JPH0431633A - Power converter of thermodynamic reciprocating engine - Google Patents

Abstract

PURPOSE:To decrease stress to a power connecting pin by forming an elongated hole on a rod for a displacer piston running through a cross head and connecting a power connecting rod pin to the cross head with a piece of the power connecting rod pin arranged through this long hole. CONSTITUTION:Pressure fluctuation generated in a cylinder liner 21 works on a power piston 22, pressure difference generated in its upper and lower spaces is converted to a force and it is transmitted to a power piston rod 23, a cross head 24 and a power connecting rod 25 and a crank shaft is rotated in a power converter 20. Additionally, it is possible to carry out reciprocating motion without interacting interfluence by way of inserting a power connecting rod pin 26 in an elongated hole 28a formed on a displacer piston rod 28 in relative motion between the power connecting rod pin 26 fixed on the cross head 24 and the displacer piston rod 28. Accordingly, it is possible to acquire a very durable connecting unit even in a sterling engine of a single cylinder and with large output.

Description

Detailed Description of the Invention (Industrial Use Valve IF) The present invention relates to a power conversion device for a thermodynamic reciprocating engine, and more specifically, for example, for a crankcase pressurized non-lubricated compressor, a heat-driven engine, etc. This invention relates to an improvement in the power output of a thermodynamic reciprocating engine having two pistons in a single cylinder.

(Prior Art) A Stirling engine is a thermodynamic reciprocating engine having two pistons in a single cylinder. Fig. 6 shows a conventional Stirling engine (displacer β type), where 1 is a cylinder liner, 2 is a power piston that slides back and forth on the inner surface of the cylinder liner 1, 3 is a cross head, and 4 is a cross head with the power piston 2. Rod for power piston connecting RAD 3, 5 is power connecting rod, 6 is cross RAD 3 and power connecting rod 5
Power connecting rod pin fixing the small end of 7
8 is a crankcase which is a container for the drive unit, 8 is a crankshaft which is rotatably held by a bearing 9 and transmits the generated power to the outside, and IO is a displacer piston connection which is rotatably connected to the crankshaft 8 by a bearing 9. A rod 11 is a displacer piston rod connected to the small end of the displacer piston connecting rod 10 by a piston pin 12 and coupled to the displacer piston 13, 14 is lubricating oil collected at the bottom of the crankcase 7, and 15 is a power piston. Distance chamber 16, which is a space between the cross head 3, indicates an oil absorbing material provided in the space between the power piston 2 and the cross head 3.

Next, the operation of the above-mentioned conventional Stirling engine will be explained. In the so-called crankshaft type Stirling engine of 1 to aKW class with 1 cylinder and 2 pistons arranged in series,
The generated pressure fluctuation (generation mechanism is omitted) acts on the power piston 2, creating a pressure difference between the upper and lower spaces of the power piston 2 (maximum pressure difference is 2 MPa), and this pressure difference produces a force (maximum force of 10,000 N). ) into power piston rod 4, crosshead 3, power connecting rod 5
are transmitted one after another to rotate the crankshaft 8. This rotational movement of the crankshaft 8 is then taken out as an output. At that time, part of the rotational movement of the crankshaft 8 is transferred to the connecting rod lO for the displacer piston.
, is transmitted to the displacer piston 13 via the displacer piston rod 11, and induces reciprocating motion to perform a Stirling cycle and operate as a Stirling engine.

(Problems to be Solved by the Invention) The conventional Stirling engine as described above was used in 1 to aKW class models with relatively low output. The power generated from this engine with an output of 1 to aKW (aKW
When transmitting the highest generated force (1000 ON) to the crank mechanism, the area where the power connecting rod pin 6 supports the small end of the power connecting rod 5 (the area of contact with the crosshead) shown in Fig. 6 is small. Therefore, it was possible to install the power connecting rod pin 6 in two parts within the crosshead 3.

