DE102015207909A1 - axial piston - Google Patents

Abstract

The invention relates to an axial piston machine (1), comprising a housing (3) in which a vapor space (4), a cylinder space (5) and a swash plate space (6) are provided, wherein in the cylinder space (5) is annular around a shaft (7) arranged cylinders (8) are provided, in which piston (9) are arranged translationally adjustable. It is essential to the invention that the housing (3) has a vapor space housing part (15), a cylinder housing part (16) and a swashplate housing part (17) which are connected to one another, that in at least one cylinder (8) has a cylinder liner (18) a radially projecting collar (19) is provided which is held in the cylinder housing part (16) via its collar (19) in a recess (21) adjoining a parting plane (20) between the vapor space housing part (15) and the cylinder housing part (16), - That the vapor space (4) via a connected to the vapor space housing part (15) and formed as a sheet-metal molded part first lid (24) is completed.

Description

The present invention relates to an axial piston machine with a housing in which a steam space, a cylinder space and a swash plate space is provided, according to the preamble of claim 1. The invention also relates to a heat recovery system in a motor vehicle with at least one such axial piston machine.

From the prior art, a plurality of generic axial piston machines with a housing is known, in which a vapor space, a cylinder chamber and a swash plate space are provided. Also arranged in the housing is a rotor with a shaft and the rotatably arranged thereon swash plate and also rotatably connected to the shaft valve disc. In the swash plate space itself, the respectively connected via a spherical bearing with one of the pistons and rotatably coupled to the shaft swash plate is arranged. Such axial piston machines are used in particular in so-called heat recovery systems in motor vehicles, in which they convert thermal energy into mechanical energy.

A disadvantage of the piston engine known from the prior art, however, is the comparatively complicated and expensive production.

The present invention therefore deals with the problem of providing for an axial piston machine of the generic type an improved or at least one alternative embodiment, which is characterized in particular by a structurally simple and cost-effective production.

This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea, a hitherto relatively complex and thus expensive to manufacture housing an axial piston now for the first time in several parts and thus to disentangle the extremely complex manufacturing process. The axial piston machine according to the invention has in a known manner a housing in which a vapor space, a cylinder chamber and a swash plate space are arranged. In the cylinder chamber are arranged annularly around a shaft arranged cylinder, in which pistons are arranged translationally adjustable. In the vapor space itself a non-rotatably connected to the shaft valve disc is arranged, which communicates depending on the rotational position of the vapor space communicating with one of the cylinders or separates. In the swash plate space is connected via a respective Kalottenlager connected to one of the pistons and rotatably coupled to the shaft swash plate. According to the invention, the housing now has a vapor space housing part, a cylinder housing part and a swashplate housing part, which are connected to one another. In addition, a cylinder liner is provided with a radially projecting collar in at least one cylinder, wherein the cylinder liner is held by its collar in a adjacent to a parting plane between the vapor space housing part and the cylinder housing part recess in the cylinder housing part. The vapor space itself is closed by a first lid connected to the vapor space housing part and designed as a shaped sheet metal part. Due to the at least three housing parts, which form the housing of the axial piston machine in the assembled state, the individual housing parts themselves can be made simpler and easier, wherein additionally insertion of the cylinder liner into the cylinder from the vapor space housing part is possible. By inserted into the respective cylinder cylinder liner, the load capacity of the axial piston according to the invention can be significantly increased and significantly reduce their manufacturing costs, since an individual and in the hitherto provided enclosures difficult to bewerkstelligende finishing the cylinder liners now completely eliminated. On the first cover, by means of which the vapor space can be completed, can also be dispensed with in this area so far integrally formed with the vapor space housing part lid, which in turn can be simplified manufacturing. In addition, by forming the first cover as a sheet-metal shaped part, this cover can not only be made more cost-effective, but also thinner, because such a sheet-metal part is capable of reliably withstanding higher forces than, for example, a cover designed as a cast component. Due to the segmentation of the housing in the individual housing parts, a comparatively simple and therefore also cost-effective production of the individual housing parts and over this of the entire housing is possible in particular.

In an advantageous development of the solution according to the invention, the cylinder liner is made of stainless steel. Such a cylinder liner made of stainless steel is particularly wear and corrosion resistant, whereby a permanent use in a steam-driven axial piston machine is easily feasible.

In a further advantageous embodiment of the solution according to the invention, the swash plate space is formed by a second sheet metal part finished lid. Analogous to the first designed as a sheet metal part lid, which limits the vapor space together with the vapor space housing part, thus on the axially opposite side of the swash plate space can be completed by such a lid, which also helps to form the swash plate housing part cheaper and easier.

