JPH0439432Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotary liquid pump equipped with an impeller made of an elastic material such as rubber, which is used, for example, in an outboard motor.

(Prior Art and its Problems) Rubber impellers have conventionally been used in cooling water pumps for outboard motors and the like. A metal bushing for fixing to the drive shaft is buried in the boss portion of this impeller, and this bushing and the drive shaft are connected with a key. Further, annular lips are extended from both upper and lower ends of the boss portion to prevent foreign matter from entering the inside.

However, when assembling a cooling water pump, a key is provided on the drive shaft in advance, and the impeller and bushing are installed from above, so a notch is required in the lower lip of the boss to pass the key through. This is undesirable in that foreign matter may enter the pump chamber through the notch.

As a prior art related to this case,
There is No. 51675.

(Purpose of the invention) The present invention provides a rotary liquid pump that can seal the key fitting part of the pump chamber around the entire circumference with the lip of the impeller boss, and can further prevent the lip from being damaged by the key during assembly work. It is intended to.

(Structure of the invention) (1) Technical means The first claim of the invention is that a bushing having higher rigidity than the boss part is embedded in the inner peripheral surface of the boss part of the impeller made of an elastic material, and the base end of the drive shaft is The part is connected to the prime mover, and the tip part is connected to the output part, and a drive shaft led into the pump chamber between the prime mover and the output part is inserted into the bush, and these drive shafts and bushes are connected to each other using a key or spline. In a rotary liquid pump that is connected by a connecting member and has an annular lip extending from both axial ends of the boss portion toward the outer circumferential surface of the drive shaft, a substantially cylindrical seal member is provided on the drive shaft on the distal side of the bush. the diameter of the outer circumferential surface of this seal member is set larger than the diameter of an imaginary circle including the outer edge of the connecting member, and the inner diameter of the distal lip that closely contacts the outer circumferential surface of the seal member is set larger than the diameter of the imaginary circle. This rotary liquid pump is characterized in that the lip on the distal end side and the seal member are in close contact with each other over the entire circumference.

The second claim of the present invention is that a bush having higher rigidity than the boss is embedded in the inner circumferential surface of the boss of the impeller made of an elastic material, the base end of the drive shaft is connected to the prime mover, and the tip of the impeller is connected to the prime mover. A drive shaft connected to the output part and guided into the pump chamber between the prime mover and the output part is inserted into the bush, and these drive shafts and the bush are connected by a connecting member, and the drive shaft is driven from both axial ends of the boss part. In a rotary liquid pump having an annular lip extending toward the outer peripheral surface of the shaft, a substantially cylindrical seal member is fitted onto the drive shaft so as to overlap the inside of the tip of the bush, and the end of the seal member on the motor side forming a continuous annular seal protrusion around the entire circumference of the bushing, and forming a seal inner circumferential surface on which the seal protrusion comes into close contact with the inner circumferential surface of the tip end of the bush;
The rotary liquid pump is characterized in that the inner diameter of the inner peripheral surface of the seal is set larger than the diameter of an imaginary circle including the outer edge of the connecting member.

(2) Effect In the first aspect, the sealing member and the distal lip seal the connecting member fitting portion of the pump chamber all around, thereby preventing foreign matter from entering the inside.

Since the inner diameter of the distal lip is larger than the outer peripheral surface of the connecting member, the lip will not be damaged by keys during assembly.

In the second aspect of the present invention, the seal protrusion is in close contact with the inner peripheral surface of the seal over the entire circumference to seal the connecting member fitting portion of the pump chamber.

Since the inner diameter of the inner circumferential surface of the seal is larger than the outer circumferential surface of the connecting member, the inner circumferential surface of the seal is not damaged by the connecting member during assembly.

(Embodiments) (1) First Embodiment In FIG. 1 showing a case where the present invention is applied to a cooling water pump for an outboard motor, reference numeral 10 indicates the outboard motor. This outboard motor 10 is attached to a transom 14 of a hull 13 with a clamp bracket 11. The outboard motor 10 is configured to drive a propeller 18 (output section) of a lower unit 17 with an engine 16 (prime mover) in a top cowling 15. The engine 16 is a water-cooled three-cylinder engine, for example.

