JPH0247211Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil pump for an engine, and particularly to an external type oil pump that is attached to the side surface of an engine body.

(Prior Art) Generally, an engine is equipped with an oil pump for pumping lubricating oil to each lubricated part of the engine, and the oil pump is driven to rotate by the driving force of the engine. And conventionally,
Such an oil pump is known, for example, from Japanese Patent Application Laid-Open No. 1983-
As disclosed in Publication No. 114845, it was installed inside the engine body, such as in the oil pan. Therefore, even if some of the oil in the pump rotating part of the oil pump leaks from the connection part with the drive shaft that is connected to the pump rotating part and transmits engine driving force, this oil will naturally be collected in the oil pan. Therefore, no countermeasures against this leaked oil were necessary.

(Problem to be solved by this invention) However, in recent years, as engines have become more compact and miniaturized, it has become difficult to incorporate the oil pump into the engine body as in the past due to its height and length. There is a tendency to For this reason, the oil pump must be mounted externally on the side of the engine body, for example in the width direction of the side of the cylinder block, but in this case, the oil leaking from the drive shaft and connection part of the pump rotating part will be dissipated to the outside. Measures must be taken to prevent this from happening.

Therefore, as such an external type oil pump, one having the following configuration can be considered. That is, the engine includes a casing that is attached to the side surface of the engine body, a pump rotating section is provided inside the casing, and a drive shaft that is connected at one end to the pump rotating section and transmits engine driving force to the pump rotating section is formed in the middle of the casing. It is rotatably supported in the casing by a large diameter bearing. Further, in order to regulate the axial position of the drive shaft, a regulating portion is provided adjacent to the drive shaft bearing portion in the axial direction on the opposite side from the pump rotating portion. A space is formed between the drive shaft and the casing on the side of the pump rotation part from the bearing part to collect oil (pressure oil) leaking from the connection part of the pump rotation part with the drive shaft. It is something. In this case, the reason why the diameter of the bearing part is made larger than that of the drive shaft is to reduce the surface pressure by increasing the bearing area, and because increasing the bearing area in the axial direction increases the overall length of the pump, so in the radial direction The reason for this is that the larger the size, the more compact the whole will be, and the rigidity of the bearing portion will be improved.

However, with this device, when enough leaked oil (pressure oil) accumulates in the space, the large diameter bearing receives the pressure of this oil, and the drive shaft moves to the opposite side of the pump rotating part (i.e., the regulating part). side),
A new problem arises in that the drive shaft bearing portion comes into pressure contact with the restriction portion, resulting in seizure.

This invention was made to further improve the external type oil pump proposed above, and by relieving the oil accumulated in the space into the oil pan, it is possible to collect the leaked oil while also improving the drive shaft bearing. The purpose is to prevent seizure from occurring due to pressure contact of the part to the regulating part.

(Means for solving the problem) In order to achieve the above object, the solution of the present invention is fixed to the side of the engine body as an engine oil pump that is attached to the side of the engine body and rotationally driven by the engine driving force. a casing provided with a casing, a pump rotating section provided in the casing, a drive shaft having one end connected to the pump rotating section and transmitting engine driving force to the pump rotating section, and an axially intermediate portion of the drive shaft. a bearing portion formed to have a larger diameter than the drive shaft and rotatably supported by the casing; and a bearing portion of the drive shaft bearing portion that is provided adjacent to the pump rotation portion in the axial direction on the opposite side of the pump rotation portion, and is provided adjacent to the bearing portion in the axial direction of the drive shaft. formed between a regulating part that regulates the position, and the drive shaft and the casing on the side of the pump rotating part from the bearing part,
The pump includes a space for storing oil leaked from the connecting portion of the pump rotating portion to the drive shaft. Furthermore, the casing is configured to form a relief passage whose one end opens into the space to relieve oil in the space to the oil pan.

(Function) With the above configuration, in the present invention, even if the pump is mounted externally on the side of the engine body, the oil leaking from the connection part of the pump rotating part to the drive shaft will accumulate in the space inside the casing and leak out to the outside. There's nothing to do. Moreover, since the oil accumulated in this space is relieved from the oil pan via the relief passage formed in the casing, the pressure of the oil in the space is relieved, and the oil pressure causes the drive shaft bearing to move to the regulating part. Seizure caused by pressure contact is prevented. Furthermore, since the leaked oil is collected in the oil pan, there is no wasteful consumption of oil.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show an engine equipped with an oil pump P according to an embodiment of the present invention. In the figure, 1 is a cylinder block, and although not shown, a cylinder head is connected to the upper part of the cylinder block 1, and an oil pan is connected to the lower part of the cylinder block 1. These constitute the engine body. There is. Further, a crankshaft extending in the longitudinal direction (front-rear direction) of the cylinder block 1 is supported at the lower part of the cylinder block 1. An oil pump P according to the present invention is attached to a side surface (left side in the figure) of the cylinder block 1.

