JPH025763A - Variable type oil-hydraulic motor - Google Patents

Abstract

PURPOSE:To obtain an oil-hydraulic motor with selectivity only between high and low speed, wherein the construction is made simple, small, and light, by varying the inclination angle of the swash plate of hydraulic motor by a pushing member. CONSTITUTION:A swash plate 4 is equipped with No.1 seat face 40 mating with the elongation side of a plunger 31 and the slide surface 42 contacted by a shoe 32. This swash plate 4 tilts round a fulcrum which consists of the intersection line of this No.1 seat face 40 with No.2 seat face 41. A pushing member P is furnished mating with the No.1 seat face 40, and the inclination angle of the swash plate 4 is varied by pressure of this pushing member P.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a uf variable hydraulic motor, and more particularly to a variable hydraulic motor in which variable control of two high and low speeds can be performed OT.

For equipment that requires high-speed and low-speed running, such as crane dozers and shovel dozers, °C has traditionally been
A modified hydraulic motor is used. In this variable hydraulic motor, a large thrust force is required to maintain the tilting state of the swash plate, and the pressing force for this purpose also needs to be applied in both directions with respect to the tilting of the swash plate. For this reason, the pressing device for tilting the swash plate must be dual-acting, or it must have at least two pressing devices that apply moments in opposite directions to the fulcrum of the swash plate. A 21 is complicated and large,
As a result, the hydraulic motor also becomes larger, which is a factor in increasing costs.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a new hydraulic motor that has a simple structure, is small in size and lightweight, and can be used only in two high and low speeds to achieve cost reduction.

To achieve this objective, the configuration of the present invention includes a casing,
It consists of a rotating shaft pivotally connected to this casing, a cylinder block connected to this rotating shaft, and a swash plate on which a shoe fitted to the end of a plunger inserted into this cylinder block comes into contact, and the swash plate corresponds to a sliding surface portion that the shoe contacts, a first seat surface that is opposite to the WJ moving surface portion and corresponds to the extension side of the plunger, and a compression side of the plunger; A hydraulic motor has a second seat surface having a different angle, and the swash plate tilts about a line of intersection between the first seat surface and the second seat surface as a fulcrum. A pressing member is provided corresponding to the seat surface of the swash plate, and the inclination angle of the swash plate is changed by pressing the pressing member.

The present invention will be explained below based on the illustrated preferred embodiments.

FIG. 1 shows a circuit diagram when the two-speed hydraulic motor A according to the present invention is used. When the engine B operates, oil from the oil pump C flows through the hydraulic motor A. , and after driving the hydraulic motor A, the return trip E is started.
The oil returns to oil pump C through .

As shown in FIG. 2, this hydraulic motor A has a casing 1, a single rotation shaft 2, a cylinder block 3, a swash plate 4, and a plate 5.

Inside the casing center L, the cylinder block 3 is installed,
A swash plate 4 and a plate 5 are provided, and the casing l has a crescent-shaped (not shown) boat 5a bored in the plate 5.

A supply oil passage 11, a discharge oil passage 12, and an auxiliary oil passage 13 are drilled to connect to the casing l, and an auxiliary cylinder 14 that communicates with the auxiliary oil passage 13 is provided in the casing l. Inside this auxiliary cylinder 14 is an auxiliary oil passage 13.
A pressing member P that slides due to hydraulic pressure applied through the auxiliary plunger 15 and an auxiliary shoe 16 is fitted, and the auxiliary shoe 16 is rotatably attached to the tip of the auxiliary plunger 15. It is fitted.

Further, oil is guided to the auxiliary oil passage 13 from the oil pump C (see FIG. 1) via a separate route and a control device 21 ([21 not shown)].

The rotary shaft 2, which is connected to the cylinder block 3 by a spline or the like, is pivotally mounted in the center of the casing 1 via a bearing 20, 21, and is sealed by a seal member 22.

The cylinder block 3 is rotatable within the inner space lO. Note that a joint hole 23 is formed at one end of the rotary shaft 2 to which a rotary shaft (not shown) of, for example, a reduction gear is connected. It goes without saying that the method of connecting the cylinder block 3 to the one-rotation shaft 2 may be arbitrarily selected other than the spline connection described above.

The cylinder block 3 has a plurality of cylinder holes 30.
or perforated. A plunger 31 is inserted into the cylinder hole 30 from an opening at one end, and a shoe 32 is rotatably fitted to the tip of the plunger 31. The tip end surface of this shoe 32 corresponds to the sliding surface portion 42 of the swash plate 4.
is in contact with. The cylinder hole 30 has a boat 33 communicating with the boat hole 5a bored in the plate 5. This boat 33 is configured to selectively communicate with the supply oil passage 11 or the discharge oil passage 12 according to the rotation of the cylinder block 3. Further, this cylinder block 3 is provided with a pressing device that always presses the cylinder block 3 against the plate 5 and the shoes 32 against the swash plate 4 at all times. That is, a space of an appropriate size is formed near the center of the cylinder block 3 and adjacent to the rotating shaft 2, and a stopper 34 is provided protruding from the cylinder block 3 into the space, and one side of the stopper 34- is provided. This piece 35a holds the = end of the spring 36, and the other end of the spring 36 is held on the other piece 35b. In addition, five cams 38 are brought into contact with the tip of the rod 37, and a protruding piece 39 attached to the shoe 32 is brought into contact with the cam surface of the cam 38. That is, in this pressing device, the cylinder block 3 is pressed against the plate 5 by the repulsive force of the spring 36, and the shoe 32 is pressed against the swash plate 4 by the stopper piece 39.

