Radial piston compressor

Abstract

The invention relates to a radial piston compressor, comprising a compressor unit (1) and a drive device (2) for driving the compressor unit (1), wherein the compressor unit (1) comprises at least one piston-working-chamber combination, preferably a plurality of piston-working-chamber combinations (13), the piston-working-chamber combination (13) being received in a cylinder housing (16) and comprising a working chamber having a piston (132) which can be moved therein, and the working chamber is equipped with an inlet valve cover (15), which is received in a corresponding receiving area (18) of the cylinder housing (16) by means of a press fit, the inlet valve cover (15') being equipped with a circumferential load-relieving notch (152) along the edge of the inlet valve cover.

Description

[0001] radial piston compressor

[0002] The present invention relates to a radial piston compressor according to the preamble of claim 1.

[0003] A radial piston compressor is a component of fluid power technology. In contrast to an axial piston compressor, in this type of compressor at least one piston-working chamber combination is arranged radially and perpendicular to the drive shaft. A radial piston compressor can also be referred to as a compressor based on the radial piston principle.

[0004] The piston's conveying or reciprocating motion is usually generated by an eccentric. Therefore, the drive shaft with the eccentric can also be referred to as an eccentric shaft. A radial piston compressor typically comprises several piston-working chamber combinations radiating outwards from the eccentric shaft in a star-shaped pattern.

[0005] A piston-working chamber combination essentially comprises a working chamber, also called a cylinder, and a piston that moves up and down within the working chamber. The piston has a central geometric axis that coincides with the piston's direction of movement. In a radial piston compressor with an eccentric shaft, the piston has a contact point on its side facing the eccentric shaft. During the rotation of the eccentric shaft, the eccentric disk strikes or rests against this contact point. The eccentric shaft has an axis of rotation around which it rotates. When the eccentric disk strikes the piston or a transmission element, it causes the piston to move upwards, compressing the medium in the working chamber.

[0006] Radial piston compressors are used, for example, to compress refrigerants in the air conditioning systems of motor vehicles, especially in electric vehicles. A refrigerant such as CO2 can be used as the medium to be compressed. However, other media and refrigerants are also conceivable.

[0007] A radial piston compressor of the aforementioned type is known, for example, from DE 10 2021 204 713 Al.

[0008] This section describes, in particular, an intake valve cover as the seal between the compressor chamber and the cylinder housing of a radial piston compressor. All seven intake valve covers are held against the cylinder housing by a retaining ring, which simultaneously makes contact with them, specifically with a radial preload of at least 3 kN per cover contact. The retaining ring thus prevents the intake valve covers from lifting off the cylinder housing. To ensure a seal between the intake valve cover and the cylinder housing, an O-ring acts as a sealing element between the intake valve cover and the cover bore.

[0009] A potential disadvantage is that the O-ring, under pressure – up to 150 bar in the high-pressure range – absorbs CO2 gas into its structure, and this can lead to material damage – explosive decompression – if the pressure drops rapidly within the O-ring. Since the pressure in the cylinder is highly dynamic (frequencies above 100 Hz, pressure from 20 to 150 bar), this O-ring is particularly vulnerable to damage. This means that the sealing effect of the O-ring diminishes with increasing compressor operating time; in the worst case, it ceases to function altogether. Furthermore, the O-ring groove in the intake valve cover is a geometric element that is either very expensive to manufacture using the sintering process or can only be implemented with compromises in functionality (tool parting at the base of the sealing ring groove, etc.).

[0010] The object of the present invention is accordingly to propose an improved radial piston compressor, in particular a radial piston compressor which is characterized by a simple and cost-effective solution for sealing the inlet valve cover for installation in the cylinder housing, without compromising functionally critical features of the compressor unit.

