Impellers and pumps

Abstract

To provide an impeller that can improve reliability.SOLUTION: An impeller 2 includes: a shaft insertion hole 50; a fastening hole 51 having a diameter that is smaller than a diameter of the shaft insertion hole 50; and a sleeve insertion hole 52 having a diameter that is larger than the diameter of the shaft insertion hole 51.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an impeller and a pump. [Background technology]

[0002] A pump that transfers a liquid by rotating an impeller fixed to the main shaft of an electric motor is known. The pump has a seal structure to prevent the liquid from coming into contact with the main shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 53-88803 [Patent Document 2] Japanese Utility Model Application Publication No. 60-88098 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 (Japanese Utility Model Application Laid-Open Publication No. 53-88803) discloses an impeller (2) fastened to a main shaft (10) by a bolt (4). The impeller (2) has a boss (22) that covers a portion of the main shaft (10), and the boss (22) and the exposed portion of the main shaft (10) are covered by a sleeve (5). In this way, the pump (1) of Patent Document 1 prevents liquid from coming into contact with the main shaft (10).

[0005] However, in the configuration of Patent Document 1, the pump (1) includes an O-ring (31) and a lock ring (40) to close the gap between the impeller (2) and the bolt (4), and further includes an O-ring (7) disposed between the boss portion (22) and the sleeve (5).

[0006] As such, the configuration of Patent Document 1 requires the use of three sealing members, but from the perspective of improving the reliability of the pump, it is desirable to reduce the number of sealing members by using sealing members that can reliably prevent the liquid from coming into contact with the main shaft.

[0007] Therefore, an object of the present invention is to provide an impeller and a pump that can improve reliability. [Means for solving the problem]

[0008] In one aspect, an impeller is provided, comprising: a shaft insertion hole into which a main shaft of an electric motor can be inserted, a fastening hole having a diameter smaller than that of the shaft insertion hole and into which a fastener to be fastened to the main shaft can be inserted, and a sleeve insertion hole having a diameter larger than that of the shaft insertion hole and into which a shaft sleeve attached to the main shaft can be inserted. The sleeve insertion hole has a seal groove formed in a surface facing the shaft sleeve when the shaft sleeve is inserted into the sleeve insertion hole.

[0009] In one aspect, the impeller includes a main plate connected to the fastening holes and having a machined surface that defines a front face of the impeller. In one aspect, the fastening hole, the shaft insertion hole, and the sleeve insertion hole are arranged in this order and aligned on a straight line.

[0010] In one aspect, a pump is provided that includes the impeller, fastener, and shaft sleeve, a seal washer that closes the gap between the head of the fastener and the fastening hole, and a seal member that is attached to the seal groove and closes the gap between the sleeve insertion hole and the shaft sleeve.

[0011] In one aspect, the seal washer, the impeller, and the shaft sleeve are arranged in a straight line in this order, and the fastener uses its fastening force to press the metal portion of the seal washer, the metal impeller, and the metal shaft sleeve against the step portion of the main shaft. In one embodiment, the shaft sleeve has a rotation prevention groove that can be fitted onto a key formed on the inner circumferential surface of the shaft insertion hole. [Effects of the Invention]

[0012] The impeller has a sleeve insertion hole with a seal groove formed on the opposing surface of the shaft sleeve. Therefore, the seal member disposed between the shaft sleeve inserted into the sleeve insertion hole and the sleeve insertion hole can reliably prevent liquid from contacting the main shaft. As a result, the reliability of the pump can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing a pump device. [Figure 2] FIG. 2 is an enlarged view of the impeller. [Figure 3] FIG. 3 is a diagram showing a sealing washer. [Figure 4] FIG. 4 is a partially enlarged view of FIG. [Figure 5] FIG. 5(a) is a diagram showing a key formed in a shaft insertion hole, and FIG. 5(b) is a diagram showing a key groove formed in a main shaft. [Figure 6] 10A and 10B are views showing anti-rotation grooves formed in a shaft sleeve. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the pump device will be described with reference to the drawings. In the following embodiments, the same or corresponding components are designated by the same reference numerals, and redundant description will be omitted.

[0015] Fig. 1 is a diagram showing a pump device. As shown in Fig. 1, the pump device PA includes a pump P that transfers a liquid and an electric motor M that operates the pump P. The pump P includes an impeller 2 fixed to a main shaft 1 of the electric motor M, and a pump casing 10 that houses the impeller 2.

[0016] The impeller 2 is fixed to the main shaft 1 by a fastener 6. The impeller 2 includes a disk-shaped main plate 3, a side plate 4 having a liquid inlet, and a plurality of blades 5 arranged between the main plate 3 and the side plate 4. The fastener 6 is a part of the components of the pump P.

