and a lower housing <NUM>, which may be coupled to each other. An inner space P may be formed by coupling of the pump housings <NUM> and <NUM>, and may be a space for accommodating the oil pump and at the same time may be a temporary low oil space to which oil is supplied.

At least a portion of the upper housing <NUM> may be inserted into the muffler <NUM>. Forward and backward movement and left and right movement of the pump housings <NUM> and <NUM> are restricted by such insertion coupling. The pump housings <NUM> and <NUM> may stably be fixed and coupled to the muffler by bolt or screw coupling. Rotation of the the pump housings <NUM> and <NUM> is restricted by such bolt or screw coupling. The center of the muffler <NUM> may be matched with the center of the pump assembly <NUM> by such a coupling structure, and such matching may stably be maintained.

Also, the fixed scroll <NUM> and the pump housings <NUM> and <NUM> may be coupled to each other by assembly. Some component of the pump housings <NUM> and <NUM> may be coupled to the fixed scroll <NUM> by being inserted into the fixed scroll <NUM>. Particularly, the fixed scroll <NUM> and the pump housings <NUM> and <NUM> may be coupled to each other such that the center of the pump housings <NUM> and <NUM> may be matched with the center of the fixed scroll <NUM>.

Although not shown in <FIG>, the rotary shaft <NUM> (see <FIG> and <FIG>) passing through the fixed scroll <NUM> up and down passes through the muffler <NUM> up and down and partially passes through the pump housings <NUM> and <NUM>. That is, after the rotary shaft <NUM> passes through the fixed scroll <NUM>, the muffler <NUM> and the upper housing <NUM> in due order, the lower end of the rotary shaft <NUM>, that is, the lower end is located inside the lower housing <NUM>.

The lower portion of the rotary shaft <NUM> may be regarded as a driving shaft that drives the oil pump <NUM> as described later. Therefore, it is very preferable that concentricity of the rotary shaft <NUM> may stably be maintained and at the same time rotation may be performed. For this reason, it is preferable that the fixed scroll <NUM>, the muffler <NUM> and the upper housing <NUM> surround the rotary shaft <NUM>.

In this case, the pump assembly <NUM> is provided at the lower end of the rotary shaft <NUM> and pumps oil by means of a driving force of the rotary shaft and at the same rotatably supports the rotary shaft.

An oil pickup <NUM> forming an oil supply path may be provided between the low oil space V4 (see <FIG>) and the pump assembly <NUM>.

The coupling relation among the fixed scroll <NUM>, the muffler <NUM> and the pink assembly <NUM> will be described in more detail.

The shaft support portion <NUM> in which the rotary shaft <NUM> is accommodated is provided at the center of the fixed scroll <NUM>, and includes a first boss <NUM> protruded toward the low oil space V4.

The first boss <NUM> may be formed to be protruded from the second end plate <NUM> to the lower portion. Therefore, the fixed scroll <NUM> surrounds the rotary shaft <NUM> as much as a length obtained by adding a thickness of the second end plate <NUM> to a thickness of the first boss <NUM>. That is, an area supporting the rotary shaft <NUM> is increased.

The first boss <NUM> may be formed in a hollow cylindrical shape, and a sub bearing may be provided inside the first boss <NUM> and the shaft support portion <NUM>. That is, the sub bearing portion <NUM> of the rotary shaft <NUM> shown in <FIG> may rotatably be supported by the shaft support portion <NUM>.

The muffler <NUM> may include a vessel shaped body <NUM>, and the body <NUM> may have a cylindrical vessel shape of which diameter is greater than a height. A flange 177a for assembling with the fixed scroll <NUM> may be formed at the outside in a radius direction above the body <NUM> of the muffler <NUM>, and the muffler <NUM> may be coupled to the fixed scroll <NUM> below the fixed scroll <NUM> through bolt or screw coupling to the flange 177a.

