DE10354038B4 - Axial piston compressor, in particular compressor for the air conditioning of a motor vehicle - Google Patents

Abstract

The invention relates to an axial piston compressor, in particular for the air conditioning system of a motor vehicle. Said compressor comprises a housing and a compressor unit, which is situated in the housing and operated by a drive shaft (104), for drawing in and compressing a coolant. The compressor unit comprises pistons (118) that are displaced axially back and forth in a cylinder block and an adjustable plate that drives the pistons, rotates with the drive shaft (104) and is configured as a swash or wobble plate or pivoting ring (107). The adjustable plate is constructed and dimensioned by the definition of the geometry and/or mass and/or centre of mass in such a way that its torque MSW as a result of the deviation torque Iyz, where MSW = Iyz * O<2>, i.e. the torque as a result of the mass inertia and the centre of mass of the adjustable plate, together with the torque Mk,ges as a result of the masses that have been displaced in a translatory manner, (in particular the pistons and optionally including the sliding blocks (121, 122), piston rods or similar), cause an increase in the tilt angle and thus an increase in the delivery output in the small tilt angle range in the event of an increase in speed and a constant pressure differential <p between the high and low pressure sides and that the tilt angle is reduced, thus reducing the delivery output, once a limiting tilt angle agrenz has been exceeded, where Msw = Mk,ges, in the event of an increase in speed and a constant pressure differential.

Description

The The invention relates to an axial piston compressor, in particular compressor for the Air conditioning system of a motor vehicle, in the design as pan or Swash plate compressor with an adjustable in its inclination and of the machine shaft driven swash plate device.

• – EP 1 172 557 A2 ,
• – DE 195 14 748 C2 ,
• – EP 0 809 027 ,
• – DE 198 39 914 ,
• – die europäische Patentanmeldung mit der Nummer 9 995 3619, welche als EP 1 151 197 A1 bzw. WO 00/14409 A1 veröffentlicht ist, und
• – US 2002/0038600.

The following patent applications may be cited in the state of the art:

• - EP 1 172 557 A2 .
• - DE 195 14 748 C2 .
• - EP 0 809 027 .
• - DE 198 39 914 .
• - European patent application number 9 995 3619, which is known as EP 1 151 197 A1 or WO 00/14409 A1 is published, and
• - US 2002/0038600.

In the two first mentioned pamphlets are primarily about the Swash plate (swash plate) and its connection to the shaft (tilt mechanism of the swash plate) as well as the mass inertia the swash plate.

By the EP 1 172 557 A2 is a two-part support device is known, which simultaneously transmits the torque between the shaft and swash plate as a driver. The attached to the machine shaft first driver part, which is designed as a bearing in the form of a receiving bore is disposed at a considerable distance next to the swash plate, and a second, in the first articulated engaging driver part is formed as a lateral extension of the swash plate. The first as well as the second driver part are in pairs. Usually, the bearing clearance of a driver and its bearing part is slightly larger in order to guide defined and thereby avoid overdetermination or a double fit. This has the consequence that such a compressor can not be operated independently of rotation, that has a defined preferred direction of rotation.

Of the removed from the tilt axis center of gravity causes an imbalance because the engine only for balanced (preferably) mean swash plate tilt angle can be.

The a thickened hub portion having swash plate has by its "lateral extension" a relatively large moment of inertia with a center of gravity substantially away from the tilt axis, so that a sudden change the rotational speed with appropriate inertia to a tilt adjustment the swivel disk leads. Furthermore determines the center of gravity essentially with the control behavior, in such a way that the compressor strongly upset, i. the mass inertia forces of the swash plate as well as their center of gravity cause a moment of deviation, which causal the translational mass forces (e.g., by the pistons and sliding blocks).

• – Das Massenträgheitsmoment der Schrägscheibe bewirkt ein Moment welches größer als das durch die Massenkräfte der Kolben erzeugte Moment ist.
• – Ein Massenschwerpunkt welcher außerhalb des Kipp- oder Drehpunktes der Schrägscheibe liegt, unterstützt diesen Effekt zusätzlich.

Such a construction has been implemented in commercially available compressors which have the following essential properties:

• - The moment of inertia of the swash plate causes a moment which is greater than the moment generated by the mass forces of the piston.
• - A center of mass which lies outside the tilt or pivot point of the swash plate, additionally supports this effect.

