JPH066237Y2 - Water pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a water pump used in a water-cooled internal combustion engine or the like, and more particularly to a water pump in which the rotation of an impeller is intermittent depending on the water temperature.

[Conventional technology]

A conventional example of this type of water pump is Japanese Patent Laid-Open No. 60-111.
The one disclosed in Japanese Patent No. 016 is known.

In the above-mentioned conventional example, as a means for connecting and disconnecting the rotating shaft and the impeller, a serrated engagement portion is used, and the impeller is moved in the axial direction by a spring biased by temperature, The engagement portion is disengaged so that the connection between the rotary shaft and the impeller is interrupted.

[Problems to be solved by the device]

In the above-mentioned conventional water pump, since the connection and disconnection of the rotary shaft and the impeller is made by engaging and disengaging the serrated teeth, the connection and disconnection is shocking, and especially the shock at the time of engagement is large, and the impact force by this is great. There was a problem such as noise. Further, once engaged, even if an overload acts on the impeller, the impeller rotates integrally with the rotating shaft, and no measures have been taken against the overload.

The present invention has been conceived in view of the above, and the connection between the rotating shaft and the impeller can be performed intermittently without causing shock, and when the impeller is overloaded, the impeller is not attached to the rotating shaft. An object of the present invention is to provide a water pump which can be idled to escape the overload.

[Means for Solving the Problems]

In order to achieve the above object, a water pump according to the present invention includes an impeller rotatably fitted to a rotating shaft supported by a bearing housing, and an impeller from a position where one end surface of the impeller contacts the bearing housing. The end surface of the fitting part of is slidable over the position where it abuts the end surface of the stopper fixed to the rotating shaft, and is spring-biased to the stopper side for fitting, and to the body side surrounding the impeller,
A thermal drive member that expands at room temperature and contracts at high temperature is provided so as to come into contact with the other end of the impeller and push toward the bearing housing during expansion.

[Action]

When the temperature of water is room temperature, the fitting portion of the impeller is pushed by the expansion of the heat-driving member, and the impeller abuts the bearing housing and its rotation is stopped. When the temperature of water becomes higher than a predetermined temperature, the heat-driving member is reduced in size, the impeller abuts on the stopper fixed to the rotary shaft by the spring, and the frictional force at this time causes the impeller to rotate together with the rotary shaft to perform a pump action.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. Note that FIG. 1 also serves to explain the operation, and the upper side of the axis of the rotating shaft 1 shows the rotating state of the impeller 2, and the lower side shows the stopped state.

The rotating shaft 1 has a bearing housing 4 via a bearing 3.
The pulley 5 is fixed to the base end of the rotary shaft 1 and to the portion protruding from the bearing housing 4. The impeller 2 is rotatably fitted in the bearing housing 4 of the rotary shaft 1 so as to be slidable in the axial direction. The rotary shaft 1 of the impeller 2
The fitting portion 2a with respect to is in the form of a flange, and the fitting portion 2a is located between the stoppers 6 and 7 fixed to the rotating shaft 1 so as to be spaced apart in the axial direction and to the stopper 6 on the base end side. The supported spring 8 urges the stopper 7 on the front end side in the direction of the end surface. The urging force of the spring 8 has such a strength that when the load acting on the impeller 2 is normal, the urging force co-rotates with the rotary shaft 1 due to the frictional force between the end face of the stopper 7. A tubular portion is formed in the fitting portion 2a of the impeller 2, and the inner surface of the tubular portion is fitted and supported by the tubular portion of the stopper 7 via a tubular sliding member 9. .

An annular sliding member 10a is provided on the outer peripheral side of the impeller 2 and on the axial end surface of the bearing housing 4 facing the inner surface.
Further, another annular sliding member 10b is fixed to the end surface of the bearing housing 4 that faces the bearing. The positional relationship between the two annular sliding members 10a and 10b is such that the fitting portion 2a of the impeller 2 is separated from the end surface of the stopper 7 on the tip side and is separated from the end surface of the stopper 7 against the spring 8. Both annular sliding members 10a, 1 in a state where the joint portions are separated from each other.
0b comes into contact.

A cylindrical thermal drive member 13 is embedded in the boss portion 12 of the frame 11 surrounding the impeller 2 and the tip end of the rotating shaft 1 facing the tip end face of the fitting portion 2a of the impeller 2. is there. The heat-driving member 13 is made of a shape memory alloy and extends in the axial direction at normal temperature and contracts in the axial direction at high temperature. The fitting portion of the impeller 2 is extended in the axial direction. It contacts the 2a and pushes it.

In the above structure, the rotary shaft 1 is rotated by the pulley 5. Then, at this time, the temperature of the water is high, and the heat driving member 13
When the temperature is high, as shown in the upper half of FIG. 1, the axial length of the heat-driving member 13 is short, so that the fitting portion 2a of the impeller 2 is located at the tip of the spring 8. The end face of the stopper 7 on the side is urged and abutted, and the frictional force on the abutting face causes the pump 7 to rotate together with the rotary shaft 1.

Next, when the temperature of water becomes low and the temperature of the heat-driving member 13 becomes low, the heat-driving member 13 is gradually expanded. As a result, the fitting portion 2a of the impeller 2 is pushed against the spring 8, and as shown in the lower half of FIG. 1, the length of the heat-driving member 13 when the temperature is room temperature causes the impeller to move. 2 and the annular sliding members 10a and 10b fixed to the bearing housing 4, respectively, come into contact with each other, and the frictional force at the contact surface at this time gradually reduces the rotational speed of the impeller 2 and finally stops. It

In the above operation, the relationship between the water temperature T and the pump flow rate Q becomes as shown in FIG. 2, and the flow rate changes from zero to the set flow rate Q _{1 with} a certain inclination angle around the set temperature T _1. However, the connection between the rotary shaft 1 and the impeller 2 can be intermittently performed without generating a shock. Further, since the rotary shaft 1 and the impeller 2 at the time of coupling are frictionally coupled, when an overload acts on the impeller 2 at the time of coupling, the above-mentioned coupling portion slips and this overload is released.

[Effect of device]

According to the present invention, the connection between the rotating shaft 1 and the impeller 2 can be intermittently performed without generating an impact, and when the impeller 2 is overloaded, the impeller 2 idles with respect to the rotating shaft 1. The above-mentioned overload can be escaped.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure and operation of an embodiment of the present invention,
FIG. 2 is a diagram showing a change in flow rate with respect to temperature. Reference numeral 1 is a rotary shaft, 2 is an impeller, 4 is a bearing housing, 7 is a stopper, 8 is a spring, 11 is a main body, and 13 is a thermal drive member.

Claims (1)

[Scope of utility model registration request] 1. An impeller 2 is rotatably fitted to a rotating shaft 1 supported by a bearing housing 4, and one end surface of the impeller 2 abuts the bearing housing 4 and the other end surface of the impeller 2 is It is slidable over the position where it abuts on the end face of the stopper 7 fixed to the rotary shaft 1, and is spring-biased and fitted to the stopper 7 side, and extends at room temperature on the main body 11 side surrounding the impeller 2. A water pump, characterized in that the heat driving member 13 that contracts at high temperature is provided so as to abut against the other end side of the impeller 2 and push it toward the bearing housing 4 side when the heat driving member 13 extends.