DE102005033706A1 - Axial piston compressor especially for air conditioning unit of motor vehicle has additional mass associated with swashplate, wherein swashplate or additional mass is pivotably mounted relative to sleeve or drive shaft - Google Patents

Abstract

The axial piston compressor, especially for the air conditioning unit of a motor vehicle, with a swash plate (12) which drives the piston, has an additional mass (13) , especially a disc or ring, associated with the swashplate. The swashplate and/or the additional mass, by at least one cylindrical pin-like bolt (14,15) which engages in corresponding holes (19,20,21) in the swashplate and/or in the additional mass on one side and on the other side in a sleeve (16) movably mounted on the drive shaft (11), is pivotably mounted in each case relative to the sleeve or drive shaft.

Description

The The invention relates to an axial piston compressor, in particular compressor for the Air conditioning system of a motor vehicle, with a housing and arranged in the housing, via a Drive shaft driven compressor unit for suction and compression a refrigerant, the compressor unit axially in and out of a cylinder block running piston and a piston driving, rotating with the drive shaft Swash plate, e.g. in the form of a swivel ring, a wobble or swash plate, includes.

Such axial piston compressor is for example from the DE 197 49 727 A1 known. This includes a housing in which a plurality of axial pistons are arranged around a rotating drive shaft in a circular arrangement. The driving force is transmitted from the drive shaft via a driver on an annular pivot plate and from this in turn to the parallel to the drive shaft translationally displaceable piston. The annular swash plate is pivotally mounted on a sleeve mounted axially displaceably on the drive shaft. In the sleeve, a slot is provided through which engages the mentioned driver. Thus, the axial mobility of the sleeve on the drive shaft is limited by the dimensions of the elongated hole. An assembly takes place by a passing through the driver through the slot. Drive shaft, driver, sliding sleeve and swivel disk are arranged in a so-called. Engine room in which a gaseous working fluid of the compressor is present at a certain pressure. The delivery volume and thus the delivery rate of the compressor are dependent on the pressure ratio between the suction side and pressure side of the piston or correspondingly dependent on the pressures in the cylinders on the one hand and in the engine room on the other.

A slightly different type of axial piston compressor is for example in the DE 198 39 914 A1 described. The swash plate is designed as a swash plate, wherein between the swash plate and the piston mounted opposite the swash plate, rotatable receiving disc is arranged.

• – DE 2 524 148
• – US 4 815 358
• – US 4 836 090
• – US 4 077 269
• – US 5 105 728

Furthermore, reference is made to the following prior art:

• - DE 2 524 148
• - US 4,815,358
• - U.S. 4,836,090
• - US 4,077,269
• - US 5,105,728

at the compressors described in these publications are concerned et al therefore, measures to avoid the imbalance of the engine during operation or reduce. Furthermore is common to the known constructions that the rotating components across from the translationally moving parts, namely piston, piston rod etc. relatively large and are accordingly heavy built. Furthermore, the known Constructions in common that on the actual swashplate device an additional disc a suitable coupling mechanism acts. The several rotating Components are intended to set up the moment of the swivel disk device effect in the direction of minimum stroke of the piston, causing influence on the Control behavior is taken.

The mentioned Constructions are all relatively complex, expensive, not very compact and for that reason for the compressors required by the automotive industry today for air conditioners not suitable.

Even with series compressors, as used in vehicles, one aims at a suitable dimensioning of the moving components (in particular mass) in order to achieve the desired control behavior. The series compressor 6SEU 12 C from DENSO, for example, has an engine with the following masses that are relevant for control behavior:

The above figures show that a considerable component mass is provided for parts which move in rotation. This is an attempt to produce a sufficient counterforce or a sufficient counter-torque with respect to the translationally moving masses. This basic idea lies also the DE 198 39 914 A1 based, where just the rotating mass of the swash plate or the pivotable portion of the same is dimensioned such that the centrifugal forces occurring during rotation of the drive pulley consciously counteract the pivotal movement of the swash plate and thus to influence the piston stroke and thus the flow rate, namely reduce or limit or in particular to keep constant.

• – Moment infolge der Gaskräfte in den Zylinderräumen (+)
• – Moment infolge der Gaskräfte aus dem Triebwerksraum (–)
• – Moment infolge einer Rückstellfeder (–)
• – Moment infolge einer Aufstellfeder (+)
• – Moment infolge rotierender Massen (–); inklusive Moment infolge Schwerpunktlage (zum Beispiel Schwenkscheibe: Kippposition ≠ Massenschwerpunkt): kann (+) oder (–) sein
• – Moment infolge der translatorisch bewegten Massen (+)

The influencing variables which act as moments about the tilting center of a swivel disk device are in detail the following moments, in each case the direction of the moments being indicated in brackets and (-) descending (in the direction of a minimum lift) and (+) upward (in the direction of the maximum lift ) mean:

• - moment due to the gas forces in the cylinder chambers (+)
• - moment due to the gas forces from the engine room (-)
• - moment due to a return spring (-)
• - moment due to an erection spring (+)
• - moment due to rotating masses (-); including moment due to center of gravity (eg swashplate: tilting position ≠ center of gravity): can be (+) or (-)
• - moment due to translationally moving masses (+)

In Reference to the mentioned Compressor 6SEU 12 C from DENSO, which is the typical design of a swash plate compressor represents It should be noted that the Mass of such a swash plate can not be increased arbitrarily can to change the control behavior with it. That's because of the compressors the type described the center of gravity of the swash plate in usually a clear distance to the tilting joint of the swash plate having. This construction is essentially based on that the Swing plate additionally to a suitable leadership on the drive shaft over an actuating mechanism with the drive shaft or one with the drive shaft connected component must be coupled.

