JPH086642B2 - Heat engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat engine such as a crankcase pressurization type unlubricated compressor or a heat-driven engine, and particularly to prevent ingress of lubricating oil into its working space. It relates to a mechanism for doing.

[Conventional technology]

FIG. 6 is a cross-sectional view for explaining an oil spill prevention mechanism of a conventional heat engine, and this figure shows a Stirling engine which is one of typical heat engines to which the present invention can be applied. In the figure, reference numeral 1 is a crankcase, which is a basic structure of all the components of the Stirling engine. Reference numeral 2 denotes a flange fixed to the hole machined in the crankcase 1 with a fastening component such as a bolt, 3 denotes a bearing housing fixed to the crankcase 1 similarly to the flange 2.
4 is a flange fixedly fastened to the crankcase 1, 5 is a bearing fixed to the bearing housing 3, 6 is a bearing fixed to the flange 2, 7 is a crankshaft and is rotatably held by the bearings 5 and 6. The power generated by the Stirling engine is transmitted to the outside. 8 is the crankshaft 7
The mechanical seal attached to the has the effect of sealing the gas in the crankcase 1.

Further, 9 and 10 are balance weights for balancing the rotation of the crankshaft 7, which are fixed to the crankshaft 7. 11,12 are power piston connecting rods connected to the crankshaft 7 by bearings, 13 is a crosshead connected to the power piston connecting rods 11 and 12, and the power is supplied via the power piston rod 14. Piston 15
Are connected. Further, the outer circumference of the crosshead 13 is fitted to the inner circumference of the cylinder 16 so as to have a bearing function so as to be able to slide back and forth. Reference numeral 17 denotes an oil absorbing material provided in the space between the crosshead 13 and the power piston 15, that is, the distance chamber 28, which is made of a material that has air permeability and oil absorption, Absorbs scattered oil and oil attached to the power piston rod 14.

An oil splash prevention plate 24 is provided near the top of the crosshead 13 and is fixed to the crosshead 13. This has the effect of suppressing the oil splashing from the sliding portion of the crosshead 13 as little as possible. Further, if the surface of the oil splash preventive plate 24 is covered with a sponge-like porous material, it is even more effective. Reference numerals 18a and 18b respectively connect the distance chamber 28, which is a space accommodating the oil absorbing material 17, and the buffer chamber portion 29 of the crank chamber portion, that is, the space inside the crankcase 1, to the first and second portions.
The communication hole 18a is provided in the crosshead 13, and the communication hole 18b is provided in the cylinder 16 and the wall of the crankcase 1. Reference numeral 26 is an oil absorbent retainer that holds the oil absorbent 17.

A displacer connecting rod 19 is rotatably connected to the crankshaft 7 by a bearing. 20 is a piston pin, 21 is a displacer rod, which is connected to the displacer connecting rod 19 with the piston pin 20 as a contact, and fixedly connected to the displacer piston 22 through the crosshead 13, the power piston rod 14, and the power piston 15. ing. The reference numeral 23 is a lubricating oil for lubricating the moving part of the Stirling engine accumulated at the bottom of the crankcase 1.

FIG. 7 shows a crosshead, and the oil splash prevention plate 24a is fixed to the crosshead 13 via a spacer 26 by a fixing screw 27. The crosshead 13 slides on the cylinder 16, and the sliding portion is oil-lubricated.

Next, the operation of the conventional Stirling engine will be described.

In a so-called 1-cylinder 2-piston serial arrangement crankshaft type Stirling engine as shown in FIG. 6, the pressure fluctuation (the pressure generating mechanism is omitted) generated in the cylinder 16 acts on the power piston 15 to generate a force. Is transmitted to the power piston rod 14, the crosshead 13, and the power piston connecting rods 11 and 12. Then, the rotary work is output to the outside by the crankshaft 7. A part of this rotating work is transmitted to the displacer piston 22 to induce a reciprocating motion, thereby operating as a Stirling engine.

Oil splashed from the cross head 13 that is lubricated with oil and reciprocally slides is absorbed by the oil splash prevention plate 24 and the oil absorbing material 17 that has air permeability and oil absorbency.

[Problems to be Solved by the Invention]

However, when the oil splash prevention plate 24 is brought into contact with the cylinder 16 in order to suppress the amount of oil splash, the oil splash prevention plate 24 vibrates due to friction, and the oil absorbed here vibrates and jumps upward. Therefore, the oil splash prevention plate 24 is arranged so that the gap between the cylinder 16 and the cylinder 16 is as narrow as possible without coming into contact with the cylinder 16.

However, the oil particles that jump out directly through this gap hit the oil absorber 17 directly, shortening the performance life of the oil absorber 17, and this tendency becomes more severe when the engine rotates at high speed. Has become.

