DE102014115041A1 - generator - Google Patents

Abstract

The invention relates to a power generator, in particular for a hybrid vehicle, with a two-cylinder reciprocating engine having two pistons, which are guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts (10, 11) connected to the piston by connecting rods and a generator (15) which can be driven by the crankshafts, wherein the crankshafts (10, 11) are mechanically coupled in phase, wherein the crankshafts (10, 11) are coupled by a double-toothed chain (14), wherein the first side of the toothed chain (14) with a sprocket (12) of a crankshaft (10) and the second side of the toothed chain (14) with a sprocket (13) of the other crankshaft (11) are engaged and wherein the toothed chain (14) and the crankshafts (10, 11) form a sprocket drive connected to the generator (15).

Description

The invention relates to a generator with the features of the preamble of claim 1. Such a generator is, for example WO 2012/056275 A1 known.

In the known power generator, the drive of the generator by a two-cylinder reciprocating engine with opposing crankshafts, which are coupled by spur gears to the shaft journal, realized. The spur gears engage with each other and synchronize the opposing crankshafts. The generator is coupled to one of the two crankshafts by an idler gear meshing on one side with the spur gear of the crankshaft in question and on the other hand with another spur gear on the drive shaft of the generator.

The reciprocating engine of the known power generator already has excellent characteristics with regard to smoothness, low vibration and the compact design. The generator is therefore preferably used for driving a hybrid vehicle. In order to dampen the noise of the engine, the spur gear set of the two crankshafts is elaborately machined.

The invention is based on the object to improve the series suitability of the known power generator, without giving up the excellent engine characteristics, such as smoothness, low vibration and compactness. The invention is further based on the object to provide a vehicle with such a generator.

The object is achieved by a generator with the features of claim 1 and by a vehicle having the features of claim 14.

The invention is based on the idea of proposing a generator, in particular for a hybrid vehicle, which has a two-cylinder reciprocating engine and a generator. The two-cylinder reciprocating engine has two pistons, which are guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts. The crankshafts are connected to the pistons by connecting rods. The generator is driven by the crankshaft, the crankshafts are mechanically coupled in phase. According to the invention, the crankshafts are coupled by a toothed chain which is toothed on both sides, wherein the first side of the toothed chain engages with a sprocket of one crankshaft and the second side of the toothed chain engages with a sprocket of the other crankshaft. The sprocket and crankshafts form a sprocket drive connected to the generator.

The direction of rotation reversal of the two crankshafts is achieved by the toothed chain on both sides, so that the two crankshafts are synchronized. For this purpose, the invention provides that the first side of the toothed chain with the one of the two sprockets and the second side of the toothed chain are in engagement with the other of the two sprockets. As a result, the two-cylinder reciprocating engine retains its excellent properties in terms of smoothness, low vibration and compactness. The sprocket wheels provided for the transmission of the drive torques from the crankshafts to the toothed chain are easy to manufacture, so that the production cost of the power pack is significantly reduced. The generator according to the invention is therefore suitable for series production in an advantageous manner.

The use of the toothed chain opens up various design possibilities, as the generator is spatially arranged with respect to the reciprocating engine. Moreover, the use of the double-sided toothed chain has the advantage that further engine components can be drive-connected to the crankshafts in a very simple and space-saving manner. The specific embodiment of these engine components is the subject of the dependent claims.

In a preferred embodiment, the generator is arranged fixedly or interchangeably laterally next to the sprockets in a housing of the engine. The reciprocating engine and the generator thus form a unit that can be installed in different positions, such as lying or standing, in a vehicle. The replaceable arrangement of the generator improves the serviceability of the generator.

In order to at least partially compensate the alternating torques of the generator, the generator and the toothed chain advantageously move in opposite directions during operation.