Of the mentioned Distance from the center of gravity of the swash plate and the tilting joint of the same leads to an imbalance of the engine, in particular depending from the swivel tilt angle (the center of gravity moves "as in a swing "below the tilting joint), and leads in the worst case Fall to an up-regulating property (so-called "center of gravity").

Consequently is in the compressors of the prior art, both according to the printed as well as actually practiced state the technique a compromise shut down in that a predetermined Mass of the swash plate is provided to a counter-moment to produce the translationally moving masses. on the other hand However, the mass of the swash plate may not be too large because then the imbalance of the engine would be excessive. Otherwise, with the formation of a swash plate in the form of a swivel ring, the increase in the mass of the same through the height limited.

To counter this problem, it has already been proposed, the piston, ie the translationally moving masses as low as possible, ie easy to build, for example, made of aluminum or other materials lower specific gravity. There is also the suggestion to use hollow piston in this regard.

Furthermore, the compressor according to the EP 0 809 027 A1 directed. It is about a particular embodiment of the coupling mechanism between the drive shaft and swivel disk device. The coupling mechanism is designed for high pressure, for example, when used as a refrigerant R744. Furthermore, the last-mentioned prior art also deals with a so-called constant regulation of the flow rate. It is proposed to design the kinematics of the compressor so that the forces acting on the swash plate, regulating tilting moments significantly dominate over the aufstellden overturning moments. It should be noted that the term "flow rate" is relatively blurred.The flow rate could be considered constant if, for example, halves the tilt angle of the swash plate when doubling the speed.This would geometrically the flow rate constant.Of course, also affect other parameters the flow rate when the tilt angle of the swash plate changes, eg. Degree of delivery, oil throw od. Like ..

For a constant control the flow rate with changing rotational speeds, the restoring torque of the Pivoting disc exploited because the swash plate of its inclination due to the dynamic forces counteracts the co-rotating disk part. This behavior can be supported by the force of a spring, so that at increasing speed of rotation or speed increasing flow by default the slant or pivot position of the swash plate at least partially compensated becomes.

As already explained above, in principle such a behavior can be achieved by, for example, integrating an additional mass into the engine, the mass inertia of which acts on the swashplate via a coupling mechanism. Furthermore, it was stated that in compressors, such as are currently used in motor vehicles, the mass of the swash plate can not be arbitrarily large, without having to accept other disadvantages. This applies in particular to the teaching according to the DE 198 39 914 A1 or EP patent no. 99 953 619. The proposed there regulation with the mass of the rotating components can lead to a control behavior by which the flow rate should be largely independent of speed. However, this is not inevitable. It can also lead to overcompensation. The design criteria are very blurred. The reason for this is that the mass of the rotating components only proportionally influences the pitching moment of the swashplate, but the speed (ω) is quadratic. That is, the flow rate can only be compensated in the higher speed range (here the dynamics play a role) and for a speed jump.

Furthermore, compressors are known, in particular series compressors for R134a, in which the stroke volume increases on the sole side due to the acting moments of up-regulating and regulating mass forces. By appropriate control intervention of the control valves used that may need to be compensated. Recent developments, especially for CO ₂ compressors, seek to reverse this behavior. The necessary control intervention can then be reduced or even dispensed with.

For better understanding, the tilting behavior described as a result of a speed fluctuation in the 1 and 2 shown. 1 shows the dependence of the engine room pressure difference with respect to the suction pressure on the tilt angle α or "alpha" of the swash plate.

high pressure 120 bar and suction pressure 35 bar.

Calculated was still at speeds:
600 rpm, 1200 rpm, 2500 rpm, 5000 rpm, 8000 rpm and 11000 rpm.

To recognize are in 1 but only five of the six calculated courses. This is because the gradients for the speeds of 600 rpm and 1200 rpm are substantially completely superimposed (due to lack of dynamics); Therefore, the promoted in the art "speed-independent flow rate" is rather a wishful imagination, which is not met with the measures outlined.

Based on the diagram according to 1 can be easily seen that give gradients that cause an adjustment of the swashplate to larger tilt angles, as the speed increases. It should be mentioned that 1 only to be considered as an example with simple geometry. However, the trend shown also applies to more complex geometries. The calculation was based on a pivot ring with a predetermined inner and outer diameter and a predetermined height.

Besides the piston mass is relevant, the pitch circle diameter on which the pistons are, and the number of pistons.

The swivel ring preferably has a mass moment of inertia J ₂ = J _η or J = m / 4 (r _a ² + r _i ² + h ^2/3 ), which is greater than 100,000 gmm ² . Preferably, the moment of inertia is greater than J = 200,000-250,000 gmm ² .

Furthermore, the swivel ring preferably has a mass moment of inertia of J ₃ = J _ζ = m / 2 (r _a ² + r _i ² ), which is greater than 200,000 gmm ² , preferably about 400,000-500,000 gmm ² .

(Anmerkung: J₃ ≈ 2 J₂
Ziel: J_yz soll eine bestimmte Größe haben
J_yz ↑ ⎬ J₃ ↑ J₂ erhöht sich zwangsläufig!)Below is the derivation of the so-called. Deviation torque is specified, which is relevant for the tilting of the swash plate or a swivel ring, and in the case shown solely for the tilting of the swash plate or the swivel ring is responsible under the condition that the center of gravity of the swash plate or of the pivot ring is located both in the tilting point and in the geometric center of the swash plate or the swivel ring. This is a desirable ideal case of construction. For the derivation of the moment of deviation applies in general with reference to 3 : J Y Z = -J 1 cos 2 cos 3 - J 2 cosβ 2 cosβ 3 - J 3 cosγ 2 cosγ 3 α ₁ = 0
β ₁ = 90 ° directional angle of the x-axis
γ ₁ = 90 ° with respect to the main axes of inertia ξ · η · ζ
α ₂ = 90 °
β ₂ = ψ Directional angle of the y-axis with respect to
γ ₂ = 90 ° + ψ main axes of inertia ξ · η · ζ
α ₃ = 90 °
β ₃ = 90 ° - ψ Direction angle of the z-axis compared to
γ ₃ = ψ main axes of inertia ξ · η · ζ