A pump holder portion <NUM> may be formed at the inner side in a radius direction of the muffler body <NUM>. The pump holder portion <NUM> may have a shape uplifted from the center of the muffler body <NUM>. In other words, a space <NUM> where the pump is arranged may be formed by the pump holder portion <NUM>. This space <NUM> may be formed by the muffler body <NUM> of which center is recessed toward the driving motor <NUM>.

Therefore, the pump holder portion <NUM> forms a cylindrical shaped recess space, and this recess space forms a space for pump arrangement.

A shaft support portion 178b for allowing the rotary shaft <NUM> to pass therethrough up and down is formed at the center of the pump holder portion <NUM>, and includes a second boss 178a protruded toward the driving motor <NUM>.

The second boss 178a may be formed in a hollow shape to accommodate the first boss <NUM> of the fixed scroll <NUM> therein. Therefore, the muffler <NUM> may be coupled to the fixed scroll <NUM> by assembly at the outside in a radius direction and coupled to the fixed scroll <NUM> by assembly at the inner side in a radius direction. Also, since the first boss <NUM> and the second boss 178a are overlapped with each other at a certain distance, their up and down or left and right movement may be restricted, whereby they may stably be coupled to each other.

An insertion depth of the first boss <NUM> is increased due to a protruded shape of the second boss 178a. That is, the insertion depth of the first boss becomes greater than the thickness of the pump holder portion <NUM>.

An O-ring groove 178d may be formed at an inner side of the second boss 178a. The first boss <NUM> is inserted through an inner hollow hole of the second boss 178a. Therefore, leakage of oil or leakage of the compressed refrigerant, which is unwanted, may occur at the outside in a radius direction of the first boss <NUM>. Therefore, this leakage may previously be avoided through O-ring.

The protruded shape of the second boss 178a may be intended to maintain concentricity among the muffler <NUM>, the fixed scroll <NUM> and the rotary shaft <NUM> as well as make sure of the O-ring arrangement length and the insertion length of the first boss <NUM>.

Meanwhile, a plurality of coupling holes 178c may be formed in the pump holder portion <NUM>. A coupling hole <NUM> may be formed even in the upper housing <NUM> of the pump assembly <NUM>. The muffler <NUM> and the upper housing <NUM> may be coupled to each other through the coupling holes 178c and <NUM>.

In other words, after the upper housing <NUM> is jointed to the pump holder portion <NUM>, the lower housing <NUM> may be jointed to the upper housing <NUM>. Therefore, the coupling holes <NUM> and <NUM> for bolt, rivet or screw coupling may be formed in the upper housing <NUM> and the lower housing <NUM>. For this reason, a plurality of coupling holes for joint of the pump holder portion <NUM> and a plurality of coupling holes for arrangement of the lower housing <NUM> may be provided in the upper housing <NUM>. These coupling holes may be formed to be spaced apart from each other along a circumferential direction.

A shaft support portion <NUM> for allowing the rotary shaft <NUM> to pass therethrough may be provided in the upper housing <NUM> of the pump assembly <NUM>, and may include a third boss <NUM> protruded toward the driving motor.

The third boss <NUM> may be formed to be protruded from the upper surface of the upper housing <NUM> to the lower portion, and the protruded portion may be inserted into the first boss <NUM>. That is, the third boss <NUM> may be assembled into the cylindrical hollow hole of the first boss <NUM>. Therefore, as the first boss <NUM> and the third boss <NUM> are overlapped with each other at a certain distance, their coupling and concentricity may stably be maintained.

Finally, according to this embodiment, the second boss 178a of the muffler <NUM>, the first boss <NUM> of the fixed scroll <NUM> and the third boss <NUM> of the pump assembly <NUM> are located to be overlapped with one another from an outer side to an inner side in a radius direction. The rotary shaft <NUM> may pass through the center of these bosses and then be supported. Therefore, concentricity of the rotary shaft <NUM> and concentricity of these bosses may be matched with each other and then stably be maintained.

