Going Old School….

Welcome back! Like the title suggests, this week we are going Old-School – looking at what entails a NON-computerized transmission. Yes…they do exist! But before we get into that, like always, time for a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Previously, we did a recap of the past few weeks – just to clear up any confusion any of you might have had. You can do a re-read of it here.

And prior to that (check it here), we discussed all the fun parts like Servo, Solenoid and just how the computerized transmission knows when to shift gears.

 

Our Growing Automotive Vocabulary

 

This week we added the following to our vocabulary: Governor, Vacuum, Modulator, Cable, Hinged, Spring, the combined specific terms of Vacuum Modulator and Throttle Cable as well as brought back a term we used awhile ago – Centrifugal. You can find them at the bottom of the list. As always, you can find our entire and current automotive dictionary here. Feel free to save its link so that you can find it again in case we use a word that happens to not be on this week’s list.

Here are the related words for this week’s topic. Enjoy expanding your vocabulary.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.

Governor – A mechanical device for automatically controlling the speed of an engine or motor as by regulating the intake of fuel, steam, etc..

Vacuum – An enclosed space, as that inside a vacuum tube, out of which most of the air or gas has been taken, as by pumping.

Modulator – Something that regulates, adjusts or adapts to the proper degree.

Cable – A thick, heavy rope, now often of wire strands.

Hinged – Jointed device on which a door, gate, lid, etc. swings.

Spring – A device, as a coil of wire, that returns to its original form after being forced out of shape: springs are used to absorb shock, and as the motive power in clocks and similar mechanisms.

Vacuum Modulator – A device that monitors the vacuum pressure in an engine and moves the throttle valve in a specific direction that is dependent upon the load of the engine.

Throttle Cable – A cable that is connected between the gas pedal and the throttle valve and monitors the position of the gas pedal.

Centrifugal – Moving or tending to move away from a center.

 

Look Ma – No Computers!

 

It’s hard to believe that there was a time when computers did not exist. They are wonderful and exasperating machines that make our lives both easier and more complicated. They are fantastic when they work properly and not so much when they don’t. And it’s also hard to believe that there was a time when there was not a single computerized part in our vehicles.

So exactly how did they work without computers? By simply using centrifugal forces, vacuums and cables.

 

                      The Governor “Arnold”

 

It all starts with the use of the Governor. Arnold here is attached to the output shaft and regulates the hydraulic pressure in the system based on the speed of the vehicle. It does this by spinning a pair of hinged weights against a pair of springs. The spinning causes a centrifugal force that pulls on the weights. As the weights get pulled out by the force, it pulls and stretches the springs. The further out the springs move, the more oil pressure is allowed to go past the Governor to then engage on the shift valves that are in the valve body. This would signal the engine on when to shift.

Also factored into this equation is the load that the engine is under. This is just simply how hard the engine is working. The higher the load on the engine, the longer the transmission will hold a gear before it will shift to the next one.

 

How to Lighten the Load

 

Non-Computerized monitoring of the load of the engine is done using one of two devices in conjunction with Arnold (aka the Governor). It is with either the Vacuum Modulator or the Throttle Cable.

                      1963 Corvette Modulator

 

The Vacuum Modulator is a device that is attached to the engine via a vacuum hose. When the engine is under a light load, a high vacuum is produced. Naturally, when an engine is under a heavy load, the vacuum pressure decreases down to non-existant. The other side of the Modulator is attached to the transmission, specifically the throttle valve in the valve body. Based on the vacuum level present, the modulator prompts the transmission to either shift early and softly or shift later and firmly.

Throttle Cable Attachment to the Transmission

 

The Throttle Cable just monitors the position of the gas pedal and prompts the throttle valve to shift based on its position.

 

For Next Week

And that’s a wrap on all things Automatic Transmission! You now know how this intricate piece of machinery works. Next Week, we’re going to discuss all the many things that can go wrong and we will give you some things to watch for in case your car needs a mechanic’s attention.

 

Until Next Time….

 Anthony’s Automotive

Your Automotive Vocabulary

In our replay from last week, I did not include any definitions for you. As we have gone on this journey, we have been adding words to your automotive vocabulary. You can always find the current list here.  But for ease of reading, here is the entire list in alphabetical order.

