EP1718867B1 - Axial piston compressor in particular a compressor for the air conditioner on a motor vehicle - Google Patents

Description

The invention relates to an axial piston compressor, in particular compressor for the air conditioning of a motor vehicle, comprising a housing and a housing arranged in the housing, driven by a drive shaft compressor unit for sucking and compressing a refrigerant, wherein the compressor unit in a cylinder block axially reciprocating piston and a the piston driving, rotating with the drive shaft swash plate, eg in the form of a swivel ring, a wobble plate or swash plate.

Such axial piston compressor is for example from the DE 197 49 727 A1 known. This comprises 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 with a certain pressure is present. 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
• DE 19 808 256

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
• DE 19 808 256

The compressors described in these publications are u.a. to take measures to prevent or reduce the imbalance of the engine during operation. Incidentally, the known constructions in common that the rotating components relative to the translationally moving parts, namely piston, piston rod, etc. are relatively large and therefore heavy built. Furthermore, the known constructions have in common that acts on the actual swash plate device an additional disc by a suitable coupling mechanism. The plurality of rotating components are intended to establish an establishment of the moment of the swash plate device in the direction of minimal stroke of the piston, whereby influence on the control behavior is taken.

The mentioned constructions are all relatively expensive, expensive, not very compact and therefore unsuitable for the air conditioning compressors required today by the automotive industry.

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: component number Mass component [g] Total mass [g] piston 6 41 246 slide 12 5 60 translationally moving masses 306 g swash plate 1 391 391 guide pins 2 20 40 rotationally moving masses 431 g

The above numbers indicate that a considerable component mass is provided for parts that 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 pivotal portion of the same is dimensioned such that the centrifugal forces occurring when turning the drive pulley deliberately counteract the pivotal movement of the swash plate regulatory 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, wherein in each case the direction of the moments is indicated in brackets and (-) abregelnd (in the direction of a minimum stroke) and (+) upward (in the direction of the maximum stroke) mean:

• Moment due to 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 upright 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 (+)

With respect to the mentioned compressor 6SEU 12 C from DENSO, which represents the typical design of a swash plate compressor, it should be noted that the mass of such a swash plate can not be increased arbitrarily in order to change the control behavior with it. This is because in the compressors of the type described the center of gravity of the swash plate usually has a significant distance from the tilting joint of the swash plate. This construction is essentially based on the fact that the swash plate must be coupled in addition to a suitable guide on the drive shaft via an adjusting mechanism with the drive shaft or a component connected to the drive shaft.

The mentioned distance from the center of gravity of the swash plate and the tilting joint thereof leads to an imbalance of the engine, in particular depending on the Schwenkscheibenkippwinkel (the focus moves "like a swing" below the Kippgelenkes), and leads in the worst case to an aufzustenden property (so-called. "center of gravity").

Thus, in the prior art compressors, both prior art and actual prior art, a trade-off is made in that a predetermined mass of the swashplate is provided to translate a counter-momentum to the translational produce moving masses. On the other hand, the mass of the swash plate may not be designed too large, because then the imbalance of the engine would be excessive. Moreover, in forming a swash plate in the form of a swivel ring, the increase in the same mass is limited by the height.

To address this problem, it has already been proposed to use the pistons, i. the translationally moving masses as low as possible, i. easy to build, e.g. made of aluminum or other materials of 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 in such a way that the decelerating tilting moments acting on the swashplate clearly dominate the overturning overturning moments. It should be noted that the term "flow rate" is relatively blurred. The delivery rate could be regarded as constant, if, for example, when doubling the speed halves the tilt angle of the swash plate. This would geometrically the flow rate constant. Of course, other parameters affect the flow rate when the tilt angle of the swash plate changes, eg. Degree of delivery, oil throw od. Like ..

For a constant control of the flow rate at varying rotational speeds, the restoring torque of the swash plate is utilized because the swash plate counteracts their inclination due to the dynamic forces on the co-rotating disc part. This behavior can be supported by the force of a spring, so that the increasing with increasing rotational speed or speed flow rate is at least partially compensated by resetting the oblique or pivotal position of the swash plate.

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, as they 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 installation torque of the swashplate, but the speed (ω) is quadratic. This means that 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.

• Hochdruck 120 bar und Saugdruck 35 bar.
• Gerechnet wurde weiterhin mit Drehzahlen:
• 600 U/min, 1200 U/min, 2500 U/min, 5000 U/min, 8000 U/min und 11000 U/min.
• Zu erkennen sind in Fig. 1 allerdings nur fünf der sechs gerechneten Verläufe. Das liegt daran, dass die Verläufe für die Drehzahlen 600 U/min und 1200 U/min im wesentlichen vollständig übereinander liegen (wegen fehlender Dynamik); deshalb ist die im Stand der Technik geförderte "drehzahlunabhängige Fördermenge" eher eine Wunschvorstellung, die mit den dargelegten Maßnahmen nicht erfüllbar ist.

