JPH04311656A - Stirling cycle apparatus with watts link - Google Patents

Abstract

PURPOSE:To provide a Stirling cycle apparatus durable with little frictional loss and provided with a compact crankcase with no need of lubricating oil supply. CONSTITUTION:A piston pin 10, the driving lower end of a piston 3 sliding in a cylinder 1, is guided by a Watts approximately Z-shape linear link mechanism 16, and nonlubricated bearings are used for all pin connecting parts (rotating pair points) of a crank device including the linear link mechanism 16. The whole crank device is then accommodated in a closed crankcase 4 to form a Stirling cycle apparatus with a wats link.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a crank device in a Stirling cycle device such as a Stirling engine or a reverse Stirling heat pump.

0002

[Prior Art] In conventional Stirling cycle equipment, a crosshead is provided below the piston in order to guide the lower driving end of the piston that reciprocates within the cylinder and causes it to reciprocate on the cylinder centerline. Liquid lubricating oil is used for lubrication inside the crankcase.

0003

[Problems to be Solved by the Invention] Conventional Stirling cycle equipment uses liquid lubricating oil in the crankcase, so it requires an oil supply pump, an oil separator, a buffer space, an oil seal mechanism for the rod, etc. The system is complicated and bulky, and it is not possible to completely prevent oil from leaking into the working space or into the heat exchanger, making long runs extremely difficult. In addition, the crosshead receives lateral forces and the slider moves over the entire stroke length, resulting in considerable friction loss. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a Stirling cycle device having a compact crankcase that has low friction loss, does not require replenishment of lubricating oil in the crankcase, is durable, and is compact.

0004

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In other words, the present invention completely eliminates sliding pairs such as crossheads that cause large friction in the mechanism inside the crank chamber, and eliminates the need for replenishing liquid lubricant, which was also troublesome in the past. The idea is to form a mechanism using only rotating pairs that can use non-lubricated bearings.As a simple mechanism consisting only of rotating pairs, Watt's is capable of achieving the highest level of linear approximation reciprocating motion. It is characterized by the use of a link mechanism.

[0005]

[Operation] Watt's link mechanism is as shown in Figure 5.
When taking a point E such that CE:BE=AB:CD on the center vertical link b of the three links a, b, and c combined in a shape, the up and down reciprocating movement of the point E in a small range It is a mechanism that performs approximate linear motion with extremely high precision. Point E is called the linear motion point of this mechanism. When the piston is held at this linear motion point E and the small end of the crank rod moves the piston up and down, the lateral force generated from the crank rod is absorbed by the Watt crank and is not transmitted to the piston. In addition, the results of actual theoretical calculations are shown in Figure 5.
Now, under the condition that AB=CD and the vertical movement range (piston stroke) of point E is approximately equal to the length of BC, the maximum value of point E that deviates from the strict straight line (i.e. maximum deviation value) is the stroke is 50mm, AB
= 0.067mm and 0.015mm respectively when the CD is made into three sizes: 75mm, 100mm, and 200mm.
, 0.000175mm, and in both cases it is 0.000175mm.
The value is sufficiently smaller than 1 mm, and it can be considered that the motion is actually in a strictly straight line.

[0006]

EXAMPLES The invention will be explained by two examples. For clarity, FIG. 1 shows a side view of only the drive mechanism of the power piston (hereinafter referred to as PP) of the first embodiment, and FIG. 2 shows a side view of only the drive mechanism of the power piston (hereinafter referred to as D) of the first embodiment.
A side view of only the drive mechanism of the drive mechanism (referred to as P) is shown in each case. Components that are common in FIGS. 1 and 2 have the same reference numerals.

First, in FIG. 1, 1 is a cylinder, 2 is D
P and 3 are PP, and DP and PP are arranged in a skewer shape. 4 is a crankcase, 5 is a rotating shaft, 6 is a main crank, 7 is a crank pin, 8 is a main crank rod, and P
The downwardly protruding arm 9 of P3 and the small end of the main crank rod 8 are connected by a piston pin 10. In this embodiment, two axial round rods 11 and 12 attached to the crankcase 4 are used as supporting points at both ends, and the horizontal forceps 1
Watt link 1 consisting of 3, 14 and vertical brace 15
6 is provided, and the piston pin 10 is penetrated so as to coincide with the linear motion point 17, and the piston pin 10 moves up and down along an approximate straight line with extremely high precision. 18 is a balance weight. What is important here is to use oil-free bearings such as oil-impregnated sintered alloys or grease-sealed ball bearings for all rotating pairs, including the piston pin 10, crank pin 7, and Watt link. . Further, although only one set of Watt links is shown in FIG. 1, in reality, it is customary to divide the link into two in the axial direction and install them in parallel, as shown in FIG. 3, for the sake of force balance.

