External heat engine device

Abstract

An external-heat engine device working on a Rankine cycle, and preferably an organic Rankine cycle. The external-heat engine, which is designed to give operational advantages, includes a cylinder block, a top cover and a bottom tray with sealing surfaces arranged to be joined together and to rest against complementarily fitting covers, each sealing surface resting sealingly against only one opposite sealing surface.

Claims

1. An external-heat engine of a piston type working on a Rankine cycle, the external-heat engine comprising a cylinder block, a cylinder head and an oil sump with sealing surfaces arranged to be joined together and to rest against complementarily fitting covers, each sealing surface being arranged to rest sealingly against only one opposite sealing surface, wherein a first valve gear and a second valve gear are arranged in the cylinder head, a first intermediate gear being arranged to engage with the second valve gear via a second intermediate gear.

2. The external-heat engine according to claim 1, wherein the first intermediate gear is arranged to engage with a crankshaft gear.

3. The external-heat engine according to claim 2, wherein the first intermediate gear is engaged with said crankshaft gear via a third intermediate gear.

4. The external-heat engine according to claim 1, wherein at least one of the valve gears is connected to a camshaft.

5. The external-heat engine according to claim 1, wherein at least one of the valve gears is connected to a rotary valve.

6. The external-heat engine according to claim 1, wherein at least one of the valve gears is connected to a valve-actuating mechanism.

7. The external-heat engine claim 1, wherein said external-heat engine is pressurized and arranged to be pressure-tight towards the surroundings.

8. The external-heat engine according to claim 7, wherein said external-heat engine is dimensioned to resist an overpressure of at least 5 bar.

9. The external-heat engine according to claim 7, wherein a generator is located inside the pressure-tight external-heat engine.

10. The external-heat engine according to claim 1, wherein lubrication channels are provided in a shaft spreader, arranged for supply of lubricant to a gear bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings, in which:

(2) FIG. 1 shows a simplified side view of an external-heat engine according to the invention;

(3) FIG. 2 shows the sealing surface of the cylinder block against the top cover in a simplified manner;

(4) FIG. 3 shows an end view of the external-heat engine in a simplified manner, in which covers have been removed; and

(5) FIG. 4 shows the same as FIG. 3, but in an alternative embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) In the drawings, the reference numeral 1 indicates an external-heat engine, which includes a cylinder block 2, a top cover 4 and a bottom tray 6.

(7) A piston 8, see FIG. 2, is connected to a crankshaft 10 (see FIG. 3) in a manner known per se.

(8) The cylinder block 2 is formed with a first sealing surface 12 facing the top cover 4 and being arranged to rest sealingly against a second sealing surface 14 of the top cover 4.

(9) FIG. 2 shows the first sealing surface 12, which has a piston opening 16 and a gear opening 18 for a first intermediate gear 20. Other openings necessary per se in the first sealing surface, such as bolt holes, are known to a person skilled in the art and are not shown.

(10) The second sealing surface 14 is thus resting, typically via a top gasket not shown, against only the first sealing surface 12, which is complete; that is to say, there are no so-called T-joints, at which the end portion of a seal is typically perpendicular to a second seal, or other forms of combined sealing surfaces.

(11) Correspondingly, sealing surfaces 22 of the cylinder block 2 seal against respective sealing surfaces of the bottom tray 6, of a timing-element cover 24 and of a generator cover 26.

(12) The sealing surfaces 22 of the top cover seals in a corresponding manner against the sealing surface of a gear cover 28 and against a sealing surface of a valve cover 30.

(13) The crankshaft 10 is provided with a crankshaft gear 32 at one end portion (see FIG. 3). The crankshaft gear 32 is formed with a first set of teeth 34 and a second set of teeth 36. It is also obvious that said two sets of teeth 34, 36 may be parts of two gears separate per se.

(14) In this preferred embodiment, the top cover 4 is formed with a rotary valve 38 on the inlet side and seat valves, not shown, on the outlet side, the seat valves being driven by a camshaft 40.

(15) The rotary valve 38 and the camshaft 40 are driven by means of a first valve gear 42 and a second valve gear 44, respectively. The valve gears 42, 44 are driven via the first intermediate gear 20, which is in mesh with the first set of teeth 34 on the crankshaft gear 32, and a second intermediate gear 43 provides for further driving between the first intermediate gear 20 and the second valve gear 44. The ratios of the tooth numbers of the valve gears 42, 44 to the tooth number of the first set of teeth 34 are chosen to be such that the rotary valve 38 and the camshaft 40 are rotated at half speed and full speed, respectively, in relation to the crankshaft 10. The first intermediate gear 20 is supported in the cylinder block 2 by means of a bearing 46 sitting on a shaft 48.

(16) A lubricant pump 50 is arranged in or at the bottom tray 6, and the lubricant pump 50 preferably consists of, among other things, a pump casing formed as part of the cylinder block 2. The lubricant pump 50 is driven by a pump gear 42 via the second set of teeth 36 on the crankshaft gear 32.

(17) By letting both valve gears 42, 44 be driven by the first intermediate gear 20 and a second intermediate gear 43, respectively, the driving line 54 including the crankshaft gear 32, the first intermediate gear 20, the second intermediate gear 43 and the valve gears 42, 44 is substantially simplified. The solution makes it possible to dismantle the top cover 4 from the cylinder block 2 without dismantling the valve gear 42 and the second intermediate gear 43 from the top cover 4 or the intermediate gear 20 from the cylinder block 2.

(18) A generator 56 (see FIG. 1) is connected to the crankshaft 10 at the opposite end portion of the crankshaft 10 relative to the crankshaft gear 32. The generator 56 is inside the generator cover 26 in the cylinder block 2. The generator 56 includes a rotor 57, which is arranged on the crankshaft 10.

(19) In this preferred embodiment, a valve-actuating mechanism 58 is arranged between the first valve gear 42 and the rotary valve 38. Examples of valve-actuating mechanisms are given in the general part of the document.

(20) A lubricant supply with a spreader 60 is arranged at a gear bearing 62. The crankshaft 10, rotary valve 38, camshaft 40, shafts 41, 48 and lubricant pump 50 constitute gear bearings 62 as they each hold a respective gear, the crankshaft gear 32, the first valve gear 42, the second valve gear 44, the intermediate gears 20, 43 and the pump gear 52, respectively.

(21) In an alternative embodiment, see FIG. 4, the first intermediate gear 20 is driven by the first set of teeth 34 on the crankshaft gear 32 via a third intermediate gear 64.

(22) This embodiment may be practical if the distance between the crankshaft gear 32 and the valve gears 42, 44 is large. A sufficiently large, single first intermediate gear 20 may then be impractical.