For better understanding, the tilting behavior described as a result of a speed fluctuation in the Fig. 1 and 2 shown. Fig. 1 shows the dependence of the engine room pressure difference relative to the suction pressure on the tilt angle α or "alpha" of the swash plate. By way of example, the following pressures were assumed for the calculation:

• 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 Fig. 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 Fig. 1 can be easily seen that arise gradients that cause an adjustment of the swashplate to larger tilt angles, as the speed increases. It should be mentioned that Fig. 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.

In addition, the piston mass is relevant, the pitch diameter on which the pistons are located, 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 .

das größer ist als 200.000 gmm², vorzugsweise etwa 400.000 - 500.000 2 gmm².Next, the pivot ring preferably has a moment of inertia of $\frac{m}{2}({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}\mathrm{)}.$

which is greater than 200,000 gmm ² , preferably about 400,000 - 500,000 2 gmm ² .

$$\begin{array}{l}{\mathrm{\alpha }}_{\mathrm{1}}\mathrm{=}\mathrm{0}\\ {\mathrm{\beta }}_{\mathrm{1}}\mathrm{=}\mathrm{90}\mathrm{°}\\ {\mathrm{\gamma }}_{\mathrm{1}}\mathrm{=}\mathrm{90}\mathrm{°}\end{array}\mathrm{\}}\mathrm{Richtungswinkel\; der\; x}\mathrm{-}\mathrm{Achse\; gegen}\ddot{\mathrm{u}}\mathrm{ber\; den\; Haupttr}\ddot{\mathrm{a}}\mathrm{gheitsachen\; \xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$$\begin{array}{l}{\mathrm{\alpha }}_{\mathrm{2}}\mathrm{=}\mathrm{90}°\\ {\mathrm{\beta }}_{\mathrm{2}}\mathrm{=}\mathrm{\psi }\\ {\mathrm{\gamma }}_{\mathrm{2}}\mathrm{=}\mathrm{90}\mathrm{°}+\mathrm{\psi }\end{array}\mathit{\}}\mathrm{Richtungswinkel\; der\; x}\mathrm{-}\mathrm{Achse\; gegen}\ddot{\mathrm{u}}\mathrm{ber\; den\; Haupttr}\ddot{\mathrm{a}}\mathrm{gheitsachen\; \xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$$\begin{array}{l}{\mathrm{\alpha }}_{\mathrm{3}}\mathrm{=}\mathrm{90}°\\ {\mathrm{\beta }}_{\mathrm{3}}\mathrm{=}90\mathrm{°}\mathrm{-}\mathrm{\psi }\\ {\mathrm{\gamma }}_{\mathrm{3}}\mathrm{=}\mathrm{\psi }\end{array}\mathit{\}}\mathrm{Richtungswinkel\; der\; x}\mathrm{-}\mathrm{Achse\; gegen}\ddot{\mathrm{u}}\mathrm{ber\; den\; Haupttr}\ddot{\mathrm{a}}\mathrm{gheitsachen\; \xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$${\mathrm{J}}_{\mathrm{2}}\mathrm{=}{\mathrm{J}}_{\mathrm{\eta }}=\frac{m}{4}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}+\frac{h^2}{3}\right)$$

$${\mathrm{J}}_{\mathrm{3}}\mathrm{=}{\mathrm{J}}_{\mathrm{\zeta }}=\frac{m}{2}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}\right)$$

(Anmerkung: J₃ ≈ 2 J₂
Ziel: J_yz soll eine bestimmte Größe haben
J_yz ↑} J₃ ↑ J₂ erhöht sich zwangsläufig!)
Deviationsmoment $${\mathrm{J}}_{\mathrm{yz}}\mathrm{=}\mathrm{-}{\mathrm{J}}_{\mathrm{2}}\mathrm{cos\psi \; sin\psi }\mathrm{+}{\mathrm{J}}_{\mathrm{3}}\mathrm{cos\psi \; sin\psi }$$

Unabhängig von Fig. 3 gilt:
Moment infolge Massenkraft der Kolben $${\mathrm{\beta }}_{\mathrm{i}}\mathrm{=}\mathrm{\theta }\mathrm{+}\mathrm{2}\mathrm{\pi }\left(\mathrm{i}-\mathrm{1}\right)\frac{1}{n}$$

$$\mathrm{Zi}\mathrm{=}\mathrm{R}\mathrm{\cdot }{\mathrm{\omega }}^{\mathrm{2}}\mathrm{tan\alpha \; cos}{\mathrm{\beta }}_{\mathrm{i}}$$

$${\mathrm{F}}_{\mathrm{ml}}\mathrm{=}{\mathrm{m}}_{\mathrm{k}}\mathrm{\cdot }{\mathrm{z}}_{\mathrm{i}}$$

$$\mathrm{M}\left({\mathrm{F}}_{\mathrm{ml}}\right)\mathrm{=}{\mathrm{m}}_{\mathrm{k}}\mathrm{\cdot }\mathrm{R}\mathrm{\cdot }{\mathrm{cos\; \beta }}_{\mathrm{i}}\mathrm{\cdot }{\mathrm{z}}_{\mathrm{i}}$$

$${\mathrm{M}}_{\mathrm{k}\mathrm{,}\mathrm{ges}}={\mathrm{m}}_{\mathrm{k}}\cdot R{\displaystyle \sum _{i=1}^n}{z}_{\mathrm{i}}\cdot {\mathrm{cos\beta }}_{\mathrm{i}}$$

