Scroll compressor

Abstract

A scroll compressor is provided, the scroll compressor comprises two scroll bodies, one of the two scroll bodies is a stationary scroll body with a scroll wrap and the other scroll body of the two scroll bodies is a moveable scroll body with a scroll wrap, the scroll wraps of the two scroll bodies engage each other forming at least one compression chamber, and the stationary scroll body comprises a base plate and the stationary scroll body has two opposing sides with respect to the base plate and on a first side of the two opposing sides the scroll wrap of the stationary scroll body is arranged and on a second side of the two opposing sides at least one pressure pocket is formed and at least one vent passage is provided through the base plate from the first side to the second side, the vent passage opens at the second side into the at least one pressure pocket and the vent passage has an opening at the first side which is arranged such that the vent passage is fluidly connected to the at least one compression chamber during a compression cycle of the at least one compression chamber at least during a time span before the at least one compression chamber is fluidly connected to a discharge chamber of the scroll compressor and at least during a time span of the period when the at least one compression chamber is fluidly connected to the discharge chamber.

1 . A scroll compressor ( 110 ), the scroll compressor ( 110 ) comprises two scroll bodies ( 192 ,  194 ), one of the two scroll bodies ( 192 , 194 ) is a stationary scroll body ( 192 ) with a scroll wrap ( 226 ) and the other scroll body of the two scroll bodies ( 192 ,  194 ) is a moveable scroll body ( 192 ) with a scroll wrap ( 228 ), the scroll wraps ( 226 ,  228 ) of the two scroll bodies ( 192 ,  194 ) engage each other forming at least one compression chamber ( 232 ), and the stationary scroll body ( 192 ) comprises a base plate ( 212 ) and the stationary scroll body ( 192 ) has two opposing sides ( 222 ,  344 ) with respect to the base plate ( 212 ) and on a first side ( 222 ) of the two opposing sides ( 222 ,  344 ) the scroll wrap ( 226 ) of the stationary scroll body ( 192 ) is arranged and on a second side ( 344 ) of the two opposing sides ( 222 ,  344 ) at least one pressure pocket ( 426 ) is formed and at least one vent passage ( 452 ) is provided through the base plate ( 212 ) from the first side ( 222 ) to the second side ( 344 ), the vent passage ( 452 ) opens at the second side ( 344 ) into the at least one pressure pocket ( 426 ) and the vent passage ( 452 ) has an opening ( 454 ) at the first side ( 222 ) which is arranged such that the vent passage ( 452 ) is fluidly connected to the at least one compression chamber ( 232 ) during a compression cycle of the at least one compression chamber ( 232 ) at least during a time span before the at least one compression chamber ( 232 ) is fluidly connected to a discharge chamber ( 138 ) of the scroll compressor ( 110 ) and at least during a time span of the period when the at least one compression chamber ( 232 ) is fluidly connected to the discharge chamber ( 138 ). 
     