In relating to this type of compressor, which is the typical design of a swash plate type compressor represents It should be noted that the mass of such a swash plate not increased arbitrarily can be to change the control behavior with it. That's because in the compressors of the type described the center of mass the swash plate usually a clear distance to the tilting joint of the swash plate having. This construction is essentially based on that the swash plate additionally to a suitable leadership on the wave over an adjusting mechanism with the shaft or connected to the shaft Component must be coupled or "steered" must.

Of the mentioned Distance from the center of gravity of the swashplate and tilting joint of the swash plate leads to an imbalance of the engine, especially in function of the swash plate tilt angle.

In the DE 195 14 748 C2 The center of gravity of a swashplate is specifically used to provide a deviation moment, even at very small tilt angles (eg at 0 °), which "upsets" the swashplate. This avoids the problem that the compressor can no longer be started (regulated) at a very low tilt angle, since the pressure difference necessary for this can no longer be produced because of the piston stroke which is too low. The publication thus aims in particular at a clutchless operation of the compressor. In this operating mode, the compressor is also supplied with speed in the "Air conditioning off" state. Consequently, the compressor is always required a certain torque, which must be minimized.

in the Starting the compressor ("Air conditioning to ") should the compressor can fix. For this purpose, in the compressors according to the prior art gas from the high-pressure side of the compressor led into the crankcase. The pressure increase leads to, that the swashplate tilt angle elevated.

Around to be able to adjust the compressor so must have a minimum tilt angle of about 0.5 ° (may scatter, depending on the constructive Implementation of various parameters) may be present. The minimum Tilt angle guaranteed a minimum piston stroke, which helps maintain the pressure is sufficient on the high pressure side. Leaks e.g. on the low pressure side of the system the expansion organ counteract this.

• – Moment infolge der Gaskräfte in den Zylinderräumen (+)
• – Moment infolge der Gaskräfte aus dem Triebwerksraum (–)
• – Moment infolge einer Rückstellfeder (–)
• – (Moment infolge einer Aufstellfeder (+))
• – Moment infolge der rotierenden Massen (–) (inklusive Moment infolge Schwerpunktlage; kann (+) sein)
• – Moment infolge der translatorisch bewegten Massen (+)

In general, it is the following moments that affect the tilting of the swash plate in the center of the tilting movement of the swash plate. In brackets, the direction of the moment is indicated, where (-) means decreasing (in the direction of the minimum stroke) and (+) (raising in the direction of the maximum stroke).

• - 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 the rotating masses (-) (including moment due to center of gravity; can be (+))
• - moment due to translationally moving masses (+)

in the Further, the focus of consideration is on the order of magnitude of the moment due to the rotating masses (-) (including the moment due to Center of gravity; can (+ or (-) ), based on the moment due to the translationally moving Masses (+).

What about the said DE 195 14 748 C2 is useful for the area very small tilt angle is extremely disadvantageous in the range medium and larger tilt angle. In this context, the EP 0 809 027 called. Their object is a particular embodiment of the coupling mechanism between the shaft and swash plate device. It should be noted that such a coupling mechanism is particularly interesting for high pressure applications.

In This document also becomes another feature (particularly relevant as state of the art), to which it generally refers to "modern" air compressors arrives. Accordingly, it is particularly interesting, a constant control the flow rate provide. It is proposed, the kinematics of the compressor be designed so that the forces acting on the swash plate, abregelden Tipping moments clearly opposite dominate the uplifting overturning moments. That's why it's special to emphasize, because this is the technical above Teachings are basically countervailing measures.

It It goes without saying that the term "flow rate" is relatively blurred is. The delivery rate would be considered constant, e.g. when doubling the speed the tilt angle of the swash plate device halved. That would be geometrically the flow rate constant. Naturally Then other parameters also affect the delivery rate, if e.g. the tilt angle changes, e.g. slightly changed Degree of delivery or oil throw or similar.

For a constant control the flow rate at changing speeds of rotation is thereby the restoring Tipping moment of the swash plate device exploited, there - like already explained - the swash plate their inclination due to the dynamic forces counteracts the co-rotating disk part.

As indicated above, prior art compressors are known in which al Because of the acting moments of up-regulating and regulating mass forces, the stroke volume tends to increase. By appropriate control intervention of the control valves used that must be compensated if necessary. New developments (especially known for CO ₂ ) are aimed at reversing this behavior. The necessary control intervention can then be reduced or unnecessary.

