JPS6341592Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvements in reinforcing ribs provided at the suction and discharge ports of Roots pumps used, for example, as superchargers for vehicles.

BACKGROUND OF THE INVENTION This type of Roots pump has an inlet port and a discharge port with relatively large openings in order to discharge a large amount of air. For this reason, the strength performance near the inlet and outlet tends to be insufficient.
Conventionally, there are devices in which reinforcing ribs are provided at these inlets and outlets. That is, the reinforcing ribs extend from one side of the edge of these openings to the other opposing side to prevent deformation of the inlet and outlet, respectively. However, these ribs usually form a square prism due to manufacturing reasons.

Problems to be solved by the invention: The rectangular prism-shaped reinforcing ribs described above create a large resistance to the air passing through the intake and exhaust ports, resulting in poor intake and exhaust efficiency. A problem arises in that sufficient efficiency cannot be obtained by increasing the opening area.

Means for Solving the Problems In order to solve the above problems, the Roots pump according to the present invention is characterized in that the cross-section of the reinforcing ribs along the fluid flow direction is streamlined.

Example The present invention will be explained below with reference to the illustrated embodiments.

Each figure shows an embodiment of the present invention. In these figures, a pair of rotors rotating about center lines I and J are housed in a casing 1 of the Roots pump. An inlet 2 and an outlet 3 are formed on both sides of the casing 1, respectively. The rotors rotate while meshing with each other, and the suction port 2
Air is sucked in from the outlet (arrow A) and is discharged from the outlet 3 (arrow B). Note that the pulley 4 provided outside the casing 1 is for rotationally driving one of the rotors.

As shown in FIG. 2, the suction port 2 has a rectangular shape when viewed from the side, and a reinforcing rib 5 extends from the center of one upper side of the edge to the center of the opposite lower side. The reinforcing rib 5 has a streamlined cross-sectional shape along the air flow direction. That is, as shown in FIG.
It is largest at , and gradually becomes smaller as it approaches the front edge 5a and the rear edge 5b from the center portion 5c. Therefore, in Figure 1a, arrow A
The intake air shown by flows smoothly around the reinforcing rib 5, and the flow does not separate at the rear edge 5b of this rib 5 to form a vortex, and the air resistance is lower than that of the case where the cross section is rectangular. significantly reduced.

On the other hand, the discharge port 3 is similarly provided with a reinforcing rib 6 extending in the vertical direction at the center, as shown in FIG. The reinforcing rib 6 also has a streamlined cross-sectional shape similar to the reinforcing rib 5, and as shown in FIG. It gradually becomes smaller as it approaches the edge 6b.
Therefore, the resistance of the air discharged by the reinforcing ribs 6 of the exhaust port 3 is also reduced.

Note that the cross-sectional shape of the reinforcing ribs 5, 6 does not necessarily have to be widest at the center portions 5c, 6c as shown in the figure, and the widest portions are formed at the front edges 5a, 6c.
It may be shifted to the 6a side.

Effects of the Invention As described above, according to the present invention, the resistance of air passing through the intake port and the exhaust port can be significantly reduced, and the effect of improving the intake and exhaust efficiency can be obtained.

[Brief explanation of the drawing]

Figure 1a shows the inlet, and Figure 2 is a sectional view taken along line IA-IA in Figure 2. Figure 1b shows the outlet, and Figure 2 is a sectional view taken along line IB-IB in Figure 3. FIG. 3 is a side view of the Roots pump viewed from the suction port side, FIG. 3 is a side view of the Roots pump viewed from the discharge port side, and FIG. 4 is a front view of the Roots pump. 1... Casing, 2... Inlet, 3... Outlet, 5, 6... Reinforcing ribs.

Claims (1)

[Scope of utility model registration request] A plurality of rotors rotate in a casing while meshing with each other, and discharge fluid sucked in from an inlet of the casing from an outlet of the casing,
In Roots pumps, each of the inlet and outlet ports is provided with a reinforcing rib extending from one side of the edge to the opposite side, the cross-sectional shape of the reinforcing rib along the fluid flow direction is streamlined. The cross-sectional width of the reinforcing rib along the fluid flow direction is set relatively large at a predetermined position between the front edge and the rear edge, gradually increases from the front edge to the predetermined position, and from the predetermined position to the rear. A roots pump characterized by a gradual taper towards the edge.