In an advantageous development of the solution according to the invention, the spherical bearing, via which the individual pistons of the axial piston machine are connected to the swash plate, a radially outwardly projecting portion. The cylinder liner in turn has an opening towards the front side cutout, in which the radially outwardly cantilevered portion of the spherical bearing can dip. On the spherical bearing itself beyond two adjacent to the section arranged and are provided on the guide bush supporting sliding feet. By such an embodiment, an exact translational adjustment of the respective spherical bearing can be forced, as this is guided over its radially outwardly cantilevered portion in the cylinder liner side cutout. The guide can be supplemented by the fact that in the swash plate housing part a guide bush is arranged with a between the cylinder housing part and the swash plate housing part inside open cutout, which is also performed in the sense of rotation in this section of the radially outwardly cantilevered portion of the spherical bearing. The section of the cylinder liner and the cutout of the guide bush thus form the entire guideway for the radially outwardly cantilevered portion of the spherical bearing.

Suitably, at least one dummy plug is provided for one of the cylinders, which can be inserted in one of the cylinders instead of a cylinder liner and closes the inlet opening facing the vapor space. As a result, in particular a comparatively simple reduction in power of the axial piston machine according to the invention can be achieved since not all cylinders are used to generate power, but only those that are not closed by such a blanking plug. By choosing the number of dummy plugs used can thus be taken individually influence on the particular desired performance of the axial piston machine.

In an advantageous development of the solution according to the invention, the first cover in the direction of the vapor space embossed projections, which reduce the volume of the vapor space. About these projections, which can also be used as a stiffener for the lid, the volume in the vapor space itself can be accurately dimensioned, which has been shown in experiments that in particular a vote, for example, the volume of the vapor space, a stroke volume of a cylinder and a Cross-section of an inlet in the steam room has a significant impact on the efficiency of the axial piston machine. In this case, the volume of the vapor space is particularly preferably between 30 cm ³ and 100 cm ³ , while a cross section of an inlet into the vapor space is between 78 mm ² and 200 mm ² . The stroke volume of the cylinder is between 25 cm ³ and 75 cm ^3. This applies in particular to an axial piston machine with six cylinders. The three aforementioned variables, that is, the volume of the vapor space, the cross section of the inlet and the stroke volume of the cylinder, are dependent on each other and thus determine not only the efficiency, but also the response of the axial piston machine crucial. In order to achieve the fastest possible response, the working space should have as little dead volume as possible. To ensure that no pressure fluctuations occur at reduced steam volume in the working space, the inlet must be selected to be correspondingly large. The rapid provision of steam also has a positive effect on a fast response of the axial piston engine. The stroke volume of a cylinder determines the amount of steam required per actuation. The volume of the vapor space is also still associated with the speed of the rotor, which determines the number of actuation per time. In the aforementioned ranges of the volume of the vapor space, the cross section of the inlet and the stroke volume of the cylinder optimum conditions can be achieved both in terms of the response and in terms of efficiency.

In a further advantageous embodiment of the solution according to the invention, the first cover has at least two connections for connecting in particular a pressure sensor or a temperature sensor, which are attached to a flat end face of the first cover. By arranging the connections to the flat end face of the first lid, a small sealing surface and a comparatively simple assembly can be achieved.

In an advantageous embodiment of the solution according to the invention, sub-ribs are arranged on the swash plate housing, wherein these ribs may be formed, for example, together with the swash plate housing part as a one-piece casting. The ribs themselves can serve both the stiffening and an enlargement of the surface, whereby improved cooling can be achieved. This cooling effect is particularly in the range of Swashplate housing to the drain channels desired.

In a further advantageous embodiment of the solution according to the invention, at least one of the housing parts has an anticorrosion layer on an inner side. By means of such a corrosion protection layer, in particular a corrosion process, triggered by the steam used in the axial piston machine for driving the same, can be at least reduced. Additionally or alternatively, it is also possible to provide an insulating element, in particular a so-called insulating sheet, which surrounds at least the vapor space, preferably also the cylinder space, up to the outlets, forming an air gap. By means of such an insulating element, an insulating layer of air can be created, in particular around the vapor space, whereby the vapor in the vapor space itself remains hot for longer and thus a comparatively high degree of efficiency can be achieved.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

1 a sectional view through an axial piston machine according to the invention,

2 a sectional view along the section plane AA.