For better understanding, the tilting behavior described as a result of the speed fluctuation in 1 specified. It should be noted that this is only an example used as an example and, of course, depending on the chosen design quantitative differences may be present. Qualitatively, the chosen design is representative of today used series compressor.

1 shows the dependence engine room pressure difference, based on the suction pressure on the tilt angle of the swash plate. An example was calculated for the pressures: high pressure 120 bar and suction pressure 35 bar. The speeds were also calculated: 600 rpm, 1200 rpm, 2500 rpm, 5000 rpm, 8000 rpm and 11,000 rpm. However, only 5 of the 6 calculated courses can be seen. This is because the gradients for the calculated speeds of 600 rpm and 1200 rpm are almost identical to each other.

From the diagram it can be seen very clearly that there are courses which cause an adjustment of the swashplate to larger tilting angles here, as the speed increases. In addition to the diagram in the attachment, the sizes used for the calculation are indicated. For reasons of simplification, a swash plate was calculated, which is geometrically described essentially by an inner diameter, an outer diameter and a height. In addition, the piston mass (assumption here: m _K = 45 g), the pitch circle diameter (assumption here: R = 29 mm), on which the pistons are, and the number of pistons (assuming here: n = 7 pieces) are relevant.

(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. Deviationsomomentes 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 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 directional angle of the z-axis with respect to
γ ₃ = ψ main axes of inertia ξ · η · ζ

(Note: J ₃ ≈ 2 J ₂ Target: J _yz should have a certain size J _yz ↑

J ₃ ↑ J ₂ inevitably increases!)

of inertia

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

Independent of 13 applies:

Moment owing Mass force of the pistons

• Zi = R · ω 2 tanα cosβ i
• F Wed.  = m k * z i
• M (F Wed. ) = m k Cosβ * R * i * z i

Moment M _sw due to moment of deviation

• M sw = J Y Z · ω 2
  

there mean the sizes used above what follows:

θ

Rotation angle of the shaft (where the above and following considerations of simplicity half for θ = 0 employed become)

η

Number of pistons

R

Distance of the piston axis to the shaft axis

ω

angular velocity the wave

α

Tilt angle of the swivel ring / swashplate

mk

Mass of a piston including sliding blocks or sliding block pair

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

G

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 as a result of Mass force of the piston i

Mk, ges

Moment as a result of Mass force of all pistons

msw

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

J

= f (g, r, h) mass moment of inertia

Finally, it should be noted that in the calculation of the Mas moments of inertia, in particular of the moment of deviation preferably still a so-called Steiner proportion (y _s · z _s · m) should be taken into account, taking into account the deviation moment as follows:

kleiner als der Steineranteil y_s·z_s·m. Der Anteil J_YZ regelt den Verdichter im mer ab, während der Anteil y_s·z_s·m stets aufregelt (eingestellt durch die Lage im Quadranten Q2, Q4 gemäß 12).For small tilt angle of the swash plate, such as a swivel ring, the proportion

smaller than the Steiner proportion y _s · z _s · m. The proportion J _YZ always regulates the compressor, while the proportion y _s · z _s · m always upregulates (set by the position in the quadrant Q2, Q4 according to FIG 12 ).

Out the above considerations So it follows that the moment of the moment of deviation has two opposing influences has, i. both an up and down.

The corresponding proportions are effective after exceeding a limit tilt angle α _G , where for α <α _G :
y _s · z _s · m> J _YZ (aufregelnd), and for
α> α _G reversed (ie, offsetting).

In 1 is another diagram showing the moment due to the rotating masses (-) (including the moment due to the center of gravity, here = 0), the moment due to the translational masses of the pistons and sliding blocks (+), and the sum of both , From the sum, it can be seen that this is positive for all tilt angles and the engine "corrects" for all tilt angles solely on the basis of the inertial forces and the mass inertia of the swashplate. Shown in the diagram were the torques for a mean speed of 2500 rpm. At lower speeds, of course, the effect is smaller, thus larger at higher speeds.

In 2 are the calculation scheme and the 1 corresponding diagram given for a nearly identical engine. However, the height of the swash plate was increased from 10 mm to 18 mm. As a consequence, the relevant mass moment of inertia J _z increases to twice the value.

In a first diagram of the figure, a regulating behavior of the swashplate engine can be seen. This trend is indicated by the inserted arrow, where "n" is to denote the speed (compare the trend with 1 !). Another (smaller) diagram here also contains the torque curves with respect to the moment due to the rotating masses (-) (including the moment due to the center of gravity, here = 0 set), the moment due to the translationally moving masses of the pistons and sliding blocks (+), as well as the sum of both. For the sum, it can be seen that this is negative for all tilt angles and "decelerates" the engine for all tilt angles solely on the basis of the mass forces and the mass inertia of the swashplate. Shown in the diagram were the torques for a mean speed of 2500 rpm.

