JPH11132157A - Trochoid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent flow direction of fluid from varying in an oil passage forming body, by adding a port plate and changing an engaging part position of an inner rotor and an outer rotor with remaining the oil passage forming body in a trochoid pump, even when rotational direction of the inner rotor is changed. SOLUTION: A port plate 20 is interposed between an oil passage forming body 1, which has a first suction port 71 and a first delivering port 81 , and an inner rotor 10 and an outer rotor 11, and a pump housing 121 is constituted to hold an engaging part of the both rotors 10, 11 at a position opposite to that before changing of the rotational direction of the inner rotor. The distance between the first suction port 71 and the first delivering port 81 is large on the engaging part side of the both rotors 10, 11 and is narrow on the un- engaging part side, and on the contrary, the distance between a second suction port 72 and a second delivering port 82 is narrow on the engaging part side of the both rotors 10, 11 and is large on the un-engaging part side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trochoid pump used for pumping a liquid such as oil.

[0002]

2. Description of the Related Art A conventional trochoid pump has a drive shaft,
A support hole for supporting the drive shaft, an oil passage forming body having arc-shaped intake ports and discharge ports arranged on both sides of the support hole, an inner rotor disposed on the oil passage forming body, and the inner rotor An outer rotor that meshes with
A pump housing that houses the outer rotor and is joined to an oil passage forming body to hold the outer rotor at a predetermined eccentric position with respect to the inner rotor. The first intake port and the discharge port have a distance between the inner rotor and the first rotor. The outer rotor is formed so as to be narrow on the side of the meshing portion and wide on the side of the non-meshing portion.

[0003]

In the conventional trochoid pump, the rotation direction of the inner rotor is defined in one direction in order to pump the fluid sucked in the suction port to the discharge port. Therefore, when the rotation direction of the inner rotor changes due to a change in the drive source of the drive shaft or the like, the flow direction of the fluid changes, and the functions of the suction and discharge ports are reversed. Although it is necessary to change the oil passage, such a change in the oil passage necessitates a change in the entire oil passage forming body, and the cost required for the change is enormous.

[0004] The present invention has been made in view of such circumstances, and when the rotation direction of the inner rotor is changed, the oil path forming body can be kept at a relatively low cost by adding and changing small parts. It is an object of the present invention to provide a trochoid pump.

[0005]

In order to achieve the above object, the present invention provides a drive shaft, a support hole for supporting the drive shaft, and first arcuate intake ports arranged on both sides of the support hole. And an oil passage forming body having a first discharge port, and an arc-shaped second intake port and a second discharge which are detachably joined to the oil passage forming body and partially overlap the first intake port and the first discharge port, respectively. A port plate having a port penetrating through the front and back, an inner rotor coupled to the drive shaft and disposed on the port plate, an outer rotor meshing with the inner rotor, and accommodating the outer rotor and having a predetermined eccentricity with respect to the inner rotor; And a pump housing removably joined to the port plate to hold the first intake port and the first discharge port. Widely Narota and meshing portion side of the outer rotor, while being formed to be narrower in the disengaged side,
The second intake port and the second discharge port are characterized in that the distance between the two is narrower on the side of the meshing portion of the inner rotor and the outer rotor, and wider on the non-meshing side.

In the above structure, when the inner rotor rotates from the first discharge port side to the first suction side at the side of the meshing portion between the two rotors, the pressure in the second suction port is reduced and the pressure in the second discharge port is increased. Transfer can be performed from the first suction port to the first discharge port via the second suction port and the second discharge port. Therefore, in the conventional general trochoid pump having no port plate and having the meshing portions of the two rotors near the first suction port and the first discharge port, as described above, the addition of the port plate and the pump housing If the eccentric position of the outer rotor is changed by the change, it is possible to cope with the change in the rotation direction of the inner rotor, and the structure of the oil path forming body, the inner rotor and the outer rotor is kept as it is, and the fluid in the oil path forming body is The flow can be maintained as before.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

[0008] First, a general trochoid pump P ₀ will be described prior to FIG. 5 and FIG. 6. Figure 5 is a longitudinal sectional view of a swash plate type hydraulic stepless transmission having the trochoid pump P _0, 6 is a sectional view along line 6-6 in FIG.