[0017] The pump casing 10 has a suction port 11 and a discharge port 12. By driving the electric motor M, the impeller 2 inside the pump casing 10 rotates, and liquid is sucked into the pump casing 10 through the suction port 11. The liquid sucked into the pump casing 10 is discharged to the outside through the discharge port 12.

[0018] The pump P includes a shaft sleeve 15 attached to the main shaft 1 and a mechanical seal 16 attached to the shaft sleeve 15. The mechanical seal 16 is disposed between the impeller 2 and the pump casing 10, and is configured to prevent the liquid from leaking to the electric motor M side.

[0019] Fig. 2 is an enlarged view of the impeller. As shown in Fig. 2, the main plate 3 has a shaft insertion hole 50 formed in its center, into which the main shaft 1 of the electric motor M can be inserted, a fastening hole 51 that communicates with the shaft insertion hole 50 and into which the fastener 6 can be inserted, and a sleeve insertion hole 52 that communicates with the shaft insertion hole 50 and into which the shaft sleeve 15 can be inserted.

[0020] Fastening hole 51, shaft insertion hole 50, and sleeve insertion hole 52 are arranged in this order on a straight line along the direction of axis CL of main shaft 1. Therefore, when an operator inserts main shaft 1 with shaft sleeve 15 attached into shaft insertion hole 50 and tightens fastener 6, impeller 2 is fixed to main shaft 1 and shaft sleeve 15 is inserted into sleeve insertion hole 52.

[0021] As shown in FIG. 2, the sleeve insertion hole 52 has an annular seal groove 36 formed on the opposing surface of the shaft sleeve 15 (i.e., the inner peripheral surface of the sleeve insertion hole 52) when the shaft sleeve 15 is inserted into the sleeve insertion hole 52. The pump P includes a seal member 35 mounted in the seal groove 36. The seal member 35 is, for example, an O-ring, and closes the gap between the sleeve insertion hole 52 and the shaft sleeve 15.

[0022] The fastening hole 51 has a diameter D2 smaller than the diameter D1 of the shaft insertion hole 50 (D2 < D1), and the sleeve insertion hole 52 has a diameter D3 larger than the diameter D1 of the shaft insertion hole 50 (D3 > D1). Thus, by forming the sleeve insertion hole 52 having a diameter D3 larger than the diameter D1 of the shaft insertion hole 50, the seal member 35 can be disposed between the main board 3 and the shaft sleeve 15.

[0023] According to the present embodiment, since the seal member 35 can surely prevent the liquid from coming into contact with the main shaft 1, the pump P can improve its reliability. As the material of the main shaft 1, carbon steel (e.g., S45C) may be employed. Carbon steel may corrode due to contact with the liquid. When the main shaft 1 corrodes, the main shaft 1 must be replaced. Since the pump P can surely prevent the liquid from coming into contact with the main shaft 1, it can surely prevent the corrosion of the main shaft 1.

[0024] FIG. 3 is a view showing a seal washer. As shown in FIGS. 2 and 3, the pump P includes a seal washer 30 that closes the gap between the head 6a of the fastener 6 and the fastening hole 51. The seal washer 30 includes an annular metal ring 31 and a rubber ring 32 disposed radially inward of the metal ring 31. By tightening the fastener 6, the rubber ring 32 of the seal washer 30 is pressed against the main board 3 by the head 6a of the fastener 6, closing the gap between the head 6a and the fastening hole 51. By disposing the seal washer 30, it is possible to prevent the liquid from entering the fastening hole 51. As a result, the seal washer 30 can surely prevent the liquid from coming into contact with the main shaft 1.

[0025] As described above, the configuration of Patent Document 1 requires the use of three seal members, but in this embodiment, by using two seal members (i.e., seal member 35 and seal washer 30), the pump P can prevent liquid from coming into contact with the main shaft 1. As a result, the overall cost of the pump P can be reduced. Furthermore, by reducing the number of seal members, the lifespan and maintainability of the pump P can be improved.

[0026] As shown in Fig. 2, the main plate 3 of the impeller 2 preferably has a machined surface 40 that is connected to the fastening hole 51 and forms the front surface of the impeller 2. The machined surface 40 is a flat surface that improves the adhesion of the seal washer 30 to the main plate 3. The seal washer 30, which is disposed between the head 6a of the fastener 6 and the machined surface 40, can more reliably close the gap between the head 6a and the fastening hole 51.

[0027] Figure 4 is a partially enlarged view of Figure 1. As shown in Figure 4, the seal washer 30, impeller 2, and shaft sleeve 15 are arranged in this order on a straight line along the axis CL. The shaft sleeve 15 is arranged between the main plate 3 of the impeller 2 and the step 1a of the main shaft 1, and movement of the shaft sleeve 15 in the axis CL direction is restricted.

