Claims
- 1. A piston-machine, in particular a piston-pump, having at least one cylinder-piston arrangement for the formation of a pulsating working space, a flexibly deformable tubular sealing member which is housed in said cylinder and serves to seal the working space and which bears via a liquid, in particular a lubricant, for sliding against a bearing surface, where a driving mechanism, in particular a rotary driving mechanism is provided for the piston, characterized in that with each piston (20) there is associated a cup-like driving member (30) which embraces the associated cylinder (25) externally and extends over at least part of the length of the cylinder and can be set in oscillatory motion by the driving mechanism and in that a pulsating secondary space (35) formed at the outside of the cylinder (25) by the driving member (30) to correspond with the oscillating working motion is connected via at least one balancing channel (40) of large cross-sectional area to a pressure-balancing chamber.
- 2. A piston-machine as in claim 1, characterized in that as the pressure-balancing chamber for the pulsating secondary space (35) a storage chamber for lubricant or conveying medium is provided.
- 3. A piston-machine as in claim 1, characterized in that the pulsating secondary space (35) is connected through a choke channel (45) to a space (42) which lies at the end (25a) of the cylinder inside the driving member (30) and pulsates to correspond with the oscillating working motion.
- 4. A piston-machine as in claim 3, characterized in that the choke channel (45) is formed by a clearance volume between the inner face of the driving member (30) and the outside of the cylinder (25).
- 5. A piston-machine, in particular a piston-pump, having at least one cylinder-piston arrangement for the formation of a pulsating working space having force-feed lubrication which comprises a pressure lubrication pump, a return collector, a return pump and a storage chamber feeding the pressure lubrication pump, a flexibly deformable tubular sealing member which is housed in said cylinder and serves to seal the working space and which bears via a liquid, in particular a lubricant, for sliding against a bearing surface, where a driving mechanism, in particular a rotary driving mechanism is provided for the piston, characterized in that with each piston (20) there is associated a cup-like driving member (30) which embraces the associated cylinder (25) externally and extends over at least part of the length of the cylinder and can be set in oscillatory motion by the driving mechanism and further characterized by a bypass channel (130) connecting the storage chamber (110) to the return collector (120).
- 6. A driving motor or work machine as in claim 5, characterized by a bypass channel (130) having an adjustable or controllable correcting member (135) for restriction of the flow from the storage chamber (110) to the return collector (120).
- 7. A driving motor or work machine as in claim 6, characterized in that for the return collector a regulating or control device (140) is provided for the maintenance of a minimum filling and that this control or regulating device (140) is in operative connection with the correcting member (135) for the flow in the bypass channel (130).
- 8. A pump assembly comprising a housing having surface means for defining a cylindrical housing chamber, a reciprocatable working member disposed in said housing chamber, said working member having a head end portion and a tubular sidewall connected to the head end portion and having a cylindrical inner side surface and a cylindrical outer side surface which is disposed in engagement with said surface means, said head end portion of said working member having an inner side surface which partially defines a fluid receiving chamber, a tubular cylinder member fixedly connected with said housing and disposed in a telescopic relationship with said tubular sidewall of said working member, said cylinder member having a cylindrical inner side surface and a cylindrical outer side surface which cooperates with the inner side surface of the tubular side wall of said working member to at least partically define a first lubricant flow passage connected in fluid communication with the fluid receiving chamber, a piston disposed within said cylinder member, deformable tubular sealing means disposed within said cylinder member, said sealing means having a first end portion connected with said housing, a second end portion connected with said piston, an inner side surface which at least partially defines a variable volume working chamber, and an outer side surface which cooperates with the inner side surface of said cylinder member to at least partially define a second lubricant flow passage connected in fluid communication with the fluid receiving chamber, working fluid supply means for supplying fluid to the variable volume working chamber, drive means for reciprocating said working member and piston relative to said housing and cylinder member to deform said tubular sealing means and vary the size of said variable volume working chamber to pump fluid from said pump assembly, and lubricating fluid supply means for inducing a flow of fluid to and from said fluid receiving chamber through said lubricant flow passages during reciprocation of said working member and deformation of said tubular sealing means.
- 9. A pump assembly as set forth in claim 8 wherein said fluid receiving chamber is least partially defined by an end portion of said cylinder member, said fluid receiving chamber being varied in volume by reciprocation of said working member to pump fluid from said fluid receiving chamber to one of said lubricant flow passages.
- 10. A pump assembly as set forth in claim 8 and further including main reservoir means for holding a supply of fluid to be conducted to said variable volume working chamber, collector reservoir means for receiving fluid conducted to said pump assembly, return pump means for pumping fluid from said collector reservoir means to said main reservoir means, bypass passage means for conducting fluid from said main reservoir means to said collector reservoir means, and control valve means for controlling fluid flow through said bypass passage means as a function of the amount of fluid in said collector reservoir means to maintain at least a minimum amount of fluid in said collector reservoir means.