     
         2 . The scroll compressor ( 110 ) of  claim 1 , wherein the scroll compressor ( 110 ) comprises two scroll bodies ( 192 ,  194 ), one of the two scroll bodies ( 192 , 194 ) is a stationary scroll body ( 192 ) with a scroll wrap ( 226 ) and the other scroll body of the two scroll bodies ( 192 ,  194 ) is a moveable scroll body ( 192 ) with a scroll wrap ( 228 ), the scroll wraps ( 226 ,  228 ) of the two scroll bodies ( 192 ,  194 ) engage each other forming at least one compression chamber ( 232 ), and the stationary scroll body comprises a base plate ( 212 ) and has two opposing sides ( 222 ,  344 ) with respect to the base plate ( 212 ) and on a first side ( 222 ) of the two opposing sides ( 222 ,  344 ) the scroll wrap ( 226 ) of the stationary scroll body ( 192 ) is arranged and on a second side ( 344 ) of the two opposing sides ( 222 ,  344 ) one pressure pocket ( 426 ) is formed or several pressure pockets ( 426 ) are formed and for each pressure pocket ( 426 ) at least one vent passage ( 452 ) is provided through the base plate ( 212 ) from the first side ( 222 ) to the second side ( 344 ), each vent passage ( 452 ) opens at the second side ( 344 ) into the respective pressure pocket ( 426 ) and each vent passage ( 452 ) has an opening ( 454 ) at the first side ( 222 ) which is arranged such that the vent passage ( 452 ) is fluidly connected to the at least one compression chamber at least during a time span during a respective compression cycle and in the one pressure pocket ( 426 ) or in the several pressure pockets ( 426 ) gaseous medium is contained and at least during operation of the scroll compressor ( 110 ) due to a pressure of the gaseous medium a force is exerted on the stationary scroll body ( 192 ), in particular in axial direction with respect to a central axis ( 246 ) of the stationary scroll body ( 192 ), and the force exerted by the pressure of the gaseous medium in the one pressure pocket ( 426 ) or in the several pressure pockets ( 426 ) is dependent on a suction pressure (PS) at which the gaseous medium enters the at least one compression chamber ( 232 ) at the very beginning of the respective compression cycle and on a discharge pressure (PD) which a gaseous medium in a discharge chamber ( 138 ) of the scroll compressor ( 110 ) has. 
     
     
         3 . The scroll compressor ( 110 ) of  claim 1 , wherein at least one pressure pocket ( 426 ) is during a compression cycle fluidly connected to at least one compression chamber ( 232 ) of a pair of compression chambers ( 232 ), in particular is fluidly connected to exactly one compression chamber ( 232 ) or both compression chambers ( 232 ) of a pair of compression chambers ( 232 ). 
     
     
         4 . The scroll compressor ( 110 ) of  claim 1 , wherein during a compression cycle of the at least one compression chamber the two scroll bodies ( 192 ,  194 ) are arranged in several different configurations to each other, the several different configurations impose different conditions on the at least one compression chamber ( 232 ), the different conditions comprise a first condition in which the at least one compression chamber ( 232 ) is fluidly connected to an intake area ( 136 ) and the different conditions comprise a second condition in which the at least one compression chamber ( 232 ) is fluidly separated from the intake area ( 136 ) and the discharge chamber ( 138 ) and the different conditions comprise a third condition in which the at least one compression chamber ( 232 ) is fluidly connected to the discharge chamber ( 138 ) and the opening ( 454 ) of the vent passage ( 452 ) is arranged at the first side ( 222 ) such that the vent passage ( 452 ) is fluidly connected to the at least one compression chamber ( 232 ) in at least one configuration of the two scroll bodies ( 192 ,  194 ) in which the second condition is imposed on the at least one compression chamber ( 232 ) and in at least one configuration of the two scroll bodies ( 192 ,  194 ) in which the third condition is imposed on the at least one compression chamber ( 232 ). 
     
     
         5 . The scroll compressor ( 110 ) of  claim 1 , wherein the opening ( 454 ) of the vent passage ( 452 ) at the first side ( 222 ) of the stationary scroll body ( 192 ) is arranged such that it opens into the at least one compression chamber ( 232 ) during the compression cycle of the at least one compression chamber ( 232 ) at least during a time span when the gaseous medium in the at least one compression chamber ( 232 ) has a pressure which depends on the suction pressure (PS) and on the course of the compression cycle but not on the discharge pressure (PD). 
     
     
         6 . The scroll compressor ( 110 ) of  claim 1 , wherein the opening ( 454 ) of the vent passage ( 452 ) at the first side ( 222 ) of the stationary scroll body ( 192 ) is arranged such that it opens into the at least one compression chamber ( 232 ) during the compression cycle of the at least one compression chamber ( 232 ) at least during a time span when the gaseous medium in the at least one compression chamber ( 232 ) is at the discharge pressure. 
     
     
         7 . The scroll compressor ( 110 ) of  claim 1 , wherein the pressure pocket ( 426 ) and the vent passage ( 452 ) are designed such that during operation of the scroll compressor ( 110 ) at least one of a lowest pressure and/or an averaged pressure of the gaseous medium in the pressure pocket ( 426 ) during a compression cycle equals to or is larger than 75% of the discharge pressure (PD). 
     