According to the 1 , Has an axial piston machine according to the invention 1 , which, for example, part of a heat recovery system 2 may be in a motor vehicle, not shown, a housing 3 on, in which a steam room 4 , a cylinder room 5 and a swash plate room 6 are provided. In the cylinder room 5 are annular around a wave 7 cylinder 8th arranged in which piston 9 are arranged translationally adjustable. In the steam room 4 turn is a rotation with the shaft 7 connected valve disc 10 arranged, with a valve disc opening 11 used in accordance with the in 1 shown representation depending on the rotation angle in alignment with an inlet opening 12 of the respective cylinder 8th is arranged. In this state can in the steam room 4 held steam over the valve disc opening 11 and the inlet opening 12 in the associated cylinder 8th inflow and the piston therein 9 Press down. In the swashplate room 6 is one over each a Kalottenlager 13 with one of the pistons 9 connected and non-rotatable with the shaft 7 coupled swash plate 14 arranged. Every calf bearing 13 has a sliding block, which has two Gleitsteinhälften. According to the invention now has the housing 3 a vapor space housing part 15 , a cylinder housing part 16 and a swash plate housing part 17 on, which are connected together and together the housing 3 form. In at least one of the cylinders 8th is also a cylinder liner 18 with a radially projecting collar 19 provided, the cylinder liner 18 about her covenant 19 in one at a parting plane 20 between the vapor space housing part 15 and the cylinder housing part 16 adjacent recess 21 in the cylinder housing part 16 is held. In addition, the steam room 4 over one with the headspace housing part 15 connected, for example screwed and formed as a sheet metal part first lid 24 completed. This opens up the possibility of the cylinder liner 18 from the steam room side into the cylinder 8th and then insert the steam chamber housing part 15 sit up. The inventive multi-part design of the housing 3 , This can be easier and cheaper to manufacture than, for example, a previously used in this context one-piece or even one-piece housing.

The cylinder liner 18 can be made of stainless steel and thereby not only have a relatively high resistance to wear, but also an insensitivity to corrosion, which in particular the steam-driven axial piston machine 1 is of great advantage. Additionally or alternatively, the cylinder liner 18 also be provided with a wear and / or friction reducing coating, in particular a polymer coating or a DLC coating.

Looking at the cylinder liner 18 more precisely, it can be seen that these have at least two passage openings 22 and 22 ' in the area of a bottom dead center of the piston 9 has, over which steam can be drained. The passage openings 22 . 22 ' communicate with a respectively associated discharge channel 23 . 23 ' in the swashplate room 6 open and through the cylinder housing part 16 on the one hand and the Cylinder liner 18 on the other hand are limited. The cylinder liner 18 moreover preferably has at least one third passage opening 38 which serves as a secondary outlet and the cylinder 8th during a movement of the piston 9 vented to top dead center (TDC).

Down is the swash plate space 6 by a second formed as a sheet metal part lid 24 ' completed in the 2 is shown.

Looking at the 1 further, one can recognize that the Kalottenlager 13 a radially outwardly projecting portion 25 has, the cylinder liner 18 one to the front, that is, in the following example downwards, open cutout 26 in which the section 25 can dive. At the calotte camp 13 are also two adjacent sections 25 arranged and attached to the guide bush 33 supporting sliding feet 27 . 27 ' arranged, like this 2 is apparent. The cutout 26 in the cylinder liner 18 is preferably in the region of the discharge channel 23 arranged and may also be guided therein.

In addition, at least one blind plug 28 for one of the cylinders 8th be provided, instead of a cylinder liner 18 in the cylinder 8th is usable and its the steam room 4 facing inlet opening 12 closes, as this according to the 1 is shown. About the variation of the number of blind plugs 28 can in a comparatively simple way the performance of the axial piston machine 1 be regulated.

Looking at the first lid 24 closer, so you can see that this is essentially planar and in the direction of the vapor space 4 embossed protrusions 29 which has both the volume of the vapor space 4 reduce as well as an additional stiffening of the first lid 24 cause. By providing corresponding projections 29 can by a simple design of the first cover 24 the volume of the steam room 4 be determined exactly.