  • Automatic – A device or process that works by itself with little or no direct human control.
  • Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.
  • Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.
  • Centrifugal – Moving or tending to move away from a center.
  • Converter – A person or thing that causes a change in form, character or function.
  • Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.
  • Driven Parts – The Wheels
  • Driveshaft – A rotating shaft that transmits torque in an engine.
  • Epicyclic – A circle whose center moves along the circumference of another, larger circle.
  • Flange – A projecting rim or collar on a wheel, pipe, rail, etc., to hold it in place, give it strength, guide it, or attach it to something else.
  • Gasket – A shaped piece or ring of rubber or other material sealing the junction between two surfaces in an engine or other device.
  • Gear – One of a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle or the crank of a bicycle) and the speed of the driven parts (the wheels).
  • Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..
  • Input – The act of putting in; or, what is put in.
  • Manual – A thing operated or done by hand rather than automatically or electronically, in particular.
  • Manual Transmission – An automotive transmission consisting of a system of interlocking gear wheels and a lever that enables the driver to shift gears manually.
  • Neutral – A disengaged position of gears in which the engine is disconnected from the driven parts.
  • Oil – Any of various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources; oils are liquid at ordinary temperatures and soluble in certain organic solvents, as ether, but not in water.
  • Output – The work done or amount produced by a person, machine, production line, manufacturing plant, etc., especially over a given period.
  • Pack – A number of similar or related persons or things.
  • Pipe – A long tube of clay, concrete, metal, wood, etc., for conveying water, gas, oil, etc. or for use in construction. Also, anything tubular in form.
  • Piston – A disk or short cylinder closely fitted in a hollow cylinder and moved back and forth by the pressure of a fluid so as to transmit reciprocating motion to the piston rod attached to it, or moved by the rod so as to exert pressure on the fluid.
  • Planetary Gear System – A gear system that consists of one or more planet gears (the gears in the middle area) that rotate or revolve around a sun gear (the gear in the center) and a ring gear (the gear on the outer edge).
  • Pump – Any of the various machines that force a liquid or gas into or through, or draw it out of, something, as by suction or pressure.
  • Radiator – A device of tubes and fins, as in an automobile, through which circulating water passes to radiate superfluous heat and thus cool the engine.
  • Regulator – A mechanism for controlling or governing the movement of machinery, the flow of liquids, gases, electricity, steam, etc..
  • Seal – A device or substance that is used to join two things together to prevent them from coming apart or to prevent anything from passing between them.
  • Servo – This is short for Servomechanism OR Servomotor.
  • Servomechanism – An automatic control system in which the output is constantly or intermittently compared with the input through feedback so that the error or difference between the two quantities can be used to bring about the desired amount of control.
  • Servomotor – A device, as an electric motor, hydraulic piston, etc., that is controlled by an amplified signal from a command device of low power, as in a servomechanism.
  • Shaft – A long, slender part or object.
  • Solenoid – A coil of wire, usually wound in the form of a helix, that acts like a bar magnet when carrying a current: used in brakes, switches, relays, etc..
  • Soluble – That can be dissolved; able to pass into solution.
  • Solvent – A substance, usually liquid, that dissolves or can dissolve another substance.
  • Spline – A flat key or strip that fits into a groove or slot between parts.
  • Sprag – A device for preventing a vehicle from rolling backward on a grade.
  • Stator – A fixed part forming the pivot or housing for a revolving part, as in a motor, dynamo, etc..
  • Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.
  • Torque – A twisting force that tends to cause rotation.
  • Torque Converter – A device that transmits or multiplies torque generated by an engine.
  • Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.
  • Tube – A hollow cylinder or pipe of metal, glass, rubber, etc., usually long in proportion to its diameter, used for conveying fluids, etc..
  • Turbine – An engine or motor driven by the pressure of steam, water, air, etc. against the curved vanes of a wheel or set of wheels fastened to a driving shaft.
  • Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

 

Thoughts for Next Week

Next week we will dive back into the transmission and take a look at the difference between what goes on with a non-computerized transmission. You will be surprised at the difference.

 

Until Next Time….

Anthony’s Automotive

One, Two, Three…Replay!

