JPH0633778B2 - Oil pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oil pump containing at least two sets of pump elements for individually providing a pressurized fluid to a plurality of fluid devices.

[Prior Art] A so-called tandem type oil pump having at least two sets of pump elements built therein is known, but in particular, the one in which the number of parts of the pump built-in portion is reduced to simplify the configuration is disclosed. There is an invention disclosed in Japanese Patent Laid-Open No. 58-180790. The oil pump of the present invention selectively supplies the pressure fluid of two sets of pumps to an automobile power steering apparatus which is one fluid device. Specifically, the discharge amount of the pump is equal to that of the engine. Since it increases / decreases in proportion to the number of revolutions, only one pump is normally used for pressure oil supply, the other is connected to the tank side for no load, and pressure fluid from both pumps is joined only when necessary. This is an improvement of the energy-saving type oil pump that is designed to supply.

As shown in FIG. 5, the structure is such that a bottomed pump storage space c is formed which opens to the front body b side at the center of the rear body a, and the main storage chamber c is opened from the bottom side in the pump storage space c. A first pump d and a sub second pump e are arranged with a side plate f interposed therebetween, and these pumps d and e are rotationally driven by a common drive shaft g supported by and extended from the front body b. Are combined as described. On the other hand, a discharge side pressure chamber h into which pressure oil is introduced from the first pump d is formed at the bottom of the pump housing space c, and the fluid pressure acting on the discharge side pressure chamber h causes the discharge side pressure chamber h and the The entire layered pump portion is pressed against the inner end surface of the front body b via the pressure plate i arranged between the pumps d and e.
It is configured to secure the side seal of.

[Problems to be Solved by the Invention] In the energy-saving type oil pump as illustrated above, the supply of the pressure oil to the discharge side pressure chamber h for ensuring the side seal of both pumps d and e is always prioritized. Even when the second pump e cooperates with the first pump d, the sub-passage j also serving as the discharge side pressure chamber of the second pump e and the discharge side pressure chamber h The side seal can be secured without any problem due to the difference in pressure receiving area.

However, when both pumps are configured for the purpose of supplying pressure fluid to a plurality of fluid devices separately,
The first pump d does not always operate preferentially. For example, the fluid device in communication with the first pump d is placed in a non-operating and unloaded state, while the fluid device in communication with the second pump e is operated so that its load is increased. Also occurs.
At this time, the discharge side pressure chamber h, which receives the supply of the fluid from the unloaded first pump d, is of course at a low pressure, and conversely, the second pump e is moved to the front body b by the pressure in the sub passage j where the load pressure is increased. As a result of being urged in the direction of being released from, it becomes extremely difficult to secure the side seal.

The present invention relates to an oil pump which can steadily secure a side seal of the entire pump even when a plurality of fluid devices individually receiving pressure fluids from at least two sets of pump elements operate independently of each other. Appearance is a technical issue to be solved.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a sealed storage space formed by coupling two housings, and one housing rotatably supported to extend into the storage space. A drive shaft that has come out, and at least two sets of base type pump elements that are rotationally coupled to the drive shaft while being allowed to move in the axial direction and that are arranged side by side in multiple layers in the storage space; A technical means is provided in which a pressure chamber, which is opposed to the side plate and communicates with the discharge passage of each pump element, is independently formed on one end wall of the storage space.

[Operation] One discharge fluid of the above-mentioned pump elements arranged in parallel in the axial direction in the pump of the present invention is supplied to, for example, a power steering apparatus for an automobile through a built-in flow control valve mechanism, and at the same time, is stored therein. The pump fluid is supplied to an annular pressure chamber formed in one end wall of the space, and the other discharge fluid of the pump element passes through a disk-shaped pressure chamber formed in the one end wall of the storage space and a fan driving device for engine cooling. Supplied directly to.