In a preferred embodiment, the generator is arranged between a tensioning wheel and a deflection wheel for the toothed chain. The first side of the toothed chain is in each case with the tensioning wheel and the guide wheel and the second side of the toothed chain with a drive pinion of the generator in engagement. The arrangement of the generator between the tensioning and deflection wheel is particularly space-saving. The direction of rotation reversal between the generator and the toothed chain is achieved in this embodiment in that one side of the toothed chain meshes with the tensioning wheel and the deflection wheel and the other side of the toothed chain engages with the drive pinion of the generator. The tensioning wheel enables automatic tensioning of the toothed chain. This can be done mechanically, for example by means of a spring, and / or hydraulically. So can with the help of a Oil pump can be built up a hydraulic pressure, which leads to a tension of the silent chain. The automatic tensioning of the toothed chain optimizes the chain run and thus reduces the wear of the toothed chain and the sprockets or drive pinions. In addition, a hydraulic damping or a friction damping for the tensioning wheel is provided. The hydraulic damping can be operated by the oil pump. The tensioning wheel may comprise a self-adjusting or self-locking mechanism.

For balancing the second-order inertial forces, two counterbalancing balance shafts are preferably connected to the toothed chain, wherein the first side of the toothed chain engages with a drive pinion of one balance shaft and the second side of the toothed chain with a drive pinion of the other balancer shaft. This coupling of the toothed chain with the balance shafts leads to a reversal of rotation of the two balance shafts, so that they rotate in opposite directions to each other.

If the pressure angle of the toothed chain in the front in the direction of movement of the toothed chain sprocket between 60 ° and 80 °, in particular between 65 ° and 75 °, a particularly good torque transfer between the silent chain and the sprocket is achieved.

If the toothed chain forms a straight chain distance in the course between the sprockets of the crankshafts, which is at least approximately 30 mm, the running properties of the toothed chain, specifically the inlet of the toothed chain, are improved in the front sprocket in the direction of movement of the toothed chain. In the case of an ignition offset of 360 °, the situation arises that the crankshaft which is located in the running direction of the toothed chain is in the working stroke while the front crankshaft is in the intake stroke. This leads to a high force which is passed over the Zugtrum the chain to the generator. Meanwhile, the front crankshaft is driven via the lobes of the silent chain in the intake stroke. At this time, the entire play of the toothed chain is in the straight piece between the two crankshafts, since both chain ends are under tension. The toothed chain on both sides can thus spread the teeth on the outside of a curvature, so that a clean running in a curved state in an opposite curvature is not possible without wear and noise. The straight chain link compensates for this, which reduces wear and noise.

It has proven to be advantageous if the toothed chain is a Wiegezapfenkette.

A further reduction of the gas exchange torque and the load of the toothed chain drive is achieved in that the ignition interval is 0 ° crank angle. This applies in the event that the engine is a four-stroke engine. The gas alternating torques of both cylinders occur at 0 ° Zündversatz at the same time and compensate each other because of the opposite movement of the crankshaft. In addition, the stress on the chain drive is significantly reduced, since both crankshafts simultaneously produce torque and transmit this via the Zugtrum the silent chain together on the generator. The Lostrum the chain experienced by less alternating load and the shrinkage of the chain in the front in the direction of movement of the toothed crankshaft is substantially free of vibration.

For the compensation of inertial forces / moments, it is particularly advantageous if the drive pinion and the sprockets of the crankshafts are in a ratio of 1: 2, so the drive pinion rotate at twice the speed. This concerns in particular the drive pinion of the balance shafts.

In a preferred embodiment, the cylinders are arranged parallel or inclined to each other with an inclination angle of 3 ° to 7 °, in particular 4 ° to 6 ° per cylinder. The angle of inclination is measured between a vertical plane and the central axis of the respective cylinder. In other words, the total angle between the two cylinders is the sum of the inclination angles of the individual cylinders. The parallel arrangement of the cylinder is structurally easy to implement. The inclined arrangement has the advantage that the housing can be made compact in the cylinder area.

By a restriction of the cylinder to the counter-pressure side and a phase-shifted arrangement of the counterweights on the crankshafts smoothness of the generator is improved overall. The distance of the cylinder center axes is smaller than the center distance of the crankshaft in this case.

The smoothness is further improved by the fact that the opposite direction to the generator rotating crankshaft has a larger flywheel than the same direction rotating to the generator crankshaft.