Welcome back! I know last time we said that we’d look at how the non-computerized transmissions work but we’re going to hold off on that. Instead, let’s review all that we have learned over the past several weeks. We want to make sure you have a good understanding of how the transmission works before we add any new data and concepts to this.

 

The Automatic Transmission

 

In this photo, you will see exactly what we’ve been talking about for the past several weeks. This is the side view of your car’s transmission. You can even see the Gear Shift attached. This photo gives a great perspective on how the transmission looks and where everything is placed in relation to each other.

Transmission with Gear Shift

Side view of transmission with the attached Gear Shift

Now…how does it work again?

You put your key in the ignition and you turn your car on. The engine is now running and the Torque Converter has been engaged. Transmission fluid is now pumping through your car’s transmission via the Pump, through the Turbine, into the Stator and into the One Way Clutch. This essentially keeps your engine running and keeps your car moving while its shifting gears, idling, etc..

When you shifted your Gear Shift into the Drive position, you have basically put it into First Gear and told your car that you want all the gears available for it to use while you are moving forward.

Now back to the One Way Clutch – the transmission fluid doesn’t just stop there. It keeps moving. Through a complex series of passages and tubes, the fluid moves into the Valve Body of your car’s transmission. And it does this only because it is under pressure the entire time.

This pressure is generated by the Oil Pump when you turn your engine on. It is connected to the torque converter which means it is connected to both the engine and the transmission. As long as there is sufficient oil located in the oil pan (on the bottom side of the transmission), it will create pressure and will allow the transmission fluid to flow through the transmission.

Now back to the Valve Body – transmission fluid is directed to the channels that lead to specific valves required to allow a gear shift to occur.

 

And how exactly does it know which channels to use?

 

In a computer controlled transmission, there are sensors that are used to capture lots of data related to your engine: brake pedal position, engine load (how ‘hard’ it’s working), engine speed, vehicle speed and many more. By compiling all this information, it can exactly pinpoint when a gear shift needs to occur. AND when it has properly identified that moment, it transmits to the Solenoid Packs in the transmission so that they can redirect the transmission fluid as needed to the correct clutch pack/band/servo to shift the gear.

Remember – a Solenoid Pack is simply a coiled wire that acts like a magnet when an electrical current is running through it and it can easily open and close valves.

 

In a Nutshell

You turn your car on. This causes the oil to create pressure that allows the transmission fluid to flow through the valve body, which selects the optimum gear for your car to be in at that specific moment. All you do is turn the car on, tell your car you want ALL the gears (putting in Drive) and put your foot on the gas pedal.

 

 

Until Next Time….

 Anthony’s Automotive

One Valve, Two Valve, Three Valve, Four….

Welcome back! This week we are going to see what exactly the Valve Body is and the purpose it plays in your automatic transmission. But before we get into that, like always, time for a quick recap & review some definitions.

Previously on Anthony’s Automotive Blog….

Last week, we drilled a well and learned all about Texas Tea and just how important Oil is to your car’s transmission. You can do a re-read of it here. Or, keep reading for the quick recap.

Oil and the pump it goes through creates the pressure necessary for your transmission to function…period. It is this pressure that keeps the transmission fluid flowing throughout your car’s system, which, in turn, keeps it cool, changes gears and lubricates just about everything else and keeps parts moving. Let’s face it – we like moving parts.

We’ve added a few words this week: Pipe, Valve, Servo, Servomechanism, Servomotor, Solenoid, and Throttle. You can find them at the bottom of the list. As always, you can find our entire and current automotive dictionary here. Feel free to save its link so that you can find it again in case we use a word that happens to not be on this week’s list.

Our Growing Automotive Vocabulary

Here are the related words for this week’s topic. Enjoy expanding your vocabulary.

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.

Pump – Any of the various machines that force a liquid or gas into or through, or draw it out of, something, as by suction or pressure.

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Oil – Any of various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources; oils are liquid at ordinary temperatures and soluble in certain organic solvents, as ether, but not in water.

Pipe – A long tube of clay, concrete, metal, wood, etc., for conveying water, gas, oil, etc. or for use in construction. Also, anything tubular in form.