Moment Msw infolge Deviationsmoment $${\mathrm{M}}_{\mathrm{sw}}\mathrm{=}{\mathrm{J}}_{\mathrm{yz}}\mathrm{\cdot }{\mathrm{\omega }}^{\mathrm{2}}$$

$${\mathrm{J}}_{\mathrm{yz}}=\left\{\frac{\mathit{msw}}{2}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}})-\frac{\mathit{msw}}{4}({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}+\frac{h^2}{3}\right)\right\}\mathrm{cos\alpha \; sin\alpha }$$

$${\mathrm{J}}_{\mathrm{yz}}=\frac{\mathit{msw}}{24}\sin \mathrm{2}\mathrm{\alpha }\left({{3\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{3\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}+{\mathrm{h}}^2\right)$$

$${\mathrm{M}}_{\mathrm{sw}}\mathrm{\ge }{\mathrm{M}}_{\mathrm{k}\mathrm{,}\mathrm{ges}}$$

bzw. $$\underset{M_{\mathrm{kges}}}{\underbrace{\mathrm{[}{\mathrm{\omega }}^{\mathrm{2}}{\mathrm{R}}^{\mathrm{2}}\mathrm{\cdot }{\mathrm{m}}_{\mathrm{k}}\mathrm{tan\alpha }{\displaystyle \mathrm{\sum }_{\mathit{i}\mathrm{=}\mathrm{1}}^{\mathit{n}}}{\cos }^{\mathrm{2}}\mathrm{\beta }}}\leqq {\mathrm{\omega }}^{\mathrm{2}}\underset{M_{\mathrm{sw}}}{\underbrace{\frac{\mathit{msw}}{\mathrm{24}}\sin \mathrm{2}\mathrm{\alpha }\left(\mathrm{3}{{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}\mathrm{3}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}\mathrm{-}{\mathrm{h}}^{\mathrm{2}}\right)\mathrm{]}}}$$

The derivation of the so-called. Deviation moment is given below, which is relevant for the tilting of the swash plate or a swivel ring, and in the case illustrated is solely responsible for the tilting of the swash plate or the swivel ring under the condition that the center of gravity of the Swivel disk or the swivel ring is located both in the tipping 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 Fig. 3 : $${\mathrm{J}}_{\mathrm{Y\; Z}}\mathrm{=}\mathrm{-}{\mathrm{<figure-callout\; id="1"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{1}}\cos {\mathrm{\alpha }}_{\mathrm{2}}\cos {\mathrm{\alpha }}_{\mathrm{3}}\mathrm{-}{\mathrm{<figure-callout\; id="2"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{2}}\cos {\mathrm{\beta }}_{\mathrm{2}}\cos {\mathrm{\beta }}_{\mathrm{3}}\mathrm{-}{\mathrm{<figure-callout\; id="3"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{3}}\cos {\mathrm{\gamma }}_{\mathrm{2}}\cos {\mathrm{\gamma }}_{\mathrm{3}}$$

$$\begin{array}{l}{\mathrm{<figure-callout\; id="1"\; label="\alpha "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_{\mathrm{1}}\mathrm{=}\mathrm{0}\\ {\mathrm{<figure-callout\; id="1"\; label="\beta "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\beta </figure-callout>}}_{\mathrm{1}}\mathrm{=}\mathrm{90}\mathrm{°}\\ {\mathrm{<figure-callout\; id="1"\; label="\gamma "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\gamma </figure-callout>}}_{\mathrm{1}}\mathrm{=}\mathrm{90}\mathrm{°}\end{array}\mathrm{\}}\mathrm{Direction\; angle\; of\; the\; x}\mathrm{-}\mathrm{Axis\; against}\ddot{\mathrm{u}}\mathrm{About\; the\; main\; tr}\ddot{\mathrm{a}}\mathrm{\xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$$\begin{array}{l}{\mathrm{<figure-callout\; id="2"\; label="\alpha "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_{\mathrm{2}}\mathrm{=}\mathrm{90}°\\ {\mathrm{<figure-callout\; id="2"\; label="\beta "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\beta </figure-callout>}}_{\mathrm{2}}\mathrm{=}\mathrm{\psi }\\ {\mathrm{\gamma }}_{\mathrm{2}}\mathrm{=}\mathrm{90}\mathrm{°}+\mathrm{\psi }\end{array}\mathit{\}}\mathrm{Direction\; angle\; of\; the\; x}\mathrm{-}\mathrm{Axis\; against}\ddot{\mathrm{u}}\mathrm{About\; the\; main\; tr}\ddot{\mathrm{a}}\mathrm{\xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$$\begin{array}{l}{\mathrm{<figure-callout\; id="3"\; label="\alpha "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\alpha </figure-callout>}}_{\mathrm{3}}\mathrm{=}\mathrm{90}°\\ {\mathrm{<figure-callout\; id="3"\; label="\beta "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\beta </figure-callout>}}_{\mathrm{3}}\mathrm{=}90\mathrm{°}\mathrm{-}\mathrm{<figure-callout\; id="3"\; label="\psi \; \gamma "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\psi \; </figure-callout>}& \\ {\mathrm{\gamma }}_{}{\mathrm{}}_{\mathrm{3}}\mathrm{=}\mathrm{\psi }\end{array}\mathit{\}}\mathrm{Direction\; angle\; of\; the\; x}\mathrm{-}\mathrm{Axis\; against}\ddot{\mathrm{u}}\mathrm{About\; the\; main\; tr}\ddot{\mathrm{a}}\mathrm{\xi }\mathrm{\cdot }\mathrm{\eta }\mathrm{\cdot }\mathrm{\zeta }$$