(Note: J ₃ ≈ 2 J ₂
Goal: J _yz should have a certain size
J _yz ↑ ⎬ J ₃ J ↑ ₂ necessarily increases!)

of inertia

J Y Z  = -J 2  cosψ sinψ + J 3  cosψ sinψ

Independent of 3 applies:

Moment due to inertia The piston

• β i = θ + 2π (i-1) 1 / n
• Zi = R · ω 2 tanα cosβ i
• M (F Wed. ) = m k * R * cosβ i * z i
  

Moment Msw due to moment of deviation

θ

Drehwinkel der Welle (wobei die vor- und nachstehenden Betrachtungen der Einfachheit halber für θ = 0 angestellt werden)

η

Anzahl der Kolben

R

Abstand der Kolbenachse zur Wellenachse

ω

Wellendrehzahl

α

Kippwinkel des Schwenkringes/Schwenkscheibe

mk

Masse eines Kolbens inklusive Gleitsteine bzw. Gleitsteinpaar

mk,ges

Masse aller Kolben inklusive Gleitsteine

msw

Masse des Schwenkringes

ra

Außenradius des Schwenkringes

ri

Innenradius des Schwenkringes

h

Höhe des Schwenkringes Dichte des Schwenkringes

V

Volumen des Schwenkringes

βi

Winkelposition des Kolbens i

zi

Beschleunigung des Kolbens i

Fmi

Massenkraft des Kolbens i (inklusive einem Gleitsteinpaar)

M(Fmi)

Moment infolge der Massenkraft des Kolbens i

Mk,ges

Moment infolge der Massenkraft aller Kolben

Msw

Moment infolge des Aufstellmomentes des Schwenkringes/Schwenkscheibe bzw. infolge des Deviationsmoments (J_yz)

J

= f (ρ, r, h) Massenträgheitsmoment

The sizes used above mean something like this:

θ

Angle of rotation of the shaft (the above and following considerations are for simplicity θ = 0)

η

Number of pistons

R

Distance of the piston axis to the shaft axis

ω

Shaft speed

α

Tilt angle of the swivel ring / swashplate

mk

Mass of a piston including sliding blocks or pair of sliding blocks

mk, ges

Mass of all pistons including sliding blocks

msw

Mass of the swivel ring

ra

Outer radius of the swivel ring

ri

Inner radius of the swivel ring

H

Height of the swivel ring Density of the swivel ring

V

Volume of the swivel ring

βi

Angular position of the piston i

zi

Acceleration of the piston i

Fmi

Mass force of the piston i (including a sliding block pair)

M (Fmi)

Moment due to the mass force of the piston i

Mk, ges

Moment due to the mass force of all pistons

msw

Moment due to the installation torque of the swivel ring / swashplate or due to the moment of deviation (J _yz )

J

= f (ρ, r, h) mass moment of inertia

Specifically, the lay 1 following tilting moment determination of the swivel or swash plate, wherein α was varied from 0 ° to 16 °:

Tipping moment determination swash plate

It let yourself recognize that the Influence of Piston masses outweighs and thus the aufregelnde behavior of the oblique or Pivoting disc at increasing speed results.

It is thus the case M _{k, ges} > M _sw

In 2 is a diagram for a nearly identical engine indicated, this diagram is based on the following calculation scheme, in which case α was varied from 0 ° to 16 °:

Tipping moment determination swash plate

Here is the case M _{k, ges} <M _sw .

This calculation scheme shows that compared to the calculation 1 the thickness or height of the inclined or swashplate of 10 mm ( 1 ) to 18 mm ( 2 ) has been increased. This has the consequence that the relevant moment of inertia J _z increases to approximately twice the value. In 2 is a derating behavior of the swashplate engine to recognize. This trend is indicated by the arrow "n" in 2 , where "n" means the rotational speed of the swash plate or drive shaft, of course, the arrow "n" in the same meaning 1 , only there is the arrow reversed, causing a Aufregeln to be displayed with increasing speed.

The 1 reflects the state of the art. Here, the aufrichtende behavior is appropriate 1 Frequently detectable in current R134a series compressors. In more recent developments, one tries rather to convert this trend into the opposite, namely accordingly 2 ,

• – bei Drehzahlerhöhungen der Kippwinkel der Schwenkscheibe weitgehend konstant bleibt, d.h. M_sw = M_k,ges; bzw.
• – bei Drehzahlerhöhungen der Kippwinkel der Schwenkscheibe sich verkleinert, d.h. M_sw > M_k,ges

Based on the cited prior art, it is an object of the present invention to provide an axial piston compressor of the aforementioned ax, in which

• - When speed increases the tilt angle of the swash plate remains largely constant, ie M _sw = M _{k, ges} ; respectively.
• - Reduced in speed increases the tilt angle of the swash plate, ie M _sw > M _{k, ges}

• – bei Drehzahlerhöhungen die Förderleistung nicht in gleichem Maße erhöht wird, sondern daß die Förderleistung insbesondere im Bereich mittlerer und höherer Drehzahlen etwa konstant bleibt.

Furthermore, it is the object of the present invention that

• - When speed increases the capacity is not increased to the same extent, but that the capacity remains constant, especially in the range of medium and higher speeds.

• – daß die Unwucht der rotierenden Teile möglichst gering gehalten wird, und
• – daß die erfindungsgemäße Konstruktion robust und unanfällig für Störungen ist.

Finally, of course, care should also be taken

• - That the imbalance of the rotating parts is kept as low as possible, and
• - That the construction of the invention is robust and not susceptible to interference.