[0011] According to the invention, this problem is solved by a radial piston compressor with the characterizing features of claim 1. By providing the inlet valve cover with a circumferential relief notch on its edge, the problem outlined above can be solved; in particular, a simple and cost-effective solution for sealing the inlet valve cover to its receptacle in the cylinder housing can be provided without compromising functionally critical features of the radial piston compressor, especially the compressor unit. In other words, a sealing concept for the radial sealing of the inlet valve cover to its receptacle is proposed in which the sealing pressure arises from an interference fit between the inlet valve cover and the receptacle, whereby the deformation / deflection is mainly directed into the inlet valve cover, and thus functionally relevant surfaces on the cylinder housing experience only minimal deformation.This flexibility is achieved on the intake valve cover via a circumferential relief groove, which, in combination with a thin wall in the press-fit area, provides a high degree of flexibility. It is therefore specifically designed that the sealing function of the intake valve cover to the cover bore is achieved via a longitudinal press fit, whereby more than 70% of the deformation from the joint pressure is transferred to the deformation of the intake valve cover itself. It is therefore specifically designed that the intake valve cover is very flexible in the area of ​​the press fit, with a circumferential relief groove running "behind" the wall. The proposed measures eliminate the need for an additional sealing element, such as an O-ring. This results in significant cost and functional advantages.The sealing effect can be achieved, for example, by means of a press fit between the intake valve cover and the cylinder housing, with tolerances that can be manufactured in series production, in particular IT7; IT8. The deformation at functionally important features of the cylinder housing, especially its functional surfaces, is kept low due to the compliant intake valve cover.

[0012] Further advantageous embodiments of the proposed invention arise in particular from the features of the dependent claims. The subject matter or features of the various claims can, in principle, be combined with one another in any way.

[0013] In an advantageous embodiment of the invention, the relief notch, viewed radially from the longitudinal axis of the intake valve cover, first comprises a side flange and then a press-fit collar, with a clearance between the side flange and the press-fit collar. The outer wall of the press-fit collar rests against the circumferential inner wall of the receptacle, forming a press fit. The clearance is bridged by a groove base that is significantly thinner than the intake valve cover. Essentially, this creates a kind of elastic collar around the intake valve cover, which is more elastic than the rest of the intake valve cover.

[0014] In a further advantageous embodiment of the invention, the receptacle can be designed as a circular recess in the cylinder housing, comprising an inner wall which, together with the press-fit collar of the received intake valve cover, forms an interference fit. The intake valve cover is also designed accordingly, and therefore preferably has a circular shape.

[0015] In a further advantageous embodiment of the invention, the press fit can have a thickness of 0.4 mm to 1 mm, particularly 0.6 mm. This provides suitable compliance for the press fit. The desired compliance of the cover in the area of ​​the press fit, relative to the compliance of the mating part, should be determined by simulation, taking into account the structure of the mating part. Wall thicknesses of 0.4 mm to 1 mm have proven advantageous during machining. Such a wall thickness is beneficial for the deformation of the cover fit. The thicker the wall thickness of the press fit on the cover, the greater the proportion of deformation that is transferred to the cylinder housing. The thin area near the exhaust valve is particularly critical in this regard.

[0016] In a further advantageous embodiment of the invention, the side plate can be tilted at an angle of 15° to 45°, approximately 30°, preferably 30°, to the longitudinal axis of the inlet valve cover. This allows for a sufficiently stable cutting edge geometry to be used during the manufacturing process.

[0017] In a further advantageous embodiment of the invention, the radial piston compressor may comprise at least two piston-working chamber combinations extending radially from a drive shaft, with an inlet valve cover arranged in a corresponding receptacle on each working chamber. The radial piston compressor is equipped with at least one retaining ring for securing all inlet valve covers, and the inlet valve covers are provided with at least one contact point for bearing against the retaining ring. It is generally advantageous to secure all inlet valve covers of the radial piston compressor with a single retaining ring. If only one contact point exists between the respective inlet valve cover and the retaining ring, no torques can act on the inlet valve cover through the retaining ring during assembly.Accordingly, no additional measures need to be taken to secure the intake valve cover against rotation.

[0018] In a further advantageous embodiment of the invention, the inlet valve covers can be provided with two contact points for bearing against the retaining ring, wherein the inlet valve cover is secured against rotation in the receptacle by positive locking elements. The positive locking element on the cover can, for example, be a spring, which is particularly designed laterally. A lug, which is particularly designed on the underside of the cover, is also conceivable as a positive locking element on the cover.

[0019] In a further advantageous embodiment of the invention, it can be provided that the inlet valve cover comprises a fluid inlet and an inlet valve, wherein the inlet valve comprises a valve plate with a valve plate tongue, wherein the valve tongue is connected to the valve plate by means of bending beams, and wherein the inlet valve cover is equipped with a relief for the bending beams.

[0020] In a further advantageous embodiment of the invention, it can be provided that the two contact points for attachment to the retaining ring are provided by means of a circular recess on the inlet valve cover.

