DE3010933A1 - Drive arrangement for piston engines - Google Patents

Abstract

Secured to a drive shaft within a housing is a main bevelled gear. Several bevelled drive gears engage the main gear, each being secured to a gear shaft which extends through the exterior of the housing. - Secured to the end of each gear shaft is a gear wheel, which meshes with a similar, free-wheeling gear. A pair of eccentric arms are secured to each pair of meshing gear wheels, their ends being secured to a block. A piston rod is also secured to the block, so that the reciprocal motion of the piston rod may be transferred through the eccentric arms and the gear wheels to the drive gear and the main gear.

Description

- 4 - HOEGER, STELi-REOHT &"PARTNER

PATENTANWÄLTE UHLANDSTRASSE 14 c D 7000 STUTTGART 1 3 0 1 Q Q 3

A 44 o5o b Applicant: Energy Dynamics, Inc «

k- 176 526 Grand Avenue

March 18, 198o Oakland, California 9461o

United States

Drive mechanism for reciprocating machines

The invention relates to a drive mechanism for connecting reciprocating pistons of a piston machine with a rotatable shaft.

In the field of heat engines, the piston engines have been widely used in the last century found, primarily because of their reliability, because of their controllability and because of their desirable output power characteristics. Lately the interest in piston machines is with external combustion, such as sterling cycle machines and Rankine cycle machines.

Typically, a piston has a mechanism for transforming the reciprocating motion of the piston connected in a smooth rotary motion. Often this mechanism includes a piston rod, over which the piston is connected to a crank of a crankshaft. The eccentric arrangement with respect to the The crankshaft enables the translational movement of the piston rod to be transmitted and transformed the periodic one generated by the piston

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their direction changing force in a steady rotary motion. To convert the back and forth motion swashplate annulations are also known from pistons.

It is known that the eccentric arrangement of the crank portions of a crankshaft and the wobbling motion a wobble plate lead to the fact that the piston rods in addition to the translational movement also lateral Perform movements. These lateral movements are generally made possible by a piston pin, via which the piston is connected to the associated end of its piston rod. With this mechanical one System, however, are side forces that arise due to the lateral movements of the piston rod surrendered, not entirely avoided. On the other hand, these side forces, which are exerted by the piston pin on the Pistons are transferred, to an uneven wear of the piston rings or corresponding seals and wear of the seal provided between the piston rod and the cylinder end is. Furthermore, the lateral forces contribute to wear of the crankshaft bearings (or the swash plate bearings) at.

Although the wear, which results from the side forces on the piston rod, is caused by careful Constructive measures, kept within narrow limits through balancing and precise machining

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can be, it ultimately remains an essential factor which determines the life expectancy of such a Machine restricts. The end of this life expectancy is often determined by the point in time at which the machine needs to be overhauled, piston rings, seals, bearings and the like being replaced have to.

Based on the prior art, the invention is based on the object of providing a drive mechanism for the transformation of the translational movement of the pistons a piston machine in a steady rotary motion, in which the side forces on the piston Tangen caused wear is reduced to an absolute minimum.

This object is achieved in a drive mechanism of the type described in the opening paragraph according to the invention solved that a main gear is provided on the shaft with which at least one drive gear meshes that a piston rod protruding therefrom is provided on each piston, that several pairs of eccentric arms are provided are that the eccentric arms of each pair are connected at one end to one of the piston rods, that a plurality of driving gears are provided, each of which rotates with one of the drive gears is connected that a plurality of idle gears are provided, each of which to form a gear pair meshes with one of the driving gears

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and that the other ends of the eccentric arms of each pair are each connected to one of the gears of an associated gear pair.

The decisive advantage of the construction according to the invention is that actually none Lateral forces are exerted more on the piston rod and pistons and that is one of the main causes for the wear of the piston machine is switched off, which leads to a corresponding extension the expected service life. In addition, a simple sliding seal can be used for the piston rod, in order to obtain a gas-tight seal on the side of the piston connected to the piston rod, as he did for gaseous hydrogen and gaseous helium in the Sterling Cycle machines is needed.

In a preferred embodiment of the invention the drive mechanism has a housing which is penetrated by the output shaft, which is in the Housing is rotatably mounted by means of bearings. It also sits on the output shaft inside the housing a main gear designed as a bevel gear, which meshes with several drive gears, which also are arranged in the housing, with each drive gear at the - in relation to the housing - inner end a gear shaft is attached, which extends through the wall of the housing, to the outside via this

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Wall protrudes and is mounted in the wall by means of bearings.

A gear is arranged at the outer end of each transmission shaft, which is directly adjacent to one another arranged idling gear meshes. On the outer gear and the idle one meshing with it Gear are also one ends of a pair of eccentric arms articulated eccentrically, the other Ends are hinged to a connecting block. With this connection block is also the outer end connected to a piston rod, the inner end of which is connected to the piston itself. If the Piston moved back and forth, then this back and forth movement is transmitted via the piston rod to the connecting block, which in turn is transferred to the eccentric arms acts through which now a rotary movement of the outer gear and the associated idling Gear is brought about. This rotary movement is then transmitted to the relevant drive gear via the gear shaft and transferred from this to the main gear. This creates a continuous rotary motion causes the output shaft of the drive mechanism.