These Task is achieved by the characterizing features of claim 1 are solved, wherein advantageous developments and structural details of the invention described in the subclaims are.

• – Kippwinkel der Schwenkscheibe nahezu konstant, oder
• – er verringert sich, wobei dadurch zumindest ein Teil der sich allein durch die Drehzahlsteigerung ergebenden steigenden Förderleistung kompensiert wird.

An essential aspect of the invention is that the abstützenden overturning moments due to the moments of inertia / Deviationmomente the swash plate assembly are so large that there is a control behavior, which qualitatively to that according to 4 equivalent. That is, the speed of the compressor increases, so remains the

• - tilt angle of the swash plate almost constant, or
• - It decreases, thereby at least part of the alone resulting from the speed increase resulting increase in capacity is compensated.

The representation in 4 the following calculation is used:

Thus, according to the invention chosen a construction in an additional mass, in particular additional disc or ring on coupled to the swashplate mechanism, whose or erecting overturning moment as a result of his or her Deviationsmoments with the erecting overturning moment as a result of the moment of deviation of the Swivel disc cooperates.

In the simplest case of coupling, the moments add up. This means that the deviation moment defined by the additional mass is superimposed on the deviation moment of the swashplate, namely the deviation moment J _yz which is effective around the tilting axis of the _swashplate . It is of course also a construction conceivable in which the additional mass transmits no moment to the swash plate, but a power transmission takes place such that a reaction force is produced on the swash plate, which triggers a corresponding additional Deviationsmoment.

One especially reliable Mechanism for pivoting the swash plate and / or the additional mass arises from the fact that the Swivel disk and / or the additional mass each with at least one, but in particular two cylinder pin-like bolts, which in corresponding recesses on the swash plate or the additional mass on the one hand and a sleeve slidably mounted on the drive shaft on the other hand intervene, relative to the sleeve or is mounted pivotably relative to the drive shaft or are. In particular, in the case where both the swash plate as Also additional mass articulated with the two cylinder pin-like bolts are, the pivotal movement of the swash plate and the additional mass independent from each other respectively. This gives the advantage that the additional mass does not have the entire angle range, over the swashplate must be swiveled, must be swiveled. Thereby will it be possible selectively and selectively use the additional mass, for example on the one hand, to accelerate the compressor up Starting to achieve the same and further, at the same time Abregelden behavior at high speeds of the compressor driving Ensure the engine. Furthermore, can thereby also (additionally or alternatively) in particular in the case of a decentralized suspension of the additional mass and / or the swash plate, the swivel angle of additional mass and Swivel disk to be synchronized. It should be mentioned at this point that it is in the aforementioned Recesses that correspond to the cylinder pin-like bolts, in a preferred simple embodiment is drilling. Such a mechanism for the swash plate or the additional mass can otherwise be very defined and with highest precision be made, which is a precise Linkage of the swash plate and / or the additional mass on the sleeve or ensures the guide sleeve. As already indicated above, which is associated with the swash plate Additional mass, especially in the form of an additional disc or a Additional ring may be present, designed or arranged, that by selbige a the Deviation moment of the swash plate largely rectified Deviationsmoment is obtained, such that the sum of the tilting moments as a result of these moments of deviation greater than or equal to the moment due to all translationally moving masses, i. in particular the piston, including, if necessary, the sliding blocks, piston rods or the like. This will be the desired control behavior of the compressor ensured in a simple manner.

The Swivel disk can additionally over at least one, in particular two articulated arms with a rigid on or on the drive shaft fixed stop disc are engaged such that at axial displacement of the sleeve the tilt angle of the swash plate is changed. Same time or but alternatively, the stop disc, the tilting movement of the Limit additional mass and / or the swash plate. By such Construction with articulated arms, which have pivots is for one low-friction deflection of the swash plate or the additional mass taken care of.

In a further preferred embodiment has the additional mass on its side facing the swash plate a sliding surface on, on which the swash plate is slidably supported. This sliding surface takes care of a low-friction and wear-resistant support the swash plate on the additional mass. Of course you can also the swash plate on a corresponding sliding surface have the additional mass facing side. Both sliding surfaces can be hardened, coated or otherwise treated so as to reduce the coefficient of friction or the wear of the reduce or minimize both components.

Optionally, the side facing the swash plate of the additional mass and / or the additional mass facing side of the swash plate on a cam surface with depressions and / or projections, which define the tilt angle-dependent relative position of the swash plate and additional mass. By such a construction, the relative positions of the swash plate and additional mass to each other can be defined in a simple manner, which is particularly advantageous if one of the two components or both components have a pivot axis which does not coincide with the center of its axial Er extension coincides. If both components are provided with cam surfaces, these are preferably formed corresponding to each other and designed such that for each deflection angle of the swash plate, the additional mass has the same deflection angle. Alternatively, of course, different tilt angle of swash plate and additional mass can be achieved with such a construction, so that additional masses of different geometry can be used as desired. The deflection angle of the additional mass can be adjusted as a function of the deflection angle of the swash plate, so that taking into account the Deviationsmoments the additional mass optimal control behavior of the compressor comes about. Preferably, the cam surface of the additional mass in the radially inner region has a recess into which the corresponding cam surface of the swash plate moves with increasing tilt angle of the same, so that the tilt angle of the swash plate and the additional mass equal or alternatively different (in particular, a smaller tilt angle of the additional mass of interest).

The Additional mass, preferably in the form of an additional disc or a Additional ring is advantageously optimized so that the ratio "moment of inertia / component mass" possible is great. The component mass should therefore as possible be low at maximum mass moment of inertia. To achieve this, is suitable in particular as an additional mass an additional ring with an outer diameter, the only slightly smaller is the inner diameter of the engine casing. Preferably, the outer circumference of the additional ring in cross-section crowned to a collision between Additional ring and engine case at Swiveling the additional ring around its tilt axis to avoid. Also the distance between additional ring and housing inner wall should be independent of the tilting position of the additional ring to be substantially constant.