A vertically continuous drive shaft 20 is accommodated in the lower unit 17. The upper end (base end) of this drive shaft 20 is connected to the crankshaft (not shown) of the engine 16, and the lower end ( The tip of the propeller 18 is connected to the propeller 18. A cooling water pump 21 is provided at an intermediate portion in the vertical direction of the drive shaft 20, and has a well-known structure for supplying cooling water sucked in from the intake port 22 of the lower unit 17 to the engine 16 to cool the engine 16.

In FIG. 2, which is a vertical cross-sectional view of FIG.
It is formed by connecting. A pump chamber 25 for the cooling water pump 21 is formed at the lower end of the upper case 23, and an impeller 26, a bush 27, etc. are housed inside the pump chamber 25. Furthermore, lower case 2
A cooling water passage 28 is formed at the upper end of 4, and the cooling water introduced from the suction port 22 is passed through the cooling water passage 28.
The cooling water is sucked up by an impeller 26 from the water and is pumped to the engine 16 from a cooling water pipe 29 communicating with the pump chamber 25.

A drive shaft 20 vertically passes through the center of the pump chamber 25, and the drive shaft 20 and the metal bush 27 are connected by a key 30 (connecting member). Butsuyu 27
The inner circumferential surface of a boss portion 31 that is continuous with the rubber impeller 26 is fixed to the outer circumferential surface of the impeller 26 by, for example, baking, and the impeller 26 and the bush 27 are integrated.
An upper lip 32 is provided at the upper and lower ends of this boss portion 31.
(proximal lip) and a lower lip 33 (distal lip) each form annular shapes and extend inward.
The upper lip 32 is in continuous contact with the outer peripheral surface of the drive shaft 20 over the entire circumference, and the lower lip 33 is in continuous contact with the outer peripheral surface of a seal ring 34 (sealing member), which will be described in detail later. are doing. The pump chamber 25 is sealed by an insert 35 on the upper surface, a washer plate 36 on the lower surface, and an outer plate 37.

The diameter of the virtual circle including the outer edge of the key 30 is D0
If D ₁ is the outer diameter of the seal ring 34 that is press-fitted to the drive shaft 20 below the bush 27, it is set to satisfy the relationship D ₀ ≦D ₁ (1). . Therefore, the inner diameter of the lower lip 33 that is in close contact with the outer circumferential surface 38 of the seal ring 34 is also larger than the virtual circular diameter D ₀ , or at least has the same diameter that allows the lower lip 33 to be inserted therethrough.

The seal ring 34 has two upper and lower bearings 40.
The sleeve 41 is fitted into the inner wall 43 of the lower case 24 via an O-ring 42. Further below the seal ring 34,
The drive shaft 20 is supported by a roller bearing 44,
The thrust bearing 45 is connected to the stepped portion 46 of the drive shaft 20.
It accepts the thrust load from Both cases 23 and 24 are fixed with bolts 47.

In the above configuration, even if foreign matter such as sand or mud is mixed in the cooling water sucked in from the suction port 22, the foreign matter is sealed by the lower lip 33 and does not enter between the key 30 and the keyway 30a. The aforementioned special public service in 1986
In No. 51675, a notch is formed in a part of the lip for the key to pass through, and foreign matter enters the key fitting part of the pump chamber 25 through this notch, causing wear and tear on the key 30 and keyway 30a. However, in the case of the present invention, the key 30 and the keyway 30a are not worn by foreign objects.

When assembling the cooling water pipe 21 as described above, the impeller 26, the bush 27, etc. are inserted into the upper end of the drive shaft 20 in advance, the key 30 is fitted onto the drive shaft 20, and the seal ring 34 is fixed. Then, push down the impeller 26 and the bush 27 from above to the bottom, and insert the key groove 30a of the bush 27 into the key 30.
Fits in. In this process of pushing down the impeller 26 and the bush, the lower lip 33 is pushed down on the outside of the key 30 with the key 30 fitted to the drive shaft 20, and the outer peripheral surface of the seal ring 34 is pushed down.
Closely attached to 8. As mentioned above, the inner diameter of the lower lip 33 is set larger than the virtual diameter of the outer edge of the key 30, so the lower lip 33 passes outside the key 30 without being damaged by the key 30, and the seal ring Closely attached to 34.

