JPH0446260U

JPH0446260U -

Info

Publication number: JPH0446260U
Application number: JP8938090U
Authority: JP
Priority date: 1990-08-27
Filing date: 1990-08-27
Publication date: 1992-04-20

Description

[Brief explanation of drawings]

第１図は本考案の実施例を示すサーボレギユレ
ータの断面図、第２図はポンプ回転数とバネ荷重
の関係を示す特性図、第３図はポンプ回転数とモ
ータ回転数の関係を示す特性図、第４図は従来の
油圧駆動回路を示す回路図、第５図は同じくサー
ボレギユレータの断面図、第６図はポンプ回転数
とチヤージポンプ吐出圧の関係を示す特性図、第
７図はポンプ回転数とバネ荷重の関係を示す特性
図、第８図はポンプ回転数とモータ回転数の関係
を示す特性図、第９図はポンプ傾転角とサーボレ
ギユレータストロークの関係を示す説明図である
。１……可変ピストンポンプ、２……チヤージポ
ンプ、３……サーボレギユレータ、４……ピスト
ンモータ、１１……レギユレータピストン、１２
ａ，１２ｂ……油室、１４……スプールバルブ、
１５……プツシユロツド、１６ａ，１６ｂ……ス
プリング。 Figure 1 is a cross-sectional view of a servo regulator showing an embodiment of the present invention, Figure 2 is a characteristic diagram showing the relationship between pump rotation speed and spring load, and Figure 3 is a diagram showing the relationship between pump rotation speed and motor rotation speed. 4 is a circuit diagram showing a conventional hydraulic drive circuit, FIG. 5 is a sectional view of the servo regulator, and FIG. 6 is a characteristic diagram showing the relationship between pump rotation speed and charge pump discharge pressure. Figure 7 is a characteristic diagram showing the relationship between pump rotation speed and spring load, Figure 8 is a characteristic diagram showing the relationship between pump rotation speed and motor rotation speed, and Figure 9 is the relationship between pump tilt angle and servo regulator stroke. FIG. 1... Variable piston pump, 2... Charge pump, 3... Servo regulator, 4... Piston motor, 11... Regulator piston, 12
a, 12b... oil chamber, 14... spool valve,
15... Push rod, 16a, 16b... Spring.

Claims

[Scope of utility model registration request]

A variable piston pump driven by the engine,
A piston motor that rotates in response to discharge oil from a variable piston pump, a charge pump that rotates in the same manner as the variable piston pump, and a servo regulator that controls a pump tilt angle to decrease in response to an increase in discharge pressure of the charge pump. In the constant speed control device for a hydraulic drive circuit, the servo regulator includes a regulator piston that controls the pump tilt angle, and a regulator piston that is slidably disposed inside the regulator piston. a spool valve that switches and controls the hydraulic pressure for the oil chamber of the rotor piston;
an oil chamber that applies charge pump discharge pressure to the spool valve, a first spring that biases the spool valve against the discharge pressure, and a first spring that biases the spool valve against the discharge pressure after the first spring is deflected by a certain amount a second spring that biases the spool valve, and the hydraulic pressure is characterized in that the piston motor rotation speed is maintained at a constant speed by reducing the discharge amount in accordance with the increase in the rotation speed of the variable piston pump. Constant speed control device for drive circuit.