Therefore, even if the load pressure of any of the pump elements increases due to the operation of the fluid device, the discharge fluid pressure acts on the pressure chambers independently formed on the one end wall of the storage space, and via the opposing side plates. Since all of the pump elements are urged toward the other end wall of the storage space comprehensively, the side seal of each pump element is always well ensured.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 3 show a first oil pump according to the present invention.
1 shows an embodiment in which two sets of vane type pump elements are built in, and each pump element is provided in different fluid equipment such as a power steering device for an automobile and a fan drive device for cooling an engine. A type in which the discharge fluid is supplied individually is shown.

In the figure, 1 is a first housing, 2 is a second housing, and a second housing 2 is provided at the center of the first housing 1.
A bottomed storage space 3 that opens toward the side is formed, and the storage space 3 is hermetically closed by the second housing 2. Reference numeral 4 penetrates the central portion of the first housing 1 to store the storage space. The drive shaft extends into the space 3 and has a first shaft on the drive shaft 4.
The first and second pump elements 5 and 6 are arranged from the housing 1 side, and the first to the third pump elements are tightly fitted to the peripheral wall of the storage space 3 so as to sandwich the side surfaces of the pump elements 5 and 6. The side plates 7, 8 and 9 are arranged side by side in a multilayer form. The pump elements 5 and 6 are rotationally driven by the common drive shaft 4 supported by the first housing 1 via a pair of bearings 10 and 11. In addition, 12 is a shaft sealing device.

The first and second pump elements 5 and 6 are vane type pumps known in the related art, and each has a rotor 14 spline-coupled to the drive shaft 4 and having a plurality of vanes 13.
It has a cam ring 15 that houses the rotor 14 and forms a working chamber. The pump elements 5 and 6 and the side plates 7, 8 and 9 are rotationally positioned with respect to the first housing 1 by the positioning pins 16 that are inserted therethrough, but are allowed to move in the axial direction. Has been done.
Reference numeral 17 denotes a substantially annular recess 17a formed in the end wall of the storage space 3 on the first housing 1 side, and an annular space 17b recessed so as to surround the outer peripheral portion of the second pump element 6.
To connect these recesses 17a and the annular space b,
Communication hole 17c formed in the lower portion of the first housing 1
In the suction chamber formed by and, the suction hole 18 shown by a chain line in FIG. 1 communicates with the recessed portions 17a, and a recovery oil passage 19 shown by a chain line for collecting the oil leaked in the vicinity of the shaft sealing device 12 is formed. It is also communicated with. The hydraulic oil fed through the recovery oil passage 19 is used not only to lubricate the bearing 11 but also to lubricate the spline joint portion of each rotor 14 via the inner holes of the first and second side plates 7 and 8. Be served.

The recessed portion 17a is provided through a pair of suction passages 20 penetrating the first side plate 7 shown by an oval broken line in FIG. 2 and the suction passage 20 and the cam ring 15 of the first pump element 5. Working chamber 22 formed in the first pump element 5 through a suction passage 20 'communicated through the small hole 21 formed in the second side plate 8 so as to align the suction passage 20. Is in communication with the suction position. On the other hand, the annular space 17b has a pair of suction passages 2 symmetrically formed on the second and third side plates 8 and 9 shown by the mountain-shaped broken lines in FIG.
It is in communication with the suction position of the working chamber 24 formed in the second pump element 6 via 3, 23 '.