On Based on the cited references can be the two mentioned Gradients "aufregelnd" and "abregelnd" as state of the art look at. Here is the "aufzustiegende" behavior in current series compressors often ascertainable. In new developments, one tries rather, this Trend to the opposite.

• – Überkompensation der Massenkräfte der Kolben durch die Massenkräfte der Schrägscheibe sowie
• – Unterkompensation der Massenkräfte der Kolben durch die Massenkräfte der Schrägscheibe,

ist es auch denkbar, eine Kompensation vorzusehen.In addition to the two explained cases

• - Overcompensation of the mass forces of the piston by the inertial forces of the swash plate as well
• Undercompensation of the mass forces of the pistons by the mass forces of the swash plate,

it is also conceivable to provide a compensation.

It can be seen from the mathematical contexts that the equation allows the speed to be shortened ( 2 ). Otherwise, geometrical variables are still included which are related to one another in certain contexts and, in principle, including the component densities and density distributions, can be chosen such that the sum of the moments can be set to zero as a result of inertial forces.

However, an influence of the tilt angle can not be avoided. This results from the courses of the terms tan (α) and sin (2α). The curves of the trigonometric functions are in the diagram of the 3 represented. From the diagram, it can be easily deduced that the influence at a small tilt angle is very small, but becomes considerable at a larger tilt angle. As a rule, the swashplate tilt angles of the compressors are limited by a minimum value and a maximum value. So are values between ei a tilt angle of about 0 ° and a maximum of about 25 ° conceivable. In practice, the values are more likely between 1 ° and 18 °. Based on this, it can be seen from the diagram that one has to reckon with a deviation of 13% in the latter range. That is, if for minimal tilt angle constructive equilibrium between aufzustesternden and abregeldenden masses was realized, one must still expect in the opposite limit of the swash plate with an undesirable tilting behavior (speed increase due to the tilt angle).

In order to achieve the greatest possible compensation of the mass forces, it makes sense to provide the compensation for a maximum tilt angle or a theoretical (virtual) tilt angle (eg α = 24 ° (> = α _max = 16 °)), which is greater than the maximum Tilt angle is. This results from the knowledge that at a small tilt angle anyway the difference of tan (α) and sin (2α) is small.

The diagram of 4 contains the result of the calculations for a design on the tilt angle 16 °, which is to be considered as the maximum tilt angle for this engine example. The height of the swash plate has been adjusted to 14.292 mm, the moment balance also shows balanced conditions. It should be mentioned again that of course other swash plate parameters can be used for the adjustment of the mass moment of inertia. For ease of comparison, however, the parameter swash plate height has been selected by way of example only.

The control behavior of the swash plate according to the diagram of 5 shows the desired result. In the entire working range of the swash plate (from the minimum to maximum tilt angle), there is no significant aufzustenden effect due to moments of moving masses, a wide dispersion of the characteristics is avoided by the fact that there is an intersection at maximum tilt angle.

A very good compensation arises in the range of small tilt angle because the small effect (difference) of tan (α) and sin (2α) as well as the maximum tilt angle of 16 °, for the the mass forces through Selection of parameters were compensated. At medium tilt angles, the curves "drift" slightly apart.

In the case of compensation of the mass forces, the following interpretations are conceivable: for α = α _max M _{K, ges} = M _SW for α ≥ α _max M _{K, ges} = M _SW

In 6 Various control characteristics for operating pressures (suction pressure / compression pressure, n = 5000 rpm) and the calculation principles are shown. The higher the compression pressure at which the compressor is operated, the greater the pressure to be regulated in the engine compartment. The lower the intake pressure, the smaller the pressure to be adjusted in the engine room. The slope of the control characteristics is essentially determined by the spring force acting on the swashplate mechanism.

As in all previously mentioned diagrams, the characteristic curves were given a Spring constant with respect to the return spring (Provision in the direction of minimum stroke) of 60 N / mm. Would the spring constant smaller selected so would the curves towards larger tilt angles be less sloping. Would the spring constant chosen larger, so would the curves towards larger tilt angles stronger to be sloping.