The invention will be explained in more detail below with reference to the accompanying schematic figure with reference to an embodiment.

The single FIGURE shows a plan view of the front of a generator according to an embodiment of the invention.

The generator shown in the single figure is preferably, but not exclusively, used in a hybrid vehicle for charging the hybrid battery. Other applications where it depends on a quiet running, low-vibration and compact reciprocating engine, are possible. Not shown in the single figure are the two pistons and the two cylinders, which are guided in tandem arrangement. The two opposing crankshafts 10 . 11 are drive-connected to the two pistons by connecting rods. In other words, each crankshaft has its own piston-cylinder arrangement. The cylinder center axes run in one and the same plane transverse to the crankshaft axes (tandem arrangement). The two crankshafts are in opposite directions, ie they rotate in the opposite direction. This is achieved by a corresponding arrangement of the crank pin and connecting rod in a conventional manner.

In the single figure, the shaft journal of the two crankshafts 10 . 11 to see that out of the case 22 of the generator. On the shaft journal are coaxial and non-rotatable two sprockets 12 . 13 arranged. The two sprockets 12 . 13 are in the same plane of rotation. To synchronize the two sprockets 12 . 13 is a double-sided toothed chain 14 provided, the first page with the first sprocket 12 and its second side with the second sprocket 13 engaged. This reverses the direction of rotation. One of the two sides of the tooth chain 14 can also be referred to as a back. The tooth chain 14 forms together with the two crankshafts 10 . 11 a sprocket drive with a generator 15 connected is. Together form the two-cylinder reciprocating engine and the generator 15 the generator or power generator, which can be used for example for charging a battery, in particular for a hybrid drive.

As can also be seen in the single figure, the generator is 15 in the same plane of rotation as the sprockets 12 . 13 arranged laterally next to these. The axis of rotation of the generator runs 15 above the two crankshaft axes, which are arranged in one and the same horizontal plane. Between the generator 15 and the two sprockets 12 . 13 runs the Zugtrum the tooth chain 14 , The coupling of the generator 15 with the tooth chain 14 done by a drive pinion 24 that on the generator drive shaft 21 sitting. The drive pinion 24 stands with the same, especially the first side of the silent chain 14 in engagement, as in the direction of movement of the toothed chain 14 front sprocket 12 , The generator drive shaft 21 and the first sprocket 12 turn in the same direction. Accordingly, the generator drive shaft rotate 21 and in the direction of movement of the toothed chain 14 rear sprocket 13 in opposite directions. The generator 15 is arranged so that the Zugtrum the toothed chain 14 approximately horizontally between the drive pinion 24 of the generator 15 and the first sprocket 12 runs. Another height position of the drive pinion 15 or of the generator 15 based on the crankshaft axes is possible.

As can be seen in the single figure, are the generator 15 and the reciprocating engine in the same housing 22 of the generator provided. This can be the generator 15 in the case 22 be arranged fixed or interchangeable.

By connecting the generator 15 with the first side of the silent chain 14 is achieved that the generator 15 and the tooth chain 14 to move in opposite directions during operation. In other words, the tooth chain moves 14 in the counterclockwise direction, whereas the generator 15 turns clockwise.

The generator 15 , specifically the drive shaft 21 of the generator, is between a tensioning wheel 16 and a diverter wheel 17 arranged. The tensioning wheel 16 is adjustable in the housing 22 stored to adjust the chain tension can. The diverter wheel 17 serves to guide the toothed chain 14 and is the tension wheel 16 in the direction of movement of the toothed chain 14 upstream. The tensioning wheel 16 is below the drive shaft 21 arranged the generator and has a pinion with the toothed chain 14 engaged. The diverter wheel 17 is above the drive shaft 21 arranged the generator and also has a pinion, with the toothed chain 14 engaged. The tensioning wheel 16 and the diverter wheel 17 each stand with the other side of the silent chain 14 as the generator 15 engaged, resulting in the reversal of direction between the tensioning wheel 16 and the diverter wheel 17 on the one hand and the generator 15 on the other hand. In other words, turn the tension wheel 16 and the diverter wheel 17 as well as in the direction of movement of the toothed chain 14 rear sprocket 13 in the same direction.

