Patent Application
20240337260
This application relates to a twin-type scroll fluid machine equipped with compression mechanisms on both sides of the drive mechanism.
The applicant invented a twin-type scroll fluid machine driven by external power as shown in the patent document (JP 2015-031248 A1). This twin-type scroll fluid machine is constituted of; a crank pulley rotated by external power; a pair of internal housings that rotatably hold the crank pulley; a central support rod on the crank pulley that rotates with the rotation of the crank pulley; a pair of swirling scrolls that are provided on both sides of the central support rod and are connected to each of the internal housings via an oldham ring mechanism; and a pair of fixed scrolls, each equipped with a scroll wrap that engages with the scroll wrap of each of these swirling scrolls to form a compression chamber, and provided together with each of said internal scrolls by fixing means; wherein a first compression mechanism consisting of one inner housing, one swirling scroll and one fixed scroll, and a second compression mechanism consisting of the other inner housing, the other swirling scroll and the other fixed scroll are arranged at both ends of the central support rod, and wherein the swirling scroll of the first compression mechanism and the swirling scroll of the second compression mechanism are connected and fixed by a central support rod and a plurality of peripheral support rods located at predetermined intervals near the periphery of the respective swirling scrolls, and the left and right swirling scrolls are freely movable in the thrust direction.
Conventionally, the twin-type scroll fluid machine uses two compression mechanisms to discharge a given capacity, and thus can be configured with a smaller diameter by reducing the radial spread of the scroll end plate, and can double the discharge capacity if the same size is used.
In the twin-type scroll fluid machinery disclosed in the patent document as described above, the central drive unit is driven by an external motor via a V-belt, but the external drive source makes the device itself larger. Therefore, this application provides a twin-type scroll fluid machine with a frameless motor inside a housing to achieve downsizing and weight reduction.
Accordingly, the present invention is a twin-type scroll fluid machine comprising a central support shaft, a pair of swirling scrolls provided at both ends of the central support shaft, and a pair of fixed scrolls intermeshing as the respective swirling scrolls to form a pair of compression chambers, said central support shaft being eccentrically fixed, and further comprising a drive shaft to which the rotor of the motor is fixed, an inner housing to which the drive shaft is rotatably fixed and to which the stator of the motor, arranged opposite to the rotor, is fixed, and an oldham mechanism arranged between the inner housing and the swirling scroll.
This causes the drive shaft to rotate by rotating the rotor fixed to the drive shaft against the stator, the eccentrically installed central support shaft swirlings with the rotation of the drive shaft, and then the swirling scroll makes a swirling motion with respect to the fixed scroll, so that the volume of the compression chamber defined by the swirling scroll and the fixed scroll shrinks from the periphery toward the center, which allows fluid to be sucked in, compressed, and discharged. Each swirling scroll performs a swirling motion with respect to the corresponding fixed scroll, whose rotation is inhibited by the oil dam mechanism between the respective swirling scroll and the inner housing.
The inner housing is preferably composed of first and second housings that are axially split, and the stator is fixed between and secured by the first and second housings. The inner housing is preferably press-fitted and secured to the outer housing as the respective fixed scroll by its outer circumference. It can also be secured with adhesive or other means.
It is preferred that the central support rod has a through hole that connects the compression chamber on one side to the compression chamber on the other side. This allows uniform adjustment of the discharge level of the compression chambers on each side to obtain a stable pressure.
Each swirling scroll should be connected and fixed by a plurality of peripheral support rods located at predetermined intervals near the periphery of each swirling scroll, and each connected swirling scroll should be movable in the thrust direction. This eliminates the need for bearings to receive pressure in the thrust direction because the thrust pressure acting on each swirling scroll can be offset.
In the twin-type scroll fluid machine with the above configuration, the frameless motor is composed of a rotor that rotates the drive shaft and a stator positioned opposite the rotor, so that the drive shaft can be rotated directly, which enables the compressor to be made smaller and lighter.
One of examples of this invention is described below by means of drawings.
The twin-type scroll fluid machine 1 of the present invention is composed of a drive unit 2 located in the center and a pair of compression mechanisms located on both sides of the drive unit 2, namely the first and second compression mechanisms 3, 4.
The drive unit 2 is composed of a pair of axially divisible inner housings 20 (20A, 20B), a drive shaft 21 rotatably supported by the pair of inner housings 20 (20A, 20B), a rotor 22 fixed to the circumference of the drive shaft 21, and a stator 23 located opposite the rotor 22 and sandwiched and fixed by the inner housings 20 (20A, 20B). Thus, when the stator 23 is energized, a rotating magnetic field is generated, the rotor 22 rotates, and the drive shaft 21 rotates. The drive shaft 21 is provided with a central support rod 24, which is eccentric to the axis of rotation of the drive shaft 21 and can rotate freely via a bearing 25.
The first compression mechanism 3 is composed of a first swirling scroll 31 which is pivotably fixed to one end of the central support rod 24, and a first fixed scroll 33 which engages the first swirling scroll 31 and forms the first compression chamber 32. The first fixed scroll 33 also serves as an external housing that freely swivels and secures the first swirling scroll 31. The fixed scroll 33 has a suction port 34 that is connected to the first compression chamber 32 at a periphery position thereof and a discharge port 35 that is connected to the first compression chamber 32 at a center position thereof. An oldham mechanism 36 is provided between the first swirling scroll 31 and the first inner housing 20A to prevent the first swirling scroll 31 from rotating on its own.
The second compression mechanism 4 is composed of a second swirling scroll 41 which is pivotably fixed to another end of the central support rod 24, and a first fixed scroll 33 which engages the second swirling scroll 41 and forms the second compression chamber 42. The second fixed scroll 43 also serves as an external housing that freely swivels and secures the second swirling scroll 43. The fixed scroll 43 has a suction port 44 that is connected to the second compression chamber 42 at the periphery thereof and a discharge port 45 that is connected to the first compression chamber 42 at the center thereof. An oldham mechanism 36 is provided between the second swirling scroll 41 and the second inner housing 20B to prevent the second swirling scroll 41 from rotating on its own. In addition, a through hole 26 is formed in said central support rod 24, which connects said first compression chamber 32 and said second compression chamber 42.
With the above configuration, when the stator 23 is energized, the rotor 22 rotates and the drive shaft 21 rotates. As a result, the central support rod 24 performs a swirling motion, so the first and second swirling scrolls 31, 41 perform a swirling motion with respect to the first and second fixed scrolls 33, 43, and the first and second compression chambers 32, 42 decrease their volume from the peripheral portion toward the center position thereof, so that the fluid is sucked from the suction ports 34, 44 and discharged from the discharge ports 35, 45.
As explained above, the drive shaft 21 is directly driven by the motor structure composed of the rotor 22 and stator 23, which allows the device itself to be compact and lightweight, maintenance-free, and cost-effective.
The stator 23 which constitutes the motor structure described above, is sandwiched and fixed by the inner housings 20A and 20B, and the rotor 22 is press-fitted and fixed to the outer circumference of the drive shaft 21.
Furthermore, although not shown, the first and second swirling scrolls 31 and 41 should be connected and secured by a plurality of peripheral support rods.
As described above, the present invention was described as a device with a compression mechanism, but by reversing the direction of rotation, it can also be used as an expansion device that suctions from a center thereof and discharges from an outside thereof, or as a vacuum pump.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-062503 | Apr 2023 | JP | national |
