JPS5996459A - Sterling engine comprised of rolling ball and guide groove mechanism - Google Patents

Abstract

PURPOSE:To reduce size of engine while to improve efficiency by realizing optimal volume change and motion of operating fluid of a Sterling engine through a simple and small mechanism comprising a rolling ball and guide groove. CONSTITUTION:Plural phases of sinusoidal guide grooves 3 having circumferential angle as phase angle and axial displacement as amplitude are provided in the outside cylinder face of a rotary shaft 1 which will not displace in axial direction then a plurality of rolling balls 5 held rotatably on the inside face of output piston 4 restricted of rotation are placed in each groove 3 to reciprocate the output piston 4 axially and periodically with rotation of rotary shaft 1. While a plurality of rotatable rolling balls 12 are held on the inside cylindrical face of said shaft 1 then placed in a plurality of sinusoidal guide grooves 11 provided in the outside cylindrical face of a displacer shaft 10 which is reciprocated axially in accordance to the rotation of rotary shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Various mechanisms have been tried for Stirling engines, but they require volume changes and mutual movement of working gas between high and low temperature regions. In the case of a single cylinder, various mechanisms are used to generate a phase difference of about 90'1tJl for the movement of the displacer and the output piston, but all of them, such as the long pick mechanism and the double crank mechanism, tend to be large in size.

-2- The present invention aims to optimally realize volume change and movement of working fluid using a simple and small device using rolling balls and guide grooves, and aims to make Stirling engines more compact and efficient.

An embodiment of the present invention applied to a wall heating type Stirling engine shown in FIG. 1 will be described. The cylinder 6 includes an output piston 4 and a displacer 8, which constitute a high-temperature expansion chamber 17 and a low-temperature compression chamber 16. The displacer 8 includes a regenerator 9, which connects the expansion chamber 17 and the compression chamber 16. are doing. The high temperature heating source is located in the space 20 and is located on the cylinder wall surface 6.
' to heat the working gas filled in chamber 17. The low-temperature coolant is in the space 21 and the cylinder wall 6'
), the working gas flowing into the compression chamber 16 through the output piston 4, etc. is cooled. The axial displacement of the piston and displacer shown in Figure tJ2 is as shown in the example below. At phase angle O, the output piston 4 rises from the center of the stroke and then compresses the working gas, but at this time the displacer 8 is at the top of Jl. The volume of the high temperature section is the smallest and the volume of the low temperature section is close to the maximum.-3- The gas is compressed while the average temperature is low. Phase angle (1/
2) When π is reached, compression ends, but the displacer 8 descends and the working gas flows into the high-temperature expansion chamber, where it is heated and the average temperature rises. If the expansion continues under conditions of high average temperature, the volume will reach its maximum near (3/2)π, but at this point the displacer 8 has already passed the lowest point and the volume of the heated part will decrease and become compressible. The average temperature is reduced to .

When the phase angle is near 2π, the volume of the compression chamber 16 is near the maximum, and the compression chamber 16 is compressed at a low average temperature. Therefore, the output piston 4
If the movement of the displacer 8 becomes like the curve shown in FIG. 2, a Stirling cycle can be realized.

The rotating shaft 1 is sealed with a shaft seal 22 and can freely rotate through the bottom part 6 of the cylinder without moving in the axial direction, and the shaft end 2 has a pipe-like cylindrical shape and has an outer cylinder. A plurality of sets of guide grooves 3 having an arcuate cross section for guiding the rolling balls 5 are provided on the surface at positions substantially balanced with the circumference. The waveform of the axial displacement with respect to the circumferential angle of one guide groove is shown in Figure 2 (
As shown in Figure 4-4 above, the waveform is smooth, almost like a sine wave, but the circumferential angle is divided so as to be approximately balanced, and a plurality of sets are provided that differ only in phase. The rolling ball 5 is rotatably held at an appropriate position on the inner surface of the output piston 4, and is set at a position corresponding to the phase difference of each guide groove on the same circumference as many as the number of guide grooves. The output piston 4 is restricted from rotating, and the rotation axis 1
According to the rotation, the guide groove 3 moves by the axial displacement of the waveform of the center line of the guide groove 3 in FIG. 2, and makes one reciprocation with one rotation.