[0021] In a further advantageous embodiment of the invention, it can be provided that the two contact points for contact with the retaining ring are provided by means of a flat top surface of the inlet valve cover, wherein the radius for the contact contour lies in the longitudinal axis of the inlet valve cover.

[0022] Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying figures. These show

[0023] Fig. 1 shows a radial piston compressor according to the prior art in a side sectional view;

[0024] Fig. 2 shows a radial piston compressor according to the prior art in a sectional view from the front;

[0025] Fig. 3 shows a radial piston compressor according to the prior art in a sectional view from the front;

[0026] Fig. 4 shows an enlarged view of a section of a radial piston compressor according to Fig. 3.

[0027] Fig. 5 Details of a radial piston compressor according to the prior art with retaining ring in a perspective view;

[0028] Fig. 6 shows an inlet valve cover for a radial piston compressor according to the invention in a cutaway side view;

[0029] Fig. 7 shows an inlet valve cover for a radial piston compressor according to the invention in a perspective view;

[0030] Fig. 8 shows an inlet valve cover for a radial piston compressor according to the invention in a perspective view;

[0031] Fig. 9 shows a detail of a radial piston compressor according to the invention, in particular the inlet valve cover in its mounting;

[0032] Fig. 10 shows a valve plate, in particular an inlet valve plate, in a perspective view;

[0033] Fig. 11 shows a detail of a radial piston compressor according to the invention, in particular the inlet valve cover in its mounting;

[0034] Fig. 12 shows a detail according to Fig. 11;

[0035] Fig. 13 shows a top view of the cylinder housing of a radial piston compressor according to the invention to illustrate a possible twisting of the cover during the assembly of the retaining ring;

[0036] Fig. 14 shows an inlet valve cover of a radial piston compressor according to the invention with two contact points;

[0037] Fig. 15 shows an inlet valve cover with a positive locking element in a perspective view;

[0038] Fig. 16 shows a perspective view of an intake valve cover with a form element; Fig. 17 shows a perspective view of an intake valve cover with a positive locking element;

[0039] Fig. 18 shows a view of an inlet valve cover with a molded element;

[0040] Fig. 19 shows an inlet valve cover for a radial piston compressor according to the invention with a clearance in the area of ​​the bending beam of the valve plate, in particular the inlet valve plate;

[0041] Fig. 20 a valve plate with bending beam of the valve plate tongue;

[0042] Fig. 21 shows an inlet valve cover with a cutout to create two contact points in a side sectional view;

[0043] Fig. 22 shows an inlet valve cover with a cutout to create two contact points in a top view;

[0044] Fig. 23 shows an intake valve cover in which the radius for the contact contour lies in the axis of the intake valve cover in a side view;

[0045] Fig. 24 shows an inlet valve cover according to Fig. 23 in a side cut view.

[0046] The following reference symbols are used in the illustrations:

[0047] A axis of rotation

[0048] K Piston axis

[0049] L Valve cover longitudinal axis

[0050] P Pass diameter a Angle of the side wall

[0051] D Thickness of the press collar bK Width at the base of the relief notch

[0052] IP Press length (press cover) t E Depth of the relief notch

[0053] M moment r lever arm

[0054] F force

[0055] 1 compressor unit

[0056] 2 Drive unit

[0057] 3. Upper edge of the exhaust valve sealing surface, retaining ring

[0058] exhaust valve plate

[0059] Inlet chamfer on the intake valve cover 15

[0060] Introduction phase at the inlet 18

[0061] Positive locking element

[0062] Release (for bending beams)

[0063] Cutout (for contact points) A parallel, flat contour for finishing in one step B entry point for radius of the high points

[0064] drive shaft

[0065] Eccentric disc

[0066] Piston-working chamber combination af further piston-working chamber combination

[0067] Piston guide ring

[0068] Intake valve cover, further intake valve covers, intake valve cover with relief notch

[0069] Cylinder housing

[0070] High-pressure lid

[0071] Recess for intake valve cover

[0072] Drive housing 1 Eccentric bearing 1 Working chamber (cylinder bore) 2 Piston 3 Transmission element 1 Seal 2 Relief notch 1 Shoulder 2 Inner wall 241 Fluid inlet