Of further, the center of gravity of the additional mass, e.g. an additional ring preferably lie on the drive shaft center axis. Also is it is advantageous if the tilting center of the additional mass with its center of mass coincides.

In Another preferred structurally simple embodiment is the additional mass parallel to the longitudinal axis of the drive shaft back and forth relocatable, in particular together with the swash plate.

optional is the Deviationsmoment the additional mass over a substantial Kippwinkelbereich the swashplate is larger than that of the swashplate. Again, it is preferable for larger tilt angles, i.e. especially at tilt angles greater than about 12 ° to 18 ° and more preferably at Tilt angles greater than about 15 ° that Deviation moment of the swash plate smaller than the Deviationsmoment the additional mass.

• – das mechanische Regelverhalten (Kippcharakteristik des Verdichters) im wesentlichen durch das Moment der zusätzlich vorgesehenen Masse, z.B. Scheibe oder Ring beeinflußt wird. Es kann durch die Bereitstellung dieses Bauteils ein großes Aufstellmoment (abregelndes Moment) bereitgestellt werden, wobei das Bauteil keinerlei Unwuchten erzeugt, wenn Schwerpunkt und Kippgelenk konstruktiv deckungsgleich vorgesehen werden.
• – durch Verringerung der Unwuchten sind die Regelkennlinien der einzelnen Drehzahlen im Diagramm „Triebwerksraumdruck p" über dem Schwenkscheiben-Kippwinkel „alpha" nicht derart stark gekrümmt sind, wie es bei Verdichtern nach dem Stand der Technik der Fall ist. Dies wird dadurch erreicht, daß der Schwerpunkt weniger weit vom Kippgelenk entfernt ist und die Masse des unwuchtigen Teils (Schwenkscheibe) reduziert werden kann.
• – bei dem zusätzlichen Bauteil mit vergleichsweise geringer Bauteilmasse die für gewünschte Regelcharakteristik erforderlichen hohen Massenträgheitsmomente bereitgestellt werden können, wodurch das notwendige hohe Deviationsmoment erhalten wird. Erreicht wird ein derartiges Verhalten durch eine Ringform der Zusatzmasse mit möglichst großem mittleren Durchmesser.
• – dadurch, daß das für das gewünschte Regelverhalten erforderliche Aufstellmoment der Schwenkscheibe, welches durch die Drehzahl und das entsprechende Deviationsmoment erreicht wird, bereits mit der Zusatzmasse in Form einer Zusatzscheibe oder eines Zusatzrings bereitgestellt wird, in Bezug auf die Schwenkscheibe nicht mehr erforderlich ist, diese konstruktiv mit entsprechenden Massenträgheitsmomenten auszustatten. Dadurch kann auch die Unwucht dieses Teiles minimiert werden.
• – sich durch die Erfindung bei entsprechender Dimensionierung der Zusatzmasse, insbesondere in Form eines Zusatzrings, nahezu jedes gewünschte Regelverhalten erreichen läßt, ohne daß größere Unwuchten entstehen.
• – durch die erfindungsgemäßen Maßnahmen ein günstiges dynamisches Verhalten erreicht wird, welches durch vermindertes Aufschwingen und Gegenregeln mittels Ventilen gekennzeichnet ist.
• – die Kennlinien eine geringe Streuung aufweisen (vgl. 4). Dadurch kann bei der Auslegung des Verdichters jeder Betriebspunkt optimal berücksichtigt, d.h. im Kennfeld plaziert werden. Das ist insbesondere für die CO₂-Anwendung von Interesse, da gegenüber einem R134a-Verdichter neben den AC(Air Conditioning)-Betriebspunkten auch HP(Heat Pump/Wärmepumpen-Beheizer)-Betriebspunkte berücksichtigt werden müssen.

The advantage of the construction according to the invention, in addition to the already enumerated advantages is that

• - The mechanical control behavior (tilting characteristic of the compressor) is essentially influenced by the moment of the additionally provided mass, eg disc or ring. It can be provided by the provision of this component a large Aufstellmoment (abregelndes moment), wherein the component does not produce any imbalance when the center of gravity and tilting joint are structurally provided congruent.
• - By reducing the imbalances are the control characteristics of the individual speeds in the diagram "engine room pressure p" on the swashplate tilt angle "alpha" are not as strong curved, as is the case with compressors according to the prior art. This is achieved in that the center of gravity is less far away from the tilting joint and the mass of the unbalanced part (swash plate) can be reduced.
• - In the additional component with comparatively low component mass required for desired control characteristic high mass moments of inertia can be provided, whereby the necessary high Deviationsmoment is obtained. Such behavior is achieved by a ring shape of the additional mass with the largest possible average diameter.
• - In that the required for the desired control behavior Aufstellmoment the swash plate, which is achieved by the speed and the corresponding Deviationsmoment is already provided with the additional mass in the form of an additional disc or an additional ring, in relation to the swash plate is no longer required, this constructive equip with appropriate mass moments of inertia. As a result, the imbalance of this part can be minimized.
• - Can be achieved by the invention with appropriate dimensioning of the additional mass, especially in the form of an additional ring, almost any desired control behavior without major imbalances arise.
• - By the inventive measures a favorable dynamic behavior is achieved, which is characterized by reduced swinging and countermeasures by means of valves.
• - The characteristics have a low dispersion (see. 4 ). As a result, each operating point can be optimally considered in the design of the compressor, ie placed in the map. This is of particular interest for the CO ₂ application since, in addition to the AC (air conditioning) operating points, HP (heat pump / heat pump heater) operating points must be taken into account in comparison to an R134a compressor.