A plurality of rolling balls 12 are rotatably held at appropriate positions on the cylindrical inner cylindrical surface of the shaft end 2, and the shaft 10 of the displacer 8 is suspended inside the inner cylindrical surface, and the outer periphery of the shaft 10 is A guide groove 11 that rolls on a surface and contacts the ball 12 and guides it.
A plurality of sets are provided at approximately balanced positions. The waveform of the axial displacement with respect to the circumferential angle of the guide groove 11 is smooth and similar to a sine wave as shown in FIG. 2 (bottom).
A stroke with an advanced phase of approximately (1/2) π is selected, and an optimum shape different from the waveform is selected. The displacer 8 moves according to the rotation of the rotary shaft 1 by an axial displacement of the waveform of the center line of the guide groove 5-11 in Fig. JII2, and reciprocates once per rotation.

According to the present invention, rolling balls 5 and 12 and guide grooves 3 and 11 are used between the outer circumferential surface and inner circumferential surface of the rotating shaft 1 and the output piston 4 and the shaft 10 of the displacer 8, respectively, to transform rotational motion into linear reciprocating motion. By using the conversion device, the most rational drive mechanism for the output piston 4 and the displacer 8 required for the Stirling engine can be realized in a small and simple manner.

In the example shown in Figure 1, the simplest wall heating type Stirling engine is used as an example, but the output piston 4 The driving of the displacer 8 is exactly the same.

In this case, the buffer space 15 can also have a pumping effect and preferably has lubricating oil circulating for cooling purposes.

7 is a piston seal. The regenerator 9 includes a group of gas flow paths that function as a regenerator, and it is also possible to use a porous material. 13 constitutes a displacer shaft seal, and -6-14 together with 15 constitute a part of the buffer space. 18, together with 18', are fins for promoting heating of the working gas;
19 is a cooling promotion fin.

In the Stirling engine of the present invention, the axis of the cylinder and the rotating shaft that is the output shaft are common, and it is also possible to reverse the fixed side and the rotating side. That is, the rotating shaft 1 is fixed,
By rotating the cylinder 6, the displacement of the output piston 4 and the displacer 8 can be made into the phase relationship necessary for a Stirling engine according to the rotation of the cylinder, similar to when the cylinder is fixed. Therefore, as a axially rotating cylinder engine, it is possible to effectively carry out the flywheel action and heat transfer action on the cylinder side.

According to the present invention, it is possible to drive the piston and displacer in a displacer type Stirling engine with an extremely compact and simple structure in an ideal phase relationship.

-7-

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the Stirling engine of the present invention, and is a schematic axial cross section of the engine body. Figure 2 is a developed view on the cylindrical surface of each of the plurality of guide grooves provided on the rotating shaft and displacer shaft, where the vertical axis represents the axial displacement and the horizontal axis represents the same phase as the circumferential angle. , 8 is the circumferential angle where the rolling ball exists. 1... Rotating shaft 2... Shaft end 3... Guide groove 4... Output piston 5... Rolling ball 6...
・Cylinder 7... Piston seal 8... Displacer 9... Regenerator 10... Displacer shaft 11... Guide groove 12... Rolling ball 13... Displacer shaft seal 14.
15...Buffer space 16...Compression chamber
17... Expansion chamber 18. 18'... Fins for promoting heating 19... Fins for promoting cooling 20...
Space 21... Space 22... Shaft seal -8-

Claims (1)

[Claims of Claims] On the outer cylindrical surface of a rotating shaft that can freely rotate without axial displacement, a substantially sinusoidal rolling ball guide groove is provided on the outer cylindrical surface of the rotating shaft, with the circumferential angle as the phase angle and the axial displacement as the amplitude. A plurality of balls of the same shape are provided in positions where they are in equilibrium, and a plurality of rolling balls held freely rotating on the inner surface of an output piston whose rotation is restrained and fitted into the cylindrical surface are placed in each groove. The output piston is moved back and forth in the axial direction periodically according to the rotation of the rotating shaft, and a plurality of freely rotatable rolling balls are held on the inner cylindrical surface of the rotating shaft. A displacer shaft whose rotation is restrained in contact with the displacer shaft is provided, and multiple sets of rolling ball guide grooves are provided on the outer cylindrical surface of the displacer shaft at approximately balanced positions. It forms a smooth wave similar to a sine wave whose amplitude is displacement, and has a mechanism that moves the displacer shaft back and forth in the axial direction according to the rotation of the rotating shaft, and moves the displacer fixed to the shaft back and forth in the axial direction. , a Stirring with a rolling ball and guide groove mechanism, which has a mechanism that causes the output piston to reciprocate in the axial direction in a substantially sinusoidal manner in the cylinder according to the rotation of the rotating shaft, and also to move and reciprocate the coaxial displacer with a phase and waveform different from this. engine.