A every curve for 5000 rpm is considered representative for a of curves to see a specific operating point. When considered is that a certain control pressure of at least 2-3 bar above the Suction pressure required and a cheap one Control behavior is achieved by the characteristic curves a certain preferably have a linear slope over a wide range, it is plausible that a closely spaced "bundle of curves" rather for all operating areas in the desired Area of the map is as a rule curves, the more "drift apart".

In such negative cases as, for example, in an uplifting behavior according to 1 It is clear that parts of control curves are very easily in the range below the level of 2-3 bar above the suction pressure. To avoid this, a softer return spring would have to be used. In particular, at high speeds but then it may happen that opposite the falling characteristic at low speeds an increasing characteristic arises. Experience shows that in such cases, very unwanted rule effects. In particular, no defined tilt angle is to be assigned to individual pressures (occurrence of relative maxima or minima or no or insufficient slope or turning points).

It It is an object of the invention to provide an improved axial piston compressor of the generic type to provide in particular by a practical Control dynamics distinguished.

These Task is by an axial piston compressor with the features of claim 1. Appropriate training of the inventive concept are the subject of the dependent claims.

It is an essential idea of the invention, a swash plate device in which the moments due to the mass forces in magnitude and direction are so effective that in the range of low tilt angle a "Aufregeln" (swash plate elevated their tilt angle, thus increasing the flow rate) of the compressor solely due to the moments resulting from the mass forces, and in the area medium to larger tilt angle a "Abregeln" (swash plate reduces its tilt angle, thus decreasing the flow rate) solely due to the moments as a result of the mass forces results.

The essential measure is that the Deviationsmoment the swash plate is structurally specified so that it causes a "Aufregeln" of the swash plate in the range of small tilt angle together with the piston or separately. For this purpose, a moment M _SW due to the deviation moment> 0 must be present in this range, and in the range of the minimum tilt angle there must be exactly one tilt angle in which the moment M _{SW is} due to the deviation moment = 0. If the tilting angle increases further, the deviation moment increases again and has a decreasing effect. The slope of the moment M _{k, ges} due to the mass forces of the pistons must be smaller than the slope of the moment due to the Deviationsmoments.

By the dimensioning of the swash plate with the aim of producing such a behavior, the results Possibility, in the range of small tilt angles to accelerate the "Aufregeln" of the swash plate, to reinforce or to improve and in the range of larger tilt angles by the "off-setting" behavior the necessary usually activities (Control valve (s) switches bypasses to vary the engine room pressure) to the necessary restrict and thus making the compressor operation more energetically effective. Farther results in a cheaper dynamic behavior, especially reduced swinging and "counter-regulation" through the valves.

advantages and expediencies The invention will be apparent in the rest from the dependent ones claims as well as the description with reference to the attached figures. From these show:

1 to 5 graphical representations as well as tables of values or calculation instructions for the design of the swashplate arrangements of axial piston compressors with regard to their tilting behavior,

6 and 7 a perspective view and side views of the invention essential components of an axial piston compressor and

8th to 12 Graphical representations or tables of values for the representation of the moments occurring under defined structural constraints.

In 6 and 7 a swash plate mechanism is specified by which the design (the subject invention) can be implemented constructively, wherein

7 this is an exploded perspective view and 8th shows two side views of the essential components at minimum and maximum tilt angle.

The illustrated swivel ring mechanism 100 comprises an annular swash plate, ie a swivel ring, 101 , via a guide or sliding sleeve 102 and a compression spring located in this 103 tilt adjustable on a drive shaft 104 is stored. The swivel ring 101 is from the drive shaft 104 driven in rotation and is about a special design of the guide sleeve 102 articulated about a pivot axis extending transversely to the drive shaft. This pivot axis is defined by two bearing pins 104a . 104b that are in bearing sleeves 105a . 105b the guide sleeve 102 and correspondingly arranged radial bores 106a . 106b of the swivel ring 101 are received rotatably. The La gerhülsen 105a . 105b are sized to fit one between the guide sleeve 102 and the swivel ring 101 bridge formed annulus.

Furthermore, the swivel ring 101 with one together with the drive shaft 104 rotating support element 107 hingedly connected, this compound is designed as Axialabstützung. It is done by a with the swivel ring 101 operatively connected support arch 108 , This support arch 108 is designed to be one between a piston 109 the arrangement and the pivot ring effective hinge assembly overlaps, in such a way that regardless of the inclination (the tilt angle) of the pivot ring 101 every collision between this and the support arch 108 on the one hand and a piston assembly comprising a joint arrangement 110 on the other hand is excluded. The support element 107 is part of one with the drive shaft 104 rotatably connected disc 111 ,

A support surface of the support arch 108 extends approximately concentric with the center of a between the piston 109 and the swivel ring 101 effective joint arrangement. The axial support is thus effective outside of said hinge assembly, with the result that it is not affected by axial support measures.