However, in a crankshaft Stirling engine with a one-cylinder, two-piston series arrangement with an output of 5 to 10 KW, as the output increases, the pressure difference acting between the power pistons approximately doubles to 4 MPa (the force is 20,000 N). do)
become. Therefore, in order for the power connecting rod pin 6 to support the small end of the power connecting rod 5 whose area has been increased to correspond to the 1-cylinder Stirling engine with an output of 5 to 10 KW, the contact area of the pin 6 with the cross rod 3 must be If it is not large enough, it cannot withstand the transmission of an output of 5 to 10 KW. Therefore, as shown in FIG. 5, the small end of this power connecting rod 5 is
The size used for KW class Stirling engines (
(approximately double the area), and when two power connecting rod pins 6 are provided and connected within the required size of the cross head 3 as in the past, the space for supporting the pins 6 against the cross head 3 is extremely large. However, there was a problem in that the surface pressure at the portion indicated by 5l5A increased significantly. On the other hand, a method can be considered to deal with this problem by enlarging the external shape of the cross head 3, but this method does not allow the distance chamber 1 due to the reciprocating movement of the cross head 3.
5, resulting in a loss due to pressure fluctuations, and the pressure fluctuations causing oil to rise.

An object of the present invention was to solve the above-mentioned conventional problems, and it is an object of the present invention to solve the above-mentioned conventional problems, and to solve the problems of the conventional power steering rod and crosshead in a thermodynamic reciprocating engine such as a single-cylinder Stirling engine with a large output. The object of the present invention is to provide a power conversion device that improves the coupling means and reduces stress on the power connecting pin.

(Means for Solving the Problems) The present invention provides a power conversion device for a thermodynamic reciprocating engine having two pistons in a single cylinder, including a displacer piston that causes pressure fluctuations in the cylinder by reciprocating motion; A power piston that extracts pressure fluctuations generated in the cylinder as a mechanical output and makes reciprocating motion; a power piston rod that is connected to the power piston and has a crosshead formed at its end on the crank mechanism side; A displacer piston rod that is connected for reciprocating motion and extends to the crank mechanism through the power piston, the power piston rod, and the crosshead, and a displacer piston rod that is formed in a portion of the displacer piston rod that passes through the crosshead. a long hole, and a single rod inserted through the long hole of the displacer piston rod to simultaneously connect the small ends of two power connecting rods operatively connected to the crank mechanism to the crosshead. It consists of a pin.

(Function) According to the power conversion device for a thermodynamic reciprocating engine of the present invention, an elongated hole is formed in the displacer piston rod passing through the crosshead, and one power connecting rod pin placed through the twenty elongated holes is used. Connect the power connecting rod to the crosshead. The length of this elongated hole is formed within the range of relative movement between the displacer piston rod and the power piston rod, so that the power connecting rod pin can move relative to the displacer piston rod and the power piston rod. The pin, which connects the power connecting rod and the crosshead, has a relatively large contact area with the crosshead without hindering the movement.

(Embodiments) Hereinafter, the power conversion device for a thermodynamic reciprocating engine of the present invention will be described in more detail with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows a power conversion device 20 for a crankshaft type Stirling engine (displacer β type) having a single cylinder and two pistons arranged in series of 5 to 10 kW class.

In FIG. 1, numerals 21 to 23 respectively correspond to the cylinder liner 1, power piston 2, and power piston rod 3 in the conventional Stirling engine shown in FIG. This power piston rod 23 has three
A crosshead 24 having three fork portions 24a, 24b, and 24c is formed at the end on the crank mechanism side, and each small end of two power connecting rods 25 is attached to each of the fork portions 24a, 24b.

24c, and are connected by one pin 26. The area of the small end of the power connecting rod 25 is approximately doubled so that it can withstand the force (maximum 20,000 N) generated by the above-mentioned 5 to 10 KW class Stirling engine. Cross rods 24 are formed on three fork portions 24a, 24b, and 24c spaced apart from each other so as to connect the small ends of the power connecting rods 25 whose area is approximately doubled.

On the other hand, a displacer piston 27 is disposed above the power piston 22 in the cylinder, and a displacer piston rod 28 extending from the displacer piston 27 is connected to the power piston 22, the power piston rod 23, and the central fork of the cross rod 24. Part 2
4b and extends to a crank mechanism (not shown).