The oil pump P includes a casing 2 fixed to the side surface of a cylinder block 1 and extending in the front-rear direction, and a trochoid type pump having an internal rotor 3a and an external rotor 3b on the rear side inside the casing 2. A pump rotating section 3 is provided, and a drive shaft 4 whose rear end is connected to the internal rotor 3a of the upper pump rotating section 3 is disposed in the casing 2 in parallel with the crankshaft. The front end of the drive shaft 4 protrudes forward from the casing 2, and a drive gear 5 connected to the crankshaft via a timing belt (not shown) is provided at the front end to drive engine driving force. The oil is transmitted to the pump rotating part 3 via the shaft 4, and the pump rotating part 3 is rotated in synchronization with the engine, so that a predetermined amount of oil corresponding to the engine speed is pumped to each lubricating part. Also,
The drive shaft 4 has a bearing portion 4a having a larger diameter than the drive shaft 4 formed in the middle thereof, and is rotatably supported by the casing 2 by the bearing portion 4a.

Further, in the casing 2, there is provided an area adjacent to the drive shaft bearing section 4a in the axial direction on the opposite side (drive gear 5 side) from the pump rotating section 3, and toward the front side of the drive shaft 4 (drive gear 5 side). A regulating portion 6 made of a thrust plate is provided to prevent movement of the shaft and regulate its axial position. Further, a space 7 is formed between the drive shaft 4 and the casing 2 on the side of the pump rotation section 3 from the bearing section 4a, and on the outer periphery of the end of the drive shaft 4 on the pump rotation section 3 side. One end communicates with the connecting part between the pump rotating part 3 and the drive shaft 4,
A spiral escape groove 8 whose other end communicates with the space 7
is formed, and a groove 8 is formed to release oil (pressure oil) leaking from the connection part of the pump rotating part 3 with the drive shaft 4.
The liquid is introduced into the space 7 through the pipes, etc., and stored therein.

In addition, the casing 2 has one end opening into the space 7 and the other end extending downward along the mating surface of the casing 2 with the cylinder block 1, through an oil passage 9 formed in the cylinder block 1. A relief passage 10 communicating with the oil pan is formed, and is configured to relieve oil (pressure oil) accumulated in the space 7 and return it to the oil pan.

Note that 11 indicates the bearing portion 4a of the drive shaft 4 and the drive gear 5.
The sprocket 11 is provided with a sprocket 1 for driving a balancer 12 provided on the front surface of the cylinder block 1.
A chain 14 is wound around the balancer 12 and the like, and the balancer 12 and the like are rotated in conjunction with the drive of the oil pump P. Further, 15 is an oil passage for supplying lubricating oil to the drive shaft bearing portion 4a.

Therefore, in the embodiment described above, the engine driving force is transmitted to the pump rotating section 3 via the timing belt, the driving gear 5, and the driving shaft 4, and the pump rotating section 3 rotates, so that each part of the engine is rotated. Oil is pumped to the lubricated parts to provide lubrication. At that time, along with the rotational drive of the pump rotating part 3,
A part (a small amount) of oil (pressure oil) leaks from the connection part of the pump rotating part 3 with the drive shaft 4, but this oil (pressure oil) leaks into the space part 7 via the relief groove 8 etc. Since it is guided and stored, it does not leak out to the outside. Moreover, the oil stored in this space 7 is relieved into the oil pan via the relief passage 10 and the oil passage 9 and is recovered without waste, so that an increase in oil consumption is not caused.

Furthermore, the pressure increase in the space 7 is moderated and suppressed by the oil relief in the space 7, so that the oil pressure in the space 7 presses the drive shaft bearing part 4a against the restriction part 6. This makes it possible to prevent burn-in and improve reliability and durability.

(Effects of the invention) As explained above, according to the invention, even if the oil pump is externally attached to the side of the engine body, oil can be prevented from leaking to the outside and the oil can be collected into the oil pan without wasting it. However, it is possible to prevent seizure due to pressure contact of the drive shaft bearing part to the regulating part.
Therefore, it is possible to provide an external oil pump that is suitable for engines that are designed to be more compact and smaller.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an enlarged cross-sectional view taken along the line - in FIG. 2, and FIG. 2 is a front view of the oil pump mounting portion of the engine. 1...Cylinder block, 2...Casing,
3... Pump rotating part, 4... Drive shaft, 4a... Bearing part, 6... Regulating part, 7... Space part, 10... Relief passage.

Claims (1)

[Scope of utility model registration request] An engine oil pump that is attached to the side of the engine body and rotationally driven by the engine driving force, which includes a casing fixed to the side of the engine body, a pump rotation part provided in the casing, and one end that rotates the pump. a drive shaft that is connected to the pump rotating section and transmits engine driving force to the pump rotating section; a bearing section that is formed at a midway point in the axial direction of the drive shaft to have a larger diameter than the drive shaft and is rotatably supported by the casing; , a regulation part that is provided adjacent to the drive shaft bearing part in the axial direction on the opposite side from the pump rotation part and regulates the axial position of the drive shaft, and a drive shaft and a casing on the side of the pump rotation part from the bearing part. formed between
It is equipped with a space for storing oil leaked from the connection part of the pump rotating part with the drive shaft,
An oil pump for an engine, wherein the casing is formed with a relief passage whose one end opens into the space to relieve oil in the space to an oil pan.