With a comparatively long length of the toothed chain 14 , Especially with a large distance between the balance shafts 18 . 19 from the tooth chain 14 must be bridged freely, can advantageously be provided a guide rail for guiding a free chain line.

The tensioning wheel 16 and the diverter wheel 17 are arranged obliquely offset one above the other. The center distance between the tensioning wheel 16 and the diverter wheel 17 is sized so that the drive shaft 21 the generator can be arranged therebetween. The tensioning wheel 16 is below the horizontal plane through the two crankshaft axes and the diverting wheel 17 arranged above this horizontal plane. The diverter wheel 17 is, based on the tensioning wheel 16 , arranged offset inwards, so that the toothed chain 14 between the tensioning wheel 16 and the diverter wheel 17 inward towards the two crankshafts 10 . 11 inclined.

The tooth chain 14 is with two counter-balance shafts 18 . 19 connected. This is the first side of the tooth chain 14 with the drive pinion of the first balancer shaft, ie in the direction of movement of the toothed chain 14 rear balancer shaft 18 , connected. The second side of the tooth chain 14 is with the drive pinion of the second balance shaft 19 that is, in the direction of movement of the toothed chain 14 front balancer shaft 19 , connected. This results in the reversal of the direction of rotation of the two balance shafts 18 . 19 , The two balance shafts 18 . 19 are at the same height as the diverter wheel 17 arranged. Another arrangement of balance shafts 18 . 19 is possible. The two balance shafts 18 . 19 are in the Lostrum of the dental chain 14 arranged. As can be seen in the single figure, the two balance shafts 18 . 19 counterweights 23 on, which are arranged in phase, but in opposite directions. The balance shafts 18 . 19 work together to balance the second-order mass forces. The center distance between the two balance shafts 18 . 19 is dimensioned so that in between space is provided for the cylinder not shown in the single figure.

Starting from the direction of movement of the toothed chain 14 first sprocket 12 the tooth chain runs 14 just between the first and second sprockets 12 . 13 and thereby forms a straight chain line 20 with a length of approx. 30 mm. The tooth chain 14 wraps around in the direction of movement of the tooth chain 14 rear sprocket 13 , After the sprocket 13 is the tooth chain 14 with the second balance shaft 19 coupled and runs from there under a change of the engagement side of the silent chain 14 to the first balance shaft 18 , From the first balance shaft 18 the tooth chain runs 14 continue to the pulley 17 , wherein here again a change of the engagement side of the toothed chain and thus a reversal of rotation takes place. From the diverter wheel 17 the tooth chain extends 14 continue to the tensioning wheel 16 that with the same side of the tooth chain 14 like the diverter wheel 17 connected is. After the tension wheel 16 is the tooth chain 14 over the drive pinion 24 of the generator 15 guided, with the engagement side and thus change the direction of rotation. After the drive pinion 24 of the generator 15 closes the course of the tooth chain 14 on the first sprocket 12 ,

The pressure angle of the toothed chain 14 in all driving sprockets 12 . 13 or the driven gears or pinions 15 . 18 . 19 is between 60 ° and 80 °, in particular between 65 ° and 75 °. The gear ratio between the drive pinions 15 . 18 . 19 and the sprockets 11 . 12 is 1: 2.

The double-sided toothed toothed chain has, in a manner known per se, toothed plates which engage in the corresponding teeth of the sprockets 12 . 13 intervene and take over the traction. The cradle link of the silent chain has pivot pins or cradles that allow movement of the cog chain. Such tooth chains are well known. The special feature of the tooth chain used above 14 is that the tooth chain is toothed on both sides.

To move a camshaft of the reciprocating engine connects a timing chain 26 the first crankshaft 10 with a camshaft sprocket 25 , which is arranged on the front side of the camshaft. This is indicated by the first crankshaft 10 a chain sprocket 27 on which is stuck with the first crankshaft 10 and / or the first sprocket 12 connected is. The gear ratio between the sprocket 27 and the camshaft sprocket 25 is in a conventional manner 1: 2.