Valve – Any device in a pipe or tube that permits a flow in one direction only, or regulates the flow of whatever is in the pipe, by means of a flap, lid, plug, etc. acting to open or block passage.

Servo – This is short for Servomechanism OR Servomotor.

Servomechanism – An automatic control system in which the output is constantly or intermittently compared with the input through feedback so that the error or difference between the two quantities can be used to bring about the desired amount of control.

Servomotor – A device, as an electric motor, hydraulic piston, etc., that is controlled by an amplified signal from a command device of low power, as in a servomechanism.

Solenoid – A coil of wire, usually wound in the form of a helix, that acts like a bar magnet when carrying a current: used in brakes, switches, relays, etc..

Throttle – The valve that regulates the amount of fuel vapor entering an internal-combustion engine or controls the flow of steam in a steam line. This is also known as the Throttle Valve.

Come in Houston! Do you read me??

Last week we talked about how the transmission fluid is the ‘blood’ that flows through your car. And, that it is the oil that creates the ‘blood pressure’ of the system. Using this same type of analogy, the Valve Body is the ‘brain’ of your vehicle. This is where everything is controlled. We touched briefly on the Valve Body and its purpose a while ago here.

 

A Valve Body

A Valve Body

 

In a nutshell, the whole purpose of the Valve Body is to smoothly shift gears as you are driving down the road. That is all. The Valve Body is an intricate & specialized maze of channels that directs the transmission fluid that activate whatever gears are needed to shift to.

For example, if the car needs to shift from second to third gear, the transmission fluid needs to flow through the channels to the specific valve that is for that function. This valve is often called the 2-3 valve. And oddly enough, there is a specific valve for shifting from third back to second and it’s commonly called the 3-2 valve. In this system, there is a valve for everything!

 

Simple Gear Shift Stick

Simple Gear Shift Stick

 

The most important valve is the Manual Valve. THIS is the valve that you actually have direct control over and basically gets the whole process going. The Manual Valve is the one that is directly connected to your gear shift. In an automatic transmission, the second you move the gear shift into the Drive position, the Manual Valve directs the transmission fluid to the clutch packs that activate 1st Gear. At the same time, it engages the monitoring of your vehicle’s speed and throttle position to best determine the correct time and force needed to do the shift from 1st Gear into 2nd Gear.

Most automatic transmissions nowadays are computer controlled with electrical solenoids mounted in the Valve Body to help with the direction of fluid to the appropriate clutch packs, bands or servos. This is done to make your car more efficient and to be more precise in determining shift points while you are moving.

My Sole….what??

It’s a Solenoid Pack. To further simplify the definition we listed above – It is simply a coiled wire that acts like a magnet when an electrical current is running through it. By acting like a magnet, it can easily open and close valves.

Now, in a computer controlled transmission, there are sensors that are used to capture lots of data related to your engine: brake pedal position, engine load (how ‘hard’ its working), engine speed, vehicle speed and many more. By compiling all of this information, it can exactly pinpoint when a gear shift needs to occur. AND when it has properly identified that moment, it transmits to the Solenoid Packs in the transmission so that they can redirect the transmission fluid as needed to the correct clutch pack/band/servo to shift the gear.

For Next Week

This week we’ve touched on how a computer controlled transmission works by interacting with sensors and solenoid packs. Next week, let’s go old school and take a look at how non-computerized transmissions work and what parts they have that differ from the computerized ones.

Until Next Time….

 Anthony’s Automotive

Time to Pump Things Up

Welcome back! This week we are going to see what role the Oil Pump plays in your automatic transmission. But before we get into that, like always, time for a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Last week, we learned all about the wonderful, complex part called the Hydraulic System. You can do a re-read of it here. Or, keep reading for the quick recap.

The Hydraulic System is what keeps the transmission fluid under pressure and sends it to all parts of the transmission and torque converter. It is essentially the blood system of your car. Even the transmission fluid itself is red in color, just like your blood. And it is most important that it remain under pressure at all times.

We’ve added a couple of words this week: Oil, Soluble, Solvent, Flange, and Regulator. You can find them at the bottom of the list. As always, you can find our entire and current automotive dictionary here. Feel free to save its link so that you can find it again in case we use a word that happens to not be on this week’s list.