[0028] The impeller 2 and the shaft sleeve 15 are each made of metal, and the seal washer 30 includes a metal ring 31. Therefore, the fastener 6 can press the metal portion of the seal washer 30 (i.e., the metal ring 31), the impeller 2, and the shaft sleeve 15 against the step 1a of the main shaft 1 with its fastening force. The fastener 6 can transmit its fastening force to the step 1a of the main shaft 1 through contact with the metal members of the pump P (i.e., the seal washer 30, the impeller 2, and the shaft sleeve 15). Therefore, the fastener 6 can fully exert its fastening force, and can reliably prevent the components of the pump P from loosening or falling off.

[0029] Figure 5(a) shows a key formed in the shaft insertion hole, and Figure 5(b) shows a keyway formed in the spindle. The main plate 3 has a key 55 (see Figure 5(a)) formed on the inner peripheral surface of the shaft insertion hole 50. The spindle 1 has a keyway 20 formed on its outer surface (see Figure 5(b)). The keyway 20 is formed by electrical discharge machining of the spindle 1.

[0030] The key 55 and the key groove 20 extend in the direction of the axis CL, and by inserting the main shaft 1 into the shaft insertion hole 50, the key 55 fits into the key groove 20. By fitting the key 55 into the key groove 20, the main shaft 1 can reliably transmit torque to the impeller 2.

[0031] Fig. 6 is a diagram showing anti-rotation grooves formed in the shaft sleeve. As shown in Fig. 6, the shaft sleeve 15 has an anti-rotation groove 25 connected to its end face 15a. The anti-rotation groove 25 extends in the direction of the axis CL and can be fitted into a key 55 formed on the inner peripheral surface of the shaft insertion hole 50. By moving the anti-rotation groove 25 in the direction of the arrow in Fig. 6, the anti-rotation groove 25 fits into the key 55. With this configuration, movement of the shaft sleeve 15 in the rotational direction is restricted.

[0032] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would naturally be possible for a person skilled in the art, and the technical concept of the present invention may also be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims. [Explanation of symbols]

[0033] 1 spindle 1a Stepped section 2 impellers 3 Main plate 4 Side panels 5 wings 6 Fasteners 6a head 10 Pump casing 11 Intake port 12 Outlet 15 shaft sleeve 15a End face 16 Mechanical seal 20 keyway 25 Anti-rotation groove 30 Seal washer 31 Metal Ring 32 Rubber ring 35 Sealing material 36 Seal groove 40 Machined surface 50 shaft insertion hole 51 Fastening holes 52 Sleeve insertion hole 55 keys

Claims

1. a shaft insertion hole into which the main shaft of the electric motor can be inserted; a fastening hole having a diameter smaller than that of the shaft insertion hole and into which a fastener to be fastened to the main shaft can be inserted; a sleeve insertion hole having a diameter larger than that of the shaft insertion hole and into which a shaft sleeve attached to the main shaft can be inserted, the sleeve insertion hole has a seal groove formed on a surface facing the shaft sleeve when the shaft sleeve is inserted into the sleeve insertion hole, The shaft sleeve is arranged in a straight line between the main plate of the impeller and the step portion of the main shaft, and the fastener is tightened to apply a tightening force to the entire shaft sleeve; the shaft sleeve has an impeller-side end portion that can be inserted into the sleeve insertion hole, and an anti-impeller-side end portion that can be pressed against a step portion of the main shaft and is aligned in a straight line with the impeller-side end portion, The impeller-side end is inserted into the sleeve insertion hole, the anti-impeller-side end is pressed against the step portion, and the fastener is tightened, thereby applying a tightening force to the entire shaft sleeve.

2. The impeller of claim 1 , wherein the impeller comprises a main plate connected to the fastening holes and having a machined surface that forms a front face of the impeller.

3. The impeller according to claim 1 or 2, wherein the fastening hole, the shaft insertion hole, and the sleeve insertion hole are arranged in this order, aligned on a straight line.

4. The impeller, fastener, and shaft sleeve according to any one of claims 1 to 3; a seal washer that closes a gap between the head of the fastener and the fastening hole; a seal member that is attached to the seal groove and closes a gap between the sleeve insertion hole and the shaft sleeve.

5. the seal washer, the impeller, and the shaft sleeve are arranged in this order in a straight line; The pump according to claim 4, wherein the fastener presses the metal portion of the seal washer, the metal impeller, and the metal shaft sleeve against a stepped portion of the main shaft with a fastening force.

6. 6. The pump according to claim 4, wherein the shaft sleeve has a rotation preventing groove formed on an inner peripheral surface of the shaft insertion hole, the rotation preventing groove being able to fit onto a key.

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