The connection between the swivel ring 101 and the support arch 108 is made by two connecting bolts 112a . 112b made in a 90 ° with respect to the aforementioned holes 106a . 106b offset bore pair 113a . 113b the swivel ring and in correspondingly arranged holes 114a . 114b intervene of the support arc itself. The joint arrangement with respect to the piston foot 110 of the piston 109 is - according to the prior art - by two spherical segment-shaped joint stones 115a . 115b formed, the spherical surfaces in a correspondingly shaped lower end face of the piston 109 on the one hand and a corresponding surface of an opposite extension 117 of the piston foot 110 on the other hand. There is a gap between the joint stones 116 formed, in which the swivel ring 101 engages such that opposite end face portions touch the flat surfaces of the hinge stones.

It can be seen that in the illustrated embodiment, the pivot bearing of the pivot ring 101 only for torque transmission and the support element 108 only for the axial support of the piston 109 or for gas force support is used. The torque transmission is thus of the axial support of the pivot ring 101 decoupled.

Of special interest is also the support surface for the support arch 108 on the support element 107 , This is as a section 118 a cylinder surface formed. To shift the support line when changing the inclination of the swivel ring 101 ie a displacement from the "center" of the piston 109 To avoid, is the support arch 108 in the radial direction relative to the pivot ring 101 slidably mounted.

In the left picture the 7 For example, four areas are labeled Q1, Q2, Q3 and Q4. In the previous examples, it was assumed that the center of gravity of the swash plate lies on the tilt axis, which is defined perpendicular to the shaft center axis. Based on this, however, compressors according to the prior art often have focal points in the region of the swashplate, in which the center of gravity of the swashplate is not on the tilting axis. In a preferred embodiment, these points coincide. In another, an "offset" is planned. Here, focal points in the quadrant Q have the following effect:
QI (positive coordinates z and y): offsetting
Q3 (negative coordinates z and y): offsetting
Q2 (positive coordinates z and negative y): up-regulating
Q4 (negative coordinates z and positive y): pending

Becomes no additional Mass balance provided, so the focus of many is the Prior art corresponding swash plates in the area Q4.

It is natural possible, that is a center of gravity located in any quadrant when tilting the swash plate the shaft side, relative to the shaft axis, changes and becomes e.g. Transforms an up-leveling behavior into a more disciplined way of managing. However, it has been recognized that in the area of the shaft axis Naturally the centrifugal force and any resulting tilting moment rather limited, i. the center of gravity only becomes special be relevant if given a certain distance to the shaft centerline is.

In connection with the invention, the following two focal points are important (Offset, which acts in an orderly manner):
Q2 (positive coordinates z and negative y): up-regulating
Q4 (negative coordinates z and positive y): pending

For better understanding, the same parameters (swash plate geometry) were used as in 1 and 2 ,

• – "aufregelndes Triebwerk" mit Schwerpunktslage 0.

These are in the diagram left, top of 8th around the case 1a:

• - "upright engine" with center of gravity 0.

• – "abregelndes Triebwerk" mit Schwerpunktslage 0,

dargestellt. Der Unterschied beider Berechnungen liegt lediglich in der Höhe der Schrägscheibe (vgl. Anlage 6 h = 10 mm, sowie Anlage 7 h = 18mm). Berechnet wurden insgesamt 4 Drehzahlen.In the diagram on the left, below the 8th Case 2a becomes:

• - "Regulating engine" with center of gravity 0,

represented. The difference between the two calculations lies only in the height of the swashplate (see Appendix 6 h = 10 mm, and Appendix 7 h = 18mm). A total of 4 speeds were calculated.

• – "aufregelndes Triebwerk" mit Schwerpunktslage in Q4.

The diagram on the right, above represents case 1b:

• - "Stopping engine" with focus in Q4.