Our Growing Automotive Vocabulary

Here are the related words for this week’s topic. Enjoy expanding your vocabulary.

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Torque Converter – A device that transmits or multiplies torque generated by an engine.

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.

Pump – Any of the various machines that force a liquid or gas into or through, or draw it out of, something, as by suction or pressure.

Sprag – A device for preventing a vehicle from rolling backward on a grade.

Radiator – A device of tubes and fins, as in an automobile, through which circulating water passes to radiate superfluous heat and thus cool the engine.

Tube – A hollow cylinder or pipe of metal, glass, rubber, tec., usually long in proportion to its diameter, used for conveying fluids, etc..

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Oil – Any of various kinds of greasy, combustible substances obtained from animal, vegetable, and mineral sources; oils are liquid at ordinary temperatures and soluble in certain organic solvents, as ether, but not in water.

Soluble – That can be dissolved; able to pass into solution.

Solvent – A substance, usually liquid, that dissolves or can dissolve another substance.

Flange – A projecting rim or collar on a wheel, pipe, rail, etc,. to hold it in place, give it strength, guide it, or attach it to something else.

Regulator – A mechanism for controlling or governing the movement of machinery, the flow of liquids, gases, electricity, steam, etc..

 

Black Gold…Texas Tea…

 The Oil Pump in your transmission is what produces all the oil pressure necessary for your car’s transmission to function. Please note that this is a separate pump from the pump that we talked about earlier in the torque converter (please recap here to clear up any confusion you may have). When you talk about getting the oil changed on your car or checking the oil on your car, THIS is the part we are talking. It works hand in hand with your car’s transmission.

 

Oil Pump

An Actual Oil Pump

 

Like I mentioned above in the recap and in last week’s post, pressure is one of the most important aspects of your transmission and its ability to operate. Yes, it does need to have transmission fluid to function. BUT that fluid absolutely must be under pressure at all times. It is the Oil Pump that creates this pressure.

The Oil Pump itself is located at the front of the transmission case. It is also connected to a flange that is on the torque converter housing. This makes the pump connected directly to both the transmission and your engine (through the torque converter.)

Because the torque converter is connected to the engine, the Oil Pump will produce pressure automatically while the engine is running and if there is transmission fluid available. This is why it is also important to have your transmission fluids checked regularly for optimum volume. The Oil Pump will not be able to produce pressure without a sufficient amount of transmission fluid located in your transmission system. Just as in the human body, if you don’t have enough blood pumping through your veins, you won’t function as well. And like I mentioned before, the transmission fluid in your car is the blood of your car.

 

Motor Oil

Car/Motor Oil

 

The oil is located in the oil pan that is typically located on the bottom side of your transmission. The oil, itself, enters the pump through a filter (yes THAT filter that you need to have checked and changed during regular maintenance.) The filter is at the bottom of the oil pan and has a tube running from it to the oil pump. This is how the oil gets to the pump. From the pump, where it is now under pressure, it is then sent to the Pressure Regulator, the Valve Body (see next week) and other parts beyond.

So the bottom line is (and bringing together what we learned last week and this), you need to have a good level of transmission fluid in your transmission AND you need to have a good level of oil in your oil pan so that it can create pressure which, in turn, allows your transmission fluid to be transmitted to other areas of your car to either keep it cool, shift gears and keep other parts lubricated and moving.

 

For Next Week

 

It’s time to crack open the skull and look at the brain of the Automatic Transmission – the Valve Body.

 

Until Next Time….

 Anthony’s Automotive

 

With a Clutch and a Band

Welcome back! We’re still on our journey learning about Transmissions – in particular, the Automatic Transmission. As always before we lift the hood, let’s do a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Last week, we talked about automatic transmissions. If you wish to do a quick re-read of it, you can find it here. For the quick recap, keep going.

 

The Planetary Gear System is what drives the Automatic Transmission vehicle. This system consists of the Ring Gear, the Sun Gear and the Planetary Gears (one or more) that rotate in between the first two. It is the combination of the locking and unlocking of one or more of these gears that allows the car to shift gears.

 

Now, let’s add the Clutch Pack and Band to this Gear System and really get moving. But first, let’s make sure you understand the lingo that we use.