A swash-plate type hydraulic pump 2 and a hydraulic motor 3 which constitute a swash-plate type hydraulic continuously variable transmission are provided on one side surface of the oil passage forming body 1 and a first transmission case 4 ₁ covering these. Are joined. A hydraulic oil passage for interconnecting the hydraulic pump 2 and the hydraulic motor 3 is provided in the oil passage forming body 1, and the trochoid pump P ₀ for replenishing the hydraulic oil passage with hydraulic oil is provided in the oil passage forming body 1. disposed on the other side, the second transmission case 4 ₂ is joined to said other side covering the. The second transmission case 4 _2, transmission for transmitting the output of the hydraulic motor 3 to the external load (not shown) is provided.

The oil passage forming body 1 is provided with a support hole 6 penetrating through both side surfaces thereof to support an end of the pump shaft 5 of the hydraulic pump 2. First
Suction port 7 ₁ and the first discharge port 8 ₁ oil passage forming body 1
On the other side. The first suction port ₇₁ communicates with the oil reservoir chamber of the second transmission case 4 in _2, the check valve first discharge port 8 ₁ to the hydraulic fluid path between the hydraulic pump 2 and the hydraulic motor 3 (not shown) Connected via

[0011] The first suction port 7 ₁ and the first discharge port 8
The ₁ on the other side of the oil passage forming body 1 having an opening, an inner rotor 10 having external teeth, an outer rotor 11 which surrounds the inner rotor 10, and the pump housing 12 ₀ for rotatably accommodating the outer rotor 11 are sequentially arranged You. At that time, the outer rotor 11 is arranged at a predetermined eccentric position with respect to the inner rotor 10 so as to mesh with the inner rotor 10 at one side.

[0012] The first suction port 7 ₁ and ₁ first discharge port 8, as shown in FIG. 2, each rotation center of the rotors 10, 11, symmetrical about the line L passing through the their meshing portion center And the straight line L between the rotors 10 and 11
Are formed along the oil chambers 13 and 14 which are partitioned by the rotor 1 and the distance between the ports 7 ₁ and 8 ₁ is the distance between both rotors 1 ₁ and 8 1.
It is narrow on the side of the meshing portions 0 and 11 and wide on the side of the non-meshing portion.

The pump shaft 5 has an outer end connected to an engine or other driving source (not shown), and an inner end connected to an inner rotor 10 via a key 15 so as to connect the inner rotor 10 in the direction of arrow A, ie, both rotors. 10 and 11 are from the first discharge port 8 ₁ side meshing portion side so as to rotate in a direction towards the first suction port ₇₁ side. Therefore,
The pump shaft 5 of the hydraulic pump 2 is also used as a drive shaft of the inner rotor 10. The pump housing 12 ₀ is removably secured to the oil passage forming body 1 with bolts 16.

Thus, the inner rotor 1 is driven by the pump shaft 5.
When 0 is rotated in the arrow A direction, the first suction port ₇₁ side of the oil chamber 13, sucks oil from the first suction port ₇₁ by vacuum action by the extension of the teeth between the volume between the rotors 10, 11 Te transferred to the oil chamber 14 of the first ejection port 8 ₁ side, the first discharge port 8 ₁ side of the oil chamber 14, a first discharge port of oil by boosting effect of reduction of the interdental volume between the rotors 10, 11 it can be discharged to the 8 _1.

According to the present invention, the oil passage forming body 1, the inner rotor 10 and the outer rotor 11 can be moved even if the rotation direction of the pump shaft 5 is opposite to the rotation direction A due to a change in the drive source or the like. orゝutilized, oil sucked from the first suction port ₇₁ as before is intended to be capable of discharging to the first discharge port 8 _1, described below with reference to in Figure 1 to 4 I do. 1 is a longitudinal sectional view of a swash plate type hydraulic continuously variable transmission having a trochoid pump P ₁ of the present invention, FIG. 2,
3 and 4 are sectional views taken along lines 2-2, 3-3, and 4-4 of FIG.

[0016] In the trochoid pump P ₁ of the present invention, and the oil passage forming member 1, the between the rotors 10 and 11, the port plate 20 with a second intake port 7 ₂ and the second ejection port 8 ₂ Is installed. The pump housing 12 _1, unlike the conventional pump housing 12 _0, constitute the outer rotor 11, which is on the straight line L, so as to hold the eccentric position meshing with the inner rotor 10 by the conventional ones and opposite side Is done. The pump housing 12 _1, while sandwiching the port plate 20 is secured to the oil passage forming body 1 with bolts 16.