$${\mathrm{<figure-callout\; id="2"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{2}}\mathrm{=}{\mathrm{J}}_{\mathrm{\eta }}=\frac{\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="imgf0003.png"\; state="\{\{state\}\}">m</figure-callout>}}{4}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{<figure-callout\; id="2"\; label="r\; i"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">r\; </figure-callout>}}_{\mathrm{i}}}^{\mathrm{2}}+\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{3}\right)$$

$${\mathrm{<figure-callout\; id="3"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{3}}\mathrm{=}{\mathrm{J}}_{\mathrm{\zeta }}=\frac{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">m</figure-callout>}}{2}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{<figure-callout\; id="2"\; label="r\; i"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">r\; </figure-callout>}}_{\mathrm{i}}}^{\mathrm{2}}\right)$$

( Note: J ₃ ≈ 2 J ₂
Goal: J _yz should have a certain size
J _yz ↑} J ₃ ↑ J ₂ inevitably increases!)
of inertia $${\mathrm{J}}_{\mathrm{Y\; Z}}\mathrm{=}\mathrm{-}{\mathrm{<figure-callout\; id="2"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{2}}\mathrm{cos\psi \; sin\psi }\mathrm{+}{\mathrm{<figure-callout\; id="3"\; label="J"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">J</figure-callout>}}_{\mathrm{3}}\mathrm{cos\psi \; sin\psi }$$

Independent of Fig. 3 applies:
Moment due to inertia of the pistons $${\mathrm{\beta }}_{\mathrm{i}}\mathrm{=}\mathrm{\theta }\mathrm{+}\mathrm{2}\mathrm{\pi }\left(\mathrm{i}-\mathrm{1}\right)\frac{1}{n}$$

$$\mathrm{Zi}\mathrm{=}\mathrm{R}\mathrm{\cdot }{\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\omega </figure-callout>}}^{\mathrm{2}}\mathrm{tan\alpha \; cos}{\mathrm{\beta }}_{\mathrm{i}}$$

$${\mathrm{F}}_{\mathrm{ml}}\mathrm{=}{\mathrm{m}}_{\mathrm{k}}\mathrm{\cdot }{\mathrm{z}}_{\mathrm{i}}$$

$$\mathrm{M}\left({\mathrm{F}}_{\mathrm{ml}}\right)\mathrm{=}{\mathrm{m}}_{\mathrm{k}}\mathrm{\cdot }\mathrm{R}\mathrm{\cdot }{\mathrm{cos\; \beta }}_{\mathrm{i}}\mathrm{\cdot }{\mathrm{z}}_{\mathrm{i}}$$

$${\mathrm{M}}_{\mathrm{k}\mathrm{.}\mathrm{ges}}={\mathrm{m}}_{\mathrm{k}}\cdot R{\displaystyle \underset{i=1}{\overset{n}{\Sigma }}}{z}_{\mathrm{i}}\cdot {\mathrm{cos\beta }}_{\mathrm{i}}$$