A certain space is formed below the third boss <NUM> of the upper housing <NUM>. The oil pump <NUM> is located in this space. This space may be referred to as a pumping space (pumping space) P or temporary low oil space <NUM>.

The lower housing <NUM> may be coupled to the upper housing <NUM> at the lower portion of the upper housing <NUM>. The pumping space P may substantially be sealed by this coupling.

An end shaft support portion <NUM> into which an end of the rotary shaft <NUM> is inserted and supported may be provided in the lower housing <NUM>. Therefore, the end of the rotary shaft <NUM> is located in inner spaces of the pump housings <NUM> and <NUM> without being exposed to the low oil space V4. The end shaft support portion <NUM> surrounds the lower end of the rotary shaft <NUM>. Therefore, the end shaft support portion <NUM> contributes to maintaining concentricity of the rotary shaft <NUM>.

Meanwhile, oil should be pumped into the pumping space P. The oil is located inside the low oil space V4. To this end, a communication portion <NUM> for communicating the pumping space P with the low oil space V4 is required. The communication portion may be formed in the lower housing <NUM>.

Also, a component for solving an oil level difference between the pumping space P and the low oil space V4 is required. This is because that the pumping space P is located to be higher than a normal oil level. To this end, the oil pickup <NUM> may be provided in the lower housing <NUM>.

The oil pickup <NUM> may have a pipe shape, and may be inserted into the lower portion of the lower housing <NUM>. To this end, an oil pickup arrangement groove <NUM> may be formed in the lower housing <NUM>. The oil pickup arrangement groove <NUM> may be communicated with the communication portion <NUM>. Therefore, the oil entering through oil pickup <NUM> may enter the pumping space P by passing through the communication portion <NUM>.

The oil pump <NUM> is a pump provided inside the aforementioned pumping space P, and may be embodied in various types. A trochoid pump is shown in <FIG> as an example. Instead of the trochoid pump, a gear pump may be provided.

The oil pump <NUM> may include an outer gear <NUM> and an inner gear <NUM>. The inner gear <NUM> is inserted into a center portion of the outer gear <NUM> and then rotated. The inner gear <NUM> may be assembled into a pump coupling portion <NUM> which is a lower end of the rotary shaft <NUM>. Therefore, the inner gear <NUM> may be rotated through rotation of the rotary shaft <NUM>.

The inner gear <NUM> may eccentrically be rotated with respect to the outer gear <NUM>. That is, the rotary shaft <NUM> and the inner gear <NUM> may be coupled to each other to have eccentricity. The number of tees of the outer gear <NUM> may be more than the number of tees of the inner gear <NUM> as much as <NUM>. As the inner gear <NUM> is eccentrically rotated, the oil is pumped from the outside of the oil pump <NUM>, and the pumped oil may be discharged to the outside after entering the oil pump <NUM>.

To this end, a hollow hole 126a to which the oil may be discharged may be formed in the rotary shaft <NUM>, especially the pump coupling portion <NUM>. The hollow hole 126a may be formed to be extended to the upper portion of the rotary shaft <NUM>. It is noted that the hollow hole 126a may be more extended to an upper side of the main bearing portion 126c of the rotary shaft <NUM>, referring to <FIG> and <FIG>. The hollow hole 126a passes through the rotary shaft <NUM> to supply oil to components such as bearing.

As shown in <FIG>, the rotary shaft <NUM> may include a motor coupling portion 126b, a main bearing portion 126c, an eccentric portion 126f, a sub bearing portion <NUM> and a pump coupling portion <NUM>. It is noted that the pump coupling portion <NUM> may additionally be provided, as compared with the case that the oil pump <NUM> is not provided.

In this case, the pump coupling portion <NUM> does not need to support a force greater than the other portion of the rotary shaft <NUM> and may have a relatively small diameter and height. Therefore, the pump coupling portion <NUM> less affects load and strength design of the rotary shaft <NUM>. As a result, since the pump coupling portion <NUM> may simply be added to the rotary shaft <NUM>, it may be easy to design and manufacture a new rotary shaft.

