Abstract:
A compressor for generating compressed air in a vehicle includes a crankshaft and an interface area for fastening a clutch device by means of which the crankshaft of the compressor can be connected to or disconnected from a drive device. The interface area is configured to receive a crucible-shaped receptacle element. The crucible-shaped receptacle element can be a cylinder for receiving a piston that can be acted on by a pressure medium for actuating the clutch device.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to embodiments of a compressor for generating compressed air in a vehicle. The compressor can be separated from or connected to a drive by means of a clutch device, for example a shut-off clutch. 
     BACKGROUND OF THE INVENTION 
     A generic compressor is known for example from DE 20 2006 019 190 U1. 
     The use of the known shut-off clutch on compressors has the advantage that the compressor can be separated from a drive, for example the drive engine of the vehicle, in order to save energy when no compressed air generation is required. Without such a shut-off clutch, it has hitherto been conventional for the compressor to always be driven along by the drive engine and to merely be switched into a pneumatically neutral state in phases in which no compressed air generation was required. 
     In the case of known compressors, it was necessary for these to be structurally adapted to the clutch device such that the compressor and clutch device form a unit. An adaptation of the structure of the compressor however requires in each case a relatively expensive and complex change of the production facilities, in particular of the casting moulds. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the invention to improve the interface between the compressor and the clutch device such that the adaptation expenditure is reduced. 
     The inventive embodiments have the advantage of specifying a modular concept for the compressor and the clutch device. The compressor may be used and sold both without and with a clutch device. The clutch device may be connected to the compressor as a separate auxiliary module. In this way, compressors can be produced with a uniform housing for applications both with and without a clutch device, which leads to a rationalization in terms of production. 
     According to an embodiment of the present invention, an annular, pot-shaped receiving element is provided, which can be produced and provided as a separate component. The pot-shaped receiving element is adapted in terms of its shape to the interface region of the compressor and can be mounted thereon in a simple manner. Through the use of different pot-shaped receiving elements as adapters, it is possible for different combinations of compressors and clutch devices to be connected to one another. The relatively complex adaptation of the compressor housing or of parts of the clutch device is thereby made superfluous. 
     Furthermore, the receiving element can be cylindrical. The pot-shaped receiving element is designed for receiving a piston, which can be acted on with pressure medium, for actuating the clutch device. As pressure medium, consideration is given for example to compressed air or pressurized oil. In this way, the pot-shaped receiving element serves additionally for the integration of the piston required for the actuation of the clutch. It is advantageously possible for an actuating piston pre-mounted in the receiving element to be arranged as a structural unit on the compressor. In this way, the clutch device can be arranged on the compressor in an easy-to-assemble manner. Furthermore, use may be made of a structural unit, which has been checked for functionality in advance, composed of the pot-shaped receiving element and the actuating piston, which reduces the testing expenditure for the finished compressor-clutch unit. 
     In one advantageous embodiment of the invention, the pot-shaped receiving element can be fixed in a depression of the compressor housing by means of a corrugated locking ring. The use of a corrugated locking ring permits not only secure fastening but at the same time also play-free mounting of the pot-shaped receiving element. As a result of the corrugated contour of the locking ring, a certain preload is imparted to the pot-shaped receiving element, such that the latter is held in a play-free manner. 
     In another embodiment of the invention, the clutch device can be fastened on the crankshaft by means of a collar nut. It is advantageously possible here for a relatively flat collar nut to be used. Simple and substantially simultaneous space-saving mounting of the clutch device on the crankshaft is possible in this way. 
     Still other objects and advantages of the present invention will in part be obvious and will in part be apparent from the specification. 
     The present invention accordingly comprises the features of construction, combination of elements, and arrangement of parts all as exemplified in the constructions herein set forth, and the scope of the invention will be indicated in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be explained in more detail below on the basis of exemplary embodiments, with reference to the appended drawings, in which: 
         FIG. 1  is a schematic illustration of a two-cylinder compressor; 
         FIG. 2  is a sectional view showing the compressor/clutch device interface; and 
         FIG. 3  is a view of the compressor from the shaft side. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawing figures, where the same reference numerals are used for corresponding elements,  FIG. 1  shows a compressor  1  having a compressor housing  2 , and a clutch device  3 , which is arranged on the compressor housing  2 . The clutch device  3  is designed as a pneumatically actuable shut-off clutch. For this purpose, the clutch device  3  has a pneumatic actuating cylinder  19  by means of which, when it is subjected to pneumatic loading, coupling  18 , for example clutch plates or clutch discs, can be pressed against one another or separated from one another. The clutch device  3  connects a crankshaft  12  of the compressor  1  via a clutch drive shaft  21  to a drive output shaft of a drive device (not illustrated in granular detail) of a vehicle, for example the vehicle engine. The clutch drive shaft  21  may be provided with a receptacle for a gearwheel for a gearwheel drive. 
     The compressor  1  has a first cylinder  8  and a second cylinder  9 . A first piston  6  is arranged in the first cylinder  8 . A second piston  7  is arranged in the second cylinder  9 . The first piston  6  is connected to the crankshaft  12  via a first connecting rod  10  and corresponding bearings. The second piston  7  is connected to the crankshaft  12  via a second connecting rod  11  and likewise via corresponding bearings. The mounting of the pistons  6 ,  7  and of the crankshaft  12  in the corresponding bearing eyes of the connecting rods  10 ,  11  is illustrated merely schematically in  FIG. 1  for simplicity. In practice, suitable plain or rolling bearings are used for this purpose. The cylinders  8 ,  9  are arranged in a cylinder housing  4  of the compressor  1 . The cylinder housing  4  is part of the housing  2 . 