Since the upper lip 32 does not descend below the bush 27 as shown in FIG. 1, it closely contacts and seals the outer peripheral surface of the drive shaft 20.

(2) Second Embodiment In FIG. 3 showing a second embodiment of the present invention, parts indicated by the same reference numerals as in FIG. 2 indicate the same or equivalent parts.

In FIG. 3, a seal ring 5 is disposed inside the lower end, that is, the tip, of the metal approximately cylindrical bush 27.
0 (sealing member) are overlapped.
A substantially cylindrical rubber seal ring 50 is attached to the drive shaft 20.
The inner circumferential surface of the seal ring 50 is in close contact with the outer circumferential surface of the drive shaft 20 so as to rotate together with the drive shaft 20, with the lower end surface placed on the stepped portion 51 of the seal ring 50. Butsuyu 27
The outer peripheral surface of is surrounded by a boss portion 31 that is integral with the impeller 26 made of rubber. A continuous annular seal projection 5 is provided on both upper and lower end surfaces of the boss portion 31 over the entire circumference.
2,53 stands out. This seal protrusion 52,
53 is in close contact with the insert 35 and the outer plate 37.

An integral lip portion 54 (seal protrusion) is continuously formed on the outer peripheral surface of the upper end portion of the seal ring 50 over the entire circumference. This lip portion 54 is in close contact with a seal inner peripheral surface 55 of the bush 27 to seal an internal chamber 56. The chamber 56 is filled with grease to prevent water from entering.

If the virtual diameter of the outer edge of the key 30 is D0, and the inner diameter of the seal inner peripheral surface 55 is D3, then D0<D3 (2). Therefore, when assembling the cooling water pump 21 by covering the bush 27 and the impeller 26 from above, the outer edge of the key 30 will not damage the seal inner circumferential surface 55.

In the configuration shown in FIG. 3, the seal ring 50, bush 27, and impeller 26 rotate together with the drive shaft 20, and no relative rotation occurs between these members.
Seal chamber 56.

FIG. 4 shows a case where the lower end 60 of the bush 27 is extended downward, and there is allowance for vertical positional deviation between the drive shaft 20 and the cooling water pump 21.

Furthermore, FIG. 5 shows a case where a spacer 61 and an O-ring 62 form a sealing member. The spacer 61 is made of metal and has a cylindrical shape, and is fixed to the outer peripheral surface of the drive shaft 20 by, for example, press fitting. The rubber O-ring 62 has a diameter d larger than the wall thickness of the spacer 61.

(Another Embodiment) (1) The pump of the present invention is not limited to being mounted on an outboard motor as in the above-mentioned one embodiment, and the pump of the present invention is not limited to the case where the lower unit 17 is protruded from the bottom of the hull 13 as shown in FIG. When the engine 16 is mounted inside the hull 13, or when a lower unit 17 is provided outside the transom 14 as shown in FIG.
It can also be applied when placed within 3. Further, the orientation of the drive shafts is not limited to the case where they are arranged vertically, but may be extended diagonally or laterally.

(2) Furthermore, the present invention is applicable not only to marine cooling water pumps but also to various rotary liquid pumps installed in the middle of the drive shaft.

(Effect of the invention) As explained above, in the rotary liquid pump according to the first aspect of the invention, the substantially cylindrical seal ring 34 is fixed to the drive shaft 20 on the distal side, that is, lower than the bush 27, and the lower lip 33 (tip side lip) and the seal ring 34 are brought into close contact all around the circumference, so foreign substances such as sand and mud mixed in the cooling water sucked from the suction port 22 are sealed by the lower lip 33, and the key 30 and the keyway are sealed. It is possible to prevent foreign matter from entering between the keys 30a and reduce wear on the key 30 and the keyway 30a.