 

Our Growing Automotive Vocabulary

 

Here is a recap of some of the automotive words we listed last week just in case there is any lingering confusion. There are a couple of new additions as well.

 

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Torque Converter – A device that transmits or multiplies torque generated by an engine.

Gear – One of a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle or the crank of a bicycle) and the speed of the driven parts (the wheels).

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.

Planetary Gear System – A gear system that consists of one or more planet gears (the gears in the middle area) that rotate or revolve around a sun gear (the gear in the center) and a ring gear (the gear on the outer edge).

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Input – The act of putting in; or, what is put in

Output – The work done or amount produced by a person, machine, production line, manufacturing plant, etc., especially over a given period.

Shaft – A long, slender part or object.

Pack – A number of similar or related person or things.

Spline – A flat key or strip that fits into a groove or slot between parts.

Piston – A disk or short cylinder closely fitted in a hollow cylinder and moved back and forth by the pressure of a fluid so as to transmit reciprocating motion to the piston rod attached to it, or moved by the rod so as to exert pressure on the fluid.

 

The Planetary Gear System continued….

 

Last week I had included a Side View image of the Planetary Gear System. Let me include it again and quickly give thanks to the people at www.carparts.com for this image. It is the simplest image that I could find for this lovely and complicated system on the great wide web.

 

planetary gear system

 

You can see the Input Shaft that is connected to the Ring Gear, as well as the Output Shaft that is connected to the Planetary Gears. What I want you to notice is that the Planetary Gears are also connected with the Clutch Pack. This is at the top and bottom of the image. The drum which houses the entire Clutch Pack is connected to the Sun Gear. So you have two parts of the Clutch Pack connected to two of the different gears.

On the outside of this whole unit, is the Band. The purpose of the Band is to tighten (and loosen) around the drum. This is another way to be able to lock the Sun Gear in place. When the Band is tightened, the Sun Gear cannot move. Or, with the assistance of the Clutch Pack, the Band, while tightened, will make the Sun Gear move in conjunction with the Planetary Gears.

 

Exactly what IS the Clutch Pack

 

I’m glad you asked that. The clutch pack consists of a drum and a bunch of disks. Now, these disks consist of two different types that are alternated as they are put in the drum. One half of these disks have splines on the outside of the disk that are designed to fit along groves that are on the inside of the drum. The other have splines on the inside of the disk that fit in the groves that are in the joining center part of the drum. In this Clutch Pack, there is a piston that, when activated by oil pressure, squeezes the disks together so they all turn as one. Which, in turn, will turn with whatever gears needed to shift the car into a different gear.

multiple-disk-clutch-pack

 

Ideas for Next Week

 

We’ve talked about the Planetary Gear System and all its parts and pieces. We have now added the new layers to this of the Clutch Pack and the Band that wraps around the outside. So, I think it is time for us to go back to where we started this whole journey and revisit Torque Conversion. You now understand the parts involved in this. So, next week, let’s really get into the nitty gritty of Torque Conversion.

 

Final Thought

 

I had a question last week of “where do I get my definitions?” Good ole…..

 

webster dictionary

 

Until Next Time….

 Anthony’s Automotive

There’s a planet IN my car???

Welcome back! It’s time to continue our look into the nooks and crannies of Transmissions. But before we lift the hood, let’s do a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Last week, we talked about automatic transmissions. If you wish to do a quick re-read of it, you can find it here. For the quick recap, keep on reading.

The automatic transmission system of a car works by using a series of gears that lock and unlock to shift them up or down in gear. This series of gears is called the Planetary Gear System and is comprised of the Ring Gear, The Planetary Gears and the Sun Gear. They rotate and revolve around each other and work together. It is the combination of locking one or two of these gears with the second and/or third being free that initiates the gear shift in the car.

planetary gear set

 

Last week, I barely scraped the grime off the surface of these gears and how they work. This week? Grab your rag and let’s get ALL the grime off them this time. Let’s make them shine!

 

Our Growing Automotive Vocabulary

 

Here is a recap of some of the automotive words we listed last week just in case there is any lingering confusion. There are a couple of new additions as well.

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Torque Converter – A device that transmits or multiplies torque generated by an engine.