     Arranged on the cylinder housing  4  is a valve and control block  5 , which comprises for example the inlet and outlet valves for the compressed-air induction and for the compressed-air discharge to downstream units such as for example compressed-air storage reservoirs. The valve block  5  may be designed, in terms of detail, for example as per DE 197 451 18 A1. 
     For lubrication of the pistons  6 ,  7  in the respective cylinders  8 ,  9 , the compressor  1  has a lubricant supply. As lubricant, use is made for example of oil, for example the engine oil of the vehicle engine. The lubricant supply of the compressor  1  has a lubricant port  14  for connecting to the engine oil supply of the vehicle engine. From the lubricant port  14 , a first lubricant duct  15  leads through the housing  2  to a lubricant supply groove  16 , which runs around the crankshaft  12 . The lubricant supply groove  16  is connected to a lubricant supply duct section  13 , which runs in the form of a hollow duct within the crankshaft  12 . The duct section  13  is connected to outlet points for the lubricant in the region of the connecting rods  10 ,  11 . The use of the encircling lubricant supply groove  16  has the advantage that the lubricant can disperse over the circumference of the crankshaft  12  and thereby be introduced relatively quickly and uniformly into the lubricant duct section  13 . 
     The lubricant is conventionally pressurized and is at a pressure of approximately 3 to 4 bar. In this way, a supply of lubricant is possible independently of the movement of the compressor, that is even when the compressor is stationary. 
     As can also be seen from  FIG. 1 , in one advantageous embodiment of the invention, the clutch device  3  protrudes beyond the housing  2  of the compressor  1 , that is the clutch device is not integrated into the housing, as is known from DE 20 2006 019 190 U1. The clutch device  3  protrudes at least with a region that comprises the coupling  18 , for example the clutch disc or plate part, out of the housing  2  of the compressor  1 . The external arrangement of the clutch device offers the advantage of modularity. The inventive compressor can therefore be used, without any structural changes, both with and without a clutch device. If required, the clutch device  3  is merely screwed onto the housing  2  of the compressor  1 . 
     The region  20  bordered by a dashed line in  FIG. 1  is illustrated in  FIG. 2  in the form of an enlarged detail.  FIG. 2  shows an interface region  40  of the compressor  1  to the clutch device  3  in a horizontal sectional illustration. As is shown, the crankshaft  12  is mounted in the housing  2  by means of a ball bearing  23 . An annular, pot-shaped receiving element  22  is arranged in a depression of the compressor housing in the illustrated position by means of a corrugated locking ring  24 . For this purpose, the pot-shaped receiving element  22  has an annularly outwardly flanged edge  27  on which the locking ring  24  is seated. 
     The pot-shaped receiving element  22  simultaneously serves as a cylinder for a compressed-air-actuable piston  19 . The compressed-air-actuable piston  19  is sealed off with respect to the pot-shaped receiving element  22  by means of seals  35 ,  36  at the inside and at the outside. Also situated on the outside of the piston  19  is a guide belt  37 . The piston  19  serves for actuating the clutch device  3 . When subjected to compressed air loading, the piston  19  is deployed to the right in the illustration of  FIG. 2  and hereby opens the clutch device  3 , or the coupling  18 . The crankshaft  12  is then separated from the drive shaft  21 , which is connected to the drive device, of the clutch device  3 , such that the compressor  1  is not driven. 
     As can also be seen from  FIG. 2 , the bearing  23  protrudes with a section  26  out of the compressor housing  2 . The section  26  serves simultaneously as a centering device for the pot-shaped receiving element  22 . For this purpose, the pot-shaped receiving element  22  is provided with a centering shoulder, that is an annular depression  25 ,  28 , which is matched in terms of its diameter to the outer diameter of the bearing  23 . Simple and fast centred mounting of the pot-shaped receiving element  22  on the compressor housing  2  is possible by means of the centering shoulder  25 ,  28  and the centering device  26 . The bearing  23  advantageously simultaneously serves for mounting the shaft  21  of the clutch device  3 . In this way, aside from the needle-roller bearings provided in the clutch device  3  in any case for a free wheel, no additional bearings and no further housing is required, which promotes a relatively inexpensive realization of the invention. 
     The clutch device  3  is fastened on the crankshaft  12  by means of the collar nut  29 . 
       FIG. 3  shows a detail of the compressor  1  in a view from the side of the shaft, with the clutch device  3  not mounted. The pot-shaped receiving element  22  has a rotation-preventing lock in the form of projecting lugs, which engage with complementarily shaped rotation-preventing locking devices  31 ,  32  integrally formed in the compressor housing. The rotation-preventing locking devices  31 ,  32  are formed as depressions in the compressor housing  2 . It is also conceivable for the rotation-preventing locking devices  31 ,  32  to be formed in the compressor housing  2  as projecting locking lugs, with complementary depressions formed in the pot-shaped receiving element  22 . The pot-shaped receiving element  22  can be locked, so as to be prevented from rotating relative to the compressor  1 , by such construction. 
     As is evident from the above description, the pot-shaped receiving element  22  constitutes a significant improvement in the region of the interface between a compressor and a clutch device. The pot-shaped receiving element is, so to speak, a multifunctional part that integrates a multiplicity of structural improvements together in the interface region  40 . The pot-shaped receiving element may advantageously be produced relatively inexpensively as a metal deep-drawn part. The inventive embodiments can be realized inexpensively in this way. 
     It will be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.