In the arrangement under consideration, the piston rod performs a pure translational movement with the eccentric arms of the same length along its longitudinal axis, so that no 'side forces on the piston rod or the

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associated piston take effect. This reduces the wear on the piston, on the piston rod, on the piston rings or the piston seals and on the cylinder wall is reduced considerably.

Further details and advantages of the invention are explained in more detail below with reference to drawings and / or are the subject of the subclaims. Show it:

Fig. 1 is a side view of a drive mechanism according to the invention in conjunction with a piston engine;

FIG. 2 is a plan view of the drive mechanism according to FIG. 1;

3 shows a section through a housing of the drive mechanism according to FIGS. 1 and 2;

Flg. 4 Schematic representations of various

until

Fi 6 working positions of essential elements

the drive mechanism according to FIGS. 1-3 to explain the function of the same;

7 shows a schematic representation of different piston positions for cylinders a piston machine for use in connection with the inventive method drive mechanism.

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As stated above, the present invention is essentially concerned with a drive mechanism for use in connection with a piston machine and for connecting the pistons of that machine with the output shaft of the same. The drive mechanism sets the reciprocating motion of the pistons into a uniform rotary movement of the output shaft and in this context offers the decisive factor Advantage that no lateral thrust is exerted on the pistons and piston rods of the machine. the Details of the concept of the invention are described below in connection with a 4-cylinder heat engine Preferred embodiment explained without applying the invention to 4-cylinder engines or to heat engines would be limited.

As shown in FIGS. 1 and 2, the drive mechanism according to the invention has a substantially rectangular one Housing 11 which is attached to one side of a base plate 12. With the other side of the basis plate 12 several cylinders 13 are connected. In each of the cylinders 13, a piston 14 is arranged, which by expanding Gases is driven, which are generated by external combustion of a fuel.

As FIG. 3 shows, a cavity 16 is provided in the housing 11 through which an output shaft 17 extends, the upper end of which still protrudes beyond the housing 11. The output shaft 17 is in at least

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two bearings 18, 19 freely rotatably mounted. Inside the housing 16 sits on the output shaft 17 Main gear 21 designed as a bevel gear.

A gear shaft 24 is provided on each of the four sides 22 of the housing, which is rectangular in cross-section, which is rotatably mounted in the associated side wall by means of a needle bearing. Furthermore sits on the inside At the end of the gear shafts 24 protruding into the housing 11, each has a gearwheel designed as a bevel gear 26, which meshes with the main gear 21. The gears 21 and 26 each have the same number of teeth, so that all four gears 26 with their associated gear shafts 24 are synchronized with the main gear 21 and the output shaft 17 rotate. Instead of the bevel gear 21, 26 can also a spur gear, a worm gear or a helical gear with any gear or reduction ratio can be used.

From the outside of each of the side walls 22 there is also a respective support arm 23, in which a gear shaft 27 is rotatably mounted, with the outer end of a gear 28 is rotatably connected. On the The outer end of each gear shaft 24 also has a gear 29, which is connected to the respectively assigned gear 28 combs. The gears 28 and 29 have the same diameter and the same number of teeth.

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An eccentric arm 31 is also attached to each of the gears 28 and 29 / with all eccentric arms 31 the have the same length. Each eccentric arm is attached to an associated crank of its gear by means of a needle bearing stored, which enables a low-friction pivoting movement of the eccentric arm 31 relative to the crank. The other ends of the eccentric arms 31 are each articulated in pairs per gear pair 28, 29 a connection block 32 connected. Each of the articulated connections again consists of a pin or stub axles and a needle bearing, so that the eccentric arms 31 also with respect to the connecting blocks 32 can be pivoted with little friction.

On each connecting block 32, a piston rod 33 is also attached, which the connecting block with the axially aligned piston 14 of the associated cylinder 13 connects. Here is for each piston rod a correspondingly aligned opening 15 is provided in the base plate 12 / in which a slide bushing or Stuffing box 25 is provided, which for example may consist of plastic material impregnated with a lubricant, so that the piston rods 33 freely rotatable and slidable in the base plate 12 are led.

The pistons 14 are in their associated cylinders 13 in a known manner as a function of the pressure difference reciprocated on both sides of the piston.

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The reciprocating movement of the pistons 14 is converted into a corresponding axial translational movement of the piston rods 33 and the attached connecting blocks 32 implemented. On the other hand are the eccentric arms 31 of each pair of eccentric arms with their associated gears 28, 29 connected so that the Center axes of the crank pin always lie on a line, which is parallel to the connecting line of the axes of rotation the gears 28, 29 runs. In addition, the central axis of the piston rods 33 extends so that they the connecting line of the axes of rotation of the associated gears 28, 29 intersects exactly in the middle. Because of this symmetrical structure is each connecting block 32 with a piston movement by its eccentric arms 31 moved along the center line between the gears 28 and 29. When there is a piston rod 33 and its associated connection block 32 to and fro and the associated gears 28, 29 over drive the eccentric arms 31, then any lateral evasive movement due to the symmetrical opposite assembly of the eccentric arms 31 prevented.

