Marine drives and cooling pumps for marine drives
A pump for pumping cooling fluid to cool a marine drive comprises a pump housing defining a chamber and an impeller in the chamber. The impeller is rotatable about an axis, and the pump is configured to automatically adjust and maintain an axial compression force on the impeller so as to maintain a consistent seal between the impeller and the pump housing. In other examples, a marine drive comprises an inlet configured to receive cooling fluid and a pump configured to pump the cooling fluid to cool a component of the marine drive. The pump comprises a pump housing that defines a chamber and an impeller compressed in the chamber. The impeller is rotatable about an axis, and the pump is configured to automatically adjust and maintain an axial compression force on the impeller so as to maintain a consistent seal between the impeller and the pump housing.
1 . A pump for pumping cooling fluid to cool a marine drive, the pump comprising:
a pump housing defining a chamber between two housing portions;
an impeller in the chamber and rotatable about an axis; and
a device in the chamber axially between one of the housing portions and the impeller to bias the impeller into engagement with the other housing portion and automatically adjust and maintain an axial compression force on the impeller so as to maintain a consistent seal between the impeller and the pump housing.
2 . The pump according to claim 1 , wherein the device maintains the seal between the impeller and the other housing portion.
3 . The pump according to claim 2 , wherein the device further maintains a seal between the device and the impeller.
4 . The pump according to claim 1 , wherein the device compresses the impeller against the pump housing.
5 . The pump according to claim 1 , wherein the two housing portions are a first housing portion and a third housing portion and the pump further comprises a second housing portion axially extending between the first housing portion and the third housing portion, and wherein the device compresses the impeller to maintain the seal between the impeller and the first housing portion and a seal between the impeller and the second housing portion.
6 . The pump according to claim 1 , wherein the device comprises a spring.
7 . The pump according to claim 1 , wherein the device comprises a plate that acts on the impeller.
8 . The pump according to claim 1 , wherein the device is a first device, and further comprising a second device that biases the other housing portion into engagement with the impeller such that the first device and the second device compress the impeller therebetween.
9 . The pump according to claim 1 , wherein the impeller has an exterior surface that engages with the other housing portion when the device biases the impeller into engagement with the other housing portion such that the seal is maintained between the exterior surface and the other housing portion.
10 . The pump according to claim 1 , wherein the pump housing further comprising a pump inlet configured to permit passage of the cooling fluid into the chamber, and wherein pressure of the cooling fluid passing into the chamber opposes the bias of the device.
11 . The pump according to claim 10 , wherein when the pressure of the cooling fluid received through the pump inlet is greater than a minimum pressure, the device is biased away from the impeller and the pressure of the cooling fluid maintains the consistent seal between the impeller and the pump housing.
12 . A marine drive comprising:
an inlet configured to receive cooling fluid; and
a pump configured to pump the cooling fluid to cool a component of the marine drive, the pump comprising a pump housing that defines a chamber between two housing portions, an impeller compressed in the chamber and rotatable about an axis, and a device in the chamber axially between one of the housing portions and the impeller to compress the impeller into engagement with the other housing portion and automatically adjust and maintain an axial compression force on the impeller so as to maintain a consistent seal between the impeller and the pump housing.
13 . The marine drive according to claim 12 , wherein the device maintains the seal between the impeller and the other housing portion.
14 . The marine drive according to claim 12 , wherein the device compresses the impeller against the pump housing.
15 . The marine drive according to claim 13 , wherein the device further maintains a seal between the device and the impeller.
16 . The marine drive according to claim 12 , wherein the two opposing housing portions are a first housing portion and a third housing portion and the pump comprises a second housing portion axially extending between the first housing portion and the third housing portion, and wherein the device compresses the impeller to maintain the seal between the impeller and the first housing portion and a seal between the impeller and the second housing portion.
17 . The marine drive according to claim 16 , wherein the device comprises a plate and a o-ring, wherein the o-ring is positioned between the plate and the second housing portion to thereby create a seal therebetween.
18 . The marine drive according to claim 12 , wherein the device is a first device, and the pump further comprises a second device that biases the other housing portion into engagement with the impeller such that the first device and the second device compress the impeller therebetween.
19 . The marine drive according to claim 13 , wherein the pump housing further comprising a pump inlet configured to permit passage of the cooling fluid into the chamber, and wherein pressure of the cooling fluid passing into the chamber opposes the bias of the device.
20 . A method of maintaining a consistent seal between an impeller and a pump housing of a pump that is for pumping cooling fluid to cool a marine drive, the method comprising:
compressing the impeller in a chamber defined between two housing portions of the pump; and
maintaining a compression force on the impeller with a device positioned between one of the housing portions and the impeller so as to compress the impeller into engagement with the other housing portion and maintain the consistent seal between the impeller and the pump housing.