- 11. A pump assembly as set forth in claim 10 further including infeed pump means for pumping fluid from said main reservoir means to the variable volume working chamber.
- 12. A pump assembly as set forth in claim 8 wherein said pump assembly further includes main reservoir means for holding fluid said lubricating fluid supply means including lubricant pump means for pumping fluid from said main reservoir means to one of said lubricant flow passages and return passage means for conducting a flow of fluid from the other one of said lubricant flow passages to said main reservoir.
- 13. A pump assembly as set forth in claim 12 wherein said working fluid supply means includes infeed pump means for pumping fluid from said main reservoir means to the variable volume working chamber.
- 14. A pump assembly as set forth in claim 13 wherein said lubricant pump means and said infeed pump means are driven by said drive means.
- 15. A pump assembly as set forth in claim 8 wherein said drive means includes a rotatable drive shaft and eccentric means connected with said drive shaft for reciprocating said working member and piston to pump fluid from said variable volume working chamber upon rotation of said drive shaft, said pump assembly further including main reservoir means for holding a supply of fluid, infeed pump means connected in fluid communication with said main reservoir means and the variable volume working chamber and driven by said drive shaft for pumping fluid from said main reservoir means to the variable volume working chamber upon rotation of said drive shaft, said lubricating fluid supply means including lubricant pump means connected in fluid communication with said main reservoir means and one of said lubricant flow passages and driven by said drive shaft for pumping fluid from said main reservoir means to the one lubricant flow passage upon rotation of said drive shaft.
- 16. A pump assembly as set forth in claim 15 further including collector reservoir means for receiving fluid conducted to said pump assembly, return fluid pump means connected in fluid communication with said collector reservoir means and said main reservoir means and driven by said drive shaft for pumping fluid from said collector reservoir means to said main reservoir means upon rotation said drive shaft.
- 17. A pump assembly as set forth in claim 16 further including bypass passage means for conducting fluid from said main reservoir means to said collector reservoir means and control valve means for controlling the flow of fluid through said bypass passage means to maintain a minimum quantity of fluid in said collector reservoir means.
Priority Claims (1)
| Number |
Date |
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| 5779/79 |
Jun 1979 |
CHX |
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Parent Case Info
This application is a continuation of application Ser. No. 159,617 filed June 16, 1980, now abandoned.
The invention refers to a driving motor or work machine, in particular a piston-pump, having at least one cylinder-piston arrangement for the formation of a pulsating working space, in particular having a flexibly deformable preferably tubular sealing member which serves to seal the working space and which bears via a liquid, in particular a lubricant, for sliding against a bearing surface, where a driving mechanism, in particular a rotary driving mechanism is provided for the piston. Machines of this kind are known, for example, from West German O/S 25 54 733.
Piston-machines which generally exhibit a crank or eccentric drive are fundamentally burdened with a comparatively high structural outlay and space requirement for the driving mechanism with respect to the usable swept volume. This applies in particular for the known piston-pumps having an elastically deformable sealing tube because the deformation during the stroke with respect to the stretching of the sealing material permissible in continuous service amounts to only a fraction of the length of tube. The structural length of the cylinder-piston arrangement with respect to the usable swept volume is thereby increased. Devices for the execution having support of the elastically deformable sealing tube by means of pressure lubrication have a similar influence. There exists therefore in the case of piston machines in general and in particular in the case of those of the kind mentioned above a need for reduction in the space requirement, as far as possible without essential increase in the structural outlay and whilst preserving a comparatively simple construction.
The object of the invention is therefore the creation of a piston driving motor or work machine which is distinguished by a comparatively short structural length of the cylinder-piston arrangement inclusive of the adjoining parts of the driving mechanism. The solution of this problem is characterized in accordance with the invention by the features specified in claim 1. The construction as therein provided form, of the driving member to surround the cylinder, being, for example, a plunger or the like, of a kind ordinary in itself, which cooperates with an eccentric driving mechanism, enables with the same length for bearing and guidance of this driving member--oscillating to correspond with the working motion--fundamentally a considerable shortening of the structural length of the cylinder-piston arrangement. The readily possible thinwalled construction of the section of the driving member which surrounds the cylinder, moreover allows the avoidance of a considerable increase in diameter of the cylinder-piston arrangement. The reduction in the structural length of the cylinder-piston arrangement becomes particularly advantageously noticeable in the case of star-shaped multi-cylinder arrangements, because this structural length reduces the overall diameter of the pump.