Reference numeral 25 denotes a discharge chamber which is annularly recessed so as to surround the outer peripheral portion of the first pump element 5 in the same manner as the annular space 17b.
A pair of discharge passages 26, 2 symmetrically engraved on the first and second side plates 7, 8 shown by mountain-shaped broken lines in FIG.
Working chamber 2 formed in the first pump element 5 via 6 '
It communicates with the two discharge positions. And the discharge chamber 25
Is communicated with the flow rate adjusting valve mechanism 28 through a communication passage 27 having an approximately rectangular cross section that extends in the axial direction in the upper portion of the first housing 1, and the controlled excess oil passes through a tank or bypass passage 40 (not shown) and the recess 17a. Is returned to. This flow rate adjusting valve mechanism has a conventionally well-known configuration, and since the difference in this configuration does not limit the present invention in particular, detailed illustration and description thereof will be omitted, but the fluid device connected to the first discharge hole 29 is of the present embodiment. In the case of a power steering system for automobiles, a valve generally equipped with a variable adjustment function to prevent power loss, hydraulic oil heating, etc., and a pressure adjustment function to protect the circuit and prevent excessive force from acting on the steering mechanism. The mechanism is adopted.
However, it goes without saying that the flow rate adjusting valve mechanism 28 may be omitted depending on the type of fluid device communicating with the first pump element 5. At the discharge position of the working chamber 24 formed in the second pump element 6, a pair of discharge passages 30 formed in an oval shape penetrating the third side plate 9 is opened, and the discharge passage 30 has a pressure balance. In order to achieve the above, the discharge groove 30 ′ formed in an oval shape in alignment with the second side plate 8 is communicated with a discharge hole 30 ′ formed in the cam ring 15 of the second pump element 6 through a small hole 21.

On the other hand, the second housing 2 is fitted and fixed to the opening end of the storage space 3 formed in the first housing 1 via the collar 31, and the flange 31 of the collar 31 and the second housing 2 is fixed.
An annular first pressure chamber 32 is formed between the first pressure chamber 32 and the first pressure chamber 32 including a disc-shaped recess between the inner end surface of the second housing 2 and the third side plate 9. Forms an independent second pressure chamber 33. And the first pressure chamber 32
Is supplied with the discharge fluid from the first pump element 5 via the pressure guiding hole 34 branched from the communication passage 27, and the second pressure chamber 33 is directly supplied from the discharge passage 30 to the second pump element 6.
However, since the second pressure chamber 33 is communicated with the second discharge hole 35 shown by the chain line in FIG. 1 through a short passage, the second pressure chamber 33 is eventually discharged. The second pump element 6 also serves as a discharge chamber. However,
When the first pump element 5 is activated, the first and third side plates 7 and 9 clamp the first and second pump elements 5 and 6 and the second side plate 8 by the pressure difference between the two sides. The pressure receiving area of the third side plate 9 by the chamber 32 needs to be set larger than the pressure receiving area of the first and second side plates 7, 8 by the discharge passages 26, 26 '. In this embodiment, the second
The discharge port 35 communicates with an engine cooling fan drive device that does not require flow rate adjustment. 36a, 36b and 37
a and 37b are oil guide holes formed in the side plates 7, 8 and 9 so as to communicate with respective discharge systems in order to supply pressure oil to the vane groove bases of the first and second pump elements 5 and 6. It is preferable that the side plates 7, 8 and 9 are made of a sintered alloy in order to effectively form the various groove holes of the suction and discharge systems including these and the oil guide grooves. Further, 38 is the above-mentioned second part for urging the third side plate 9 for the purpose of initial sealing.
A coil spring 39 is provided in the pressure chamber 33, and a corrugated washer 39 is provided in the first pressure chamber 32 to prevent the collar 31 from inching.