, the swash plate 4 is formed to have a donut-shaped planar shape as a whole as shown in FIG. 3(a), and has a horizontal side surface shape as a whole as shown in FIG. It is formed to have. Sliding surface portion 42 of swash plate 4
The adjacent surface on the casing l side provided on the opposite side is composed of a first seat surface 40 and a second seat surface 41 having different angles, and the first seat surface 40 corresponds to the extension side of the plunger 31. The second seat surface 41 is also provided corresponding to the compression side of the plunger 31, and either the first seat surface 40 or the second seat surface 41 is used as a stopper to maintain the temperature of the casing l at °C. The angle of the swash plate 4 is changed in two ways by bringing it into contact with the inner wall la, which is a single plane,
Variable control to two speeds is possible depending on the angle of the swash plate 4.

That is, changing the swash plate angle changes the plunger stroke, which changes the amount of oil sucked in, changes the shaft speed, and changes the output. Sliding surface portion 42 on the shoe 32 side
is formed into an inclined surface with a larger angle than the inclination angle of the second seat surface 41, and allows the shoe 32 to slide. The swash plate 4 tilts about a line 0 where the first seat surface 40 and the second seat surface 41 intersect (hereinafter referred to as an intersection line O) as a fulcrum. Further, a ball hole 43 centered on the intersection line O between the first seat surface 40 and the second seat surface 41 is formed, and a position corresponding to this ball hole 43 is formed. A ball 44 serving as a positioning member is held between a ball hole (not shown) formed in the inner wall of the casing l with a slight gap therebetween, and the swash plate 4 is positioned by the ball 44. 9th grade.

Auxiliary sheet ↓-16 adjacent to the upper end of the first sheet surface 40
is the 2nd U'! Move to the left in I and move to the first seat surface 40.
When separating from the inner wall of the casing l, the ball 44
While guided by the swash plate 4, the swash plate 4 tilts at a constant angle using the intersection line 0 as a fulcrum.

That is, when no hydraulic pressure is applied to the auxiliary plunger 15 in the auxiliary cylinder 14, the swash plate 4 is always supported with only its first seat surface 40 as a stopper in contact with the inner wall la of the casing l ( (See Figure 4 (a)).

However, when pressurized oil is fed into the auxiliary cylinder 14 from the auxiliary oil passage 13 and the auxiliary plunger 15 moves to the left in FIG. 2, the swash plate 4 tilts about the intersection line 0, At this time, the first seat surface 40 is separated from the inner wall of the casing 1, and instead the second seat surface 41 of the swash plate 4 is supported by contacting the inner gl 1 a of the casing l as a stopper (Fig. 4). (see (b)), at this time, the pressing force f acting on the auxiliary shoe 16 and the pressing force F acting on the swash plate 4
If the following equation holds true between , the swash plate 4 will maintain stable contact with the inner wall of the casing l with its second seat surface 41. That is, f>b/aXF and f<b+
1/a ten sentences x F. When f=0, that is, the swash plate 4 stably contacts the inner wall of the casing l with its first seat surface 40 as shown in FIG. 4(a).
This is because, as shown in the figure, the pressing force F acting on the swash plate 4 acts at a position eccentrically b in the figure from the center of the intersection wAO to the upper end side. Incidentally, the swash plate 4 is provided with the rotation shaft 2.
Of course, an opening 45 is formed to allow insertion of the swash plate 4, and a groove 46 and a stopper piece 39 attached to the shoe 32 are formed to prevent contact with the bearing 21 when the swash plate 4 rotates. Considerations have been taken, such as forming a notch 47 to avoid contact (Figure 3 (a)).
b) see).

As the positioning member, a hemispherical protrusion or a cylindrical or semi-cylindrical member is protruded at a position corresponding to the ball hole 43, and a corresponding receiving part is formed on the inner wall of the adjacent casing 1 for positioning. It may also be one that allows rotation of the member.

The hydraulic motor A according to the embodiment of the present invention configured as described above operates as follows.

When the auxiliary plunger 15 installed on the back of the swash plate 4 is in an unpressurized state, the cylinder block 3 is pressed against the plate 5, and the shoes 32 are pressed against the swash plate 4, so that the plate 5 and the cylinder block If oil is supplied into the cylinder hole 30, the cylinder block 3 will be removed immediately without causing oil leakage from adjacent locations such as between the cylinder It will rotate.