[0073] 242 Inlet valve

[0074] 243 Fluid outlet / outlet valve

[0075] 1521 Pressbund

[0076] 1522 site area

[0077] 1523 Side cheek

[0078] 1524 free space

[0079] 1525 Excavation in the area of ​​the outlet channel

[0080] 1526 Contact point / contact area

[0081] 1526A contact point / contact area

[0082] 1527 Mounting hole

[0083] 1528 Nutgrund

[0084] 2421 Valve plate

[0085] 2422 Valve tongue

[0086] 2423 Bending beams

[0087] Features and details described in connection with a method naturally also apply to the device according to the invention, and vice versa, so that the disclosure regarding the individual aspects of the invention always makes or can make reciprocal reference. Furthermore, any described method according to the invention can be carried out with the device according to the invention.

[0088] The terminology used herein serves only to describe certain embodiments and is not intended to limit the disclosure. As used herein, the singular forms "a" and "the" are intended to include the plural forms unless the context otherwise makes clear. It will also be clear that the expressions "indicates" and / or "indicating," when used in this description, specify the presence of the aforementioned features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the expression "and / or" includes any and all combinations of one or more of the associated, listed elements.

[0089] First, reference is made to Figures 1 and 2.

[0090] A radial piston compressor essentially comprises a compressor unit 1 and a drive unit 2. The radial piston compressor includes a housing, which can be composed of individual housing components, such as, for example, in the present embodiment, a drive housing 21, a cylinder housing 16, and a high-pressure cover 17. Other housing configurations are also conceivable.

[0091] The compressor unit 1 comprises a drive shaft 11 with an eccentric disc 12. The combination of drive shaft 11 and eccentric disc 12 can also be referred to as an eccentric shaft. The drive shaft 11 has an axis of rotation A. The compressor unit comprises at least one piston-working chamber combination 13, preferably several piston-working chamber combinations 13, 13a, 13b... 13f, arranged radially around the drive shaft 11. The piston-working chamber combination 13 can also be described as having a star-shaped arrangement around the drive shaft 11. The piston-working chamber combination 13 comprises a working chamber 131 with a piston 132 slidably arranged therein. The piston 132 has a piston axis K. The direction of displacement of the piston 132 corresponds to the piston axis K. The working chamber 131 can also be referred to as a cylinder or cylinder bore.Accordingly, the piston-working chamber combination can also be referred to as a piston-cylinder combination or piston-cylinder assembly. The working chamber 131 is equipped with an inlet valve cover 15 on the cylinder head side. The working chambers 131 of the piston-working chamber combinations 13 can be formed, at least partially, from the cylinder housing 16.

[0092] The drive shaft 11, in turn, can be set in rotation by the drive unit 2, which can, for example, be designed as an electric motor. As the drive shaft 11 rotates, the eccentric disk 12 engages the piston 132 and moves it within the working chamber 131, thereby compressing the medium in the working chamber, for example, a refrigerant. The return movement of the piston 132 can be effected, for example, by a piston guide ring 14 in contact with the piston 132. In this way, the piston 132 can be moved back to bottom dead center (BDC) until the eccentric disk 12 again engages the piston crown. The piston 132, in particular the piston crown, can also be equipped with a transmission element 133, or a transmission element 133 can be arranged between the eccentric disk 12 and the piston 132.The transmission element 133 transfers the stroke of the eccentric disc 12 to the piston 132, enabling the piston to perform the compression movement towards top dead center (TDC). The transmission element 133 can be made of a different material than the piston 132 and eccentric disc 12, particularly plastic. This can, for example, reduce wear or provide some damping when the eccentric disc 12 impacts the piston. The eccentric disc 12 can also be equipped with an eccentric bearing 121, particularly a needle bearing.

[0093] The further details and operation of a radial piston compressor are sufficiently known to those skilled in the art. For further details, reference can be made, for example, to DE 10 2020 211 680 A1.

[0094] Particular reference is made below to Figures 3 to 5.

[0095] The intake valve cover 15 is received in a receptacle 18 above the respective working chamber 13. The receptacle 18 is designed as a recess in the cylinder housing 16 and includes a shoulder 181 for supporting the intake valve cover 15. The receptacle 18 also includes a circumferential inner wall 182 with which the intake valve cover 15 can form a press fit.

