TWI532913B - Gear means in fluid - Google Patents

Description

Gear fluid device

The present invention relates to a gear fluid device.

Conventionally, as a gear fluid device, there is a gear pump which, as shown in FIG. 5, has a thrust load (arrows R101, R102) for axially acting on the mesh gears that are meshing with each other, that is, the drive gear 101 and the driven gear 102. In the end, the ends of the shafts 111 and 112 are pushed back by the pistons 130 and 140 by the discharge pressure of the gear pump as the pressure source (see, for example, Japanese Laid-Open Patent Publication No. 2013-15108 (Patent Document 1)). The thrust load is caused by the meshing force and the hydraulic pressure of the teeth 101a of the drive gear 101 and the teeth 102a of the driven gear 102.

In the drive gear 101 of the gear pump and the driven gear 102, the thrust load acting on each of them is different. Therefore, the diameters of the pistons 130 and 140 are changed, and the force for canceling the thrust load is appropriately adjusted.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-15108

Further, in the above-described gear pump, the fitting portions of the pistons 130 and 140 and the cover 122 are narrow but have a gap, so that the pressure oil of the high pressure introduction passages 123 and 124 leaks to the low pressure side of the gear pump. Therefore, there is a problem that the discharge flow rate of the gear pump is reduced and the volumetric efficiency is lowered.

In order to reduce the oil leakage from the gap between the fitting portions of the pistons 130, 140 and the cover 122, it is preferable that the pistons 130, 140 are long, but if the pistons 130, 140 are made longer, the total length of the gear pump Will grow longer accordingly.

Accordingly, an object of the present invention is to provide a gear fluid device which can prevent leakage of an actuating fluid with a simple configuration and can prevent a decrease in volumetric efficiency.

In order to solve the above problems, the gear fluid device of the present invention is characterized by comprising: a casing; a driving gear and a driven gear, which are housed in the casing and are meshing helical gears; and a first piston to act The end surface of the rotating shaft of the driving gear is pressurized by the actuating fluid from the high pressure side, and the second piston is acted upon by the driven gear. The end surface of the rotating shaft of the driven gear is pressed by the actuating fluid from the high pressure side in a manner of canceling the thrust load of the rotating shaft; the first cylinder chamber is provided in the outer casing, and slidably accommodates the first a piston; a second cylinder chamber provided in the outer casing and slidably receiving the second piston; and a first sealing member sealing between an outer circumference of the first piston and an inner circumference of the first cylinder chamber; And a second sealing member that seals between the outer circumference of the second piston and the inner circumference of the second cylinder chamber.

According to the above configuration, the outer circumference of the first piston and the inner circumference of the first cylinder chamber are sealed by the first sealing member, and the outer circumference of the second piston and the second cylinder are used by the second sealing member. The inner circumference of the chamber is sealed, whereby the working fluid from the high pressure side that presses the first and second pistons against the rotating shaft of the driving gear and the driven gear does not leak to the low pressure side of the pump. That is, the discharge flow rate of the pump does not decrease.

Further, by sealing with the first and second sealing members (for example, O-rings), the first and second members can be sealed as long as they have a width required for sealing by the first and second sealing members. The total length of the piston is shortened, so that the total length of the gear pump body is correspondingly shortened.

Further, the gear fluid device according to the embodiment includes: a first rotation preventing mechanism that prevents rotation of the first piston in a circumferential direction with respect to a rotational axis of the drive gear; and a second rotation preventing mechanism that blocks the second rotation The piston is rotated relative to the circumferential direction of the rotation of the driven gear.

According to the above embodiment, the first rotation preventing mechanism prevents the first piston from rotating in the circumferential direction of the rotation axis of the drive gear, and the second rotation preventing mechanism prevents the second piston from being driven relative to the driven gear. Since the rotation of the rotation in the circumferential direction is prevented, the first and second sealing members are prevented from being worn by the rotation of the first and second pistons, and the sealing performance can be maintained.