In addition, a heat engine invented by the authors (Practical application Sho 63-7462)
Due to the pressure difference between the buffer chamber 29 and the distance chamber 28 generated by the above, even if the engine is rotated at a high speed even if it is pushed back to the buffer chamber, the oil splashed from the sliding surface of the crosshead 13 is not oiled. There has been a problem that the amount of passage between the splash prevention plate 24 and the cylinder 16 increases.

The present invention has been made to solve the above problems, and an object thereof is to obtain a heat engine that can suppress the amount of splashing oil even in a high rotation state and can be used more stably. And

[Means for solving the problem]

In the hot gas engine according to the present invention, the pressure in the internal space of the power rod is kept higher than that in the lower space of the crosshead, and the seal mechanism for closing the sliding portion gap between the crosshead and the cylinder liner is attached to the upper part of the crosshead to provide the crosshead. The closed space for decelerating the flow velocity of the lubricating oil splashing from the sliding part between the cylinder and the peripheral wall of the cylinder is configured with the upper surface of the crosshead and the inner surface of the inner wall of the cylinder.

[Action]

In the present invention, the sealing mechanism is attached to the upper portion of the crosshead to form the closed space for reducing the flow velocity of the lubricating oil splashing from the sliding portion between the crosshead and the cylinder peripheral wall. The splashed oil can be stopped after decelerating its flow velocity, which can effectively prevent the splashed oil from directly splashing between the oil splash prevention plate and the cylinder. .

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining an oil intrusion prevention mechanism of a heat engine according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the oil intrusion prevention mechanism, showing a crosshead portion. In the figure, 31 is a crankcase, and the lower structure of the crankcase is omitted. 33 is a connecting rod fitted to an eccentric pin of a crankshaft (not shown), 34 is a crosshead connected to the other end of the connecting rod 33, and the outer peripheral portion of the upper surface is largely chamfered, and 35 is fixed to the crosshead 34. It is a piston rod.

Further, 24a is a porous body 24b fixed to the crosshead 34.
An oil splash prevention plate made of (foamed metal, etc.), 50 is provided on the upper part of the crosshead, slides closely in the cylinder 39, and the sponge sandwiched between the oil splash prevention plate 24a and the pressing plate 52 is used as the material. A sealing member, 51 a spacer provided at the fastening portion of the sandwiched sponge, 52 a pressing plate provided on the upper surface of the crosshead, and 36 a piston fixed to this piston rod 35, where the sealing mechanism is a sponge. It is composed of a material 50 and a pressing plate 52, which is fixed to the upper surface of the crosshead 34 together with the foam metal 24a by a fixing screw 27.

Further, 28 is a distance chamber which is a space between the piston 36 and the crosshead 34, 29 is a buffer chamber, 17 is an oil absorbing material provided in the distance chamber 28, and 37 is a piston.
A compression chamber that is the upper space of 36, and 38 is a cylinder that is mounted in the groove of piston 36 and is located above crankcase 31.
A piston ring 40, which is a piston ring that closely slides on the inner circumference of the part and seals the compression chamber 37, is attached to the crosshead 34, and appropriately seals both spaces 28 and 29. 41 is a communication pipe connecting the buffer chamber 29 and the distance chamber 28,
An oil separator 42 and a check valve 43 are provided in the middle of the pipe. In the check valve 43, gas flows from bottom to top as indicated by the arrow in the figure.

 Next, the operation will be described.

When the oil rises, lubricating oil such as a bearing portion of a crankshaft (not shown) scatters and enters the sliding surface of the crosshead 34. When the crosshead 34 in the lubricated state reciprocates, the lubricating oil on the sliding surface is pumped up in an amount substantially proportional to the rotation speed of the engine and collects on the upper surface of the crosshead. The oil that has been mechanically pumped up by the oil intrusion prevention mechanism invented by the authors and the like and accumulated on the upper surface of the crosshead causes the pressure difference (Pd-Pb) between the buffer chamber 29 and the distance chamber 28 to cause the buffer in the lower portion of the crosshead. It is pushed back to the chamber side through the sliding part of the crosshead. Originally, if the pumped-up lubricating oil scatters and enters the compression chamber 37, various inconveniences such as deterioration of the performance of the heat exchanger and increase of the pressure loss in the flow path occur. However, when the rotation speed increases, the lubricating oil tends to scatter in the middle of being pumped up.

Therefore, with the seal 50 made of a sponge attached to the upper surface of the crosshead, which is the subject of the present invention, the oil splashed from the sliding surface of the crosshead is stopped, and most of it is in the chamfered portion of the crosshead 34 Allow it to collect on the top of the crosshead. As a result, the directly splashed oil will not pass between the oil splash prevention plate 24a and the inner peripheral surface of the cylinder 16, and the oil accumulated on the upper surface of the crosshead 34 will be pushed back to the buffer chamber 29 side due to the pressure difference. Therefore, even if the engine rotates at a high speed, the amount of oil entering the compression chamber beyond the oil absorber 17 can be suppressed to a minute amount. Further, in the chamfered portion of the crosshead, the flow velocity of the splashing oil is reduced, so that the seal 50 works more effectively.