[0096] The shape of the recess 18 ultimately depends on the shape of the intake valve cover 15, such that an interference fit can be created between the circumferential edge of the intake valve cover 15 and the circumferential inner wall 182 of the recess 18. A circular cylindrical recess 18 and a flat circular cylindrical intake valve cover 15 are shown here. The circular cylindrical recess 18 can also be referred to as a cover bore.

[0097] The inlet valve cover 15 further comprises a fluid inlet 241 with an inlet valve 242. The inlet valve 242 is configured to selectively close or open the fluid inlet 241.

[0098] The fluid to be compressed flows into the working chamber 131 via the fluid inlet 241 or the inlet valve 242, is compressed there by the stroke of the piston 132, and leaves the working chamber 131 through an outlet valve 243 or fluid outlet. The design of the valves, for example as spring-loaded valves, is well known to those skilled in the art and requires no further explanation here.

[0099] Figure 4, in particular, illustrates the system pressures acting on the intake valve cover 15 and the pressure surfaces involved, which are arranged radially to the drive shaft 1. The intake valve cover 15 also includes a seal 151. The intake valve 242 essentially comprises a valve plate 2421 with a valve tongue 2422. The valve tongue 2422 is resiliently connected to the valve plate 2421 via bending beams 2423. The valve plate 2421 rests at its edge on the shoulder 181 of the receptacle 18 and is pressed onto the shoulder 181 by the intake valve cover 15.

[0100] When the piston 132 moves from its upper end position to its lower end position, a vacuum is created in the working chamber between the piston head and the inlet valve cover. The inlet valve 242 opens into the working chamber, and fresh gas is drawn in through the fluid inlet 241. After reaching bottom dead center (BDC), the piston 132 moves upwards again, the inlet valve 242 closes, and the gas in the working chamber is compressed. The compressed gas then exits the working chamber 131 through the fluid outlet 243. Such a radial piston compressor is known, for example, from DE 10 2021 204 713 A1.

[0101] The radial piston compressor can be equipped with at least one, preferably one, retaining ring 4 for securing all inlet valve covers 15, 15a to 15e of the radial piston compressor. The retaining ring 4 can be designed as a housing part, as in the embodiment shown here (external retaining ring), or also within the housing (internal retaining ring). In other words, it is particularly intended to secure the inlet valve covers 15 (ae) of all piston-working chamber combinations 13 (ae) simultaneously by means of only one common retaining ring 4. This is shown in particular in Fig. 5 using the example of a 6-cylinder radial piston compressor. Thus, the retaining ring 4 generates the necessary holding force to keep all inlet valve covers 15 in position under operating conditions.

[0102] Figures 1 and 2 on the one hand, and 3 and 5 on the other, show embodiments with a different number of piston-working chamber combinations 13 on the one hand and correspondingly assigned intake valve covers 15 on the other, resulting in a correspondingly different number of indices. In principle, each piston-working chamber combination 13 is assigned a valve cover 15.

[0103] Particular reference is made below to Figures 6 to 8.

[0104] Figures 6 to 8 show an inlet valve cover 15 for a radial piston compressor according to the invention. A longitudinal axis L of the valve cover is shown for geometric orientation. In a mounted state of the inlet valve cover 15, the piston axis K of the respective associated piston-working chamber combination is coincident with, or at least parallel to, the respective longitudinal axis L of the valve cover.

[0105] According to the invention, the inlet valve cover 15' is provided with a circumferential relief notch 152 on its edge. For a radial piston compressor according to the invention, the radial piston compressor is equipped with at least one inlet valve cover 15' with a circumferential relief notch 152, for example, a radial piston compressor as shown in Figures 1 to 5.

[0106] The relief notch 152 is bounded externally by a circumferential vertical press collar 1521, the outer side of which, i.e., the side facing away from the circumferential relief notch 152, forms a contact surface 1522 of the inlet valve cover 15' for contact with the inner wall 182 of the receptacle 18. The press collar 1521 can also be referred to as a sealing collar. The inlet valve cover 15' is pressed into the receptacle 18, so that the press collar 1521, with its contact surface 1522, together with the inner wall 182 of the recess 18, forms an interference fit.

[0107] It is further preferably provided that the press collar 1521 is designed to be thin, so that high compliance can be achieved. Preferably, the thickness D of 0.4 mm to 1 mm, preferably 0.6 mm, is provided for the press collar 1521.