In addition, the outer peripheral surface diameter D ₁ of the seal ring 34 is
The inner diameter of the lower lip 33 that is in close contact with the outer peripheral surface 38 of the seal ring is set to be larger than the virtual circle diameter D ₀ that includes the outer edge of the key 30, and
Since it is set larger than D ₀ , the cooling water pump 2
1, the inner diameter of the lower lip 33 is larger than the virtual circular diameter D ₀ of the outer edge of the key 30 as described above, and even if the impeller 26 and the bush 27 are fitted into the key 30 from above, the lower lip 33 can be prevented from being damaged by the key 30, and the cooling water pump 2 can be prevented from being damaged by the key 30.
The assembly work in step 1 becomes easier.

In the rotary liquid pump according to the second aspect of the present invention, a substantially cylindrical seal ring 50 (seal member) is fitted onto the drive shaft 20 so as to overlap the inside of the tip end of the bush 27, and the driving shaft of the seal ring 50 is A continuous annular lip portion 54 (seal protrusion) is formed at the side end portion over the entire circumference, and a seal inner peripheral surface 55 is formed on the inner peripheral surface of the tip portion of the bush 27 to which the lip portion 54 is in close contact. Since the inner diameter D3 of the seal inner peripheral surface 55 is set larger than the virtual diameter _D0 including the outer edge of the key 30 (connecting member), the seal ring 50, bush 27, and impeller 26 are rotated together with the drive shaft 20. , no relative rotation occurs between these members,
The sealing performance of the chamber 56 can be improved.

Furthermore, when assembling the cooling water pump 21 by covering the bush 27 and the impeller 26 from above, it is possible to prevent the outer edge of the key 30 from damaging the inner circumferential surface 55 of the seal.

[Brief explanation of the drawing]

Fig. 1 is a structural schematic diagram of an outboard motor adopting the first embodiment of the present invention, Fig. 2 is a vertical cross-sectional view of the part shown in Fig. 1, and Fig. 3 is an outboard motor adopting the second embodiment of the present invention. Vertical sectional views of machine cooling water pumps, Figures 4, 5, and 6
7 and 7 are structural diagrams showing different embodiments, respectively. 20... Drive shaft, 21... Cooling water pump, 25
... Pump chamber, 26 ... Impeller, 27 ... Bush, 30 ... Key, 33 ... Lower lip, 34
……Seal ring.

Claims (1)

[Claims for Utility Model Registration] (1) A bushing with higher rigidity than the boss is embedded in the inner peripheral surface of the boss of the impeller made of an elastic material, and the base end of the drive shaft is connected to the prime mover, and the tip A drive shaft guided into a pump chamber between the prime mover and the output part is inserted into the bush, and these drive shafts and the bush are connected by a connecting member, and both axial ends of the boss part are connected to the output part. In a rotary liquid pump having an annular lip extending toward the outer peripheral surface of the drive shaft, a substantially cylindrical seal member is fitted onto the drive shaft on the distal side of the bush, and the outer peripheral surface diameter of this seal member is The diameter of the imaginary circle including the outer edge of the connecting member is set to be larger than the diameter of the imaginary circle, and the inner diameter of the distal lip that comes into close contact with the outer peripheral surface of the seal member is set to be larger than the diameter of the imaginary circle, so that the distal lip and the seal member are connected all around the circumference. A rotary liquid pump that is characterized by being in close contact with each other. (2) A bush that is more rigid than the boss is embedded in the inner peripheral surface of the boss of the impeller made of an elastic material, the base end of the drive shaft is connected to the prime mover, and the tip is connected to the output part, The drive shaft guided into the pump chamber between the prime mover and the output section is inserted into the bush, the drive shaft and the bush are connected by a connecting member, and the drive shaft is inserted from both axial ends of the boss section toward the outer peripheral surface of the drive shaft. In a rotary liquid pump having an elongated annular lip, a substantially cylindrical seal member is fitted onto the drive shaft so as to overlap the inner side of the tip of the bush, and a seal member is fitted around the entire circumference at the end of the seal member on the motor side. to form a continuous annular seal protrusion, and to form a seal inner circumferential surface on which the seal protrusion is in close contact with the inner circumferential surface of the tip end of the bush, the inner diameter of this seal inner circumferential surface is an imaginary circle including the outer edge of the connecting member. A rotary liquid pump characterized by being larger than its diameter.