Moment Msw due to moment of deviation $${\mathrm{M}}_{\mathrm{sw}}\mathrm{=}{\mathrm{J}}_{\mathrm{Y\; Z}}\mathrm{\cdot }{\mathrm{\omega }}^{\mathrm{2}}$$

$${\mathrm{J}}_{\mathrm{Y\; Z}}=\left\{\frac{\mathit{<figure-callout\; id="2"\; label="msw"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">msw</figure-callout>}}{2}\left({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}})-\frac{\mathit{msw}}{4}({{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{\mathrm{<figure-callout\; id="2"\; label="r\; i"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">r\; </figure-callout>}}_{\mathrm{i}}}^{\mathrm{2}}+\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{3}\right)\right\}\mathrm{cos\alpha \; sin\alpha }$$

$${\mathrm{J}}_{\mathrm{Y\; Z}}=\frac{\mathit{msw}}{24}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">sin</figure-callout>}\mathrm{2}\mathrm{\alpha }\left({{3\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}{{3\mathrm{<figure-callout\; id="2"\; label="r\; i"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">r\; </figure-callout>}}_{\mathrm{i}}}^{\mathrm{2}}+{\mathrm{H}}^2\right)$$

$${\mathrm{M}}_{\mathrm{sw}}\mathrm{\ge }{\mathrm{M}}_{\mathrm{k}\mathrm{.}\mathrm{ges}}$$

respectively. $$\underset{M_{\mathrm{kges}}}{\underset{\}}{\mathrm{[}{\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">\omega </figure-callout>}}^{\mathrm{2}}{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">R</figure-callout>}}^{\mathrm{2}}\mathrm{\cdot }{\mathrm{m}}_{\mathrm{k}}\mathrm{tan\alpha }{\displaystyle \underset{\mathit{i}\mathrm{=}\mathrm{1}}{\overset{\mathit{<figure-callout\; id="2"\; label="n\; cos"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">n\; </figure-callout>}}{\mathrm{\Sigma }}}}{\cos }^{}{}^{\mathrm{2}}\mathrm{\beta }}}\leqq {\mathrm{\omega }}^{\mathrm{2}}\underset{M_{\mathrm{sw}}}{\underset{\}}{\frac{\mathit{msw}}{\mathrm{24}}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="imgf0001.png,imgf0003.png"\; state="\{\{state\}\}">sin</figure-callout>}\mathrm{2}\mathrm{\alpha }\left(\mathrm{3}{{\mathrm{r}}_{\mathrm{a}}}^{\mathrm{2}}\mathrm{+}\mathrm{3}{{\mathrm{r}}_{\mathrm{i}}}^{\mathrm{2}}\mathrm{-}{\mathrm{H}}^{\mathrm{2}}\right)\mathrm{]}}}$$

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

δ

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 (δ, 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

δ

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 (δ, r, h) mass moment of inertia

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

It can be seen that the influence of the piston masses predominates and thus the aufregelnde behavior of the oblique or. Pivoting disc at increasing speed results.

It is therefore the case M _{k, ges} > M _SW

In Fig. 2 is a diagram for a nearly identical engine specified, this diagram is based on the following calculation scheme, where also α was varied from 0 ° to 16 °:

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

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

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

• at speed increases the tilt angle of the swash plate remains largely constant, ie M _SW = M _{k, ges} ; respectively.
• at speed increases the tilt angle of the swash plate is reduced, 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 aim of the present invention that

• in speed increases, the delivery rate is not increased to the same extent, but that the capacity remains approximately constant, especially in the range of medium and high speeds.

• die Unwucht der rotierenden Teile möglichst gering gehalten wird.

Finally, of course, should be taken to ensure that

• the imbalance of the rotating parts is kept as low as possible.

This object is achieved by the characterizing features of claim 1, wherein advantageous developments and structural details of the invention are described in the dependent claims.

• 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 according to Fig. 4 equivalent. That is, the speed of the compressor increases, so remains the

• Tilt angle of the swash plate almost constant, or
• it decreases, whereby at least a part of the resulting alone by the speed increase increasing capacity is compensated.

The representation in Fig. 4 the following calculation is used:

According to the invention, therefore, a construction is selected in which an additional mass, in particular additional disc or ring is coupled to the swashplate mechanism, whose or its erecting tilting moment due to his or her Deviationsmoments cooperating with the erecting tilting moment due to the Deviationsmoments the swash plate.

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 moment of deviation of the swashplate, specifically the deviation moment J _yz 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 formed on the swash plate, which triggers a corresponding additional Deviationsmoment.

The additional mass, preferably in the form of an additional disk or an additional ring is advantageously optimized such that the ratio "mass moment of inertia / component mass" is as large as possible. The component mass should therefore be as low as possible with maximum mass moment of inertia. To achieve this, is suitable as additional mass in particular an additional ring with an outer diameter, which only slightly smaller than the inner diameter of the engine casing. Preferably, the outer circumference of the additional ring is designed to be spherical in cross-section in order to avoid a collision between the auxiliary ring and the engine housing when pivoting the additional ring about its tilt axis. Also, the distance between the auxiliary ring and the housing inner wall should be substantially constant regardless of the tilted position of the additional ring.

Furthermore, the center of gravity of the additional mass, e.g. an additional ring preferably lie on the drive shaft center axis. It is also advantageous if the tilt center of the additional mass coincides with its center of mass.

