Axial Piston Compressor

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, the compressor unit comprising pistons, which move axially back and forth in a cylinder block, and a tilt plate (swash plate, wobble plate or tilt ring) which drives the pistons and rotates together with the drive shaft, wherein the tilt plate is so constructed or mounted that its tilting behaviour acts in a self-limiting manner such that at high speeds of rotation of the compressor, especially at very high speeds of rotation or at the maximum speed of rotation, the angle of maximum deflection of the tilt plate is less than the angle of maximum deflection α max at low speeds of rotation of the compressor.

1 . 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, the compressor unit comprising pistons, which move axially back and forth in a cylinder block, and a tilt plate (swash plate, wobble plate or tilt ring) which drives the pistons and rotates together with the drive shaft,
 characterised in that   the tilting behaviour of the tilt plate acts in a self-limiting manner such that at high speeds of rotation of the compressor, especially at very high speeds of rotation or at the maximum speed of rotation, the angle of maximum deflection of the tilt plate is less than the angle of maximum deflection α max  at low speeds of rotation of the compressor.   
   
   
       2 . Compressor according to  claim 1 ,
 characterised in that   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 predetermined tilt angles of the tilt plate, especially between a predetermined minimum tilt angle and a predetermined maximum tilt angle, the moment M k,ges  due to the masses moved in translation, especially that of the pistons, where appropriate including sliding blocks, piston rods or the like, is so selected as to be less than the moment M SW  due to the moment of deviation, that is to say than the moment due to the mass inertia of the tilt plate, that at high speeds of rotation of the compressor, especially at very high speeds of rotation or at a maximum speed of rotation, the angle of maximum deflection of the tilt plate is less than the angle of maximum deflection α max  at lower speeds of rotation of the compressor.   
   
   
       3 . Compressor according to  claim 1 ,
 characterised by   at least one arrangement which exerts an adjusting force on the tilt plate.   
   
   
       4 . Compressor according to  claim 3 ,
 characterised in that   the at least one arrangement for exerting the adjusting force is associated with the compressor in addition to an arrangement for adjusting the pressure in the drive mechanism chamber.   
   
   
       5 . Compressor according to  claim 3 ,
 characterised in that   the at least one arrangement for exerting the adjusting force comprises an actuator or an adjusting piston.   
   
   
       6 . Compressor according to  claim 3 ,
 characterised in that   the at least one arrangement for exerting the adjusting force comprises an adjusting member which is dependent on centrifugal force.   
   
   
       7 . Compressor according to  claim 3 ,
 characterised in that   the at least one arrangement for exerting the adjusting force comprises a spring, especially in addition to a restoring spring.   
   
   
       8 . Compressor according to  claim 3 ,
 characterised in that   the at least one arrangement for exerting the adjusting force comprises a throttling location.   
   
   
       9 . Compressor according to  claim 8 ,
 characterised in that   the throttling location is arranged on the intake side of the compressor.   
   
   
       10 . Compressor according to  claim 8 ,
 characterised in that   the cross-section of the throttling location is variable by means of an adjusting member, especially an adjusting piston.   
   
   
       11 . Compressor according to  claim 10 ,
 characterised in that   the pressure (P c ) prevailing in the drive mechanism chamber of the compressor and/or the pressure (P d ) prevailing on the output side serve(s) as the adjusting variable for the adjusting member, especially the adjusting piston.   
   
   
       12 . Compressor according to  claim 10 ,
 characterised in that   the adjusting member is regulated or controlled internally, especially by means of a solenoid or like apparatus.   
   
   
       13 . Compressor according to  claim 8 ,
 characterised in that   the throttling location has a constant cross-section.   
   
   
       14 . Compressor according to  claim 1 ,
 characterised in that   the centre of gravity of the tilt plate is located on the tilt axis thereof.   
   
   
       15 . Compressor according to  claim 14 ,
 characterised in that   the tilt axis of the tilt plate is located on the central axis of the drive shaft.   
   
   
       16 . Compressor according to  claim 1 ,
 characterised in that   the tilt plate is ring-shaped, that is to say in the form of a tilt ring.   
   
   
       17 . Compressor according to  claim 1 ,
 characterised in that   the angle of maximum deflection of the tilt plate in the region of low and medium speeds of rotation up to about half the maximum speed of rotation of the compressor, especially in a range from 0 to 4000 revolutions per minute, corresponds to an angle α max , whereas at the maximum speed of rotation of the compressor it corresponds approximately to an angle of α max /2.   
   
   
       18 . Compressor according to  claim 1 ,
 characterised in that,   for speeds of rotation from about 4000 revolutions per minute to 5000 revolutions per minute upwards, the tilt plate is no longer capable of being pivoted up to an/the angle amax.   
   
   
       19 . Compressor according to  claim 1 ,
 characterised in that   the limitation of the pivot angle becomes greater for increasing speeds of rotation of the compressor.   
   
   
       20 . Compressor according to  claim 2 ,
 characterised in that   the ratio of the moment of deviation in the y direction to the total mass of all parts moved in translation such as, for example, pistons and, where appropriate, sliding blocks and the like, J y /m ges , is at least about 1000 gmm 2 /g, especially more than 1500 gmm 2 /g.   
   
   
       21 . Compressor according to  claim 2 ,
 characterised in that   the ratio of the moment of deviation in the z direction to the total mass of all parts moved in translation such as, for example, pistons and, where appropriate, sliding blocks and the like, J y /m ges , is at least about 2000 gmm 2 /g, especially more than 3000 gmm 2 /g.   
   
   
       22 . Compressor according to  claim 4 ,
 characterised in that   a or the restoring spring has a spring constant of less than about 60 N/mm, especially less than 30 N/mm.   
   
   
       23 . Compressor according to  claim 1 ,
 characterised by   an end-stop which is dependent on the speed of rotation and which limits the angle of maximum deflection of the tilt plate in dependence on the speed of rotation of the compressor.