This displacer piston rod is shown in Figure 1 on the 2nd day.
As shown in FIGS. 2(a) and 2(b), a long hole 28a is formed in the passage portion of the cross head 24, and fork portions 24a, 24c at both ends of the cross head 24 are formed.
A single pin 26, which is attached so as to be bridged, passes through this elongated hole 28a.

According to such a power conversion device 20, pressure fluctuations generated within the cylinder liner 21 (pressure generation mechanism is omitted) act on the power piston 22, and the power piston 2
A pressure difference is generated between the upper and lower spaces of 2 (the maximum pressure difference is 4 M
Pa), this pressure difference is force (maximum 20000 N”)
The power is converted into power and transmitted to the power piston rod 23, cross rod 24, and power connecting rod 25, thereby rotating a crankshaft (not shown). Since the area of the small end of the power connecting rod 25 is approximately doubled, it can withstand an output of 5 to 10 KW without seizure, and the power connecting rod pin 26 can be used as a single piece. Therefore, even if the small end of the power connecting rod 25 becomes large, the pin 26 can be supported without enlarging the shape of the crosshead 24. Then, the power connecting rod pin 26 fixed to the cross rod 24 and the displacer piston rod 2
Even in the relative movement of the rods 8 and 8, reciprocating movement is possible without mutual interference by passing the pin 26 through the elongated hole 28a formed in the rod 28.

FIG. 3 shows a power conversion device for a thermodynamic reciprocating engine according to another embodiment of the present invention. In the power conversion device of this embodiment, as shown in FIG. 4(a) and FIG. And, on the contrary, the central fork part 24b of the cross head 24 is formed with increased thickness so as to overhang the constricted part 28b of the displacer piston rod 28, and as a result, the central fork part 24b of the cross head 24 The contact surface between 24b and one power connecting rod pin 26 can be increased. As a result, the surface pressure of the B portion (FIG. 3) of the pin 26 that contacts the central fork portion 24b of the crosshead 24 can be lowered from the surface pressure of the A portion shown in FIG. It is possible to provide a connection structure between a power connecting rod and a crosshead that is compatible with a 1 OKW class single cylinder two piston cooling engine.

(Effects of the Invention) As explained above, according to the power conversion device for a thermodynamic reciprocating engine according to the present invention, the power connecting rod is extremely durable even in a single-cylinder Stirling engine with a large output. and a crosshead.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a power conversion device for a thermodynamic reciprocating engine according to an embodiment of the present invention, and FIG. 2(a) is a front view showing a displacer piston rod of the power conversion device shown in FIG. 2(b) is a side view of the displacer piston rod shown in FIG. 2(a), and FIG. 3 shows a power conversion device for a thermodynamic reciprocating engine according to another embodiment of the present invention. 4(a) is a front view showing the displacer piston rod of the power converter shown in FIG. 3, and FIG. 4(c) is the displacer piston rod shown in FIG. 4(a). A side view of the rod, Figure 5 is a cross-sectional view showing the connection structure between the power connecting rod and crosshead that is compatible with a conventional 5-10 KW class single cylinder Stirling engine, and Figure 6 is a conventional Stirling heat engine. FIG. 2 is a sectional view showing the engine. DESCRIPTION OF SYMBOLS 20... Power conversion device, 21... Cylinder liner 22... Power piston, 23... Rod for dynamic capistor, 24... Cross head, 25... Power connecting rod, 26... Power Connecting rod pin, 27... Displacer piston, 28...
Displacer piston rod, 28a... long hole. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] In a power conversion device for a thermodynamic reciprocating engine having two pistons in a single cylinder, there is a displacer piston that causes pressure fluctuations in the cylinder by reciprocating motion, and a mechanical output that generates pressure fluctuations in the cylinder. a power piston that is taken out and reciprocated; a power piston rod that is connected to the power piston and has a crosshead formed at its end on the crank mechanism side; and a power piston rod that is connected to reciprocate the displacer piston, A displacer piston rod extending through the piston rod and the crosshead to the crank mechanism, and an elongated hole formed in the crosshead passing portion of the displacer piston rod, and operatively connected to the crank mechanism. a single pin inserted through the elongated hole of the displacer piston rod to simultaneously connect the small ends of two power connecting rods to the crosshead; Device.