Further, in the gear fluid device according to the first aspect of the invention, the first rotation preventing mechanism includes: a first engagement portion provided on a side opposite to the drive gear of the first cylinder chamber; and a first engagement portion Provided on an end surface of the first piston opposite to the drive gear, and locked to the first engagement portion to prevent the rotation of the first piston; and the second rotation prevention mechanism has a second An engaging portion provided on a side opposite to the driven gear of the second cylinder chamber; and a second locking portion provided on an end surface of the second piston opposite to the driven gear, and The second engagement portion is locked to the second engagement portion so as to prevent the rotation of the second piston.

According to the above embodiment, the first locking portion is locked to the first cylinder chamber. The first engagement portion on the side opposite to the drive gear and the second engagement portion are locked to the second engagement portion provided on the opposite side of the second cylinder chamber from the driven gear, which is simple The rotation of the first and second pistons is prevented.

Further, in the gear fluid device of the first embodiment, the first and second engaging portions of the first and second rotation preventing mechanisms are introduced into at least a part of the opening of the high pressure introduction path of the operating fluid from the high pressure side, The first and second locking portions of the first and second rotation preventing mechanisms are engaged with the convex portions of at least a part of the opening of the high pressure introduction path.

According to the above embodiment, the operating fluid is introduced into the high pressure introduction passage of the first cylinder chamber from the high pressure side, whereby the first piston presses the end surface of the rotation shaft of the drive gear toward the drive gear side. Further, the operating fluid is introduced into the high pressure introduction path of the second cylinder chamber from the high pressure side, whereby the second piston presses the end surface of the rotating shaft of the driven gear toward the driven gear side. At this time, since the first and second locking portions of the first and second rotation preventing mechanisms are locked to at least a part of the opening of the high pressure introduction path, the high pressure introduction path can be used for the introduction of the active fluid and the first and the first. 2 Both of the rotation preventing mechanisms can simplify the configuration.

As apparent from the above, according to the present invention, it is possible to realize a gear fluid device which can prevent leakage of the operating fluid with a simple configuration and can prevent a decrease in volumetric efficiency.

1‧‧‧ drive gear

1a‧‧‧ teeth

2‧‧‧ driven gear

2a‧‧‧ teeth

5‧‧‧1st side panel

6‧‧‧2nd side panel

10‧‧‧ Subject

11‧‧‧1st rotating shaft

11a‧‧‧Connecting Department

12‧‧‧2nd rotation axis

13A‧‧‧ bearing

13B‧‧‧ bearing

14A‧‧‧ bearing

14B‧‧‧ bearing

15‧‧‧ oil seal

20‧‧‧ bearing box

21‧‧‧Rack

22‧‧‧ Cover

22a‧‧‧1st cylinder chamber

22b‧‧‧2nd cylinder chamber

23‧‧‧Spray pressure introduction

24‧‧‧Spoke pressure introduction

30‧‧‧1st piston

30a‧‧‧ convex

31‧‧‧1st sealing member

40‧‧‧2nd piston

40a‧‧‧ convex

41‧‧‧2nd sealing member

101‧‧‧ drive gear

101a‧‧‧ teeth

102‧‧‧ driven gear

102a‧‧‧ teeth

111, 112‧‧‧ axis

122‧‧‧ Cover

123, 124‧‧‧High pressure introduction road

R101, R102‧‧‧ arrows

Fig. 1 is a cross-sectional view showing a gear pump as an example of a gear fluid device according to an embodiment of the present invention.

Fig. 2 is an enlarged cross-sectional view showing the main part of the above gear pump.

Fig. 3 is a perspective view of the first piston of the gear pump.

Figure 4 is a perspective view of the second piston of the gear pump.

Figure 5 is a cross-sectional view of a prior gear pump.

Hereinafter, the gear fluid device of the present invention will be described in detail based on the illustrated embodiment.

Fig. 1 is a cross-sectional view showing a gear pump as an example of a gear fluid device according to an embodiment of the present invention.

As shown in FIG. 1, the gear pump of this embodiment includes a main body 10 having two cylindrical spaces in which the shafts are parallel and partially overlapped, and two bearing housings 20 and 20 which are disposed at a predetermined interval. In the main body 10; a drive gear 1 disposed between the bearing housings 20 and 20 and a helical gear; and a driven gear 2 disposed between the bearing housings 20 and 20, and A helical gear that meshes with the drive gear 1 . The main body 10 is provided with an intake port (not shown) and a discharge port (not shown). Further, the main body 10 is made of cast iron, aluminum alloy or the like. Further, the drive gear 1 and the driven gear 2 are made of carburized and hardened steel.

