JP2533487Y2 - Gear pump - Google Patents

Description

[Detailed description of the invention] [Industrial applications]

The present invention relates to a gear pump that sends out a fluid by rotating a gear in a pump casing.

[Prior art]

As shown in FIG. 2, the gear pump normally has a drive shaft 20.
Gear 2 and a driven gear 3 meshing with the gear 2 are housed in the pump casing 1. When both gears 2, 3 are rotated by the motor 4, the gear 2, Fluid is pumped between 3 and the inner surface of the pump casing 1. In the figure, reference numeral 5 denotes a motor mount, 12 denotes a joint connecting the output shaft of the motor 4 and the drive shaft 20, and 30 denotes a shaft supporting the gear 3.

[Problems to be solved by the invention]

At this time, the leakage of the fluid is prevented by disposing the shaft seal packing 15 at the penetrating portion of the drive shaft 20 in the pump casing 1 as shown in FIG.
The shaft seal packing 15, which is mounted by press-fitting into a recess formed in the pump casing 1 and is sandwiched and fixed between a seal holding plate 16 and a seal collar 14 disposed in the recess of the pump casing 1, Not only in the axial direction, but also because the outer peripheral surface thereof is to be pressed against the inner periphery of the recess of the pump casing 1, a force is applied to the shaft seal packing 15 in the radial direction. The contact pressure between the drive shaft 20 penetrating the center and the shaft seal packing 15 largely depends on variations in the inner diameter of the recess of the pump casing 1 and the outer diameter of the shaft seal packing 15. In many cases, the drive torque of the drive shaft 20 becomes unnecessarily large. The present invention has been made in view of such a point, and a purpose thereof is to stabilize a contact pressure between a drive shaft and a shaft seal packing, and to reduce unnecessary drive torque. It is to provide a gear pump that does not require a gear pump.

[Means for Solving the Problems]

Thus, the present invention includes a drive shaft that penetrates the pump casing and is provided with a gear housed in the pump casing, and a shaft seal packing that is mounted on the pump casing and penetrates the drive shaft. In a gear pump, a plurality of protrusions provided on an inner peripheral surface of the shaft seal packing are in contact with the drive shaft, and annular convex ribs provided on both axial surfaces of an outer peripheral portion thereof are tightened in the axial direction of the drive shaft. It is characterized in that it is mounted on the pump casing and a gap is formed between the outer peripheral surface of the shaft seal packing and the pump casing. [Operation] According to the present invention, no axial compressive force is applied to the shaft seal packing, and the axial tightening force hardly affects the inner diameter of the shaft seal packing. As a result, the contact pressure between the shaft seal packing and the drive shaft becomes constant. [Embodiment] Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In a gear pump as shown in FIG. 2, in the present invention, the outer diameter of a shaft seal packing 15 through which a drive shaft 20 penetrates is determined. Pump casing 1 in which seal packing 15 is provided
Smaller than the inner diameter of the recess, as shown in FIG.
When the shaft seal packing 15 is arranged in the recess, and the outer peripheral flange portion of the shaft seal packing 15 is compressed and sandwiched in the axial direction between the pump casing 1 and the motor mounting base 5, the shaft seal packing is performed. A gap is formed between the outer peripheral surface of the pump 15 and the inner peripheral surface of the recess of the pump casing 1. In other words, the force applied to the shaft seal packing 15 is only in the axial direction, and the diametrical force that directly affects the inner diameter, which is a penetrating portion of the drive shaft 20, is not applied. The contact pressure between the seal packing 15 and the seal packing 15 becomes stable, and unnecessary drive torque is not required. In the figure, reference numeral 17 denotes an annular convex rib formed on the surface of the outer peripheral flange portion of the shaft seal packing 15 and in contact with the pump casing 1 and the motor mount 5. The presence of the convex ribs 17 reduces the influence of the axial tightening force applied to the shaft seal packing 15 on the inner diameter of the shaft seal packing 15. Therefore,
The stability of the contact pressure is extremely high even if the axial tightening force changes. Further, the shaft seal packing 15 has a plurality of protrusions 18 on the inner peripheral surface thereof, and the protrusions 18 are brought into contact with the drive shaft 20, and the frictional resistance between the two is reduced because the contact area is small. Things. For this reason, the combination of the stable contact pressure and the low frictional resistance makes it possible to drive the drive shaft 20 extremely smoothly.

[Effect of the invention]

As described above, in the present invention, the outer peripheral portion of the shaft seal packing whose inner peripheral surface is in contact with the drive shaft is tightened in the axial direction of the drive shaft to form a pump casing, and the outer peripheral surface of the shaft seal packing and the pump casing are Because a gap is formed between the shaft seal packing and the drive shaft, the shaft seal packing does not receive a compressive force in the diametrical direction, and the inner diameter of the shaft seal packing becomes stable. The contact pressure is constant, and the driving torque of the drive shaft does not become unnecessarily large. Due to the presence of the ribs, the contact pressure between the drive shaft and the shaft seal packing hardly changes even if the force holding the shaft seal packing changes, and the contact pressure between the drive shaft and the shaft seal packing changes. Stable There is a very high, there is also that the contact to the drive shaft of the shaft seal packing frictional resistance is small have been made by plural rows of projections is added,
The drive of the drive shaft can be performed smoothly.

[Brief description of the drawings]

1 is a sectional view of one embodiment of the present invention, FIG. 2 is a sectional view of a gear pump, FIG. 3 is a sectional view of a conventional example, 1 is a pump casing, 15 is a shaft seal packing, and 20 is a drive shaft. Is shown.

Claims (1)

(57) [Scope of request for utility model registration] 1. A gear pump having a drive shaft penetrating a pump casing and having a gear housed in the pump casing mounted thereon, and a shaft seal packing mounted on the pump casing and penetrating the drive shaft. In the shaft seal packing in which a plurality of protrusions provided on the inner peripheral surface are in contact with the drive shaft, annular convex ribs provided on both axial surfaces of the outer peripheral portion are tightened in the axial direction of the drive shaft. A gear pump characterized in that a gap is formed between the outer peripheral surface of the shaft seal packing and the pump casing while being attached to the pump casing.