Next, FIG. 2 shows the drive mechanism of the DP 2 in this first embodiment. 19 is a drive rod for driving DP2 from below through PP3;
A handle portion 20 shaped like a shovel handle is provided below, and a DP drive pin 22 is attached to the center of the grip portion 21 . Further, the round bars 11 and 12 are provided with another Watt link 26 consisting of horizontal braces 23 and 24 and a vertical brace 25, using them as both fulcrums, and the linear motion point 27 of the Watt link 26 is connected to the DP drive pin 22. are congruent and rotationally coupled.

Here, the DP drive mechanism in FIG. 2 is the same as the PP drive mechanism in FIG.
What is different from the drive mechanism is that the lower horizontal pin 24 is provided with branch branches 28 that branch at right angles, and the horizontal pin 2
4 and the branch branch 28 form an inverted L-shaped lever 29, and a pin 30 is provided at the tip of the branch branch 28, and a pin 30 is provided at the tip of the branch branch 28, and the crank pin 7 of the main crank 6 is connected to the main crank rod 8 by approx. The small end of the sub-crank rod 31 extending in a 90 degree direction is combined with the pin 30.

Now, when the main crank 6 rotates, the DP is moved up and down via the sub crank rod 31, the inverted L-shaped lever 29, the Watt link vertical bar 25, and the drive rod 19. As is clear from FIGS. 1 and 2, even if the main crank 6 is in the same position, the phases of the positions of DP2 and PP3 are different, and both move with a phase angle difference of approximately 90 degrees. What is important here is that in the DP drive mechanism shown in FIG. 2, oil-free bearings are also used at the rotational pairs of all the pins.

FIG. 3 is a diagonal sketch of the entire crank mechanism of a Stirling cycle machine incorporating both the Watt links according to the first embodiment of FIGS. 1 and 2. As shown in Figure 3, there are three sets of Z-shaped Watt links, two sets at both ends share and control the vertical movement of PP, and one set in the center controls the D
It shares control over the vertical movement of P. That is, in FIG. 3, the PP Watt links 16 and 32 shown in FIG. 1 are on both left and right sides, and the DP Watt link 26 shown in FIG.
is provided.

[0012] Furthermore, it is possible to divide one set of the two sets of Watt links into two in the axial direction and have two Watt links of the same shape take charge of the movement of PP or DP. As a Stirling cycle device, the DP and PP are not necessarily arranged in a cylinder having the same axis, but also include cases where their respective center lines are located at different positions.

Next, the present invention will be explained with reference to a second embodiment. FIG. 4 schematically shows a side view of the second embodiment as seen from the axial direction. For ease of viewing, one set of Watt links is shown in thick solid lines in this figure, and the other set is shown in dotted lines. The parts names and functions of parts numbered 32 and below are the same as in the first embodiment. That is, on the horizontal pin 13 of the Watt link 16, which uses the support rods 11 and 12 as fulcrums at both ends, a rod 33 extending in the opposite direction from the support point is attached in a dogleg shape, and a pin 34 is attached to the tip of the rod 33. The small end of the crank rod 35 from the crank pin 7 is connected thereto. Further, in the crankcase 4 of this embodiment, two other support rods 36 and 37 are provided completely axially symmetrically with the support rods 11 and 12, and the support rods 36 and 37 are used as supporting points at both ends, and the upper and lower horizontal Watt link 41 for DP, which is composed of forceps 38, 39 and vertical forceps 40,
It is provided symmetrically with the Watt link 16 for PP, and the horizontal pin 38 is also attached with an overhanging rod 42 that overhangs in the shape of a dogleg in the front, and a pin 43 at the tip thereof is connected to the crank pin 7. It is connected to the small end of another sub-crank rod 44.