The Invention will be described below with regard to further advantages and Features by way of example and with reference to the enclosed Drawings described. The drawings show in:

5 the engine of a compressor according to the invention in a perspective exploded view;

6a + b the engine according to 5 in a perspective view, wherein the engine is in a position in which the piston stroke is minimal (a) and in a position in which the piston stroke is maximum (b);

7 a detailed view of the engine, in which a swash plate and an additional mass of the compressor according to the invention are shown;

8a + b the swivel disk and the additional mass according to 8th for a maximum deflection angle (a) and a minimum deflection angle (b);

9 the engine of the preferred embodiment of the compressor according to the invention in side view;

10a - 14b Control behavior of compressors with and without additional mass; and

15 an exemplary representation of the course of the Deviationsmomente J _yz1 and J _yz2 , of _swashplate and additional mass on the tilt angle of the _{swash plate} .

The preferred embodiment of a compressor according to the invention for the air conditioning of a motor vehicle comprises an engine housing which is cup-shaped and at the peripheral edge of which a cylinder block connects. Within the cylinder block, there are seven axially reciprocating pistons, the distribution of the pistons being uniform about a central axis of the housing. It should be noted at this point that compressors with a different number of pistons, for example, five or six pistons, are conceivable. Through the bottom of the cup-shaped housing extending through a driven pulley drive shaft extends 11 (see. 5 ) into the interior of the housing or into the engine room. The storage of the drive shaft takes place in the region of the bottom of the cup-shaped housing within the cylinder block. Incidentally, it should be noted at this point that the above-mentioned engine room is limited by the housing of the compressor.

Within the engine room, a swashplate mechanism is operative to control the rotational movement of the drive shaft 11 is converted into an axial movement of the piston. For this purpose, engages a swash plate in the form of a swash plate 12 with its peripheral edge via a hinge assembly in C-shaped recesses on the back of the piston. The joint arrangement is defined as in the prior art by two spherical segment-like joint stones, between which the swash plate 12 sliding intervenes. The hinge blocks have spherical bearing surfaces, wherein the corresponding spherical recesses are assigned to the mutually facing end faces of the C-shaped recesses of the piston.

The swash plate 12 is an additional mass 13 assigned, which is formed approximately disc-shaped. Both the swash plate 12 as well as the additional mass 13 are each with two cylinder pin-like bolts 14 respectively. 15 on a sleeve 16 hinged, which axially displaceable against the action of an elastic element in the form of a spring 17 on the drive shaft 11 is stored. Bolts 14 respectively. 15 engage in corresponding recesses 18 respectively. 19 in the swash plate 12 or in the additional mass 13 and in corresponding recesses 20 . 21 in the sleeve 16 one. The swash plate 12 is also over two Ge steering arms 23 , which by means of two bolts 24 at a rigid on the drive shaft 11 attached stop disc 26 and by means of a bolt 25 on the swash plate 12 are articulated, at the stop disc 26 hinged. The bolt 25 engages in a corresponding holder 27 on the swash plate 12 one while the bolts 24 in corresponding brackets 28 at the stop disc 26 intervention. With an axial displacement of the sleeve 16 on the drive shaft 11 is about the articulated arms 23 the tilting or deflection angle of the swash plate 12 changed. The stop disc 26 also serves as a stop to limit the tilting movement of the additional mass 13 or the swash plate 12 , The tilt angle of the swash plate 12 conditioned by the fact that the swash plate 12 and the additional mass 13 touch, also the deflection angle of the additional mass 13 ,

The interaction between swash plate 12 and additional mass 13 is also from the 6a and b, in which the preferred embodiment of the compressor according to the invention again in the assembled state for a minimum tilt angle of the swash plate 12 from 0 ° ( 6a ) and for an angle of maximum deflection ( 6b ) is shown.

In the 7 and 8a and b are the swash plate 12 and the additional mass 13 the preferred embodiment of the compressor according to the invention shown enlarged, in particular from the 8a and b, in which the swash plate 12 and the additional mass 13 are shown for different tilt angles of the same, the interaction between swash plate 12 and additional mass 13 becomes clear.

In particular 7 it can be seen, the additional mass 13 on her swash plate 12 facing side 29 sliding surfaces 30 on which the swash plate 12 is slidably supported. It should be noted at this point that the sliding surfaces 30 can be provided with a low-friction coating. Alternatively or additionally, the sliding surfaces 30 also be hardened, thus ensuring low wear and low friction. The swash plate 12 facing side 29 the additional mass 13 is not flat, but has a cam surface 31 with depressions and projections on, wherein the sliding surfaces 30 Part of the cam surface 31 are. The slanted disc 12 is also not planed, but has one to the cam surface 31 corresponding or complementary cam surface 32 on. This points to the cam surface 31 corresponding recesses and projections, whereby by the interaction of the two cam surfaces 31 and 32 the tilt angle dependent relative position of the swash plate 12 and the additional mass 13 is defined or fixed. Such as from the 8a and 8b can be seen, are the cam surfaces 31 . 32 designed such that for each inclination of the swash plate 12 relative to the drive shaft, the additional mass 13 is equally inclined or vice versa. Thus, the varying with increasing or decreasing tilt angle distance between the swash plate 12 and the additional mass 13 compensated, which results from the fact that the swash plate 12 is stored decentrally in the axial direction. As in particular from the 7 it can be seen has the cam surface 31 the additional mass 13 in the radially inner region of a recess into which the corresponding cam surface 32 the swash plate 12 moved with increasing tilt angle of the same, so that the tilt angle of the two components mentioned above 12 . 13 stay the same.

