JPH0633797B2 - Shaft fixing device for ceramic impeller for submersible pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention The present invention relates to a shaft fixing device for a ceramic impeller for a submersible pump.

Since the pump used in water sucks in sand and sand, the metal impeller is heavily worn, and if worn, it needs to be replaced with a new one in order not to deteriorate the pump performance. There is a problem in that repair costs are high.

Recently, ceramics such as silicon carbide have attracted attention as a material that is lightweight, has high hardness, and is excellent in abrasion resistance, but has the drawback that it is extremely difficult to process and is weak against impact. Precise finishing is required because the shaft hole of the boss portion must be statically fitted to the pump shaft and the key groove must be engraved in the boss portion. Further, when the impeller is removed, a method of applying a spanner or the like to the back surface of the back plate and hitting it with a hammer is often used, so that it is necessary to have a strength capable of withstanding the impact. Therefore, it has been considered practically difficult to make the impeller made of ceramic.

In the present invention, a ceramic having a high hardness is used for a portion requiring abrasion resistance, and a metal or an inflexible synthetic resin having excellent workability is used for a portion requiring precision finishing. An object of the present invention is to provide a shaft fixing device that configures an impeller having excellent durability that can exhibit the characteristics of different materials and that can be easily attached to and removed from the pump shaft of the impeller.

(2) Structure of the Invention In the shaft fixing device for a ceramic impeller for a submersible pump according to the present invention, a shaft hole is bored in the central portion, the outer peripheral surface is formed into a non-round shape, and the locking collar is projected at one end. A set of two bosses made of metal or inflexible synthetic resin is provided, and a non-round circular boss fitting hole corresponding to the outer peripheral surface of the boss is formed in the center of the back plate of the ceramic impeller. When the boss member is inserted into the boss fitting hole from both sides of the back plate and the outer peripheral portion of the fitting hole is clamped by the locking brim, the boss member may slightly face each other. The gap is formed, the pump shaft is inserted into the shaft hole, the locking flange on one of the boss members is brought into contact with the step portion of the pump shaft, and the screw is tightened at the tip of the pump shaft. The nut is axially tightened so that the outer peripheral portion of the boss-fitting hole is fixed between the locking collars in a sandwiched manner.

Referring to the drawings of the embodiments, reference numerals 1a and 1b denote a pair of boss members made of metal or inflexible synthetic resin, each of which has a shaft hole 2 at its center and a polygonal outer peripheral surface. It is formed in a non-round shape, and a locking flange 3 is provided on one end so as to project. K is a key groove formed in the shaft hole 2. Reference numeral 4 denotes an impeller made of ceramic such as silicon carbide. A non-round circular boss material fitting hole 5 corresponding to the outer peripheral surface shapes of the boss materials 1a and 1b is bored at the center of the back plate. It is forced. Reference numeral 6 is a pump shaft, and 7 is a tightening nut screwed onto the tip of the pump shaft 6.

When the boss members 1a and 1b are fitted into the boss member fitting holes 5 from both sides of the back plate and the outer peripheral portions 8a and 8b of the fitting holes 5 are clamped by the locking flanges 3 and 3, both boss members are A slight gap g is formed between the facing surfaces of 1a and 1b.
The pump shaft 6 is inserted into the pump shaft 6 and the locking flange 3 of the one boss 1a is brought into contact with the step portion 9 of the pump shaft 6, and the tightening nut 7 screwed on the tip of the pump shaft 6 is axially moved. If you tighten,
The outer peripheral portion of the boss material fitting hole 5 is firmly fixed in a state of being clamped between the locking flanges 3 and 3.

Further, if the tightening nut 7 is removed and the boss member 1b is separated, it is extremely easy to use the impeller 4 without using any tools.
Can be extracted.

(3) Effect of the Invention According to the device of the present invention, when the boss members 1a and 1b are fitted into the boss member fitting holes 5, a slight gap g is formed between the facing surfaces of the boss members 1a and 1b. Therefore, by screwing the tightening nut 7, the outer peripheral surfaces 8a and 8b of the boss material fitting hole 5 are firmly fixed in a clasping manner between the locking collars 1a and 1b, and the boss materials 1a and 1b. Since the mating surface between the boss material fitting hole 5 and the boss material fitting hole 5 has a non-round shape, no slippage occurs. Also, since the boss 1b can be separated by removing the tightening nut 7 and the impeller 4 can be easily extracted, it is necessary to remove the impeller while hitting it with a wooden hammer as in the conventional case. Absent. Therefore, it is possible to provide the shaft fixing device which is easily mounted and extracted by using the impeller 4 made of ceramic and having excellent wear resistance. Since only the boss members 1a and 1b are made of metal or plastic with good workability, the shaft hole 2 that slides with the pump shaft 6 can be precisely drilled, and the key groove K is engraved. Is also easy.

[Brief description of drawings]

FIG. 1 is a side view of a longitudinal section of an essential part showing a shaft fixing device of the present invention. FIG. 2 is a side view of an essential part of the axial fixing device showing a state in which the boss material is unclipped. FIG. 4 is a plan view of the impeller of the invention shaft fixing device as seen from the front side, FIG. 4 is a half cross-sectional view showing a state in which two pairs of boss members of the invention shaft fixing device are opposed, and FIG. It is a top view which shows the state which developed the opposing surface of the boss material of one set in a fixing device. 1a, 1b ...... 2 sets of 1 boss, 2 ... Shaft hole, 3 ...
Locking collar, 4 ... Ceramic impeller, 5 ... Boss fitting hole, 6 ... Pump shaft, 7 ... Tightening nut, 8a, 8b ...
... Outer peripheral part of boss material fitting hole, 9 ... step, g ... gap.

Claims (1)

[Claims] 1. A boss made of metal or inflexible synthetic resin, which has a shaft hole (2) formed in a central portion thereof, an outer peripheral surface of which is formed into a non-round shape, and a locking flange (3) is provided at one end of which is protruded. 2 pieces of material (1a) (1b)
One set, and a non-round circular boss material fitting hole (5) corresponding to the outer peripheral surface of the boss material (1a) (1b) of the back plate center of the ceramic impeller (4), The boss members (1a) and (1b) are fitted into the boss fitting holes (5) from both sides of the back plate, and the outer peripheral portions (8a) and (8b) of the fitting holes (5) are locked with the locking collars (3). ) When sandwiched between (3), both bosses (1a) (1
b) A slight gap (g) is formed between the facing surfaces, the pump shaft (6) is inserted into the shaft hole (2), and the locking collar (3) on one of the boss members (1a). Is brought into contact with the stepped portion (9) of the pump shaft (6), and a tightening nut (7) screwed to the tip of the pump shaft (6) is axially tightened, whereby a boss member fitting hole ( A shaft fixing device for a ceramic impeller for a submersible pump, which is configured such that the outer peripheral portions (8a) and (8b) of 5) are fixed in a sandwiched manner between the locking collars (3) and (3).