With this structure, the crank rods 35 and 44 are always oriented at about 90 degrees to each other, so the rotation of the rotating shaft 5 causes the Watt links 16 and 4 to
1 and swings with a phase angle difference of about 90 degrees, and therefore PP and DP also make vertical linear reciprocating motion with that phase angle difference.

[0015]

[Effects of the Invention] According to the present invention, with regard to Stirling cycle equipment, by making frequent use of modified Watt links consisting of only rotating pairs, there is no need to replenish or splash lubricating oil when using a crosshead as in the past. Moreover, the lower part of the PP can directly face the space inside the crank chamber, and the oil pump, oil separator, buffer space to prevent oil from rising, and buffer tank installed in conventional Stirling cycle equipment where oil supply was essential. As a result, the Stirling cycle equipment becomes extremely compact and simple compared to the past, and friction loss is greatly reduced, resulting in special effects such as a rapid increase in economic efficiency. Furthermore, the maintenance required in the past for removing contamination from the heat exchanger due to the phenomenon of oil rising into the cylinder can be reduced, and the durability of the Stirling cycle equipment can be significantly increased. Also, since there is no oil pan, the engine can be placed in any vertical or horizontal direction, making it suitable for solar power applications. Particularly important in Stirling cycle equipment is the reduction of mechanical friction loss, and the use of Watt links is highly consistent with that purpose. In other words, as a result of Stirling engine experiments conducted in the inventor's laboratory, the adoption of this system reduces mechanical friction loss by approximately two-thirds or less compared to conventional crosshead refueling systems and Scott Russell link systems, and the engine's It has shown good results, with the weight being 75% or less. It has also been proven that it is dramatically superior in terms of maintenance.

[0016] As described above, by slightly modifying the Watt link that has been known since its discovery by James Watt, and using multiple links, there have been problems with maintenance and durability, and practical implementation has been delayed. It simplifies complex Stirling cycle equipment, requiring no lubrication or maintenance, and at the same time providing high durability. Also,
It is much more compact than the conventional type, which requires an oil separator in the case. It is also well suited for solar power applications where the engine position changes. Therefore, the present invention makes an extremely innovative contribution to the practical application of Stirling cycle equipment such as various Stirling engines and reverse Stirling heat pumps for solar and biomass applications, which will attract attention in the coming era of new energy usage. It is recognized that

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a power piston drive mechanism according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a displacer piston drive mechanism according to the first embodiment of the present invention.

FIG. 3 is a partially sectional perspective view of the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of Watt's Z-shaped approximate linear link mechanism.

[Explanation of symbols]

1 cylinder 2 displacer piston 3
power piston 4
crank case 5
Crankshaft 6 Main crank 7 Crank pins 8, 35
Main crank rod 9
Arm (of the piston) 10 Piston pin 16, 32 Watt link for power piston 1
9 Displacer drive rod 26
, 41 Watt link 29 for displacer piston Inverted L-shaped lever 31, 44
Deputy crank rod

Claims (2)

[Claims] Claim 1: A driving lower end of a piston extending from a piston sliding in a cylinder is rotatably coupled to a pin provided at a linear motion point of Watt's Z-shaped approximate linear link mechanism, and the Z A Stirling cycle device having a Watt link, characterized in that oil-free bearings are used in all pin joints of the crank device including the approximate linear link mechanism, and the entire crank device is housed in a sealed crankcase. [Claim 2] In a Stirling cycle device in which a displacer piston and a power piston are arranged one above the other in a skewer shape, a Watt's Z-shaped approximate straight link mechanism is provided in the crankcase to guide the displacer piston and the power piston, and each A pin is provided at the linear motion point on the pin to hold the lower driving end of the power piston on one hand and the lower driving end of the displacer piston on the other hand, so as to perform highly accurate approximate linear motion along the center line of the cylinder. In addition, two crank rods are provided in directions approximately 90 degrees apart from one crank pin provided on the rotating shaft, and the small end of each crank rod is connected to the linear motion point of each Watt link or any arbitrary point. 2. The Stirling cycle device having a Watt link according to claim 1, wherein the Stirling cycle device is rotatably attached to an arbitrary point on the armature or a point on a side bar projecting from the armature in an arbitrary direction with a pin.