• Das mechanische Regelverhalten (Kippcharakteristik des Verdichters) wird im wesentlichen durch das Moment der zusätzlich vorgesehenen Masse, z.B. Scheibe oder Ring beeinflusst. 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 SchwenkscheibenKippwinkel "alpha" nicht derart stark gekrümmt, 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 können mit vergleichsweise geringer Bauteilmasse die für gewünschte Regelcharakteristik erforderlichen hohen Massenträgheitsmomente bereitgestellt werden, 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, ist in Bezug auf die Schwenkscheibe nicht mehr erforderlich, diese konstruktiv mit entsprechenden Massenträgheitsmomenten auszustatten. Dadurch kann auch die Unwucht dieses Teiles minimiert werden.
• Durch die Erfindung lässt sich bei entsprechender Dimensionierung der Zusatzmasse, insbesondere in Form eines Zusatzrings, nahezu jedes gewünschte Regelverhalten erreichen, ohne dass größere Unwuchten entstehen.
• Durch die erfindungsgemäßen Maßnahmen wird ein günstiges dynamisches Verhalten erreicht, welches durch vermindertes Aufschwingen und Gegenregeln mittels Ventilen gekennzeichnet ist.
• Fig. 4 läßt erkennen, dass die Kennlinien eine geringe Streuung aufweisen. Dadurch kann bei der Auslegung des Verdichters jeder Betriebspunkt optimal berücksichtigt, d.h. im Kennfeld platziert 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 lies in the following:

• 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, the control characteristics of the individual rotational speeds in the diagram "engine room pressure p" over the swashplate tilt angle "alpha" are not as strongly curved, as is the case with compressors according to the prior art. This is achieved by having the center of gravity less far away from the tilting joint and reducing the mass of the unbalanced part (swashplate).
• In the case of the additional component, the high moments of inertia required for the desired control characteristic can be provided with a comparatively low component mass, as a result of which the necessary high deviation moment is obtained. Such behavior is achieved by a ring shape of the additional mass with the largest possible average diameter.
• The fact 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, with respect to the swash plate is no longer required, this constructive equipped with appropriate mass moments of inertia. As a result, the imbalance of this part can be minimized.
• With the invention, with appropriate dimensioning of the additional mass, in particular in the form of an additional ring, almost any desired control behavior can be achieved without causing major imbalances.
• The inventive measures a favorable dynamic behavior is achieved, which is characterized by reduced swinging and countermeasures by means of valves.
• Fig. 4 indicates that the characteristics have a low dispersion. 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.

Fig. 5

einen Verdichter gemäß Erfindung im Längsschnitt, wobei das Triebwerk sich in einer Stellung für maximalen Kolbenhub befindet;

Fig. 6

den Verdichter entsprechend Fig. 5, wobei das Triebwerk sich in einer Stellung befindet, in der der Kolbenhub minimal ist;

Fig. 7

das Triebwerk des Verdichters gemäß den Fig. 5 und 6 in perspektivischer Explosionsdarstellung;

Fig. 8a - 12b

Regelverhalten von Verdichtern mit und ohne Zusatzmasse gemäß Erfindung; und

Fig. 13

Beispielhafte Darstellung des Verlaufs der Deviationsmomente J_yz1 und J_yz2 von Schwenkscheibe und Zusatzmasse über den Kippwinkel der Schwenkscheibe.

An embodiment of a compressor designed according to the invention will be explained below with reference to the attached drawing. This shows in:

Fig. 5

a compressor according to the invention in longitudinal section, wherein the engine is in a position for maximum piston stroke;

Fig. 6

corresponding to the compressor Fig. 5 wherein the engine is in a position where the piston stroke is minimal;

Fig. 7

the engine of the compressor according to the Fig. 5 and 6 in a perspective exploded view;

Fig. 8a - 12b

Control behavior of compressors with and without additional mass according to the invention; and

Fig. 13

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 in the Fig. 5 and 6 in longitudinal section axial piston compressor for the air conditioning of a motor vehicle comprises an engine housing 10 which is cup-shaped and at the peripheral edge of a cylinder block 12 connects. Inside the cylinder block 12 a plurality of, preferably 5, 6 or 7 axially reciprocating pistons are arranged, wherein the distribution of the pistons around the housing center axis 18 around is uniform. Through the bottom of the cup-shaped housing 10 through a driven via a pulley 21 drive shaft 11 extends into the housing interior or in the engine room into it. The storage of the drive shaft takes place, on the one hand, in the region of the bottom of the cup-shaped housing 10 and, on the other hand, within the cylinder block 12. The engine compartment bounded by the housing 10 is identified by the reference numeral 22. Within the same is a swash plate mechanism is effective, by which the rotational movement of the drive shaft 11 is converted into axial movement of the piston 13. For this purpose, a swash plate 14 engages with its peripheral edge via a hinge assembly in C-shaped recesses on the back of the piston 13 a. As in the prior art, the joint arrangement is defined by two spherical segment-like joint stones 16, 17, between which the swash plate 14 slidably engages. The spherical bearing surfaces of the hinge blocks 16, 17 are associated with corresponding spherical recesses on the mutually facing end faces of the C-shaped recesses of the piston 13.