Gear – One of a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle or the crank of a bicycle) and the speed of the driven parts (the wheels).

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Band – Something that binds, ties together, restrains, etc.; a strip or ring of wood, metal, rubber, etc. fastened around something to bind or tie it together.

Epicyclic – A circle whose center moves along the circumference of another, larger circle.

Planetary Gear System – A gear system that consists of one or more planet gears (the gears in the middle area) that rotate or revolve around a sun gear (the gear in the center) and a ring gear (the gear on the outer edge).

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

Input – The act of putting in; or, what is put in

Output – The work done or amount produced by a person, machine, production line, manufacturing plant, etc., especially over a given period.

Shaft – A long, slender part or object.

 

The Planetary Gear System

 

As mentioned before, the Planetary Gear System is comprised of three parts: the Ring Gear, the Planetary Gears and the Sun Gear. The Ring Gear is located on the outer edge. The Planetary Gears (which typically number two or more) are in the middle area and are mounted on a carrier or plate. The Sun Gear is located in the very center. The Planetary Gears rotate around the Sun Gear in the center and the Ring Gear along the outside.

How this system works is by moving one or more of these parts, while keeping one or more locked or still. Here’s an example that should really break this down for you to help you see what I’m talking about.

planetary gear system

 

Let’s say the Ring Gear is connected to the Input Shaft that is coming in from the engine and the Planetary Gear Carrier is connected to the Output Shaft, which is connected to the wheels. Now, in this example, let’s lock the Sun Gear in place so that it can’t move. As we turn the Ring Gear, the Planetary Gears will move in the same direction along the locked Sun Gear. This causes the Planetary Gear Carrier to turn the Output Shaft. This means that the Input Shaft and the Output Shaft are moving in the same direction. BUT, the Output Shaft is moving at a slower speed. Remember that the Input Shaft is connected to the Ring Gear and the Output Shaft is connected to the Planetary Gear Carrier? So the wheels are moving slower than the power of the engine. This is a car that is in First Gear.

Still with me? Good!

Now, let’s unlock the Sun Gear and lock the other two – the Ring Gear and the Planetary Gears. By doing this, all three of these will turn together as one. You now have the Input Shaft (power from the engine) and the Output Shaft (the wheels) turning at the same speed. This is a car that is in Third Gear or higher.

Makes sense right? Now we’re moving!

Finally, let’s lock the Planetary Gears and leave the Ring Gear and Sun Gear unlocked. By locking the Planetary Gears, you lock the Planetary Gear Carrier, which is connected to what again? The Output Shaft (the wheels). You give some power to the Ring Gear (aka the Input Shaft). This causes the Sun Gear to turn. But it’s going to turn in the opposite direction. And this means?

You guessed it! This is a car going in Reverse.

 

Food for Thought

 

There are many, many combinations that are possible when you use two or more planetary gears. They can be connected in various ways and provide many different forward speeds and reverse. There are some very clever gear arrangements that you will find in today’s modern automatic transmissions.

 

8 speed chevrolet corvette

 

Nowadays we have four-, five-, six-, seven and even eight-speed vehicles! Now that you know what a first and third gear looks like (Side Note – you CAN substitute the word ‘speed’ for ‘gear’ here to help), imagine trying to understand the combinations that these eight-speed cars must go through as they shift from first gear to their top gear as they head on down the highway. Talk about being complex! It is no surprise that we now have computers in today’s cars.

 

Ideas for Next Week

 

I feel that you should now have a good idea of how the gear system works in an Automatic Transmission. Next week, I’m going to build on that and we are going to add another level to this Planetary Gear System and expand your automotive knowledge a little further by talking about clutches and bands.

 

Until then,

Anthony’s Automotive

 

 

 

 

All about the Valves

Welcome back! This week we’re still on the topic of Transmissions. But this time, let’s get a little more technical know-how under your belts. But before we jump right in, let’s do a quick recap & review some definitions.

 

Previously on Anthony’s Automotive Blog….

 

Last week, we talked about just the basics when it comes to transmissions. If you wish to do a quick re-read of it, you can find it here. For a quick recap, keep reading.