Second suction port 7_TwoAnd second discharge port 8
_TwoPenetrates the port plate 20 in the front-to-back direction,
1 port 7₁And second discharge port 8₁And some of each
Overlapping and symmetric with respect to the straight line L
With the oil chambers 13 and 14 defined by the straight line L
Each port has an arc shape, but both ports 7_Two, 8_TwoDistance
The separation is narrow at the meshing portion side of the rotors 10 and 11,
Wide on the side. Other configurations are the same as those of the conventional
The same is true. Therefore, both rotors 10,
The position of the first port 7₁And the first
1 discharge port 8 ₁The distance between the second suction port 7_Twoas well as
Second discharge port 8_TwoOn the contrary, both rotors 10 and 11
It is wide on the meshing side and narrow on the non-engaging side.

Thus, the inner rotor 1 is driven by the pump shaft 5.
When 0 is rotated in the arrow B direction opposite to the above-mentioned conventional rotation direction A, the second intake port 7 ₂ side of the oil chamber 14, the vacuum action of extension of the teeth between the volume between the rotors 10, 11 first And sucks oil from the second suction ports 7 ₁ and 7 ₂ to
The second discharge port 8 is sent to the oil chamber 14 on the discharge port 8 ₂ side.
In ₂ side of the oil chamber 14 can be discharged with oil to the second discharge port 8 ₂ and first discharge port 8 ₁ by the step-up action by the reduction of the interdental volume between the rotors 10, 11. Therefore, even when the rotation direction of the inner rotor 10 is changed, the oil can flow in the oil passage forming body 1 in the same direction as before. Moreover, an additional port plate 20, the pump housing 12 _1, because the outer rotor 11 may correspond with the change of the inner peripheral surface position to be fitted, it is possible to suppress cost of it is relatively low.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof. For example, due to changes of the inner circumferential surface position of the pump housing 12 _1, it may be adapted to adjust the fixation position of the oil passage forming body 1 of the pump housing 12 _1.

[0020]

As described above, according to the present invention, there is provided a conventional general trochoid pump which does not have a port plate but has a meshing portion of an inner rotor and an outer rotor arranged on a side close to a first suction port and a first discharge port. Only by adding a port plate and changing the eccentric position of the outer rotor by changing the pump housing, it is possible to cope with a change in the rotation direction of the inner rotor, and the structure of the oil passage forming body, the inner rotor and the outer rotor can be maintained. Thus, the flow of the fluid in the oil passage forming body can be secured as before. In addition, the cost required for changing the partial structure as described above can be kept relatively low, which is economical.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a swash plate type hydraulic continuously variable transmission equipped with a trochoid pump according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a sectional view corresponding to FIG. 1, showing a conventional general trochoid pump;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

[Explanation of symbols]

P ₁ ··· Trochoid pump ₁ ····· Oil passage forming body 5 ···· Drive shaft (pump shaft) 6 ··· Support hole 7 ₁ ··· First suction port 7 ₂ ... Second suction port 8 ₁ ... First discharge port 8 ₂ ... Second discharge port 10... Inner rotor 11... Outer rotor 20.

Claims (1)

[Claims] A drive shaft (5) and a support shaft (5) for supporting the drive shaft (5).
The supporting hole (6) to hold and both sides of the supporting hole (6)
The arcuate first intake port (7₁) And first discharge
Port (8₁), And the oil passage
A first intake port detachably joined to the formation (1);
(7₁) And the first discharge port (8₁) And part of each
The arcuate second intake port (7_Two) And the second discharge port
To (8 _Two) The port plate (20) penetrating the front and back
And the port plate (2) connected to the drive shaft (5).
0) and an inner rotor (10)
An outer rotor (11) meshed with the narrotor (10);
This outer rotor (11) is housed and
To maintain a predetermined eccentric position with respect to the motor (10).
Pump removably joined to the plate (20)
Uzzing (12₁) And the first intake port
(7₁) And the first discharge port (8₁) Is the distance between the two
Separation of inner rotor (10) and outer rotor (11)
It is formed so that it is wide on the meshing side and narrow on the non-meshing side
On the other hand, the second intake port (7_Two) And the second discharge port (8
_Two) Indicates that the distance between them is the inner rotor (10) and
Narrow on the meshing part side of the outer rotor (11), wide on the non-meshing side
Trochoidal lip, characterized by being formed
Pump.