     
         8 . The scroll compressor ( 110 ) of  claim 1 , wherein the one pressure pocket ( 426 ) and the one vent passage ( 452 ) or the several pressure pockets ( 426 ) and the respective vent passages ( 452 ) are designed such that during operation of the scroll compressor ( 110 ) a force exerted on the stationary scroll body ( 192 ) by the gaseous medium within the one pressure pocket ( 426 ) or within at least one pressure pocket ( 426 ) and/or a total force exerted by the gaseous medium contained in the several pressure pockets ( 426 ) equals to or is larger than a minimal force exerted by the gaseous medium contained in the at least one compression chamber ( 232 ) during a respective compression cycle and/or equals to or is smaller than one and a half times a maximal force exerted by the gaseous medium within the at least one compression chamber during a respective compression cycle with the force exerted by the gaseous medium in the at least one compression chamber is exerted on the stationary scroll body ( 192 ). 
     
     
         9 . The scroll compressor ( 110 ) of  claim 1 , wherein the vent passage ( 452 ) allows exchange of gaseous medium between the at least one compression chamber ( 262 ) and the pressure pocket ( 426 ) when they are fluidly connected but in particular the vent passage ( 426 ) is sufficiently small to prevent an instantaneous pressure balance between the at least one compression chamber ( 232 ) and the pressure pocket ( 426 ) when the pressure pocket ( 426 ) and the at least one compression chamber ( 232 ) are fluidly connected by the vent passage ( 452 ). 
     
     
         10 . The scroll compressor ( 110 ) of  claim 1 , wherein the pressure pocket ( 426 ) is formed partly by the stationary scroll body ( 192 ) and partly by a closing element ( 422 ) which is fluid tight connected to the part of the stationary scroll body ( 192 ) which partly forms the pressure pocket ( 426 ). 
     
     
         11 . The scroll compressor ( 110 ) of  claim 10 , wherein the closing element ( 422 ) and the stationary scroll body ( 192 ) are fluid tight connected by a floating seal arrangement. 
     
     
         12 . The scroll compressor ( 110 ) of  claim 1 , wherein a portion ( 394 ) of the base plate ( 212 ) of the stationary scroll body partly limits the pressure pocket ( 426 ). 
     
     
         13 . The scroll compressor ( 110 ) of  claim 1 , wherein an inner ridge ( 382 ) and an outer ridge ( 384 ) each of which surround a central axis ( 246 ) of the stationary scroll body ( 192 ) are arranged at the second side ( 344 ) of the stationary scroll body ( 192 ) and project from the base plate ( 212 ) of the stationary scroll body ( 192 ) and the pressure pocket ( 426 ) is arranged in radial direction of the central axis ( 246 ) of the stationary scroll body ( 192 ) between the inner ridge ( 382 ) and the outer ridge ( 384 ). 
     
     
         14 . The scroll compressor ( 110 ) of  claim 13 , wherein a closing element ( 422 ) is arranged in radial direction of the central axis ( 246 ) of the stationary scroll body ( 192 ) between the inner ridge ( 382 ) and the outer ridge ( 384 ) for limiting the pressure pocket ( 426 ). 
     
     
         15 . The scroll compressor ( 110 ) of  claim 1 , wherein the closing element ( 422 ) limits the pressure pocket ( 426 ) in the axial direction with respect to the central axis ( 246 ) of the stationary scroll body ( 192 ) opposite to the base plate ( 212 ) of the stationary scroll body ( 192 ). 
     