When a piston 14 moves from its top dead center via intermediate positions to its bottom dead center, as, this is shown in Fig. 7, then the gears 28, 29 on the eccentric arms 31 to corresponding Twisted angle as shown in Fig. 4-6. The connecting block 32 and the piston rod 33

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are always on the same of the eccentric arms 31 Axis held so that there is a purely axial translational movement for the piston rods and connecting blocks results. On the connection block or on the piston rod or on the guide 25 for the piston rod so there are no laterally directed forces, so that no such forces the piston rod 33 can be transferred to the piston 14 itself.

The direction of rotation of the output shaft 17 can be changed by changing the phase angle of each pair of each other opposite gears 26 (i.e. by specifying a different angular position of the gears by 180 ° for a specified piston position).

The above description shows that the drive mechanism according to the invention does not only perform the reciprocating motion the piston 14 converts into a rotary movement of the output shaft 17, but at the same time all lateral forces avoids which are transmitted from the piston rods to their bearings or the associated pistons could become. In this way, a major cause of wear on pistons, cylinders and bearings or Seals avoided. In addition, the efficiency of the associated machine is increased because the compression in the cylinders does not deteriorate during the running time of the machine. In addition, the life expectancy the machine is greatly increased because of the lack of side forces on the piston is greatly reduced.

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It should also be noted that each of the gear assemblies 28, 29 is dynamically balanced to avoid unwanted vibrations that occur at high speeds could avoid. Furthermore, the eccentric arms 31 are dynamically balanced in pairs, while at the same time tight manufacturing tolerances are observed.

A major advantage of the invention is that the requirements in terms of lubrication can be lowered because of the significantly reduced lateral forces on the pistons and piston rods. It is therefore possible to impregnate the gears and seals or guides and the bearings by means of suitable impregnations or to lubricate coatings, so that the usual lubrication systems, which use oil pumps, Oil centrifugal devices or oil spray devices work can be dispensed with. This is e.g. especially for sterling cycle machines, essential where the effectiveness of the heat exchangers has so far often been impaired by lubricating oil, which is fed to the provided seals emerges.

Finally, it should be emphasized once again that the piston machine used in each case is not a component of the invention. In addition, the drive mechanism according to the invention can be used in any form of machine reciprocating piston are used, for example in machines with external combustion, in steam engines and the same.

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Claims (7)

HOEGER, ST £ LLRfe £> H ¥ & .PA ^: RTNER PATENTANWÄLTE UHLANDSTRASSE 14 c D 70OO STUTTGART 1 3010933 Ά 44 o5o b Applicant: Energy Dynamics, Inc. March 18, 198o 526 Grand Avenue k - 176. Oakland, California 9461o United States Claims Drive mechanism for connecting reciprocating pistons of a reciprocating machine to a rotatable shaft, characterized in that on the shaft (17) a Main gear (21) is provided with which at least one drive gear (26) meshes that on each piston (14) a protruding piston rod (33) is provided that several pairs of Eccentric arms (31) are provided that the eccentric arms (31) of each pair at one end are connected to one of the piston rods (33) that several driving gears (28) are provided are, each of which is non-rotatably connected to one of the drive sz gear wheel (26) that several idling gears (29) are provided, each of which forming a gear pair (28, 29) meshes with one of the driving gears (28) and that the other ends of the eccentric arms (31) of each pair are connected to one of the gears (28, 29) of an associated gear pair. -2- 130040/0292 A 44 o5o b k - 176 - 2 - March 18, 198ο 2. Drive mechanism according to claim 1, characterized in that that all eccentric arms (31) have the same length and with the gears (28, 29) of their associated gear pair are symmetrically oppositely connected. 3. Drive mechanism according to claim 1, characterized in that the driving gears (28) and the idle gears (29) all have the same diameter and number of Have teeth. 4. Drive mechanism according to claim 1, characterized in that one ends of the eccentric arms (31) in pairs via a connecting block (32) are connected to their associated piston rod (33). 5. Drive mechanism according to claim 1, characterized in that the main gear (21) and the drive gears (26) are designed as bevel gears and that several gear shafts (24) are provided are, one of which is connected to each of the drive gears (26). -3- 130040/0292 A 44 o5o b k - 176 - 3 - March 18, 198ο 6. Drive mechanism according to claim 5, characterized in that each of the gear shafts (24) with one of the driving gears (28) is connected. 7. Drive mechanism according to claim 1, characterized in that that the drive gears (21) are arranged opposite one another in pairs and that the phase angle of each pair of drive gears (26) for reversing the direction of rotation of the rotatable Shaft (17) are selectively interchangeable. —4 "* 130040/0292