It should be noted at this point that by a construction with cam surfaces 31 . 32 Of course, any other desired movement characteristics of the swash plate 12 and the additional mass 13 is feasible. For example, it can be ensured that the swash plate 12 and the additional mass 13 have different tilt angle. Whether to prefer that is both swashplate 12 as well as additional mass 13 have the same tilt angle, or whether it is preferable that they have different tilt angles, for example, depends on the geometry of the additional mass 13 and also from the bearing of the swash plate 12 and / or the additional mass 13 from. Depending on how the distribution of the deviation moments is pronounced as a function of the tilt angle, and depending on whether and how the distance between the swash plate 12 and additional mass 13 varies with the deflection angle, can be through the cam surfaces 31 . 32 an optimal tilting or movement characteristic can be achieved. This makes it possible, especially in the design of the additional mass 13 take into account other factors, such as housing size of the compressor and the like, wherein the additional mass 13 can be easily adapted to these factors.

In 9 is again the preferred embodiment of the compressor according to the invention shown in a schematic representation. From this figure, in particular, the interaction of the articulated arms 23 with the swash plate 12 seen.

The 10a and 10b show the control behavior of a compressor with additional mass ( 10a ) or without additional mass ( 10b ). It can be seen that with the help of the additional mass, the characteristics are closely related lie, as in 10a is shown. The control behavior is such that almost a certain independence of the tilt angle from the speed results (M _sw ≈ M _{k, ges} ). The behavior according to 10a (with additional mass) is slightly aufregelnd compared to the behavior without additional mass accordingly 10b , The characteristics are in 10a . 10b as well as in the 11a . 11b . 12 . 13 and 14a . 14b as pressure characteristics ".DELTA.P = Pc - Ps" or "Pc", where Pc = pressure in the engine chamber and Ps = suction pressure (pressure on the suction side), on the delivery or displacement "V" (or alternatively on the tilt angle of the swash plate 12 are applied.

Similar results from a comparison of 11a and 11b , in which 11a the behavior with additional mass and 11b without additional mass shows.

In the conditions according to 12a (with additional mass) shows a regulating behavior; ie the moment M _SW is greater than the moment M _{k, ges} in the range up to about 85% of the maximum stroke volume. In the range of about 85% of the maximum stroke volume results in an intersection M _SW = M _{k / ges} (see trend reversal line "TU" in 12a ). In the range greater than 85% of the maximum stroke volume, the behavior is slightly off-setting, ie M _SW is less than M _{k / tot} . The situation is similar in 16 below some changed conditions.

• – M_SW (= M_SW1 + M_SW2) ungefähr = M_k,ges (dabei liegen die Kennlinien vielleicht etwa 1–2 bar auseinander) für αmin<α<αmax (10a/11a (ungefähr))
• – M_SW>M_k,ges für αmin<α<αmax und
• – M_SW>M_k,ges für αmin<α<αgrenz; M_SW = M_k,ges für α=αgrenz; (13/14a/14b) M_SW<M_k,ges für αgrenz<α<αmax sowie
• – M_SW<M_k,ges für αmin<α<αgrenz; M_SW = M_k,ges für α=αgrenz; M_SW>M_k,ges für αgrenz<α<αmax

In connection with the additional mass according to the invention, therefore, the following control behavior is particularly stressed:

• - M _SW (= M _SW1 + M _SW2 ) approximately = M _{k, ges} (the characteristic curves are perhaps about 1-2 bar apart) for αmin <α <αmax ( 10a / 11a (approximately))
• M _SW > M _{k, ges} for αmin <α <αmax and
• - M _SW > M _{k, ges} for αmin <α <αlimit; M _SW = M _{k, ges} for α = α limit; ( 13 / 14a / 14b ) M _SW <M _{k, ges} for αlimit <α <αmax and
• - M _SW <M _{k, ges} for αmin <α <αlimit; M _SW = M _{k, ges} for α = α limit; M _SW > M _{k, ges} for α limit <α <αmax

The 14a . 14b include an invoice based on the last used additional mass for operating conditions with about 20 bar suction pressure and 60 and 90 bar high pressure (heat pump mode HP-mode). The set control characteristic is also suitable for this application, since in HP operation there is generally the problem that the engine does not reach the maximum stroke. It can be seen that in the configuration calculated here, at least 70% of the maximum stroke volume is achieved. Better values would be achieved by using a lower spring stiffness for the return spring. A lower spring rate would remove the characteristics slightly more from the X-axis.

Especially due to the latter feature is associated with the additional mass also has a spring constant in the range 30 ... 200 N / mm in particular 30 ... 90 N / mm and preferably about 60 N / mm.

For explanation, it should be mentioned that the 14a as well as the 14b show the behavior with additional mass.

15 shows, by way of example, according to the invention, the deviation moment J _yz2 , the additional mass and the deviation moment J _{yz1 of} the _swashplate over the tilt angle of the _latter are substantially rectified. Of course, the exact course of the deviation moments depends on the construction or geometry of swashplate and additional mass. The 15 also shows that for larger tilt angles, here> 16 °, J _yz2 > J _yz1 . Furthermore, lets 15 still recognize that up to a tilt angle of about 4 ° to 5 °, the Deviationsmomente of swashplate and additional mass are approximately parallel to increase linearly. As the tilting angle increases, the course of the deviation moment J _{yz1 of} the _{swashplate compensates} , ie the swashplate then acts "in a regulating manner." The course of the deviation moment J _{yz2 of} the additional mass increases essentially linearly.

Of course it is 15 an example, which qualitatively reflects the basic idea of the described doctrine. By constructive changes of the swash plate and / or additional mass can be the two Deviationkurve influence and move relative to each other in a predetermined manner to obtain according to predetermined control behavior of the compressor.

Although the invention will be described with reference to embodiments with a fixed combination of features, but it also includes the conceivable further advantageous combinations of these features, as they are given in particular, but not exhaustive, by the dependent claims. All in the application documents disclosed features are claimed as essential to the invention, as far as they are new individually or in combination over the prior art.