[0108] It is further evident that the relief notch 152 has a side flange 1523 angled at an angle α. Preferably, the side flange 1523 is oriented at an angle α of 30° with respect to the longitudinal axis L of the valve cover. This results in a relief notch 152 with an approximately V-shaped cross-section. A clearance 1524 is formed between the pressed collar 1521 and the side flange 1523. It is further evident that, viewed radially from the longitudinal axis L of the inlet valve cover 15', the relief notch 152 first encompasses the side flange 1523 and then the pressed collar 1521, with the clearance 1524 being provided between the side flange 1523 and the pressed collar 1521. The clearance 1524 is bridged by a groove base 1528, which is thinner, in particular significantly thinner, than the rest of the intake valve cover 15'. Since the relief groove 152 is preferably designed circumferentially, it can also be referred to as an annular groove.

[0109] Figures 6 to 8 show further details of the inlet valve cover, in particular a clearance 1525 in the area of ​​the outlet channel 243, a central contact point 1526 inlet valve cover / retaining ring and mounting bores 1527.

[0110] The intake valve cover 15' is preferably characterized by further features or advantages. The intake valve cover 15' preferably does not have an O-ring as a seal. However, the press-fit collar 1521 preferably has a press fit l P to the inner wall 182 of the recording 18.

[0111] The seal between the intake valve cover 15' and the cylinder housing 16 is preferably created by the outer surface, i.e., the contact surface 1522 of the radially circumferential press-fit collar 1521, which bears against the inner wall 182 of the recess 18. The relief notch 152 in the intake valve cover 15' increases the compliance of the intake valve cover 15', so that pressure-induced deformation occurs primarily in the intake valve cover 15' and not in the cylinder housing 16.

[0112] The clearance 1525 in the area of ​​the exhaust port 243 is incorporated into the intake valve cover 15' to prevent the exhaust port cross-section from being restricted when the piston 132 is at top dead center (TDC). Without this clearance 1525, the exhaust port cross-section necessary for expelling the compressed gas would be reduced.

[0113] The two bores 1527 serve in particular for engagement of assembly tools which ensure the angular orientation of the inlet valve cover 15' to the cylinder housing 16 during assembly.

[0114] The intake valve cover 15' preferably has a contact point or contact area 1526 with the retaining ring 4, which is specifically designed to prevent the intake valve cover 15' from rotating during the installation of the housing retaining ring 4. Alternatively, the intake valve cover 15' can be designed with two contact points 1526, 1526A, but would then preferably need to be secured against possible rotation (during installation of the retaining ring). This variant counteracts the risk of deflection at the underside of the cover, i.e., the "intake valve sealing surface".

[0115] Particular reference is made below to Figures 9 and 10.

[0116] Fig. 9 shows in particular the inlet valve cover 15' in its mounting 18.

[0117] Figure 10 shows a perspective view of part of an inlet valve 242. A valve plate 2421, a valve tongue 2422, and bending beams 2423 are particularly visible.

[0118] Particular reference is made below to Figures 11 and 12.

[0119] Further details of the radial piston compressor according to the invention, in particular of the inlet valve cover 15' or the receptacle 18 for the inlet valve cover 15', are shown here.

[0120] In particular, a fitting diameter P is required with reference to the inlet valve cover 15' and the receptacle 18, and an effective press length l. P with reference to intake valve cover 15' and receptacle 18, an upper edge 3 of the exhaust valve sealing surface, an exhaust valve plate 5, an insertion chamfer 6 on the intake valve cover 15', an insertion chamfer 7 on the receptacle 18, a depth tE the relief notch 152 in the intake valve cover 15' , a width b K The thickness D of the press collar 1521 (for press overlap) on the inlet valve cover 15', and the angle a of the side wall of the relief notch 152 are shown in the notch base of the relief notch 152.

[0121] In particular, key features of the press fit between the inlet valve cover 15' and the receptacle 18 in the cylinder housing 16 are to be presented. The fit diameter P is shown with respect to the effective press length l. PThe intake valve cover is positioned above the upper edge of the exhaust valve sealing surface 3 to prevent any potential deformation of the sealing surface of the exhaust valve 243. For easy installation of the intake valve cover, a chamfer 6 is provided on the intake valve cover 15' and on the receptacle 18 of the cylinder housing 16. To ensure a sufficiently stable cutting geometry during the manufacturing process, the groove and its side wall 1523 are provided with a bevel of a = 30° towards the center of the cover. Preferably, the angle a is in the range of 15° to 45°. Reference is made in particular to Figures 13 to 18 below.