Further, the first side plate 5 and the second side plate 6 are disposed in the main body 10 so as to sandwich both side faces of the drive gear 1 and the driven gear 2. The side surfaces of the drive gear 1 and the driven gear 2 are sealed to the surfaces of the first and second side plates 5 and 6 by the first side plate 5 and the second side plate 6, thereby forming a low pressure chamber and a discharge port that communicate with the suction port. Connected to the high pressure chamber. Also, the left end of the main body 10 is covered by a mounting 21, and the right side of the main body 10 is covered by a cover 22. The main body 10, the mount 21, and the cover 22 constitute an outer casing. Inside the casing, a drive gear 1 and a driven gear 2 having teeth 1a, 2a that mesh with each other are housed.

One end (the right side in FIG. 1) of the first rotating shaft 11 that drives the drive gear 1 is rotatably supported by the bearing housing 20 via a bearing 13A, and the other end (the left side in FIG. 1) of the first rotating shaft 11 passes through the bearing 13B. It is rotatably supported by the bearing housing 20. The connecting portion 11a on the other end side of the first rotating shaft 11 protrudes from the mount 21, and a drive shaft of a motor (not shown) is coupled to the connecting portion 11a. Further, one end (the right side in FIG. 1) of the second rotating shaft 12 of the driven gear 2 is rotatably supported by the bearing housing 20 via the bearing 14A, and the other end (the left side in FIG. 1) of the second rotating shaft 12 is via The bearing 14B is rotatably supported by the bearing housing 20. In the picture In 1, 1 is an oil seal.

Further, the gear pump includes a first cylinder chamber 22a (shown in FIG. 2) provided at a position of the cover 22 facing the end surface of the first rotating shaft 11 of the drive gear 1, and a second cylinder chamber 22b (Fig. 2 is shown in the position where the cover 22 faces the end surface of the second rotating shaft 12 of the driven gear 2; the first piston 30 is slidably accommodated in the first cylinder chamber 22a in the axial direction. The second piston 40 is slidably accommodated in the second cylinder chamber 22b in the axial direction, and the first sealing member 31 seals between the outer circumference of the first piston 30 and the inner circumference of the first cylinder chamber 22a; The second seal member 41 seals between the outer circumference of the second piston 40 and the inner circumference of the second cylinder chamber 22b. In the first embodiment, the first and second sealing members 31 and 41 are fitted to the O-rings that are fitted to the fitting grooves provided in the first piston 30 and the fitting grooves provided in the second piston 40.

Fig. 2 is an enlarged cross-sectional view showing the main part of the gear pump. In FIG. 2, the same components shown in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 2, on the side opposite to the drive gear 1 (shown in FIG. 1) of the first cylinder chamber 22a, a discharge pressure introduction path 23 as an example of a high pressure introduction path is provided. Further, on the side opposite to the driven gear 2 (shown in FIG. 1) of the second cylinder chamber 22b, a discharge pressure introduction path 24 as an example of a high pressure introduction path is provided. The discharge pressure introduction paths 23 and 24 communicate with the discharge port.

3 is a perspective view showing the first piston 30 of the gear pump, and FIG. 4 is a perspective view showing the second piston 40.

The actuating fluid from the high pressure side is introduced into the discharge pressure introduction path 23 shown in FIGS. 1 and 2, whereby the first piston 30 abuts the drive gear so as to cancel the thrust load acting on the first rotating shaft 11 of the drive gear 1. The end surface of the first rotating shaft 11 of 1 is pressed. Further, the actuating fluid from the high pressure side is introduced into the discharge pressure introduction passage 24 shown in FIGS. 1 and 2, whereby the second piston 40 cancels the thrust load acting on the second rotating shaft 12 of the driven gear 2 The end surface of the second rotating shaft 12 of the driven gear 2 is pressed.

By using the end face provided on the side opposite to the drive gear 1 of the first piston 30 The convex portion 30a (shown in FIGS. 2 and 3), which is an example of the first locking portion, is locked to the discharge pressure introduction path 23 (first engagement) provided on the side opposite to the drive gear 1 of the first cylinder chamber 22a. And prevents the first piston 30 from rotating. The first thrust stop mechanism is configured by the discharge pressure introduction passage 23 and the convex portion 30a of the first piston 30.