The swash plate 14 is supported on a rotatably connected to the drive shaft 11 driver 20, preferably via roller ball, barrel or needle roller bearings, both axially and radially.

The tilt angle of the swash plate 14 is between the positions according to Fig. 5 and according to Fig. 6 changeable, with in Fig. 5 the tilt angle of the swash plate 14 maximum and in Fig. 6 is minimal. Accordingly, the stroke of the piston 13 is maximum or minimum.

The swash plate 14 is assigned an additional mass in the form of an additional ring 15 such that swash plate 14 and additional ring 15 tilt in the same way. The swash plate and the additional ring each provide a deviation moment I _yz , which in turn both initiate a tilting moment in the joint of the swash plate 14 (M _SW = ω ² * I _yz ). This then results in an equilibrium or mass ratios which are determined according to the equation M _{k, ges} = (or <) M _SW1 + M _SW2 . In principle, of course, other coupling mechanisms are conceivable in which there are deviations in the above equation, as shown above. In the present case, therefore, the swash plate 14, which provides an insufficient moment of inertia or Deviationsmoment for a desired control behavior, supported by a further component, namely the auxiliary ring 16, which also provides a Deviationsmoment.

In the illustrated embodiment, the Deviationmomentes of swash plate 14 and auxiliary ring 15 are largely rectified. Both components cause a negative moment (see above for definitions), ie M _SW / M _{SW1 /} M _SW2 have a negative effect. It should be noted that at very small tilt angles quite a "Aufregeln" may arise (but not necessarily). This depends on the concrete construction.

A characteristic is obtained in accordance with the illustrated embodiment Fig. 4 , The Deviationsmomente of swash plate 14 and auxiliary ring 15 are preferably dimensioned so that the sum M _{SW of} the overturning moments M _SW1 + M _SW2 due to the aforementioned Deviationsmomente greater than or equal to the moment M _{k, ges} due to all translationally moving masses, namely piston 13 and sliding blocks 16, 17 is. Preferably, the additional ring 15 is dimensioned so that it has a greater Deviationsmoment than the Deviationsmoment the swash plate 14th

Like a comparison of Fig. 5 With Fig. 6 can be seen, the additional ring 15 is slidably supported or stored in the direction parallel to the swivel plate plane relative to the swash plate. In this respect, additional ring 15 and swash plate 14 are mechanically decoupled.

The leadership of this relative movement is ensured on the side of the additional ring 15 by a parallel to the swash plate plane extending guide pin 19 which is slidably mounted on the rotatably connected to the drive shaft 11 driver 20.

In the Fig. 5 and 6 is designated by the reference numeral 23 nor a cylinder head. Between cylinder head 23 and cylinder block 12 intake and exhaust valves are arranged in a conventional manner.

Fig. 7 shows the engine according to the Fig. 5 and 6 in exploded view.

It should also be mentioned at this point that the swash plate 14 is tiltable about a spherical segment ring 24 which is mounted longitudinally displaceably on the drive shaft 11 and is held by a helical compression spring in the operating position.

The additional ring 15 is, in particular Fig. 7 can recognize, on the driver 20, in particular hinged to a yoke 26. The corresponding hinge pin is identified by the reference numeral 27. This ensures that the association between additional ring 15 and swash plate 14 is maintained.

The Fig. 8a and 8b show the control behavior of a compressor with additional mass ( Fig. 8a ) or without additional mass ( Fig. 8b ). It can be seen that with the help of the additional mass, the characteristics are close to each other, as in Fig. 8a is shown. The control behavior is such that almost a certain independence of the Tilt angle of the speed results (M _SW ≈ M _{k, ges} ). The behavior according to Fig. 8a (with additional mass) is slightly aufregelnd compared to the behavior without additional mass accordingly Fig. 8b , The characteristics are in Fig. 8a, 8b as well as in the Fig. 9a, 9b . 10, 11 and 12a, 12b 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), via the delivery or displacement volume "V" (or alternatively on the tilt angle of the Swash plate 14 are applied.

Similar results from a comparison of Fig. 9a and 9b , in which Fig. 9a the behavior with additional mass and Fig. 9b without additional mass shows.

In the proportions according to FIGS. 10a (with additional mass), a behavior which regulates is shown; 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 Fig. 10a). 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 Fig. 11 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 (Fig. 8a/9a (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; (Fig. 11/12a/12b)
  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, tot} (the characteristic curves may be approximately 1-2 bar apart) for αmin <α <αmax ( Fig. 8a / 9a (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; ( Fig. 11 / 12a / 12b )
  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 Fig. 12a, 12b 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 25. A lower spring rate would remove the characteristics slightly more from the X-axis.

In particular, due to the last-mentioned feature, a spring constant in the range 30... 200 N / mm is claimed in connection with the additional mass, in particular 30... 90 N / mm and preferably about 60 N / mm.

To explain it should be mentioned that the Fig. 12a as well as the Fig. 12b show the behavior with additional mass.

