JPH05582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-speed gear motor that is rotatably driven by pressure fluid and whose rotational speed can be varied in multiple stages.

[Conventional technology]

Conventionally, gear motors have been widely used in various industrial machines including construction machines because they have a simple structure and can be manufactured at low cost.

A conventional gear motor consists of a casing with a gear chamber, a drive shaft passing through the casing, a support shaft provided parallel to the drive shaft, a drive gear mounted in the gear chamber so as to rotate integrally with the drive shaft, and gears. It consists of a driven gear attached to a support shaft in the chamber and meshing with a driving gear, and a port provided in a casing for supplying and discharging pressurized fluid (for example, Japanese Patent Publication No. 45-25058).

In addition, in order to increase the output of a gear motor, a multiple gear motor, which is constructed by connecting multiple gear motors in the axial direction, is used (for example,
No. 51423).

[Problem to be solved by the invention]

However, in the conventional gear motor described above, in order to vary the rotational speed, it is necessary to vary the flow rate of pressurized fluid. For example, when the pressure fluid is pressure oil, in order to vary its flow rate, a throttle valve and a relief valve must be used together, and the adjustment thereof also requires some effort.

Further, when the rotational speed is varied by adjusting the flow rate, the output of the gear motor decreases because the pressure of the pressure fluid remains the same, and the efficiency of the entire hydraulic system decreases.

These problems can be solved by using a swash plate or oblique shaft type piston motor, but piston motors have a complicated structure and a large number of parts, resulting in high costs. There is.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to provide a low-cost multi-speed gear motor that can vary the rotational speed without varying the flow rate of pressurized fluid.

[Means to solve the problem]

In order to solve the above-mentioned problems, a multi-speed gear motor according to the present invention includes a casing having a plurality of gear chambers, a drive shaft passing through the casing across the plurality of gear chambers, and a drive shaft extending parallel to the drive shaft. a support shaft that is provided and passes through the casing across the plurality of gear chambers; a plurality of drive gears having mutually different diameters that are attached to rotate integrally with respect to the drive shaft in each of the gear chambers;
In each of the gear chambers, a plurality of driven gears having mutually different diameters are attached to be rotatable relative to the support shaft and mesh with the driving gear to constitute external gear motors, and for each of the external gear motors. and a port for supplying and discharging pressurized fluid.

[Effect]

A driving gear and a driven gear having different diameters constitute an external gear motor that has different rotational speeds for the same flow rate.

By appropriately selecting the ports for supplying pressurized fluid, either drive gear will rotate. Since each of the drive gears rotates integrally with the drive shaft, when any of the drive gears rotates, rotational driving forces having different rotational speeds are extracted from the drive shaft.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional front view of a gear motor according to the present invention.

The gear motor includes a casing 1 having a plurality of gear chambers 3 partitioned by a plurality of inner walls 2, a drive shaft 5 passing through the casing 1 across the plurality of gear chambers 3, and a drive shaft 5 provided parallel to the drive shaft 5. A support shaft 7 passing through the plurality of gear chambers 3 , a plurality of drive gears 4 having mutually different diameters attached to rotate integrally with respect to the drive shaft 5 in each gear chamber 3 , and each gear chamber 3 , the support shaft 7
It is comprised of a plurality of driven gears 6 having mutually different diameters, each meshing with a drive gear 4 which is attached so as to be rotatable relative to the drive gear, thereby forming an external gear motor.

The casing 1 is provided with a plurality of ports (not shown) for supplying and discharging pressurized fluid to each external gear motor configured within the casing 1. A suitable conduit 14, such as a hose, is connected as shown.

Next, the operation of the gear motor configured as described above will be explained.

Among the ports provided in the casing 1, for example, one pipe line 14 communicating with the rightmost gear chamber 3 in FIG. 1 is connected to a pressure oil source, and the other pipe line 14 is connected to a return circuit (or tank), respectively. Along with connecting,
The drive gear 4 connected to the pressure oil source by keeping the other pairs of pipes 14 in communication with each other.
The driven gear 6 rotates according to the principle of a normal external gear motor, and drives the drive shaft 5 to rotate.

Furthermore, by switching the pipe line 14 connected to the pressure oil source, the drive gears 4 having different diameters are rotated by the pressure oil, and each drive shaft 5 is rotationally driven.