Meanwhile, the end shaft support portion <NUM> provided in the pump housings <NUM> and <NUM> is located below the pumping space P. Therefore, the end shaft support portion <NUM> may be regarded as a space where oil is filled earlier than the pumping space P. In other words, if the pump is not driven, the oil is stored in the end shaft support portion <NUM>.

The oil may continuously be supplied through the end shaft support portion <NUM>. That is, this is because that a hollow portion at a lower end of the pump coupling portion <NUM> provided in the end shaft support portion <NUM> starts from the end shaft support portion <NUM>. Since oil pumping always starts from the space where oil is stored, continuous and stable oil supply may be performed.

The end shaft support portion <NUM> surrounds the lower end of the rotary shaft <NUM>. Therefore, the end shaft support portion <NUM> contributes to maintaining concentricity of the rotary shaft <NUM>.

According to the aforementioned embodiment, in the compressor where a refrigerant is compressed at the upstream of the driving motor, it is possible to make sure of reliability of oil supply in a driving area of low load/low pressure ratio while enlarging a driving area of the compressor. That is, a differential pressure may additionally be generated by driving of the oil pump in an area of low pressure ratio, which is lack of a differential pressure source. Also, concentricity of the oil pump and the rotary shaft may be maintained effectively and stably.

Meanwhile, according to this embodiment, it is noted that oil may be supplied as much as twice of oil supply based on a differential pressure. That is, the amount of oil supply may be increased.

Claim 1:
A compressor comprising:
a case (<NUM>);
a driving motor (<NUM>) including a stator (<NUM>) provided at an inner side of the case (<NUM>) and a rotor (<NUM>) rotatably provided at an inner side in a radius direction of the stator (<NUM>);
a centrifugation space (V1) defined inside the case (<NUM>) by a downstream side of the driving motor (<NUM>) and the case (<NUM>), enabling centrifugation of a compressed refrigerant and a lubricant oil;
a discharge pipe (<NUM>) provided in the case (<NUM>), discharging the refrigerant inside the centrifugation space (V1) to the outside of the case (<NUM>);
a rotary shaft (<NUM>) rotated by being coupled to the rotor (<NUM>) and provided with an oil supply path (126a);
a compression portion (<NUM>) provided at an upstream side of the driving motor (<NUM>), compressing the refrigerant through rotation of the rotary shaft (<NUM>); wherein the compression portion includes
a muffler (<NUM>) accommodating the compressed refrigerant discharged from the compression portion (<NUM>), provided to guide the compressed refrigerant to the discharge pipe (<NUM>), and
a fixed scroll (<NUM>) and an orbiting scroll (<NUM>) provided to compress the refrigerant through orbiting movement with respect to the fixed scroll, the compressor being characterised in that it further comprises
a pump assembly (<NUM>) provided below the rotary shaft (<NUM>), pumping oil by being rotated in a single body with the rotary shaft (<NUM>); and
an oil pickup (<NUM>) forming an oil supply path between the pump assembly (<NUM>) and a low oil space (V4) formed inside the case (<NUM>),
wherein a shaft support portion (<NUM>) in which the rotary shaft (<NUM>) is accommodated by passing therethrough is provided at a center of the fixed scroll (<NUM>) and includes a first boss (<NUM>) protruded toward the low oil space (V4),
a pump holder portion (<NUM>) recessed toward the driving motor (<NUM>) to allow the pump assembly (<NUM>) to be arranged therein is formed at a center of the muffler (<NUM>),
wherein a shaft support portion (178b) in which the rotary shaft (<NUM>) is accommodated by passing therethrough is provided at a center of the pump holder portion (<NUM>), and includes a second boss (178a) protruded toward the driving motor (<NUM>), and
wherein at least a portion of the first boss (<NUM>) is inserted into the second boss (178a), and the first boss (<NUM>) and the second boss (178a) are overlapped with each other.