Fig. 13 shows, by way of example, how according to the invention the deviation moment _{Y yz2 of} the additional mass and the deviation moment J _{yz1 of} the _swashplate are substantially rectified over the tilting angle thereof. Of course, the exact course of the deviation moments depends on the construction or geometry of swashplate and additional mass. The Fig. 13 also shows that for larger tilt angles, here> 16 °, J _yz2 > J _yz1 . Furthermore, lets Fig. 13 still recognize that up to a tilt angle of about 4 ° to 5 °, the Deviationsmomente of swashplate and additional mass approximately linearly increase linearly. As the tilting angle increases, the course of the deviation moment J _{yz1 of} the _{swashplate is equalized} , ie the swashplate then acts "in a regulating manner". The course of the deviation moment J _{yz2 of} the additional mass increases substantially linearly.

Of course it is Fig. 13 an example, which qualitatively reflects the basic idea of the described doctrine. By constructive changes of the swash plate and / or additional mass, the two deviation curves can be influenced and relative to each other in a predetermined manner shift in order to obtain according to predetermined control behavior of the compressor.

All disclosed in the application documents features are claimed as essential to the invention, as far as they are new individually or in combination over the prior art.

reference numeral

10

casing

11

drive shaft

12

cylinder block

13

piston

14

swash plate

15

Additional ring (additional mass)

16

slide

17

slide

18

Drive shaft center axis or housing center axis

19

guide pin

20

takeaway

21

pulley

22

Machine Room

23

cylinder head

24

Spherical segment ring

25

Helical compression spring

26

yoke

27

pintle

Claims (8)

1. Axial piston compressor, especially a compressor for the air-conditioning unit of a motor vehicle, with a housing (10) and a compressor unit disposed within the housing (10) and driven by a drive shaft (11) for the intake and compression of a cooling medium, wherein the compressor unit comprises pistons (13) displaceable axially to and fro within a cylinder block (12) and a captive-C-washer (captive-C-ring, swash plate or wobble plate (14)) driving the pistons and rotating with the drive shaft (11),
   wherein
   a supplementary mass, especially in the form of a supplementary washer or a supplementary ring (15) is allocated to the captive-C-washer (14), by means of which a deviation moment (J_yz2) acting largely in the same direction as the deviation moment (J_yz1) of the captive-C-washer (14) is obtained, in such a manner, that the sum (M_SW) of the tilting moments (M_SW1+M_SW2) is greater than or equal to the moment (M_k,ges) resulting from all translatory masses, especially pistons (13), optionally including sliding blocks (16, 17), piston rods or similar,
   characterised in that
   the centre of gravity of the supplementary mass (15) is disposed on the central axis (18) of the drive shaft, and that,
   in the design of the supplementary mass as a supplementary ring (15) capable of being rotated with the captive-C-washer (14), the centre of gravity of the supplementary ring is disposed in the region of its tilting joint.
2. Axial piston compressor according to claim 1,
   characterised in that
   the supplementary mass (15) is capable of being displaced to and fro parallel to the longitudinal axis of the drive shaft (11), especially together with the captive-C-washer (14).
3. Axial piston compressor according to any one of claims 1 or 2,
   characterised in that
   the deviation moment (J_yz2) of the supplementary mass (15) is greater than the deviation moment (J_yz1) of the captive-C-washer (14) over a substantial tilting-angle range of the captive-C-washer (14), wherein, with a relatively-large tilting angle, especially a tilting angle larger than approximately 12° to 18°, in particular, approximately 15°, the deviation moment (J_yz1) of the captive-C-washer is preferably smaller than the deviation moment (J_yz2) of the supplementary mass.
4. Axial piston compressor according to any one of claims 1 to 3,
   characterised in that,
   in the design of the supplementary mass as a supplementary ring (15), the supplementary ring provides an external diameter, which is only slightly smaller than the internal diameter of the drive housing (10).
5. Axial piston compressor according to claim 4,
   characterised in that
   the outer peripheral edge of the supplementary ring (15) is designed with a crowned cross-section, in such a manner that, while maintaining a minimum distance relative to the internal wall of the drive-housing, a collision with the latter during rotation is precluded.
6. Axial piston compressor according to any one of claims 1 to 5,
   characterised in that
   the supplementary mass, especially the supplementary ring (15), is mounted relative to the captive-C-washer (14) to be displaceable in the direction parallel to the plane of the captive-C-washer.
7. Axial piston compressor according to claim 6,
   characterised in that
   the supplementary mass or respectively the supplementary ring (15) is held in a displaceable manner by a guide pin (19) extending parallel to the axis of the captive-C-washer on a driving pin (20) connected in a rotationally-rigid manner to the drive shaft (11).
8. Axial piston compressor according to any one of claims 1 to 7,
   characterised in that
   the supplementary mass extends at least partially around the captive-C-washer (14), especially in a concentric manner around its central axis.

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