In the case of constructions of the present kind there results on the outside of the cylinder enclosed by the driving member corresponding with the oscillating working motion of the latter, a pulsating secondary space which in the case of ordinary pistons with seepage from the working space or respectively in the case of hermetical sealing of the working space by means of the aforesaid elastically deformable sealing tube supported by pressure lubrication, can fill with the discharged lubricant. For mastery of the problems resulting from this, of the carrying away of the liquid, an advantageous further developement of the invention provides for at least one balancing channel of large cross-sectional area between the pulsating secondary space and a pressure-balancing chamber. Shock pressures inside the cylinder-piston arrangement are thereby avoided in a simple way and in particular satisfactory carrying away is guaranteed even of fairly large throughput quantities of lubricant. In that case a storage chamber which exists in any case for lubricant or conveying medium (with regard to the carrying away of circulating lubricant or respectively leaking conveying medium out of the working space) is advantageously provided as the pressure-balancing chamber for the pulsating secondary space.
A further development of the invention, extending from the aforesaid aspects, provides that the pulsating secondary space is connected through a choke channel to a space which lies at the end of the cylinder inside the driving member and pulsates to correspond with the oscillating working motion. Through this construction the pulsating space between the end of the cylinder and the driving member in which collects the lubricant escaping from the cylinder or from the sealing tube or respectively the seepage from the working space, is employed as a pumping or auxiliary working space for the continuous ejection of the liquid which collects, in which case the choke channel in a particularly simple way restricts the return of the liquid from the secondary space relieved of pressure at the other end of the driving member to a small amount. Hence the choke channel acts after the style of a non-return valve.
Another further development of the invention which may be applied particularly advantageously in combination with the aforesaid features of the invention, but if necessary also independently of them in the case of other kinds of driving motors or work machines, e.g., piston machines, refers to a forced-feed lubrication such as may be employed in particular for the lubrication and support of an elastically deformable sealing tube in the case of its sliding motion against a bearing surface. In the case of a machine having forced-feed lubrication which exhibits a pressure lubrication pump, a return collector, a return pump and a storage chamber feeding the pressure lubrication pump, this further development of the invention is characterized by a bypass channel connecting the storage chamber to the return collector and having an adjustable or controllable correcting member for restriction of the flow from the storage chamber to the return collector. This construction in a simple way enables reliable filling and thereby satisfactory operation of the return pump and hence the maintenance of the lubricant pressure essential to the overall safety in operation. This is particularly significant in the case of high-pressure pumps having lubricated sealing tubes, because a breakdown of the lubrication at the bearing surface may very quickly have damage to the sealing tube as a result.
Driving motors and work machines, in particular piston-machines, of the present kind, in the case of high power-densities demand special measures for reliable lubrication of the highly loaded bearing points and the sliding surfaces of the piston. For doing this in general a forced-feed lubrication is provided with a lubricant cooling device. The object of the invention, namely, primarily the reduction of the space requirement whilst preserving a comparatively low structural outlay extends accordingly also to the construction of the forced-feed lubrication and in particular the cooling device, because these structural units--above all the cooling device--in the case of ordinary executions exhibit comparatively large dimensions.
In solution of the posing of the problem as regards the forced-feed lubrication and the cooling device it is in accordance with the invention provided that the cooling device exhibits at least one heat exchanger to which the lubricant and the working medium of the machine are admitted. In this way not only can the usual costly and spatially large devices for the admission to coolers or heat exchangers of external cooling media, say, outside air set in motion by a fan, be saved, but on the contrary particularly advantageous possibilities of integration of such a heat exchanger into the machine housing also result, from which follows a further saving of space. In that case it proves particularly advantageous to arrange the heat exchanger in the region of a lubricant storage chamber or collector of the forced-feed lubrication.
A further development of the invention refers to that known construction of work machines made as pumps, in which a prefeed pump for pressure-feeding the working medium to the inlet side of the pump is provided. A particularly intensive exchange of heat between the working medium and the lubricant and thereby again the possibility of reducing the space for the cooling device results if instead in accordance with the invention the working medium inlet side of the heat exchanger is connected to the outlet side of the prefeed pump. The prefeed pump which exists anyhow is thereby made use of for forced circulation of the cooling working medium in the lubricant heat exchanger. A particularly advantageous execution results in this connection by the construction of the working medium system of the heat exchanger as a return flow branch between the outlet side and the inlet side of the prefeed pump. In order in this case to keep the return flow of the working medium within proper limits, in accordance with an advantageous refinement of the invention a choke, preferably an adjustable choke, may be arranged in the heat exchanger return flow branch.
US Referenced Citations (10)
Continuations (1)
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Number |
Date |
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| Parent |
159617 |
Jun 1980 |
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Patent Grant
4671743