Basically, your car’s transmission is what keeps it moving. They come in two flavors: Automatic or Manual (aka Stick Shift). Automatic transmissions require little to no interaction from the driver, while Manual transmissions require 100% interaction from the driver. Your transmission needs a special fluid to keep all of its parts working together. We also touched on some common problems that can occur & how to tell if it’s about to die.

gearshift

 

We also covered some basic definitions of various automotive-speak words that you could understand exactly what it was that I was saying. Let me recap a couple of those words here just in case. I will also add some new ones, as they do pertain to this week’s particular topic.

Transmission – The mechanism by which power is transmitted from an engine to the wheels of a motor vehicle.

Torque Converter – A device that transmits or multiplies torque generated by an engine.

Gear – One of a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine of a vehicle or the crank of a bicycle) and the speed of the driven parts (the wheels).

Automatic – A device or process that works by itself with little or no direct human control.

Automatic Transmission – An automotive transmission that can automatically change gears as the vehicle moves, freeing the driver from having to shift gears manually.

Manual – A thing operated or done by hand rather than automatically or electronically, in particular.

Manual Transmission – An automotive transmission consisting of a system of interlocking gear wheels and a lever that enables the driver to shift gears manually.

Neutral – A disengaged position of gears in which the engine is disconnected from the driven parts.

Clutch – A mechanism for connecting and disconnecting a vehicle engine from its transmission system.

Epicyclic – A circle whose center moves along the circumference of another, larger circle.

Planetary Gear System – A gear system that consists of one or more planet gears (the gears in the middle area) that rotate or revolve around a sun gear (the gear in the center) and a ring gear (the gear on the outer edge).

Hydraulic – Operated by the movement and force of liquid; specifically, operated by the pressure created when a liquid is forced through an aperture, tube, etc..

 

The Nuts and Bolts of an Automatic Transmission

 

As you recall, an automatic transmission is the type of transmission that requires little to no interaction from the driver (outside of putting your foot on the gas pedal that is) in order to work. But it is so much more complex than you think.

An automatic transmission system works by utilizing a series of gears that lock and unlock in order to change the gears of the vehicle. The transmission also uses a torque converter instead of a clutch to disconnect the transmission from the engine when the car needs to come to a stop.

The series of gears used actually have their own name. They are referred to as the Planetary Gear System (or Gear Set). The system has three main parts: the Ring Gear, the Planetary Gears and the Sun Gear. The Ring Gear is on the outer edge. The Planetary Gears are in the middle area (usually mounted to a carrier or plate). The Sun Gear is in the very center. The Planetary Gears rotate and revolve around the Sun Gear in the center and the Ring Gear on the outer edge.

 

planetary gear set

 

This system works by moving two of these parts, while keeping the third one still. By doing this, it can transmit the torque created by the engine to the wheels of the car, which, in turn, makes it move.

In addition to the above gear set, you also have what is called the Valve Body. It is what allows the automatic transmission of your car to smoothly shift gears as you are driving down the road. It is a hydraulic system that uses a pump to bring transmission fluid into the valve body. It then directs the fluid through a maze of channels and valves that, in turn, activate whatever gears are needed to shift to.

This maze is quite intricate and specialized. For example, if the car needs to shift from second to third gear, the transmission fluid needs to flow through the channels to the specific valve that is for that function. This valve is often called the 2-3 valve. And oddly enough, there is a specific valve for shifting from third back to second and it’s commonly called the 3-2 valve. In this system, there is a valve for everything!

 

Food for Thought

 

I hope you were able to learn a little more this week about exactly how an Automatic Transmission works. In a nutshell, fluid is pumped through the system and through a specific valve which tells the vehicle which gear it needs to shift to.

Next week, we’ll continue to learn more about how an Automatic Transmission works. In truth, we’ve just begun to scratch the surface.

Until then, I’ll leave you with something to think about. We’ve all seen those big semi trucks that are always slow to start moving and we all curse and moan when we get stuck behind them at a stoplight. They typically have anywhere from 12 to 18 gears that their engine has to shift through to get moving. Just imagine the number of valves that transmission would need in order to shift up and down all of those gears IF they were an automatic transmission. How big would that engine be??!!??

 

Until next time,

Anthony’s Automotive