Nabco Limited

Ts Corporation

Nippon Air Brake Kabushiki Kaisha

Masahiro Tsunemi

Hidekazu Okufuji

Yuji Kondo

Teruhisa Ando

Masataka Kojima

Kenichi Shimoura

In a gear mechanism, inner gear teeth and outer gear teeth are formed of high-tooth. An engagement ratio of the inner and outer gear teeth is configured so as to be 2.0 or more, whereby a load can be transferred between the inner and outer teeth via a continuous gear engagement of at least two pairs of gear teeth thereof. Accordingly, a contact face pressure and a bending stress occurring to inner and outer gear teeth can be reduced, the limitation of the durability of the gear mechanism due to the large difference of durability between the inner and outer gear teeth can be improved, and the necessity of increasing hardness of the inner gear teeth can be lessened.

Gear mechanism and reduction planetary gear

The present invention relates to a driving unit comprising a multiple-stage planetary gear type reducer used to reduce rotation speed of a hydraulic motor and output the reduced rotation speed, which is used as a driving device for a traveling apparatus. The driving unit of the present invention is so structured that a trunnion boss for rotatably supporting a planetary gear train of a final state is supported at opposite ends thereof. This structure enables the load applied to the trunnion boss to be dispersed to the both ends, and as such can allow the trannion boss to be reduced in diameter or can allow the fixed casing to be reduced in circumferential dimension. This can produce a downsized driving unit. The present invention has additional features, such as the feature that an output shaft of the hydraulic motor and an input shaft of the reducer are formed in the form of a single rotating shaft. This can provide a driving unit structurally optimized for every principal part, to provide downsizing and improved durability.

Driving unit that comprises a hydraulic motor and a reduction gear

A crawler drive unit for propelling a construction machine such as a shovel-type excavator having a pair of crawler track assemblies comprises a hydraulic motor (11) and a speed reducer (12), the latter including a stationary carrier (29) having carrier pins journaled therein, carrier gears (28) keyed to the carrier pins respectively, a first disk-type portion (40), and a second disktype portion (46) radially inwardly projecting from the first disk-type portion (40). An end face of the casing (13) of the hydraulic motor (11) is substantially coplanar with a surface of the stationary carrier (29) in which the annularly hollowed-out portion (47) is provided and another surface of the stationary carrier (29) which allows one end face of each carrier pin to abut thereagainst. With this arrangement, the stationary carrier (29) can be disposed in close proximity to the end portion (35) of the casing (13). This allows a compact arrangement requiring less dimension in the axial direction of the speed reducer (12) to be obtained. The casing (13) is allowed to have a thin wall, because it is free from excessive stresses which are commonly caused by the load set up in the sprocket wheel when a prior art unit is started.

Crawler drive unit

A hydraulic motor control circuit for use in a device for driving construction equipment, such as shovel loader, which comprises a hydraulic driving motor, a pump for feeding compressed oil to the hydraulic motor and a tank for receiving the compressed oil discharged from the hydraulic motor. The circuit comprises a pilot operation type main valve for controlling the oil flow between the pump and the motor and between the motor and the tank, and a remote control valve for feeding a pilot oil pressure to a pilot chamber of the main valve to turn the main valve to a first position for driving the hydraulic motor. As a feature of this invention, the control circuit further comprises an apparatus for detecting the slanting angle of a downward slope and feeding an oil pressure corresponding to the slanting angle to a second pilot chamber of the main valve. The main valve is adapted to turn from its first position to its second position in which the speed of rotation of the hydraulic motor is confined in accordance with the slanting angle.

Growing community of inventors

Kobe, Japan

Masahiro Tsunemi