题目

The system consists of a hydraulic pump and motor. The rotational speed of the motor is required to be n_2=1200(r/min) when the load torque is T_2=150(Nm). This calls for input pressure of p=14(MPa) at the inlet port of the motor. The total efficiency of the motor is n_(t2)=0.82. For pump, rotational speed is n_1=1450(r/min), volumetric efficiency is n_(v1)=0.92 and the total efficiency is n_(t1)=0.83.(1) The required output power of the hydraulic motor is _______ kW.(2) The required input power of the hydraulic motor is _______ kW.(3) The required inlet flow to the motor is _______ L/min.(4) The inlet flow to the hydraulic motor is equal to pumps outlet flow, so the required displacement of the pump is _______ mL/r.(5) The input power to the hydraulic pump is _______ kW.

The system consists of a hydraulic pump and motor. The rotational speed of the motor is required to be $n_2=1200\text{r/min}$ when the load torque is $T_2=150\text{Nm}$. This calls for input pressure of $p=14\text{MPa}$ at the inlet port of the motor. The total efficiency of the motor is $n_{t2}=0.82$. For pump, rotational speed is $n_1=1450\text{r/min}$, volumetric efficiency is $n_{v1}=0.92$ and the total efficiency is $n_{t1}=0.83$.

(1) The required output power of the hydraulic motor is _______ kW.

(2) The required input power of the hydraulic motor is _______ kW.

(3) The required inlet flow to the motor is _______ L/min.

(4) The inlet flow to the hydraulic motor is equal to pumps outlet flow, so the required displacement of the pump is _______ mL/r.

(5) The input power to the hydraulic pump is _______ kW.

题目解答

答案

1. 马达输出功率： \[ P_{\text{out}} = \frac{T_2 \times n_2}{9550} = \frac{150 \times 1200}{9550} \approx 18.85 \, \text{kW} \] 2. 马达输入功率： \[ P_{\text{in}} = \frac{P_{\text{out}}}{\eta_{t2}} = \frac{18.85}{0.82} \approx 23.0 \, \text{kW} \] 3. 马达输入流量： \[ q = \frac{P_{\text{in}} \times 60 \times 10^3}{p} = \frac{23000 \times 60000}{14 \times 10^6} \approx 98.6 \, \text{L/min} \] 4. 泵的排量： \[ V = \frac{q}{n_1 \times \eta_{v1}} = \frac{98.57}{1450 \times 0.92} \approx 74 \, \text{mL/r} \] 5. 泵的输入功率： \[ P_{\text{out, pump}} = 23.0 \, \text{kW}, \quad P_{\text{in, pump}} = \frac{23.0}{0.83} \approx 27.7 \, \text{kW} \] 最终答案： 1. 18.85 kW 2. 23.0 kW 3. 98.6 L/min 4. 74 mL/r 5. 27.7 kW