• – "auf- bzw. abregelndes Triebwerk" durch Schwerpunktslage in Q4

dargestellt. Dabei können die Fälle 1a, 1b, 2a als bekannt angesehen werden; Quellen und Beispiele wurden weiter oben erläutert. Der Fall 2b steht im Zusammenhang mit der Erfindung.Conversely, in the diagram "right, bottom", case 2b:

• - "up or down regulating engine" by center of gravity position in Q4

represented. The cases 1a, 1b, 2a can be regarded as known; Sources and examples have been explained above. Case 2b is related to the invention.

In the 8th only the resulting moment, that is (M _{K, ges} + M _SW ), is represented as a result of the mass forces, which decide the criterion of "Aufregelns" or "Abregelns". In 9 the value tables are given, the basis for the diagrams of the 8th are. In the 10 be in addition to 8th Cases 1b and 2b are shown in more detail. The diagrams on the right, top and right, below correspond to those of 9 , In each case the diagrams in the individual moments are given, and for a selected speed of n = 6000 U / min.

Special reference to the invention has the image right, bottom. The moment due to the mass forces of the pistons is at a tilt angle of 0 ° of the swash plate = 0. The moment due to the deviation moment (M _SW ) of the swash plate is> 0 and causes a positive (up-regulating moment). Due to the deviation moment of> 0, the resulting moment (M _SW + M _{K, ges} ) is equal in magnitude and direction.

Starting from a tilt angle of 0 ° increases the tilting moment M _{K, ges} , because of the increasing piston stroke, as the mass forces of the piston are larger. In contrast, the tilting moment corresponding to the moment due Deviation moment, due to the swash plate (M _SW ) tends to its zero position (Deviationsmoment = 0 °), which is approximately at a tilt angle of 0.6 °. If the tilt angle increases further, then the moment of deviation of the swashplate no longer acts as an uplifting, but off-set. Nevertheless, the effect of the swash plate in the range 0.6 ° to 2 ° is not sufficient to provide in the moment sum (M _{K, ges} + M _SW ) in total for a "Abregeln". As a result, the sum of the momentums (M _{K, ges} + M _SW ) is positive up to about 2 ° and has a regulating effect.

• – Bis ca. 2° wirken die Momente infolge der Massenkräfte des Triebwerkes aufregelnd.
• – Ab ca. 2° wirken die Momente infolge der Massenkräfte des Triebwerkes abregelnd.

Since the slope of the moment due to the swash plate is greater in magnitude than the slope of the moment due to the piston, the trend reversal is reached at 2 °:

• - Up to about 2 °, the moments act as a result of the mass forces of the engine aufregelnd.
• - From about 2 °, the moments acting as a result of the inertial forces of the engine abregelnd.

It is obvious that over a slight change in the center of gravity of the swash plate the intersection of the course of the resulting moment with the x-axis in the diagram can be moved almost arbitrarily. The The center of gravity is determined by the tax component within the moment of deviation considered. In principle, let also with a center of gravity position (0/0) thus without tax share of the moment of deviation constructively provide so that the moment of deviation in the range e.g. <0.6 ° has its "zero position".

Furthermore, the invention initially aims at the conventional tilt angle range between a minimum and a maximum tilt angle and in a further step to minimize the mini paint tilt angle in the direction of 0 °.

From the diagrams of the 8th and 10 as well as the value tables in 9 shows that, of course, at low compressor speeds (eg 800 ... 3000 U / min) the moments are extremely small, especially in the range of small tilt angles. The question arises, how to manage such small moments at all.

From the value table ( 9 ) to the right, down can be estimated for a standard minimum tilt angle of, for example, 0.9 ° and a compressor speed of 1500 rev / min by linear interpolation, a torque of 0.04 Nm. Even such a small moment can shift the swash plate against the spring force by a few l / 10mm, which corresponds to some 1/10 ° tilt angle change. It should be noted that the possibility of Kippwinkelverkleinerung already in the range of 0.9 ° to eg 0.7 ° energetically very significant for the application "clutchless operation" of the compressor can be.

In 11 and 12 the control curves for the cases already described are shown. To take into account are the spring constants chosen differently for the "upset" case and the "offsetting" case. The choice of different spring constants is necessary to set a meaningful slope of the characteristics, which is necessary for control. Characteristic of the control characteristics in the diagram according to the subject invention is also the intersection at about 2 °, which shows the "trend reversal" of the resulting moment.

The execution The invention is not limited to the example described above and the limited emphasis on interpretation but also in one Variety of modifications possible, in the context of professional action lie. This is especially true of the specific dimensions the swashplate and its center of gravity leeway for the designer if present in the attached claims taken into account.