[0122] The aforementioned figures are intended to illustrate in particular the task of pressing on the retaining ring 4 with two contacts or a possible twisting of the cover during assembly of the retaining ring 4.

[0123] In Fig. 13, a first contact point 1526 and a second contact point 1526A are shown.

[0124] With intake valve covers 15' that have two contact points 1526, 1526A with the retaining ring 4, the intake valve cover 15' can rotate during installation of the retaining ring 4. Due to tolerances in the individual parts, it is possible that there may be situations in which only one of the two contact points 1526 or 1526A makes contact. In this case, a moment M is generated when the retaining ring 4 is pushed on, resulting from the lever arm r and the force F. To prevent the intake valve cover 15' from rotating, it should be secured against rotation during installation using a longitudinal press fit.

[0125] To counteract this undesirable effect, positive locking elements 8 can be provided on the intake valve cover and cylinder housing. In particular, Figures 15 to 18 show exemplary embodiments of positive locking elements on the intake valve cover and cylinder housing 16. The positive locking elements can be attached either radially, i.e., around the circumference of the intake valve cover 15' (see Figures 15 and 16), or axially (see Figures 17 and 18). Figures 15 and 16 show a tongue-and-groove system, and Figures 17 and 18 show a pin-and-bore system.

[0126] Particular reference is made below to Figures 19 and 20.

[0127] As described above, the valve plate 2421 comprises one or more bending beams 2423, which support the valve tongue 2422, which in turn selectively closes or opens the valve opening. The proper function of the valve depends essentially on the bending beam 2423 resting flat on the inlet valve cover 15' or above the valve opening. As also explained above, there is a possibility that the inlet valve cover 15' could deform under pressure. This could negatively affect the valve function, particularly the closing function.

[0128] To counteract this undesirable effect, the inlet valve cover can be equipped with a clearance 9 for the bending beam 2423 of the valve plate 2421.

[0129] Fig. 19 shows an embodiment of the recess 9 on the inlet valve cover 15' in the area of ​​the valve plate support. The recess 9 is designed here as milled pockets (approx. 0.1 mm deep), the milled pockets preferably being designed such that the bending beams 2423 of the valve plate 2421 are free of the inlet valve cover 15'. This ensures that the cover deformation due to the contact force of the retaining ring 4 (on the order of 30 ppm), which forms on the inside of the cover, does not lead to a deformation of the valve tongue 2422, or only to a minimal deformation. This ensures a better sealing function.

[0130] Particular reference is made below to Figures 21 and 22.

[0131] Figures 21 and 22 show a preferred embodiment of the contact points 1526, 1526A using a circular recess 10 in the intake valve cover 15'. It can be seen that the recess 10 for creating the contact points 1526, 1526A on the intake valve cover 15' is designed as a rotary contour, in particular concentric to the center of the cover. Accordingly, the rotary contour is a circular contour.

[0132] In conjunction with the retaining ring 4 also shown, it is evident that the proposed embodiment creates two contacts 1526, 1526A between the intake valve cover 15' and the retaining ring 4. The contact points 1526, 1526A can be easily produced, for example by a lathe, by creating a circular recess 10 in the intake valve cover 15'.

[0133] Particular reference is made below to Figures 23 and 24.

[0134] Figures 23 and 24 show another preferred embodiment of the contact points 1526, 1526A. This variant is shown in which the radius for the contact contour lies on the axis of the intake valve cover 15'. Furthermore, the top and bottom surfaces of the cover are flat and parallel, which facilitates simple machining in a single operation. This allows the contact point to be machined precisely to the reference (and in a single setup).

[0135] Reference symbol 10A denotes a parallel, planar contour for finishing in one step. Reference symbol 10B denotes a starting point for the radius of the high points.

[0136] In principle, the invention is not limited to the embodiments outlined above. Rather, variations are conceivable without deviating from the inventive idea, particularly with regard to the number of contact points 1526, 1526A of the intake valve cover 15' to the retaining ring 4, for example one contact point 1526 (coaxial with the center of the cover) or two contact points 1526, 1526A. Furthermore, a mechanism to prevent rotation of the intake valve cover to the cylinder housing can be provided, for example by a positive locking element 8 on the intake valve cover and cylinder housing, such as a bore / pin or spring / groove.