Here, the spacer 51 plays a role of controlling the amount of the seal 50 in contact with the cylinder 39 by controlling the gap to be sandwiched, and the pressing plate 52 regulates the seal made of a sponge body so that it does not move beyond the required seal width, Improves the life of the material and prevents the oil from splashing due to self-excited vibration of the seal plate.

Thus, in this embodiment, the sponge material 50 and the pressing plate 52 are
Since the sealing mechanism consisting of and was screwed together with the foam metal on the chamfered crosshead 34 and closed the gap between the cylinder liner and the sliding part of the crosshead, oil splashing directly from the oil splash prevention plate 24a Between the inner peripheral surface of the cylinder 16 and the inner peripheral surface of the cylinder 16, and the oil accumulated on the upper surface of the crosshead 34 is pushed back to the buffer chamber 29 side due to the pressure difference. It is possible to suppress the amount of oil that flows into the compression chamber over a small amount to a minute amount. Further, since the flow velocity of the splashing oil is reduced in the chamfered portion of the crosshead, the seal 50 works more effectively.

In the above embodiment, the pressing plate 52 is shown as a separate member from the spacer 51. However, as shown in FIG.
It may be formed integrally with 53.

Further, in the above embodiment, the case where the seal mechanism is composed of the sponge 50 and the pressing plate 52 is shown, but this may be composed of the O-ring 54 and the seal housing 55.

FIG. 4 shows a crosshead using such a sealing mechanism, and the configuration other than the sealing mechanism is the same as that shown in FIGS. 2 and 3 above. Also here, instead of the O-ring 54, a piston ring 56 and an endless seal 57
(Cap seal) or the like may be used. Further, this seal housing may be provided on the crosshead.

FIG. 5 shows a crosshead having such a seal housing, in which the crosshead 58 has a seal housing part 55a for inserting a seal member, and the lower part of this housing 55a is cut out. A seal such as an O-ring 54, a piston ring 56 or an endless seal 57 is inserted in the seal housing portion. The other structure is similar to that shown in FIG.

In short, in the present invention, the seal may be of any type and any material, and the important point is that in the sealing mechanism, the flow velocity of the oil splashing from the crosshead sliding portion is once reduced, and the decelerated oil is stopped by the seal to directly seal. The purpose is to eliminate oil particles that fly over.

〔The invention's effect〕

As described above, according to the present invention, the seal mechanism that closes the sliding portion gap between the crosshead and the cylinder liner is attached to the upper portion of the crosshead, and the flow velocity of the lubricating oil splashing from the sliding portion between the crosshead and the cylinder peripheral wall is increased. Since the closed space for deceleration is configured with the upper surface of the crosshead and the inner surface of the inner wall of the cylinder, the oil spattered from the sliding surface of the crosshead can be stopped after decelerating its flow velocity. It is possible to obtain a heat engine that suppresses the rise and can operate stably.

[Brief description of drawings]

FIG. 1 is a sectional view showing an oil intrusion prevention mechanism of a heat engine according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a crosshead portion for explaining this oil intrusion prevention mechanism, and FIGS. 5 is a sectional side view showing an oil intrusion prevention mechanism of a heat engine according to another embodiment, FIG. 6 is a sectional side view showing an oil intrusion prevention mechanism of a typical Stirling engine of a conventional heat engine, and FIG. The figure is an enlarged view of the crosshead portion of this engine. 17 …… Oil absorber, 24 …… Oil splash plate, 31 …… Crankcase, 28 …… Distance chamber, 29 …… Buffer chamber, 33
...... Conrod, 34 ...... Crosshead, 35 ...... Piston rod, 36 ...... Piston, 37 ...... Compression chamber, 38 ...... Piston ring, 39 ...... Cylinder, 40 ...... Piston ring, 41
...... Communication pipe, 42 …… Oil separator, 43 …… Check valve, 50 …… Seal, 51 …… Spacer, 52 …… Presser plate. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A displacer for producing a pressure change in a cylinder, a power piston for taking out this pressure change as a mechanical output, and a piston for connecting the piston and a cylindrical power rod below the power piston. And a crosshead that forms a distance chamber with a small or no change in volume due to reciprocating motion of the engine together with the power piston and the cylinder, and is disposed in a buffer chamber below the crosshead to crank the reciprocating motion of the power piston. A crank mechanism for converting the shaft into rotary motion; and a displacer rod slidably provided inside the power piston, the power rod, and the crosshead for connecting the displacer and the crank mechanism. Maintains a higher pressure than the buffer chamber on average in the distance chamber In the above heat engine, a closed space that is provided above the crosshead and that reduces the flow velocity of the lubricating oil that splashes from the sliding portion between the crosshead and the cylinder peripheral wall is configured with the crosshead upper surface and the cylinder inner wall inner surface. A heat engine having a sealing mechanism.