Axial Piston Compressor, Especially for the Air Conditioning System of a Motor Vehicle

Abstract

Axial piston compressor, especially a compressor for the air-conditioning system of a motor vehicle, having a housing and, for drawing in and compressing a coolant, a compressor unit arranged in the housing and driven by means of a drive shaft ( 104 ), the compressor unit comprising pistons ( 118 ), which move axially back and forth in a cylinder block, and a tilt plate (swash plate or wobble plate; or tilt ring ( 107 ) which drives the pistons and rotates together with the drive shaft ( 104 ). The geometry and dimensioning of all parts moved in translation, such as axial pistons ( 118 ), piston rods or sliding blocks ( 121, 122 ) or the like, on the one hand, and all parts moved in rotation, such as the tilt plate ( 107 ), members for conjoint movement or the like, on the other hand, are such that, for any desired tilt angles (α) of the tilt plate ( 107 ), between a predetermined minimum tilt angle (α min ) and a predetermined maximum tilt angle (α max ), the moment M k,ges due to the masses moved in translation, such as pistons ( 118 ), sliding blocks ( 121, 122 ), piston rods or the like, is approximately equal to the moment M SW due to the moment of deviation, that is to say the moment due to the mass inertia of the tilt plate ( 107 ).

1 . A compressor selected from the group consisting of an axial piston compressor, and an axial piston compressor for the air-conditioning system of a motor vehicle, said compressor having a housing and, operative to draw in and compress a coolant, a compressor unit arranged in the housing and driven by means of a drive shaft, the compressor unit comprising pistons operative to move axially back and forth in a cylinder block, and a tilt plate, swash plate or wobble plate; or tilt ring operative to drive said pistons and to rotate together with said drive shaft, wherein: 
 the geometry and dimensioning of all parts moved in translation, such as axial pistons, piston rods or sliding blocks or the like, on the one hand, and all parts moved in rotation, such as the tilt plate, members for conjoint movement or the like, on the other hand, are such that, for angles selected from the group consisting of any desired tilt angles of the tilt plate and between a predetermined minimum tilt angle and a predetermined maximum tilt angle, the moment due to integers selected from the group consisting of the masses moved in translation, that masses of the pistons, where appropriate including sliding blocks, piston rods or the like, is approximately equal to the moment due to the moment of deviation, that is to say the moment due to the mass inertia of the tilt plate.    
   
   
       2 . A compressor according to  claim 1 , wherein the balancing of moments is set for an angle selected from the group consisting of a predetermined tile angle, a tilt angle α=(α max −α min )/2, α=α max , and a predetermined virtual tilt angle α>α max .  
   
   
       3 . A compressor according to  claim 1  wherein the centre of gravity of the tilt plate is located on the tilt axis thereof.  
   
   
       4 . A compressor according to  claim 1  wherein given division of the space surrounding the drive shaft and the tilt plate into four quadrants, the centre of gravity of the tilt plate is offset into a quadrant selected from the group consisting of a first, front quadrant (Q 1 ) delimited by the drive shaft and the front face of the tilt plate including the piston support and facing the pistons, a second, front quadrant located on the side opposite the first quadrant relative to the drive shaft, a third, rear quadrant arranged relative to the tilt plate at the height of the second quadrant behind the tilt plate, that is to say on that side of the tilt plate which is remote from the pistons, and a fourth, rear quadrant arranged relative to the tilt plate at the height of the first quadrant behind the tilt plate, that is to say on that side of the tilt plate which is remote from the pistons.  
   
   
       5 . A compressor according to  claim 1 , said compressor is down-regulatable in the relatively high speed of rotation range and up-regulatable in the relatively low speed of rotation range.  
   
   
       6 . A compressor according to  claim 4 , wherein the arrangement is such that the location of the centre of gravity moves, with a change in the tilt angle of the tilt plate, from an up-regulating quadrant into a down-regulating quadrant or vice-versa.  
   
   
       7 . A compressor according to  claim 1 , wherein an integer selected from the group consisting of the piston stroke, the tilt angle of the tilt plate, and the piston stroke and the tilt angle of the tile plate is substantially constant in the case of changes in the speed of rotation.  
   
   
       8 . A compressor according to  claim 1 , wherein the speed-of-rotation-dependent characteristic curves of the drive mechanism chamber pressure difference, relative to the suction pressure, set against the tilt angle of the tilt plate have a relationship selected from the group consisting of intersecting at one point, and converging at one point.  
   
   
       9 . A compressor according to  claim 8 , wherein the point of intersection of the characteristic curves separates the up-regulating from the down-regulating speed of rotation range.  
   
   
       10 . A compressor according to  claim 1 , wherein the characteristic curves (regulation curves) for different speeds of rotation run approximately parallel to one another.  
   
   
       11 . A compressor according to  claim 1 , wherein the tilt angle of the tilt plate or tilt ring changes by about 2° to 4° in the event of a change in the speed of rotation from minimum to maximum, especially under the condition of an approximately constant pressure in the drive mechanism chamber.  
   
   
       12 . A compressor according to  claim 1 , wherein the spring constant of a restoring spring acting on the tilt plate or tilt ring is selected from the group consisting of between about 40 and 90 N/mm, and of between about 40 and 70 N/mm, the selected spring constant having been optimised for a group of regulation characteristic curves.  
   
   
       13 . A compressor according to  claim 1 , wherein the moment of deviation, taking into account a so-called Steiner component, includes both an up-regulating and a down-regulating term, those terms predominating, in each case, after a threshold tilt angle of the tilt plate has been exceeded, especially, in the case of 
 α<α G  in up-regulating manner, and    α>α G  in down-regulating manner.