11

drive shaft

12

swash plate

13

additional mass

14 15

bolt

16

shell

17

feather

18

Recess in the swash plate 12

19

Recess in the additional mass 13

20 21

Recess in the sleeve 16

23

articulated arm

24 25

bolt

26

stop disc

27

Holder on the swashplate 12

28

Holder on the stop disc 26

29

the swash plate 12 associated side of the additional mass 13

30

sliding surface

31 32

cam surface

Claims (16)

Axial piston compressor, in particular compressor for the air conditioning system of a motor vehicle, having a housing and a housing arranged in the housing, via a drive shaft ( 11 ) driven compressor unit for sucking and compressing a refrigerant, wherein the compressor unit in a cylinder block axially reciprocating piston and the piston driving, with the drive shaft ( 11 ) rotating swash plate (swivel ring, swash plate or swash plate ( 12 )), characterized in that the swash plate ( 12 ) an additional mass ( 13 ), in particular additional disc or additional ring, is assigned, and that the swash plate ( 12 ) and / or the additional mass ( 13 ) each with at least one, in particular two cylinder pin-like bolt ( 14 . 15 ), which in corresponding recesses, in particular holes ( 18 . 19 . 20 . 21 ) on the swash plate ( 12 ) and / or the additional mass ( 13 ) on the one hand and on the drive shaft ( 11 ) slidably mounted sleeve ( 16 ) on the other hand, relative to the sleeve ( 16 ) or to the drive shaft ( 11 ) (independently of each other) is pivotally mounted or are. Compressor according to claim 1, characterized in that the swivel disk ( 12 ) associated additional mass, in particular additional disc or additional ring ( 13 ), is formed and / or arranged such that by the same one of the Deviationsmoment ( _{y yz1} ) of the _{swash plate} ( 12 ) weitge starting rectified Deviationsmoment (J _yz2 ) is obtained, such that the sum (M _SW ) of the overturning moments (M _SW1 + M _SW2 ) as a result of these Deviationsmomente greater than / equal to the moment (M _{k, ges} ) due to all translationally moving masses, in particular piston, if necessary, including sliding blocks, piston rods od. Like., Is. Compressor according to one of the preceding claims, characterized in that the swash plate ( 12 ) via at least one, in particular two articulated arms ( 23 ) with one on the drive shaft ( 11 ) fixed stop disc ( 26 ) is in engagement such that upon axial displacement of the sleeve ( 16 ) the tilt angle of the swash plate ( 12 ) is changed. Compressor according to one of the preceding claims, characterized in that the stop disc ( 26 ) the tilting movement of the additional mass ( 13 ) and / or the swash plate ( 12 ) limited. Compressor according to one of the preceding claims, characterized in that the additional mass ( 13 ) on its swashplate ( 12 ) facing side has a sliding surface on which the swash plate is slidably supported. Compressor according to one of the preceding claims, characterized in that the swivel disk ( 12 ) facing side ( 29 ) of the additional mass ( 13 ) and / or vice versa a cam surface ( 31 . 32 ) having recesses and / or projections, which the tilt angle-dependent relative position of swash plate ( 12 ) and additional mass ( 13 ) Are defined. Compressor according to claim 6, characterized in that the mutually corresponding cam surfaces ( 31 . 32 ) of swashplate ( 12 ) and additional mass ( 13 ) are designed such that with increasing inclination of the swash plate ( 12 ) relative to the drive shaft ( 11 ) the additional mass ( 13 ) has a same inclination angle as the swash plate ( 12 ). Compressor according to claim 6 or 7, characterized in that the cam surface ( 31 ) of the additional mass ( 13 ) has in the radially inner region a recess into which the corresponding cam surface ( 32 ) of the swash plate ( 12 ) with increasing tilt angle of the same moves in, so that the tilt angle relative to the tilt angle of the additional mass ( 13 ) remains constant. Compressor according to claim 6, characterized in that the mutually corresponding cam surfaces ( 31 . 32 ) of swashplate ( 12 ) and additional mass ( 13 ) are designed such that with increasing inclination of the swash plate ( 12 ) relative to the drive shaft ( 11 ) the additional mass ( 13 ) is less inclined or vice versa. Compressor according to claim 6 or 7, characterized in that the cam surface ( 31 ) of the additional mass ( 13 ) has in the radially inner region a recess into which the corresponding cam surface ( 32 ) of the swash plate ( 12 ) with increasing tilt angle of the same moves in, so that the tilt angle relative to the tilt angle of the additional mass ( 13 ) increases more. Compressor according to one of the preceding claims, characterized in that the center of gravity of the additional mass ( 13 ) is located on the drive shaft centerline. Compressor according to one of the preceding claims, characterized in that when the additional mass ( 13 ) possibly as a with the swash plate ( 12 ) with pivotable additional ring ( 13 ) the center of gravity of which lies in the region of its tilting joint. Compressor according to one of the preceding claims, characterized in that the additional mass ( 13 ) parallel to the longitudinal axis of the drive shaft ( 11 ) is displaceable back and forth, in particular together with the swash plate ( 12 ). Compressor according to one of the preceding claims, characterized in that the moment of deviation (J _yz2 ) of the additional mass ( 13 ) over a substantial tilt angle range of the swash plate ( 12 ) is greater than that (J _yz1 ) of the _{swash plate} ( 12 ), wherein preferably at larger tilt angles, in particular a tilt angle greater than about 12 ° to 18 °, in particular about 15 °, the deviation moment ( _{y yz1} ) of the _{swash plate is} smaller than the moment of deviation ( _{y yz2} ) of the additional mass. Compressor according to one of the preceding claims, characterized in that when the additional mass ( 13 ) As an additional ring this has an outer diameter which is only slightly smaller than the inner diameter of the engine housing. Compressor according to claim 15, characterized in that the outer peripheral edge of the additional ring ( 13 ) is formed spherically in cross-section, such that upon pivoting while maintaining a minimum distance to the engine housing inner wall a collision with this is excluded.