Has proved to be particularly advantageous, a volume of the vapor space 4 between 30 and 100 cm ³ , a cross section of an inlet 30 between 78 mm ² and 200 mm ² and a stroke volume of a cylinder 8th between 25 cm ³ and 75 cm ³ . The three aforementioned sizes, that is the volume of the vapor space 4 , the cross section of the inlet 30 and the stroke volume of the cylinder 8th are dependent on each other and determined both the response of the axial piston machine 1 as well as their efficiency crucial. The working space should have as little dead volume as possible in order to improve the response. To ensure that no pressure fluctuations occur at reduced steam volume in the working space, the inlet must be selected to be correspondingly large. The volume of the stroke of the piston 9 then of course determines the required amount per actuation. This is then also still associated with the speed, the number of actuations per time determined. For a quick operation would be a large steam room 4 ideal, because then there is always enough steam and there are no pressure fluctuations.

Looking at the 1 and 2 Further, it can be seen that on the swash plate housing part 17 ribs 32 are arranged, wherein the swashplate housing part 17 including the ribs 32 For example, may be formed as a one-piece casting. Ribs 32 not only stiffen the swashplate housing part 17 but also increase its surface to the outside and thereby cause improved cooling. The one-piece design of the ribs 32 with the swashplate housing part 17 , this can be manufactured inexpensively.

In the swashplate housing part 17 In addition, a guide bush 33 with a to between the cylinder housing part 16 and the swash plate housing part 17 open neckline 26 ' be provided, in which the section 25 dips. The guide bush 33 can also be made of stainless steel and thus both wear resistant and corrosion resistant. Particularly advantageous, this can also be provided with a friction and / or wear-reducing coating. The cutout 26 ' the guide bush 33 Aligns in the assembled state with the neckline 26 the cylinder liner 18 and thereby forms a guide track for the radially outwardly projecting portion 25 of the calotte camp 13 ,

To the guide bush 33 also reliable in the housing 3 the axial piston machine 1 to be able to mount, this has a radially projecting collar 19 ' on which they are in a dividing plane 20 ' between the cylinder housing part 16 and the swash plate housing part 17 is held. The guide bushing is used for mounting 33 from above (referring to the 1 ) in the swash plate housing 17 pushed in until she with her waistband 19 ' in the parting plane 20 ' to come to rest.

At least one of the housing parts 15 . 16 . 17 Can on an inner side in addition a corrosion protection layer 34 can also be increased by the corrosion resistance.

Looking at the 1 again, so you can use an insulating element 35 , in particular an insulating sheet, which at least the vapor space 4 and in the present case also the cylinder space 5 forming an air gap 36 surrounds and thereby isolated. As a result, too fast cooling of the vapor in the vapor space 4 combined with the concomitant loss of efficiency can be avoided. A fixation of the insulating 35 on the housing 3 , especially on the lid 24 can be done for example via a screw connection. At the first lid 24 In addition, at least two ports 37 and 37 ' be arranged for connecting a measuring sensor, in particular for connecting a pressure sensor and / or a temperature sensor, in particular in the region of a flat end face of the first lid 24 are attached. In this way, a flat sealing surface can be provided, which is easy or easy to seal.

With the axial piston machine according to the invention 1 can be a particularly simple and therefore inexpensive built axial piston machine 1 realize that due to the multi-part housing also extremely flexible, especially with regard to a possible adaptation. Of great advantage beyond that by the first, designed as a sheet metal part lid 24 also the steam room housing part 15 can be made lighter and cheaper compared to conventional housing parts installed there.

Claims (19)