In the oil pump configured as described above, when the drive shaft 4 is rotationally driven in conjunction with engine rotation, the working oil in the tank is sucked from the suction hole 18 into the suction chamber 17 and the suction passages 2, 20 'and 23. , 23 ', into the working chambers 22, 24 of the first and second pump elements 5, 6 and the pressure oil discharged from the first pop element 5 is discharged into the discharge passages 26, 26', the discharge chamber 25, the communication chamber. The pressure oil sent out from the first discharge hole 29 to the power steering device via the passage 27 and the flow rate adjusting valve mechanism 28 and discharged from the second pump element 6 is discharged from the discharge passage 30, the second pressure chamber 33, and the second pressure chamber 33. It is supplied to the engine cooling fan drive device through the second discharge hole 35. Even when the engine speed is low or becomes high to some extent as in the early stage of operation, the fluid pressure in each circuit is low when no fluid is loaded and no load is applied. The side seal of each pump element 5 and 6 is mainly the second
It is ensured in a form dependent on the coil spring 38 arranged in the force chamber 33. After that, when the load of the first pump element 5 increases due to the operation of the power steering device, for example, the high pressure oil guided to the first pressure chamber 32 from the pressure guiding hole 34 urges the third side plate 9 via the collar 31. As described above, the pressure receiving area of the third side plate 9 at this time is the first and the second by the discharge passages 26, 26 '.
Since it is set to be larger than the pressure receiving area of the side plates 7 and 8, the first and second pump elements 5 and 6 and the second side plate 8 are sandwiched between the first and third side plates 7 and 9, and their side seals are Secured well. Further, when only the engine cooling fan drive device is operated while the power steering device is inactive, the third side plate 9 causes the high pressure oil in the second pressure chamber 33 to discharge the discharge passage of the second pump element 6. Since the pressure is applied with a pressure receiving area significantly larger than 30, the side seals of both pump elements are well secured as in the above. Of course, even if both of the fluid devices are operated, the function of the side seal does not affect the bearing.

In the above embodiment, the pressure chamber provided in the one end wall of the storage space 3 so as to face the third side plate 9, the second housing 2 and the collar 3 are provided.
1 and the first and second pressure chambers 32 and 33, respectively.
As shown in FIG. 4 as a second embodiment, the outer peripheral portion of the third side plate 9 and a third side plate 9 ′ integrally extending in the direction of the second housing 2 are provided. None,
Both pressure chambers 3 are formed by the third side plate 9'and the second housing 2.
By separating 2 and 33, it is possible to contribute to simplification of the configuration such as omission of the collar 31 and the corrugated washer 39.

[Effects of the Invention] As described above, the oil pump of the present invention discharges even if any load pressure rises due to the operation of the fluid equipment that individually communicates with at least two sets of built-in pump elements. The fluid pressure acts on the pressure chambers independently formed on one end wall of the storage space, and comprehensively urges all the pump elements toward the other end wall of the storage space through the opposing side plates. Moreover, since the pressure is set to be larger than the reaction force of the fluid discharged from each pump element acting on the side plate via the discharge passage, it is always good regardless of the operation of multiple fluid devices. It is possible to exert a good sealing function to prevent leakage and steadily secure volume efficiency.

[Brief description of drawings]

FIG. 1 is a first embodiment of an oil pump according to the present invention, and is a longitudinal sectional view schematically showing the entire structure thereof, FIG. 2 and FIG.
FIG. 4 is a sectional view taken along the line II-II and III-III in FIG. 1, FIG. 4 is a longitudinal sectional view schematically showing only an essential part of the second embodiment, and FIG. 5 shows the entire conventional oil pump. FIG. 3 is a schematic vertical sectional view. 1 ... First housing, 2 ... Second housing 3 ... Storage space, 4 ... Drive shaft 5 ... First pump element, 6 ... Second pump element 7 ... First side plate, 8 ... 2 side plate 9 ... third side plate, 17 ... suction chamber 22, 24 ... working chamber, 25 ... discharge chamber 26, 26 ', 30 ... discharge passage 31 ... collar, 32 ... first pressure chamber 33 ...... Second pressure chamber, 34 ...... oil guide hole 38 ...... coil spring, 39 ...... corrugated washer

Claims (1)

[Claims] 1. A sealed storage space formed by joining two housings, a drive shaft rotatably supported by one housing and extending into the storage space, and an axial direction on the drive shaft. At least two sets of vane-type pump elements that are allowed to move and are rotatably coupled and that are arranged side by side in a multilayer manner in the storage space via side plates, and the side plate is provided on one end wall of the storage space. An oil pump characterized in that pressure chambers that are opposed to each other and communicate with the discharge passages of each pump element are formed independently.