Further, the convex portion 40a (shown in FIGS. 2 and 4), which is an example of the second locking portion, which is provided on the end surface of the second piston 40 opposite to the driven gear 2, is locked to the above-mentioned The discharge pressure introduction passage 24 (second engagement portion) of the second cylinder chamber 22b opposite to the driven gear 2 prevents the second piston 40 from rotating. The second rotation preventing mechanism is configured by the discharge pressure introduction passage 24 and the convex portion 40a of the second piston 30.

In the gear pump having the above configuration, as shown in FIG. 1, when the drive gear 1 is rotated by the rotation of the first rotating shaft 11 coupled to the drive gear 1, the driven gear 2 is oriented on the second rotating shaft 12 Rotate at the center. As a result, the fluid sucked in from the suction port is sent to the high pressure chamber side communicating with the discharge port by the teeth 1a and 2a of the drive gear 1 and the driven gear 2.

At this time, the outer circumference of the first piston 30 and the inner circumference of the first cylinder chamber 22a are sealed by the first sealing member 31, and the outer circumference of the second piston 40 and the second cylinder chamber are used by the second sealing member 41. The inner circumference of 22b is sealed, and the operating fluid on the high pressure side that presses the first and second rotating shafts 11 and 12 of the driving gear 1 and the driven gear 2 by the first and second pistons 30 and 40 does not Leakage on the low pressure side of the pump. That is, the discharge flow rate of the pump does not decrease.

Moreover, by sealing with the first and second sealing members 31 and 41 (for example, an O-ring), the width required for sealing by the first and second sealing members 31 and 41 can be sealed, so that it can be sealed. The total length of the first and second pistons 30, 40 is shortened, so that the total length of the gear pump body is correspondingly shortened.

Further, the first rotation preventing mechanism (23, 30a) prevents the first piston 30 from rotating in the circumferential direction with respect to the first rotating shaft 11 of the driving gear 1, and the second rotation preventing mechanism (24, 40a) prevents the second piston 40 from rotating in the circumferential direction with respect to the second rotating shaft 12 of the driven gear 2. Thereby, it is possible to prevent the first and second pistons 30 and 40 from rotating in the first and second steams. The first and second sealing members 31 and 41 due to the sliding of the inner surfaces of the cylinder chambers 22a and 22b are worn to maintain the sealing performance.

Further, the convex portion 30a (first locking portion) is locked to the discharge pressure introduction path 23 (first engagement portion) provided on the side opposite to the drive gear 1 of the first cylinder chamber 22a, and The convex portion 40a (second locking portion) is locked to the discharge pressure introduction path 24 (second engagement portion) provided on the side opposite to the driven gear 2 of the second cylinder chamber 22b, and can be prevented with a simple configuration. The first and second pistons 30 and 40 are rotated.

Further, the actuation fluid is introduced into the discharge pressure introduction passage 23 (high pressure introduction passage) of the first cylinder chamber 22a from the high pressure side, whereby the first piston 30 faces the end surface of the first rotation shaft 11 of the drive gear 1 toward the drive gear 1 side. Apply pressure. Further, the actuating fluid is introduced from the high pressure side to the discharge pressure introduction passage 24 (high pressure introduction passage) of the second cylinder chamber 22b, whereby the second piston 40 is directed to the second rotating shaft 12 of the driven gear 2 toward the driven gear 2 side. The end face is pressed. At this time, the convex portions 30a and 40a (the first and second locking portions) of the first and second rotation preventing mechanisms are locked to one of the opening portions of the discharge pressure introduction paths 23 and 24 (high pressure introduction paths). The discharge pressure introduction paths 23 and 24 are used for both the introduction of the actuation fluid and the first and second rotation preventing mechanisms, thereby simplifying the configuration.

In the above embodiment, the gear pump as an example of the gear fluid device has been described. However, the gear motor can be applied to the same structure only because the operation is the same.