As oil is fed into the cylinder hole 30 and the plunger 31 slides, the oil in the cylinder hole 30 is sequentially supplied and discharged. That is, when the cylinder block 3 is rotated in either direction, the plunger 31 is compressed and enters the cylinder hole 30, and the boat 33 is moved into the plate 5.
The oil in the cylinder hole 30 is discharged through communication with the crescent-shaped hole 5a formed in the cylinder hole 30. On the other hand, when the plunger 31 is extended, the boat 5b at the rear end of the cylinder block 3 and the boat 33 are brought into communication, and oil begins to enter the cylinder hole 30, and these operations are selectively repeated until a plurality of A plunger 31 in a certain cylinder hole 30 is
fl motion 1! ! By moving the cylinder block 3, the cylinder block 3 rotates, and the rotating shaft 2 connected thereto is also rotationally driven. Therefore, the rotational drive of the one-rotation shaft 2 can be stopped by canceling the supply of oil. As described above, the shoe 32 is always pressed against the swash plate 4 even when oil is not supplied.

The above operation is the same whether the swash plate 4 is in either of the cases shown in FIG. 4 (a) or (b). However, in the case of FIG. When the surface 40 is supported in surface contact with the inner wall of the casing 1, in the case of FIG.
The only difference is that the rotation of the rotating shaft 2 is slower than when the seat surface 41 of the rotary shaft 2 is supported in surface contact with the inner wall of the casing l. The tilting operation of the swash plate 4 has been described above, but the auxiliary plunger 15 and the auxiliary shoe 16 are
The first seat surface 40 of the swash plate 4 is not always pressed against the casing 1 when no oil is supplied to the auxiliary cylinder 14.
Since it is in surface contact with the inner wall of the cylinder, no thrust is required from the auxiliary plunger 15 during this depression, and when the inside of the auxiliary cylinder 14 is supplied with oil from the auxiliary oil passage 13 and becomes pressurized. The second seat surface 41 of the swash plate 4 comes into surface contact with the inner wall of the casing 1 and is stabilized. Further, the thrust required for the auxiliary plunger 15 is sufficient as long as the above-mentioned formula is satisfied.

The above configuration and operation are an embodiment of the present invention as a hydraulic motor, but it goes without saying that when the present invention is used as an embodiment of a hydraulic pump, it is sufficient to rotate the rotary shaft 2 as a drive shaft. Needless to say, high-speed discharge and low-speed discharge can be performed at will.

As described above, according to the present invention, it is possible to obtain a hydraulic motor that can be freely changed to two speeds, high speed or low speed. Moreover, since the pressing members are only provided at l locations corresponding to the first sheet surface, the structure of the pressing members is I! I-primed,
As a result, the hydraulic motor itself can be made smaller and lighter, and manufacturing costs can be reduced.Since the swash plate tilts around the intersection line, the tilting moment of the swash plate can be made relatively small, and the swash plate can be tilted around the intersection line. It is stable because one of the first sheet surface or the second sheet surface of the back of the plate tightly abuts the inner surface of the casing. Moreover, contact can be made even with a relatively low surface pressure, which improves the durability of the swash plate and casing.

Furthermore, due to the miniaturization of the hydraulic motor, not only does it not require a large volume for installation and use, but it also eliminates the need for the installation and preparation of complex operating devices, and has the advantage that it can be used with a simple operation. .

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a variable hydraulic motor according to the present invention, Fig. 2 is a circuit diagram of a variable hydraulic motor according to the present invention;
The figure is a longitudinal cross-sectional view showing the hydraulic motor according to this embodiment, FIG. 3 (A) is a front view of the swash plate, and FIG. 3 (B) is a side view of the swash plate.
Figure 4 (a) and Figure 4 (Ron is a side view showing the operating state of the swash plate. 1... Casing, 2... Rotating shaft, 3... Cylinder block, 4... Oblique Plate, 5...Plate, 13.
... Auxiliary oil passage, 14... Auxiliary cylinder, 15... Auxiliary plunger, 16... Auxiliary shoe, 31... Plunger, 32... Shoe, 40... First seat surface, 41 ...Second sheet surface, 42...Sliding surface portion, 4
4...Ball, 0...Cross line, P...Press member. Figure 1 A/l, / f2 Pa+25b 1 Figure 2 Figure 8 (A) Pull Figure 4 (A) (B) (B)

Claims (1)

[Claims] a casing, a rotating shaft pivotally connected to the casing,
It consists of a cylinder block connected to the rotating shaft, and a swash plate on which a shoe fitted to the end of a plunger inserted into the cylinder block comes into contact, and the swash plate has a sliding surface portion on which the shoe comes into contact, and a swash plate on which the shoe comes into contact. A first seat surface opposite to the sliding surface portion and corresponding to the extension side of the plunger; and a second seat surface corresponding to the compression side of the plunger and having a different angle from the first seat surface. In a hydraulic motor in which the swash plate tilts about a line of intersection between a first seat surface and a second seat surface as a fulcrum, a pressing member is provided in the casing corresponding to the first seat surface of the swash plate. A variable hydraulic motor characterized in that the inclination angle of the swash plate is changed by pressing a pressing member.