[0137] Variations can also occur with regard to the size of the press coverage l P and the tolerance range for the overlap should be specified. However, a minimum overlap of 2 mm should be provided.

[0138] Variations are conceivable, particularly in the number and shape of the mounting holes 1527 in the inlet valve cover 15'. The mounting holes 1527 are specifically designed for tool engagement and angular joining.

[0139] Variations are conceivable in the size and shape of the relief notch 152 on the inlet valve cover 15' and thus also in the wall thickness D of the press collar 1521 on the inlet valve cover 15'.

[0140] Variations also exist regarding the size and shape of the cutout for the exhaust port on the intake valve cover, the size and shape of the cutout for the bending beams of the valve sheet in the intake valve cover, the shape and size of the cutout geometry on the intake valve cover in the area of ​​the contact points with the retaining ring, as well as the manufacturing process of the intake valve cover, for example by sintering; MIM process; sheet metal bending, machining, etc.

Claims

Claims 1. Radial piston compressor, comprising - a compressor unit (1) and a drive unit (2) for driving the compressor unit (1), wherein - the compressor unit (1) comprises at least one, preferably a plurality of piston-working chamber combinations (13), wherein - the piston-working chamber combination (13) is accommodated in a cylinder housing (16) and comprises a working chamber (131) with a piston (132) that can be displaced therein, wherein - the working chamber (131) is equipped with an inlet valve cover (15) which is received by means of a press fit in a corresponding receptacle (18) of the cylinder housing (16), characterized in that the inlet valve cover (15') is equipped on its edge with a circumferential relief notch (152).

2. Radial piston compressor according to claim 1, characterized in that the relief notch (152) comprises a side wall (1523) and a press collar (1521) in a radial direction from the longitudinal axis (L) of the inlet valve cover (15'), wherein a clearance (1524) is provided between the side wall (1523) and the press collar (1521).

3. Radial piston compressor according to at least one of the preceding claims, characterized in that the receptacle (18) is designed as a circular recess in the cylinder housing (16), comprising an inner wall (182) which together with the press collar (1521) of the received inlet valve cover (15') forms an interference fit.

4. Radial piston compressor according to at least one of the preceding claims, characterized in that the press collar (1521) has a thickness (D) of 0.4mm to 1mm, in particular 0.6 mm.

5. Radial piston compressor according to at least one of the preceding claims, characterized in that the side wall (1523) is tilted at an angle (a) in a range of 15° degrees to 45° degrees, in particular at an angle (a) of 30° degrees, to the longitudinal axis (L) of the inlet valve cover (15').

6. Radial piston compressor according to at least one of the preceding claims, characterized in that the radial piston compressor comprises at least two piston-working chamber combinations (13) extending radially from a drive shaft (11), wherein an inlet valve cover (15') is arranged in an associated receptacle (18) on each working chamber, wherein the radial piston compressor is equipped with at least one retaining ring (4) for fixing all inlet valve covers (15'), wherein the inlet valve covers (15') are equipped with at least one contact point (1526) for bearing against the retaining ring (4).

7. Radial piston compressor according to at least one of the preceding claims, characterized in that the inlet valve covers (15') are equipped with two contact points (1526) for contact with the retaining ring (4), wherein the inlet valve cover (15') is secured against rotation in the receptacle (18) by positive locking elements (8).

8. Radial piston compressor according to at least one of the preceding claims, characterized in that the inlet valve cover (15') comprises a fluid inlet (241) and an inlet valve (242), wherein the inlet valve (242) comprises a valve plate (2421) with a valve tongue (2422), wherein the valve tongue (2422) is connected to the valve plate (2421) by means of bending beams (2423), wherein the inlet valve cover (15') is provided with a relief (9) for the bending beams (2423).

9. Radial piston compressor according to at least one of the preceding claims, characterized in that the two contact points (1526) for contact with the retaining ring (4) are provided by means of a circular recess (10) on the inlet valve cover (15').

10. Radial piston compressor according to at least one of the preceding claims, characterized in that the two contact points (1526) for contact with the retaining ring (4) are provided by means of a flat top surface of the inlet valve cover (15'), wherein the radius for the contact contour lies in the longitudinal axis (L) of the inlet valve cover (15').

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