The rotational speed of the drive shaft 5 at that time is inversely proportional to the diameter of the drive gear 4 if the flow rate of the pressure oil is constant. Therefore, the rightmost drive gear 4 in FIG. 1 is driven by the pressure oil. When the driving gear 4 is driven, the speed is the lowest, and when the leftmost drive gear 4 is driven, the speed is the highest.

Furthermore, since the torque of the drive shaft 5 is proportional to the diameter of the drive gear 4, it is greatest when the rightmost drive gear 4 in FIG. 1 is driven by pressure oil.

In this way, according to the gear motor of this embodiment,
By switching ports or conduits 14,
Multiple rotational speeds can be easily obtained. Also, since the torque changes in inverse proportion to the rotation speed,
The output of the gear motor is kept constant, and the power of the pressure oil source is effectively used, resulting in high efficiency.

Furthermore, since the gear motor has a simple structure and a small number of parts, the gear motor can be manufactured at low cost and is easy to maintain.

Note that as the drive shaft 5 rotates, other drive gears 4 and driven gears 6 that are not driven by pressure oil also rotate, but the internal oil flows through each pair of pipes 1.
4, so it does not become a load.

FIG. 6 is a perspective view showing an example of the configuration of a hydraulic system for operating the gear motor of this embodiment.

The hydraulic system includes a prime mover 8 such as an electric motor, a gear pump 9 rotationally driven by the prime mover 8, a switching valve 11 for switching between operation and stop, a switching valve 16 for switching speed, and a relief valve 2.
It consists of 0 etc.

2 is a cross-sectional front view of the gear pump 9, FIG. 3 is a cross-sectional side view of the gear pump 9, and FIG. 4 is a cross-sectional side view of the gear pump 9.
1 is an exploded perspective view of the switching valve 16, and FIG. 5 is an exploded perspective view of the switching valve 16.

As shown in these figures, the pressure oil discharged from the discharge port 10a of the gear pump 9 flows through the pipe line 1.
4 and enters one of the ports 13, 13a provided on the lid 11a of the switching valve 11, and connects the connecting groove 12 depending on the relative angular position with the lid 11a.
a, b to ports 15, 15a or central groove 1
2, respectively.

The pressure oil that has flowed into either one of the ports 15, 15a enters either one of the ports 18, 18a provided on the lid 16a of the switching valve 16, and depending on the relative angular position of the lid 16a, It flows into one port 17, 17a to 17k.

The pressure oil that has flowed into any of the ports 17, 17a to 17k flows into the gear motor through the pipe line 14, rotates the drive gear 4, flows out from the pipe line 14, and moves toward the center of the switching valve 16. Then return to the other ports 17, 17a to 17k at point symmetrical positions, and then return to the other ports 18, 18a and the other ports 15, 15a.
through which it returns to the inlet 10 of the gear pump 9. Ports 17 and 17 not connected to ports 18 and 18a
a to 17k are communicated with each other through a recess provided in the lid 16a.

Therefore, by lever 19a etc., lid body 1
By switching the relative angular position of 6a, the rotation speed, torque, or rotation direction of the gear motor can be switched.

〔Effect of the invention〕

According to the present invention, it is possible to provide a low-cost multi-speed gear motor that can vary the rotational speed without varying the flow rate of pressure fluid.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional front view of a gear motor according to the present invention, Fig. 2 is a cross-sectional front view of a gear pump, Fig. 3 is a cross-sectional side view of the gear pump, and Fig. 4 is a switch for switching between operation and stop. Exploded perspective view of valve, 5th
The figure is an exploded perspective view of a switching valve for switching speed, and FIG. 6 is a perspective view showing an example of the configuration of a hydraulic system for operating the gear motor of this embodiment. DESCRIPTION OF SYMBOLS 1... Casing, 3... Gear chamber, 4... Drive gear, 5... Drive shaft, 6... Driven gear, 7... Support shaft, 14... Conduit (port).

Claims (1)

[Scope of Claims] 1. A casing having a plurality of gear chambers, a drive shaft passing through the casing across the plurality of gear chambers, and a drive shaft provided parallel to the drive shaft and connecting the casing to the plurality of gear chambers. a support shaft penetrating through the entire gear chamber; a plurality of drive gears having mutually different diameters that are attached to rotate together with the drive shaft in each of the gear chambers; a plurality of driven gears having mutually different diameters, each of which is mounted so as to be relatively rotatable and meshes with the drive gear to constitute an external gear motor; and a port for supplying and discharging pressurized fluid to each of the external gear motors. A multi-speed gear motor comprising: