JPS6246708B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a direct connection structure between an engine and a refrigeration compressor when the engine drives the refrigeration compressor.

Conventional Structure and Problems Conventionally, an electric motor has generally been used as a heat source for driving a refrigeration compressor for cooling or heat pump heating. However, recently, engine-driven air conditioners have become known that are promoting energy alternatives to petroleum and are highly efficient in total in terms of primary energy.

However, it is generally very difficult to match the engine specifications and the load on the refrigeration compressor side of the refrigerant circuit.
If you select an engine with a load that is higher than the refrigeration compressor load, you will always use it in an area where the engine efficiency is low.
On the other hand, if a small engine was selected, there were problems such as the refrigeration compressor stopping abnormally or seizing up. In addition, even if the drive source engine has a flywheel, the output torque fluctuates per revolution, while the refrigeration compressor on the load side also has a fluctuation in the required torque per revolution, and the difference between the engine and the refrigeration compressor. Depending on the direct connection system of each main shaft, there were cases where the engine did not output torque even though the refrigeration compressor required a large torque. or,
Some conventional engine refrigeration compressor drive systems use belts or clutches, but in this case, the engine drive shaft and the refrigeration compressor load shaft may be randomly coupled, and the engine output may vary depending on the refrigeration compression. There is no problem if the engine is sufficiently larger than the machine, but if you reduce the engine output to use it in a place where the engine is highly efficient, the engine may be forced to stop due to the load of the refrigeration compressor, or the drive shaft may be momentarily overloaded. There was a problem with excessive stress.

This problem will be explained with reference to FIG. Figure 1 shows the output torque of a one-cylinder reciprocating engine alone, and it can be seen that even if explosive torque is generated at top dead center, it takes time to store it in the rotational energy of the flywheel. Further, FIG. 2 shows a load torque diagram of a rotary type refrigeration compressor, and the maximum load torque is generated around a rotation angle of 200 degrees. Figure 3 shows the change in main shaft torque when the top dead center position of a one-cylinder reciprocating engine and the rotation angle at which the maximum load torque of the refrigeration compressor is generated are directly connected or randomly connected, and the average torque The value is T _n , but since a large load torque is required from the refrigeration compressor before energy is stored in the flywheel, the maximum torque value T′ _nax becomes large, and as mentioned above, the engine The torque was reduced and excessive stress was being applied to the main shaft.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, to use an engine at a highly efficient operating point without torque loss, and to avoid applying excessive stress to the main shaft of the engine and refrigeration compressor.

Composition of the Invention In order to achieve the present invention, in the drive structure of an engine-driven refrigeration compressor, the present invention provides a rotation angle position of the main shaft that generates the maximum load torque of the refrigeration compressor, and a bottom dead center position of the engine rotation shaft. It is something to match.

DESCRIPTION OF EMBODIMENTS The present invention will be described below with reference to FIGS. 4 and 5 showing one embodiment thereof.
This will be explained with reference to the diagram.

FIG. 4 is a schematic configuration diagram of the engine-driven refrigeration compressor of the present invention, and FIG. 5 shows the relationship between the main shaft torque and the main shaft rotation angle of the engine-driven refrigeration compressor of the present invention. In addition, Fig. 1 shows the relationship between the output torque and main shaft rotation angle of a single one-cylinder reciprocating engine, and Fig. 2 shows the relationship between the load torque and main shaft rotation angle of a rotary refrigeration compressor as an example. figure,
FIG. 3 shows the relationship between the main shaft torque and the main shaft rotation angle when the engine and the refrigeration compressor are directly connected in a conventional or random manner.

In Fig. 4, 1 is a one-cylinder reciprocating engine, 2 is a flywheel connected to the main shaft 3, and 4 is a one-cylinder reciprocating engine.
is a piston connected to the crank part 5 of the main shaft 3,
6 is a starter motor for starting the one-cylinder reciprocating engine 1. 7 is a refrigeration compressor, and the main shaft 8 of the refrigeration compressor 7 is connected to 1 through a coupling 9.
It is directly connected to the main shaft 3 of the cylinder reciprocating engine 1. 10 is a piston of the refrigeration compressor 7. In particular, the rotation angle of the piston 10 when the maximum load torque of the refrigeration compressor 7 is generated (in this case, the rotation angle of the piston 10
Directly connect the main shaft 8 of the refrigeration compressor 7 and the main shaft 3 of the reciprocating engine 1 so that the position of the piston 4 of the one-cylinder reciprocating engine 1 is approximately at the bottom dead center (approximately 200 degrees from the start of compression). are doing.

In the above configuration, the one-cylinder reciprocating engine 1
The starter motor 6 starts the engine, the piston 4 is pushed down by explosive combustion, the main shaft 3 is driven by the rotation of the crank part 5, rotational energy is given to the flywheel 2, and the refrigeration compressor 7 is activated via the coupling ring 9. The power is transmitted to the main shaft 8 of the piston 10.
rotates to compress refrigerant (not shown).

Fig. 5 shows the torque fluctuation of the main shaft 8 of the refrigeration compressor 7 in the above configuration. When the piston 4 of the one-cylinder reciprocating engine 1 explodes from the top dead center position and generates torque, The rotation angle of the main shaft 8 of No. 7 is approximately 0°, and the load torque is also small. Therefore, rotational energy (inertia force) is stored in the flywheel 2. When the piston 4 gradually descends and reaches the bottom dead center position, the flywheel 2
The rotational energy is stored in
The rotational energy (inertia force) of the flywheel 2 is output to drive the refrigeration compressor 7. Therefore, the torque corresponding to the load of the refrigeration compressor 7 can always be output from the flywheel 2 side, and the torque fluctuation of the main shaft 8 can be
As shown in the figure, the average torque T _n is the same, but the maximum load torque T _nax is It can be smaller than T′ _nax . As a result, not only is it possible to use the one-cylinder reciprocating engine 1 in the most efficient manner,
The stress applied to the main shaft 8 is also reduced, which is very advantageous in terms of strength design.

Effects of the Invention As is clear from the above description, according to the present invention, the main shaft torque of the engine increases before the load torque of the refrigeration compressor increases, increasing the rotational inertia of the flywheel. There is no sudden decrease in the rotational angular velocity of the main shaft, and the flywheel inertia of the engine also decreases during the process of decreasing the load fluctuation torque, so the main shaft of the refrigeration compressor does not accelerate. Therefore, both the refrigeration compressor and the engine have small fluctuations in torque and rotational speed of the main shaft, which is very effective in terms of noise and vibration. In addition, because the torque fluctuation is small, there is little mechanical loss on bearings and piston sliding surfaces, allowing the engine to be used efficiently, and at the same time, the stress on the main shaft is also small, which is very advantageous in terms of strength design. It has great effects such as:

[Brief explanation of the drawing]

Figure 1 is a diagram of output torque fluctuation of a one-cylinder reciprocating engine, Figure 2 is a diagram of load torque fluctuation of a refrigeration compressor, Figure 3 is a diagram of main shaft torque fluctuation of a conventional engine-driven refrigeration compressor, and Figure 4 is a diagram of the present invention. FIG. 5 is a sectional view of an engine-driven refrigeration compressor showing one embodiment of the present invention, and FIG. 5 is a main shaft torque fluctuation diagram of the engine-driven refrigeration compressor. 1...1-cylinder reciprocating engine, 2...flywheel, 3, 8...main shaft, 9...coupling.

Claims (1)

[Claims] 1 The flywheel is connected via a coupling to a one-cylinder reciprocating engine that is connected to the main shaft.
The main shaft rotation angle for generating the maximum load torque of the refrigeration compressor is adjusted through the coupling so that it is approximately at the bottom dead center position of the one-cylinder reciprocating engine.
An engine-driven refrigeration compressor in which the main shaft of a cylinder reciprocating engine and the main shaft of the refrigeration compressor are directly connected.