LIST OF REFERENCE NUMBERS

10, 11

crankshafts

12, 13

Sprocket

14

toothed chain

15

generator

16

tensioning wheel

17

guide wheel

18, 19

balancer shafts

20

chain track

21

Generator drive shaft

22

casing

23

counterweight

24

Drive pinion of the generator

25

camshaft sprocket

26

timing chain

27

sprocket

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012/056275 A1 [0001]

Claims (14)

Generator, in particular for a hybrid vehicle, having a two-cylinder reciprocating engine, the two pistons, which are guided in two cylinders in tandem arrangement, and two counter-rotating crankshafts ( 10 . 11 ), which are connected to the piston by connecting rods, and a generator which is drivable by the crankshaft, wherein the crankshafts ( 10 . 11 ) are mechanically coupled in phase, characterized in that the crankshafts ( 10 . 11 ) by a toothed chain ( 14 ), wherein the first side of the silent chain ( 14 ) with a sprocket ( 12 ) of a crankshaft ( 10 ) and the second side of the silent chain ( 14 ) with a sprocket ( 13 ) of the other crankshaft ( 11 ) and wherein the toothed chain ( 14 ) and the crankshafts ( 10 . 11 ) form a toothed chain drive which is connected to the generator ( 15 ) connected is. Generator according to claim 1, characterized in that the generator ( 15 ) laterally next to the sprockets ( 12 . 13 ) is fixedly or interchangeably arranged in a housing of the motor. Generator according to claim 1 or 2, characterized in that the generator ( 15 ) and the tooth chain ( 14 ) move in opposite directions during operation. Generator according to one of the preceding claims, characterized in that the generator ( 15 ) between a tensioning wheel ( 16 ) and a deflection wheel ( 17 ) for the tooth chain ( 14 ), wherein the first side of the silent chain ( 14 ) each with the tensioning wheel ( 16 ) and the deflection wheel ( 17 ) and the second side of the silent chain ( 14 ) with a drive pinion ( 21 ) of the generator ( 15 ) are engaged. Generator according to one of the preceding claims, characterized in that two counter-rotating balancing shafts ( 18 . 19 ) with the toothed chain ( 14 ), wherein the first side of the silent chain ( 14 ) with a drive pinion of a balance shaft ( 18 ) and the second side of the silent chain ( 14 ) with a drive pinion of the other balance shaft ( 19 ) are engaged. Generator according to one of the preceding claims, characterized in that an engagement angle of the toothed chain ( 14 ) in the direction of movement of the toothed chain ( 14 ) front sprocket ( 12 ) is between 60 ° and 80 °, in particular between 65 ° and 75 °. Generator according to one of the preceding claims, characterized in that the toothed chain ( 14 ) in the course between the sprockets ( 12 . 13 ) of crankshafts ( 10 . 11 ) a straight chain line ( 20 ), which is at least about 30mm. Generator according to one of the preceding claims, characterized in that the toothed chain ( 14 ) is a cradle chain. Generator according to one of the preceding claims, characterized in that the engine is a four-stroke engine, wherein the ignition interval is 0 °. Generator according to one of the preceding claims, characterized in that the drive pinions and the sprockets ( 12 . 13 ) of crankshafts ( 10 . 11 ) in a ratio of about 1: 2 are. Generator according to one of the preceding claims, characterized in that the cylinders are arranged parallel or inclined to each other with an inclination angle of 3 ° to 7 °, in particular 4 ° to 6 °, per cylinder. Generator according to one of the preceding claims, characterized by an offset of the cylinders to the counter-pressure side and a phase-shifted arrangement of the counterweights on the crankshafts ( 10 . 11 ). Generator according to one of the preceding claims, characterized by the crankshaft rotating in opposite directions to the generator ( 11 ) a larger flywheel than the same direction to the generator rotating crankshaft ( 10 ) having.  Vehicle, in particular hybrid vehicle, with a generator according to one of the preceding claims.

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