Axial piston machine ( 1 ), - with a housing ( 3 ), in which a steam room ( 4 ), a cylinder space ( 5 ) and a swash plate space ( 6 ) are provided, - in the cylinder space ( 5 ) annularly around a shaft ( 7 ) arranged cylinders ( 8th ) are provided, in which piston ( 9 ) are arranged translationally adjustable, - wherein in the vapor space ( 4 ) a rotationally fixed with the shaft ( 7 ) connected valve disc ( 10 ) is arranged, - wherein in the swash plate space ( 6 ) one on each a Kalottenlager ( 13 ) with one of the pistons ( 9 ) and non-rotatable with the shaft ( 7 ) coupled swash plate ( 14 ), characterized in that - the housing ( 3 ) a steam space housing part ( 15 ), a cylinder housing part ( 16 ) and a swashplate housing part ( 17 ), which are connected to each other, - that in at least one cylinder ( 8th ) a cylinder liner ( 18 ) with a radially projecting collar ( 19 ) is provided, wherein the cylinder liner ( 18 ) about her covenant ( 19 ) in one at a parting plane ( 20 ) between the vapor space housing part ( 15 ) and the cylinder housing part ( 16 ) adjacent recess ( 21 ) in the cylinder housing part ( 16 ), - that the vapor space ( 4 ) via one with the vapor space housing part ( 15 ) and formed as a sheet-metal molded part first cover ( 24 ) is completed. Axial piston machine according to claim 1, characterized in that - the cylinder liner ( 18 ) is made of stainless steel, and / or - that the cylinder liner ( 18 ) is provided with a wear and / or friction reducing coating, in particular with a polymer coating or a DLC coating. Axial piston machine according to claim 1 or 2, characterized in that the at least one cylinder liner ( 18 ) at least two passage openings ( 22 . 22 ' ) for discharging steam, which with a respective associated discharge channel ( 23 . 23 ' ) in the cylinder housing part ( 16 ), the drainage channel ( 23 . 23 ' ) through the cylinder housing part ( 16 ) and the cylinder liner ( 18 ) are limited. Axial piston machine according to one of claims 1 to 3, characterized in that the cylinder liner ( 18 ) at least a third passage opening ( 38 ), which serves as a secondary outlet and the cylinder ( 8th ) during a movement of the piston ( 9 ) to top dead center (TDC). Axial piston machine according to one of claims 1 to 4, characterized in that the swash plate space ( 6 ) by a second formed as a sheet metal part lid ( 24 ' ) is completed. Axial piston machine according to one of the preceding claims, characterized - the spherical bearing ( 13 ) a radially outwardly projecting portion ( 25 ), - that the cylinder liner ( 18 ) a cutout open to the front side ( 26 ), in which the section ( 25 ) is guided in the sense of an anti-rotation, - that at the spherical bearing ( 13 ) two adjacent to the section ( 25 ) and located on the guide bush ( 33 ) supporting sliding feet ( 27 . 27 ' ) are provided. Axial piston machine according to one of the preceding claims, characterized in that at least one dummy plug ( 28 ) for one of the cylinders ( 8th ) is provided, which instead of a cylinder liner ( 18 ) in a cylinder ( 8th ) can be used and whose the steam room ( 4 ) facing inlet opening ( 12 ) closes. Axial piston machine according to one of claims 1 to 7, characterized in that the first cover ( 24 ) in the direction of the vapor space ( 4 ) embossed projections ( 29 ), which defines the volume of the vapor space ( 4 ) to reduce. Axial piston machine according to one of claims 1 to 8, characterized in that the first cover ( 24 ) at least two ports ( 37 . 37 ' ) for connecting in particular a pressure sensor or a temperature sensor, which on a flat end face of the first lid ( 24 ) are mounted. Axial piston machine according to one of claims 1 to 9, characterized in that - a volume of the vapor space ( 4 ) is between 30 and 100 cm ³ , and / or - that a cross-section of an inlet ( 30 ) in the steam room ( 4 ) is between 78 mm ² and 200 mm ² , and / or - that a stroke volume of a cylinder ( 8th ) is between 25 cm ³ and 75 cm ³ . Axial piston machine according to one of claims 1 to 10, characterized in that on the swash plate housing part ( 17 ) Ribs ( 32 ) are arranged. Axial piston machine according to claim 11, characterized in that the swash plate housing part ( 17 ) together with the ribs ( 32 ) is formed as a one-piece casting. Axial piston machine according to one of claims 6 to 12, characterized in that in the swash plate housing part ( 17 ) a guide bush ( 33 ) with a to between the cylinder housing part ( 16 ) and the swashplate housing part ( 17 ) open cutout ( 26 ' ), in which the section ( 25 immersed). Axial piston machine according to claim 13, characterized in that the guide bush ( 33 ) is made of stainless steel. Axial piston machine according to claim 13 or 14, characterized in that the guide bush ( 33 ) a radially projecting collar ( 19 ' ), over which they are in a parting plane ( 20 ' ) between the cylinder housing part ( 16 ) and the swashplate housing part ( 17 ) is held. Axial piston machine according to one of the preceding claims, characterized in that at least one of the housing parts ( 15 . 16 . 17 ) on an inner side a corrosion protection layer ( 34 ) having. Axial piston machine according to one of the preceding claims, characterized in that an insulating element ( 35 ), in particular an insulating sheet, is provided which at least the vapor space ( 4 ), preferably also the cylinder space ( 5 ), forming an air gap ( 36 ) surrounds. Axial piston machine according to claim 17, characterized in that the insulating element ( 35 ) with the vapor space housing part ( 15 ) is screwed. Heat recovery system ( 2 ) in a motor vehicle with an axial piston machine ( 1 ) according to any one of the preceding claims.

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