Further, in the above-described embodiment, the O-rings that are fitted into the fitting grooves provided in the first piston 30 and the fitting grooves provided in the second piston 40 are used as the first and second sealing members 31 and 41, respectively. Although the gear pump has been described, the first and second sealing members may be provided on the outer casing side as long as the outer circumference of the first piston and the inner circumference of the first cylinder chamber or the outer circumference of the second piston and the second cylinder are used. The first and second sealing members sealed between the inner circumferences of the chamber may be used.

Further, in the above-described embodiment, the convex portions 30a and 40a (the first and second locking portions) of the first and second rotation preventing mechanisms are locked to the opening portions of the discharge pressure introduction paths 23 and 24 (high pressure introduction paths). In some cases, the first and second rotation preventing mechanisms are not limited thereto, and may be outside the first and second pistons. The pin groove structure is provided, or a pin that is inserted freely from the eccentric position of the first and second pistons from the high pressure introduction path side of the first and second cylinder chambers is provided.

Although the specific embodiments of the present invention have been described, the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the invention.

1‧‧‧ drive gear

1a‧‧‧ teeth

2‧‧‧ driven gear

2a‧‧‧ teeth

5‧‧‧1st side panel

6‧‧‧2nd side panel

10‧‧‧ Subject

11‧‧‧1st rotating shaft

11a‧‧‧Connecting Department

12‧‧‧2nd rotation axis

13A‧‧‧ bearing

13B‧‧‧ bearing

14A‧‧‧ bearing

14B‧‧‧ bearing

15‧‧‧ oil seal

20‧‧‧ bearing box

21‧‧‧Rack

22‧‧‧ Cover

23‧‧‧Spray pressure introduction

24‧‧‧Spoke pressure introduction

30‧‧‧1st piston

31‧‧‧1st sealing member

40‧‧‧2nd piston

41‧‧‧2nd sealing member

Claims (4)

A gear fluid device, comprising: a casing (10, 21, 22); a driving gear (1) and a driven gear (2), which are housed in the casing (10, 21, 22) and are mutually a meshing helical gear; a first piston (30) that cancels the thrust load acting on the rotating shaft (11) of the driving gear (1) by the actuating fluid from the high pressure side (1) the end surface of the rotating shaft is pressed; the second piston (40) is offset from the thrust load acting on the rotating shaft (12) of the driven gear (2) by the high pressure side The end surface of the rotating shaft of the driven gear (2) is pressed by the actuating fluid; the first cylinder chamber (22a) is provided in the outer casing (10, 21, 22), and slidably accommodates the first piston (30); a second cylinder chamber (22b) provided in the outer casing (10, 21, 22) and slidably receiving the second piston (40); and a first sealing member (31) 1 is sealed between the outer circumference of the piston (30) and the inner circumference of the first cylinder chamber (22a); and the second sealing member (41) is configured to surround the outer circumference of the second piston (40) with the second steam A seal between the inner periphery of the chamber (22b) of. A gear fluid device according to claim 1, comprising: a first rotation preventing mechanism that prevents a rotation of the first piston (30) relative to a rotation axis (11) of the drive gear (1) in a circumferential direction; and The rotation stop mechanism prevents the second piston (40) from rotating in the circumferential direction with respect to the rotation shaft (12) of the driven gear (2). The gear fluid device of claim 2, wherein the first rotation preventing mechanism has: a first card a joint portion (23) provided on a side opposite to the drive gear (1) of the first cylinder chamber (22a); and a first lock portion (30a) provided in the first piston (30) An end surface on a side opposite to the drive gear (1) is locked to the first engaging portion (23) so as to prevent the first piston (30) from rotating; and the second rotation preventing mechanism has: a second engaging portion (24) provided on a side opposite to the driven gear (2) of the second cylinder chamber (22b); and a second locking portion (40a) provided on the second piston (40) an end surface on a side opposite to the driven gear (2), and is locked to the second engaging portion (24) so as to prevent the second piston (40) from being rotated. The gear fluid device according to claim 3, wherein the first and second engaging portions (23, 24) of the first and second rotation preventing mechanisms are introduced into an opening of a high pressure introduction path of the operating fluid from the high pressure side. At least a part of the first and second locking portions (30a, 40a) of the first and second rotation preventing mechanisms are engaged with the convex portions of at least a part of the opening of the high pressure introduction path.