Claims (8)

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 ( 104 ) driven compressor unit for sucking and compressing a refrigerant, wherein the compressor unit in a cylinder block axially reciprocating piston ( 109 ) and a piston driving, with the drive shaft ( 104 ) rotating swash plate, as an inclined or swash plate or swivel ring ( 101 ), characterized in that the swash plate is designed and dimensioned by fixing the geometry and / or the mass and / or the center of gravity such that its moment M _SW due to the Deviationsmomentes J _yz and the angular velocity ω, where M _SW = J _yz · ω ² , ie the moment due to the mass inertia and the center of gravity of the swash plate, together with a moment M _{k, ges} due to the translationally moving masses, in particular the piston, possibly including sliding blocks ( 115a . 115b ) Piston rods or the like, in the range of small tilting angle increases the rotational speed and constant pressure difference .DELTA.p between high and low pressure side causes an increase in the tilt angle and thereby an increase in flow and after exceeding a Grenzkippwinkels α _limit , where M _SW = M _{k , ges} , with increase in speed and constant pressure difference, a reduction in the tilt angle and thereby results in a reduction in flow rate. Axial piston compressor according to claim 1, characterized in that the swash plate ( 101 ) constructed and dimensioned such that the course of the moment M _SW due to the Deviationmomentes J _yz as a function of the tilt angle α at the same speed substantially greater slope than the course of the moment M _{k, ges} due to the translationally moving masses in dependence from the tilt angle. Axial piston compressor according to claim 1 or 2, characterized in that the sum of the moment M _{k, ges} due to the translationally moving masses and the moment M _SW due to the Deviationsmomentes _{Y yz} in Kippwinkelbereich between a predetermined minimum tilt angle α _min and a maximum tilt angle α _max the Sign, in particular from "plus" to "minus", changes, which means a transition from an increase in the tilt angle and a consequent increase in the capacity to a reduction in the tilt angle and thereby the capacity. Axial piston compressor according to one of the preceding claims, characterized in that a tilting point of the swash plate ( 101 ) as an intersection of the axes of rotation of the drive shaft ( 104 ) and the Swing disk is fixed. Axial piston compressor according to one of the preceding claims, characterized in that when dividing the drive shaft ( 104 ) and swash plate ( 101 ) in four quadrants (Q1, Q2, Q3, Q4) the center of gravity of the swashplate either in a first, front, by the drive shaft and the piston support, the piston facing front of the swashplate limited quadrant (Q1), or in a second, front, at the relative to the drive shaft to the first quadrant (Q1) opposite side lying quadrant (Q2), or in a third, rear, relative to the swash plate at the level of the second quadrant (Q2) behind, ie on the side facing away from the piston of the swashplate arranged quadrants (Q3), or in a fourth, rear, relative to the swashplate at the level of the first quadrant (Q1) behind, ie on the side facing away from the piston, the swashplate arranged quadrant (Q4) is laid. Axial piston compressor according to one of the preceding claims, characterized in that the swash plate ( 101 ) on the one hand and piston ( 109 ), if necessary including sliding blocks ( 115a . 115b ), Piston rods or the like., On the other hand designed and dimensioned such that at a tilt angle α of substantially 0 °, the moment M _SW due to the Deviationsmomentes J _yz the swash plate greater than zero and the moment M _{k, ges} due to the translationally moving masses is substantially equal to zero, such that a positive total torque causes an increase in the tilt angle α of the swash plate, while above a predetermined tilt angle in the range between 1.5 ° and 2.5 °, in particular at about 2 °, the slope of Moment M _{k, ges} due to the translationally moving masses, the slope of the moment M _SW due to the Deviationsmomentes _{Y yz} overcompensated such that from this value, a reduction of the tilt angle of the swash plate is effected. Axial piston compressor according to one of the preceding claims, characterized in that the swivel disk ( 101 ) is constructed and dimensioned such that its moment M _SW due to the deviation moment J _yz at a tilt angle α in the range between 0.4 ° and 0.8 °, in particular at about 0.6 °, is equal to zero. Axial piston compressor according to claim 6 or 7, characterized in that the tilt angle value, from which the total moment from the moment M _{k, ges} the translationally moving masses and the moment M _SW causes a reduction of the tilt angle due to the Deviationsmomentes J _yz of the swash plate , and / or the tilt angle value at which the moment M _SW due to the Deviationsmomentes J _{yz is} equal to zero, by suitable predetermination of the center of gravity of the swash plate ( 107 ) are set.