     
         16 . A scroll compressor ( 110 ), wherein the scroll compressor ( 110 ) comprises two scroll bodies ( 192 ,  194 ), one of the two scroll bodies ( 192 ,  194 ) is a stationary scroll body ( 192 ) with a scroll wrap ( 226 ) and the other scroll body of the two scroll bodies ( 192 ,  194 ) is a moveable scroll body ( 192 ) with a scroll wrap ( 228 ), the scroll wraps ( 226 ,  228 ) of the two scroll bodies ( 192 ,  194 ) engage each other to form at least one compression chamber ( 232 ) and the stationary scroll body ( 192 ) comprises a base plate ( 212 ) and has two opposing sides ( 222 ,  344 ) with respect to the base plate ( 212 ) and on a first side ( 222 ) of the two opposing sides ( 222 ,  344 ) the scroll wrap ( 226 ) of the stationary scroll body ( 192 ) is arranged and on the second side ( 344 ) of the two opposing sides ( 222 ,  344 ) at least two pressure pockets ( 426 ) are formed and each of the at least two pressure pockets ( 426 ) is connected to at least one respective vent passage ( 452 ) and the vent passages ( 452 ) are formed through the base plate ( 212 ) of the stationary scroll body ( 192 ) from the second side ( 344 ) at which they open into their respective pressure pocket ( 426 ) to the first side ( 222 ) at which each vent passage ( 452 ) has an opening ( 454 ) which is arranged to fluidly connect the respective pressure pocket ( 426 ) with the at least one compression chamber ( 232 ) in a time span during the compression cycle of the at least one compression chamber ( 232 ). 
     
     
         17 . The scroll compressor ( 110 ) of  claim 16 , wherein at least two pressure pockets ( 426 ) are fluidly connected to the at least one compression chamber ( 232 ) during different time spans during a compression cycle. 
     
     
         18 . The scroll compressor ( 110 ) of  claim 16 , wherein the scroll compressor ( 110 ) further comprises a drive unit ( 122 ) for driving the moveable scroll body ( 194 ), in particular for driving the moveable scroll body ( 194 ) relative to the stationary scroll body ( 192 ) and/or relative to a housing ( 112 ) of the scroll compressor ( 110 ). 
     
     
         19 . The scroll compressor ( 110 ) of  claim 16 , wherein the scroll compressor ( 110 ) comprises a support member ( 196 ) which supports the moveable scroll body ( 194 ) in axial direction with respect to a shaft axis ( 154 ) of a shaft ( 152 ) of the drive unit ( 122 ). 
     
     
         20 . The scroll compressor ( 110 ) of  claim 16 , the scroll compressor ( 110 ) further comprising a holding assembly ( 312 ) which prevents a motion of the stationary scroll body ( 192 ) in at least one of a radial direction and/or a rotational direction with respect to the central axis ( 246 ) of the stationary scroll body ( 192 ). 
     
     
         21 . The scroll compressor ( 110 ) of  claim 16 , wherein an axial movement of the stationary scroll body ( 192 ) with respect to the central axis ( 246 ) of the stationary scroll body ( 192 ) is in one direction limited by the moveable scroll body ( 194 ) and in the opposite direction by a holding assembly ( 312 ) for the stationary scroll body ( 192 ). 
     
     
         22 . The scroll compressor ( 110 ) of  claim 16 , wherein the stationary scroll body ( 192 ) and the moveable scroll body ( 194 ) are parts of a compression unit ( 120 ) of the scroll compressor ( 110 ) and the compression unit ( 120 ) receives from the intake area ( 136 ) the gaseous medium at a suction pressure (PS) and compresses the gaseous medium to a higher pressure than the suction pressure (PS), in particular to a maximal intermediate pressure (PF), and discharges the compressed gaseous medium to the discharge chamber ( 138 ) in which the gaseous medium is at a discharge pressure (PD). 
     
     
         23 . The scroll compressor ( 110 ) of  claim 16 , wherein at least a portion ( 434 ) of the discharge chamber ( 138 ) is arranged at the first side ( 222 ) of the stationary scroll body and is in particular surrounded in radial direction with respect to the central axis ( 246 ) of the stationary scroll body ( 194 ) by the scroll wrap ( 226 ) of the stationary scroll body ( 192 ) and the scroll wrap ( 228 ) of the moveable scroll body ( 194 ).