Johnson & Johnson Mechanical Engineer Intern Interview Questions and Answers

To find out a worn bearing number, inspect the bearing for visible signs of wear and refer to the bearing manufacturer's documentation.

• Inspect the bearing for signs of wear such as discoloration, pitting, or scoring on the bearing surface.

• Check for excessive play or looseness in the bearing when it is rotated.

• Refer to the bearing manufacturer's documentation or catalog to identify the bearing number based on its physic...read more

Seal numbers can be found on the seal itself or in the equipment manual.

• Check the seal itself for any visible numbers or markings.

• Refer to the equipment manual for information on the seal.

• Contact the manufacturer or supplier for assistance in identifying the seal number.

Types of pumps include centrifugal, positive displacement, axial flow, and jet pumps.

• Centrifugal pumps use a rotating impeller to create a flow of fluid.

• Positive displacement pumps move fluid by trapping a fixed amount and forcing it through the system.

• Axial flow pumps move fluid parallel to the axis of rotation.

• Jet pumps use a jet of high-pressure fluid to create a low-pressure area and move fluid.

• Other types of pumps...read more

Gear boxes are used to transmit power and torque from one rotating shaft to another. There are several types of gear boxes.

• Manual transmission

• Automatic transmission

• Semi-automatic transmission

• Continuously variable transmission (CVT)

• Dual-clutch transmission (DCT)

• Epicyclic gear train

• Planetary gear train

• Worm gear box

• Bevel gear box

• Helical gear box

Pumps can be classified based on their working principle, design, and application.

• Based on working principle: centrifugal, positive displacement, and jet pumps

• Based on design: single-stage, multi-stage, axial, and mixed flow pumps

• Based on application: water, chemical, slurry, and oil pumps

• Other classifications: reciprocating, rotary, and diaphragm pumps

Mechanical seals are used to prevent leakage in rotating equipment. They can be classified into various types based on their design and application.

• Types of mechanical seals include pusher seals, non-pusher seals, cartridge seals, and split seals.

• Pusher seals use springs to maintain contact between the seal faces.

• Non-pusher seals rely on the pressure of the fluid being sealed to maintain contact.

• Cartridge seals are pre...read more

Maintenance of compressors involves regular inspection, cleaning, lubrication, and replacement of worn-out parts.

• Regular inspection of compressor components such as valves, pistons, and bearings

• Cleaning of air filters, coolers, and intercoolers to prevent clogging

• Lubrication of moving parts to reduce friction and wear

• Replacement of worn-out parts such as belts, hoses, and seals

• Monitoring of compressor performance and a

Pneumatic cylinders use compressed air while hydraulic cylinders use pressurized fluid to generate force.

• Pneumatic cylinders are lighter and cheaper than hydraulic cylinders.

• Hydraulic cylinders can generate more force than pneumatic cylinders.

• Single-acting, double-acting, and telescoping are common types of hydraulic cylinders.

• Diaphragm, bellows, and rodless are common types of pneumatic cylinders.

Solenoid valves are used to control the flow of fluids or gases in mechanical systems.

• Solenoid valves are commonly used in hydraulic and pneumatic systems.

• They can be used to control the flow of water, oil, gas, or air.

• They are often used in HVAC systems to control the flow of refrigerant.

• Solenoid valves can be controlled by electrical signals to open or close the valve.

• They are also used in automatic irrigation system...read more

There are various types of oils used in mechanical maintenance, each with different grades and purposes.

• Mineral oils: Derived from crude oil and commonly used in engines and machinery.

• Synthetic oils: Man-made oils with superior performance and stability, often used in high-performance engines.

• Semi-synthetic oils: Blend of mineral and synthetic oils, offering a balance between performance and cost.

• Multi-grade oils: Desi...read more

A torque spanner is a tool used to apply a specific amount of torque to fasteners.

• A torque spanner is also known as a torque wrench.

• It is commonly used in mechanical maintenance to ensure proper tightening of bolts and nuts.

• Torque spanners have a calibrated scale or digital display to set the desired torque value.

• They provide a clicking sound or visual indicator when the set torque is reached.

• Different types of torque ...read more

Alignment of pump and motor involves ensuring proper positioning and parallelism to optimize performance and prevent damage.

• Start by checking the alignment specifications provided by the pump and motor manufacturers.

• Use alignment tools such as dial indicators, laser alignment systems, or reverse indicator method.

• Ensure the pump and motor shafts are clean and free from any debris or damage.

• Check and adjust the motor and...read more

The purpose of a gear box is to transmit and control power between the engine and the wheels or other driven components.

• Transmits power from the engine to the wheels or other driven components

• Provides torque multiplication and speed reduction

• Allows for the selection of different gear ratios to optimize performance

• Enables the vehicle to operate at different speeds and handle various loads

• Protects the engine and drivetra